User manual and reference guide version 4.8.0
CodeMirror is a code-editor component that can be embedded in Web pages. The core library provides only the editor component, no accompanying buttons, auto-completion, or other IDE functionality. It does provide a rich API on top of which such functionality can be straightforwardly implemented. See the addons included in the distribution, and the list of externally hosted addons, for reusable implementations of extra features.
CodeMirror works with language-specific modes. Modes are
JavaScript programs that help color (and optionally indent) text
written in a given language. The distribution comes with a number
of modes (see the mode/
directory), and it isn't hard to write new
ones for other languages.
Basic Usage
The easiest way to use CodeMirror is to simply load the script
and style sheet found under lib/
in the distribution,
plus a mode script from one of the mode/
directories.
(See the compression helper for an
easy way to combine scripts.) For example:
<script src="lib/codemirror.js"></script> <link rel="stylesheet" href="../lib/codemirror.css"> <script src="mode/javascript/javascript.js"></script>
(Alternatively, use a module loader. More about that later.)
Having done this, an editor instance can be created like this:
var myCodeMirror = CodeMirror(document.body);
The editor will be appended to the document body, will start
empty, and will use the mode that we loaded. To have more control
over the new editor, a configuration object can be passed
to CodeMirror
as a second
argument:
var myCodeMirror = CodeMirror(document.body, { value: "function myScript(){return 100;}\n", mode: "javascript" });
This will initialize the editor with a piece of code already in it, and explicitly tell it to use the JavaScript mode (which is useful when multiple modes are loaded). See below for a full discussion of the configuration options that CodeMirror accepts.
In cases where you don't want to append the editor to an
element, and need more control over the way it is inserted, the
first argument to the CodeMirror
function can also
be a function that, when given a DOM element, inserts it into the
document somewhere. This could be used to, for example, replace a
textarea with a real editor:
var myCodeMirror = CodeMirror(function(elt) { myTextArea.parentNode.replaceChild(elt, myTextArea); }, {value: myTextArea.value});
However, for this use case, which is a common way to use CodeMirror, the library provides a much more powerful shortcut:
var myCodeMirror = CodeMirror.fromTextArea(myTextArea);
This will, among other things, ensure that the textarea's value is updated with the editor's contents when the form (if it is part of a form) is submitted. See the API reference for a full description of this method.
Module loaders
The files in the CodeMirror distribution contain shims for
loading them (and their dependencies) in AMD or CommonJS
environments. If the variables exports
and module
exist and have type object, CommonJS-style
require will be used. If not, but there is a
function define
with an amd
property
present, AMD-style (RequireJS) will be used.
It is possible to use Browserify or similar tools to statically build modules using CodeMirror. Alternatively, use RequireJS to dynamically load dependencies at runtime. Both of these approaches have the advantage that they don't use the global namespace and can, thus, do things like load multiple versions of CodeMirror alongside each other.
Here's a simple example of using RequireJS to load CodeMirror:
require([ "cm/lib/codemirror", "cm/mode/htmlmixed/htmlmixed" ], function(CodeMirror) { CodeMirror.fromTextArea(document.getElementById("code"), { lineNumbers: true, mode: "htmlmixed" }); });
It will automatically load the modes that the mixed HTML mode depends on (XML, JavaScript, and CSS).
Configuration
Both the CodeMirror
function and its fromTextArea
method take as second
(optional) argument an object containing configuration options.
Any option not supplied like this will be taken
from CodeMirror.defaults
, an
object containing the default options. You can update this object
to change the defaults on your page.
Options are not checked in any way, so setting bogus option values is bound to lead to odd errors.
These are the supported options:
value: string|CodeMirror.Doc
- The starting value of the editor. Can be a string, or a document object.
mode: string|object
- The mode to use. When not given, this will default to the
first mode that was loaded. It may be a string, which either
simply names the mode or is
a MIME type
associated with the mode. Alternatively, it may be an object
containing configuration options for the mode, with
a
name
property that names the mode (for example{name: "javascript", json: true}
). The demo pages for each mode contain information about what configuration parameters the mode supports. You can ask CodeMirror which modes and MIME types have been defined by inspecting theCodeMirror.modes
andCodeMirror.mimeModes
objects. The first maps mode names to their constructors, and the second maps MIME types to mode specs. theme: string
- The theme to style the editor with. You must make sure the
CSS file defining the corresponding
.cm-s-[name]
styles is loaded (see thetheme
directory in the distribution). The default is"default"
, for which colors are included incodemirror.css
. It is possible to use multiple theming classes at once—for example"foo bar"
will assign both thecm-s-foo
and thecm-s-bar
classes to the editor. indentUnit: integer
- How many spaces a block (whatever that means in the edited language) should be indented. The default is 2.
smartIndent: boolean
- Whether to use the context-sensitive indentation that the mode provides (or just indent the same as the line before). Defaults to true.
tabSize: integer
- The width of a tab character. Defaults to 4.
indentWithTabs: boolean
- Whether, when indenting, the first N*
tabSize
spaces should be replaced by N tabs. Default is false. electricChars: boolean
- Configures whether the editor should re-indent the current line when a character is typed that might change its proper indentation (only works if the mode supports indentation). Default is true.
specialChars: RegExp
- A regular expression used to determine which characters
should be replaced by a
special placeholder.
Mostly useful for non-printing special characters. The default
is
/[\u0000-\u0019\u00ad\u200b\u2028\u2029\ufeff]/
. specialCharPlaceholder: function(char) → Element
- A function that, given a special character identified by
the
specialChars
option, produces a DOM node that is used to represent the character. By default, a red dot (•) is shown, with a title tooltip to indicate the character code. rtlMoveVisually: boolean
- Determines whether horizontal cursor movement through
right-to-left (Arabic, Hebrew) text is visual (pressing the left
arrow moves the cursor left) or logical (pressing the left arrow
moves to the next lower index in the string, which is visually
right in right-to-left text). The default is
false
on Windows, andtrue
on other platforms. keyMap: string
- Configures the key map to use. The default
is
"default"
, which is the only key map defined incodemirror.js
itself. Extra key maps are found in thekey map
directory. See the section on key maps for more information. extraKeys: object
- Can be used to specify extra key bindings for the editor,
alongside the ones defined
by
keyMap
. Should be either null, or a valid key map value. lineWrapping: boolean
- Whether CodeMirror should scroll or wrap for long lines.
Defaults to
false
(scroll). lineNumbers: boolean
- Whether to show line numbers to the left of the editor.
firstLineNumber: integer
- At which number to start counting lines. Default is 1.
lineNumberFormatter: function(line: integer) → string
- A function used to format line numbers. The function is passed the line number, and should return a string that will be shown in the gutter.
gutters: array<string>
- Can be used to add extra gutters (beyond or instead of the
line number gutter). Should be an array of CSS class names, each
of which defines a
width
(and optionally a background), and which will be used to draw the background of the gutters. May include theCodeMirror-linenumbers
class, in order to explicitly set the position of the line number gutter (it will default to be to the right of all other gutters). These class names are the keys passed tosetGutterMarker
. fixedGutter: boolean
- Determines whether the gutter scrolls along with the content horizontally (false) or whether it stays fixed during horizontal scrolling (true, the default).
coverGutterNextToScrollbar: boolean
- When
fixedGutter
is on, and there is a horizontal scrollbar, by default the gutter will be visible to the left of this scrollbar. If this option is set to true, it will be covered by an element with classCodeMirror-gutter-filler
. readOnly: boolean|string
- This disables editing of the editor content by the user. If
the special value
"nocursor"
is given (instead of simplytrue
), focusing of the editor is also disallowed. showCursorWhenSelecting: boolean
- Whether the cursor should be drawn when a selection is active. Defaults to false.
undoDepth: integer
- The maximum number of undo levels that the editor stores. Note that this includes selection change events. Defaults to 200.
historyEventDelay: integer
- The period of inactivity (in milliseconds) that will cause a new history event to be started when typing or deleting. Defaults to 1250.
tabindex: integer
- The tab index to assign to the editor. If not given, no tab index will be assigned.
autofocus: boolean
- Can be used to make CodeMirror focus itself on
initialization. Defaults to off.
When
fromTextArea
is used, and no explicit value is given for this option, it will be set to true when either the source textarea is focused, or it has anautofocus
attribute and no other element is focused.
Below this a few more specialized, low-level options are listed. These are only useful in very specific situations, you might want to skip them the first time you read this manual.
dragDrop: boolean
- Controls whether drag-and-drop is enabled. On by default.
cursorBlinkRate: number
- Half-period in milliseconds used for cursor blinking. The default blink rate is 530ms. By setting this to zero, blinking can be disabled. A negative value hides the cursor entirely.
cursorScrollMargin: number
- How much extra space to always keep above and below the cursor when approaching the top or bottom of the visible view in a scrollable document. Default is 0.
cursorHeight: number
- Determines the height of the cursor. Default is 1, meaning
it spans the whole height of the line. For some fonts (and by
some tastes) a smaller height (for example
0.85
), which causes the cursor to not reach all the way to the bottom of the line, looks better resetSelectionOnContextMenu: boolean
- Controls whether, when the context menu is opened with a
click outside of the current selection, the cursor is moved to
the point of the click. Defaults to
true
. workTime, workDelay: number
- Highlighting is done by a pseudo background-thread that will
work for
workTime
milliseconds, and then use timeout to sleep forworkDelay
milliseconds. The defaults are 200 and 300, you can change these options to make the highlighting more or less aggressive. pollInterval: number
- Indicates how quickly CodeMirror should poll its input textarea for changes (when focused). Most input is captured by events, but some things, like IME input on some browsers, don't generate events that allow CodeMirror to properly detect it. Thus, it polls. Default is 100 milliseconds.
flattenSpans: boolean
- By default, CodeMirror will combine adjacent tokens into a single span if they have the same class. This will result in a simpler DOM tree, and thus perform better. With some kinds of styling (such as rounded corners), this will change the way the document looks. You can set this option to false to disable this behavior.
addModeClass: boolean
- When enabled (off by default), an extra CSS class will be
added to each token, indicating the
(inner) mode that produced it, prefixed
with
"cm-m-"
. For example, tokens from the XML mode will get thecm-m-xml
class. maxHighlightLength: number
- When highlighting long lines, in order to stay responsive,
the editor will give up and simply style the rest of the line as
plain text when it reaches a certain position. The default is
10 000. You can set this to
Infinity
to turn off this behavior. crudeMeasuringFrom: number
- When measuring the character positions in long lines, any line longer than this number (default is 10 000), when line wrapping is off, will simply be assumed to consist of same-sized characters. This means that, on the one hand, measuring will be inaccurate when characters of varying size, right-to-left text, markers, or other irregular elements are present. On the other hand, it means that having such a line won't freeze the user interface because of the expensiveness of the measurements.
viewportMargin: integer
- Specifies the amount of lines that are rendered above and
below the part of the document that's currently scrolled into
view. This affects the amount of updates needed when scrolling,
and the amount of work that such an update does. You should
usually leave it at its default, 10. Can be set
to
Infinity
to make sure the whole document is always rendered, and thus the browser's text search works on it. This will have bad effects on performance of big documents.
Events
Various CodeMirror-related objects emit events, which allow
client code to react to various situations. Handlers for such
events can be registered with the on
and off
methods on the objects
that the event fires on. To fire your own events,
use CodeMirror.signal(target, name, args...)
,
where target
is a non-DOM-node object.
An editor instance fires the following events.
The instance
argument always refers to the editor
itself.
"change" (instance: CodeMirror, changeObj: object)
- Fires every time the content of the editor is changed.
The
changeObj
is a{from, to, text, removed, origin}
object containing information about the changes that occurred as second argument.from
andto
are the positions (in the pre-change coordinate system) where the change started and ended (for example, it might be{ch:0, line:18}
if the position is at the beginning of line #19).text
is an array of strings representing the text that replaced the changed range (split by line).removed
is the text that used to be betweenfrom
andto
, which is overwritten by this change. "changes" (instance: CodeMirror, changes: array<object>)
- Like the
"change"
event, but batched per operation, passing an array containing all the changes that happened in the operation. "beforeChange" (instance: CodeMirror, changeObj: object)
- This event is fired before a change is applied, and its
handler may choose to modify or cancel the change.
The
changeObj
object hasfrom
,to
, andtext
properties, as with the"change"
event. It also has acancel()
method, which can be called to cancel the change, and, if the change isn't coming from an undo or redo event, anupdate(from, to, text)
method, which may be used to modify the change. Undo or redo changes can't be modified, because they hold some metainformation for restoring old marked ranges that is only valid for that specific change. All three arguments toupdate
are optional, and can be left off to leave the existing value for that field intact. Note: you may not do anything from a"beforeChange"
handler that would cause changes to the document or its visualization. Doing so will, since this handler is called directly from the bowels of the CodeMirror implementation, probably cause the editor to become corrupted. "cursorActivity" (instance: CodeMirror)
- Will be fired when the cursor or selection moves, or any change is made to the editor content.
"keyHandled" (instance: CodeMirror, name: string, event: Event)
- Fired after a key is handled through a
key map.
name
is the name of the handled key (for example"Ctrl-X"
or"'q'"
), andevent
is the DOMkeydown
orkeypress
event. "inputRead" (instance: CodeMirror, changeObj: object)
- Fired whenever new input is read from the hidden textarea (typed or pasted by the user).
"beforeSelectionChange" (instance: CodeMirror, obj: {ranges, update})
- This event is fired before the selection is moved. Its
handler may inspect the set of selection ranges, present as an
array of
{anchor, head}
objects in theranges
property of theobj
argument, and optionally change them by calling theupdate
method on this object, passing an array of ranges in the same format. Handlers for this event have the same restriction as"beforeChange"
handlers — they should not do anything to directly update the state of the editor. "viewportChange" (instance: CodeMirror, from: number, to: number)
- Fires whenever the view port of
the editor changes (due to scrolling, editing, or any other
factor). The
from
andto
arguments give the new start and end of the viewport. "swapDoc" (instance: CodeMirror, oldDoc: Doc)
- This is signalled when the editor's document is replaced
using the
swapDoc
method. "gutterClick" (instance: CodeMirror, line: integer, gutter: string, clickEvent: Event)
- Fires when the editor gutter (the line-number area) is
clicked. Will pass the editor instance as first argument, the
(zero-based) number of the line that was clicked as second
argument, the CSS class of the gutter that was clicked as third
argument, and the raw
mousedown
event object as fourth argument. "gutterContextMenu" (instance: CodeMirror, line: integer, gutter: string, contextMenu: Event: Event)
- Fires when the editor gutter (the line-number area)
receives a
contextmenu
event. Will pass the editor instance as first argument, the (zero-based) number of the line that was clicked as second argument, the CSS class of the gutter that was clicked as third argument, and the rawcontextmenu
mouse event object as fourth argument. You canpreventDefault
the event, to signal that CodeMirror should do no further handling. "focus" (instance: CodeMirror)
- Fires whenever the editor is focused.
"blur" (instance: CodeMirror)
- Fires whenever the editor is unfocused.
"scroll" (instance: CodeMirror)
- Fires when the editor is scrolled.
"scrollCursorIntoView" (instance: CodeMirror, event: Event)
- Fires when the editor tries to scroll its cursor into view.
Can be hooked into to take care of additional scrollable
containers around the editor. When the event object has
its
preventDefault
method called, CodeMirror will not itself try to scroll the window. "update" (instance: CodeMirror)
- Will be fired whenever CodeMirror updates its DOM display.
"renderLine" (instance: CodeMirror, line: LineHandle, element: Element)
- Fired whenever a line is (re-)rendered to the DOM. Fired right after the DOM element is built, before it is added to the document. The handler may mess with the style of the resulting element, or add event handlers, but should not try to change the state of the editor.
"mousedown", "dblclick", "contextmenu", "keydown", "keypress", "keyup", "dragstart", "dragenter", "dragover", "drop" (instance: CodeMirror, event: Event)
- Fired when CodeMirror is handling a DOM event of this type.
You can
preventDefault
the event, or give it a truthycodemirrorIgnore
property, to signal that CodeMirror should do no further handling.
Document objects (instances
of CodeMirror.Doc
) emit the
following events:
"change" (doc: CodeMirror.Doc, changeObj: object)
- Fired whenever a change occurs to the
document.
changeObj
has a similar type as the object passed to the editor's"change"
event. "beforeChange" (doc: CodeMirror.Doc, change: object)
- See the description of the same event on editor instances.
"cursorActivity" (doc: CodeMirror.Doc)
- Fired whenever the cursor or selection in this document changes.
"beforeSelectionChange" (doc: CodeMirror.Doc, selection: {head, anchor})
- Equivalent to the event by the same name as fired on editor instances.
Line handles (as returned by, for
example, getLineHandle
)
support these events:
"delete" ()
- Will be fired when the line object is deleted. A line object is associated with the start of the line. Mostly useful when you need to find out when your gutter markers on a given line are removed.
"change" (line: LineHandle, changeObj: object)
- Fires when the line's text content is changed in any way
(but the line is not deleted outright). The
change
object is similar to the one passed to change event on the editor object.
Marked range handles (CodeMirror.TextMarker
), as returned
by markText
and setBookmark
, emit the
following events:
"beforeCursorEnter" ()
- Fired when the cursor enters the marked range. From this event handler, the editor state may be inspected but not modified, with the exception that the range on which the event fires may be cleared.
"clear" (from: {line, ch}, to: {line, ch})
- Fired when the range is cleared, either through cursor
movement in combination
with
clearOnEnter
or through a call to itsclear()
method. Will only be fired once per handle. Note that deleting the range through text editing does not fire this event, because an undo action might bring the range back into existence.from
andto
give the part of the document that the range spanned when it was cleared. "hide" ()
- Fired when the last part of the marker is removed from the document by editing operations.
"unhide" ()
- Fired when, after the marker was removed by editing, a undo operation brought the marker back.
Line widgets (CodeMirror.LineWidget
), returned
by addLineWidget
, fire
these events:
"redraw" ()
- Fired whenever the editor re-adds the widget to the DOM. This will happen once right after the widget is added (if it is scrolled into view), and then again whenever it is scrolled out of view and back in again, or when changes to the editor options or the line the widget is on require the widget to be redrawn.
Key Maps
Key maps are ways to associate keys with functionality. A key map is an object mapping strings that identify the keys to functions that implement their functionality.
The CodeMirror distributions comes with Emacs, Vim, and Sublime Text-style keymaps.
Keys are identified either by name or by character.
The CodeMirror.keyNames
object defines names for
common keys and associates them with their key codes. Examples of
names defined here are Enter
, F5
,
and Q
. These can be prefixed
with Shift-
, Cmd-
, Ctrl-
,
and Alt-
to specify a modifier. So for
example, Shift-Ctrl-Space
would be a valid key
identifier.
Common example: map the Tab key to insert spaces instead of a tab character.
editor.setOption("extraKeys", { Tab: function(cm) { var spaces = Array(cm.getOption("indentUnit") + 1).join(" "); cm.replaceSelection(spaces); } });
Alternatively, a character can be specified directly by
surrounding it in single quotes, for example '$'
or 'q'
. Due to limitations in the way browsers fire
key events, these may not be prefixed with modifiers.
Multi-stroke key bindings can be specified
by separating the key names by spaces in the property name, for
example Ctrl-X Ctrl-V
. When a map contains
multi-stoke bindings or keys with modifiers that are not specified
in the default order (Shift-Cmd-Ctrl-Alt
), you must
call CodeMirror.normalizeKeyMap
on it before it can
be used. This function takes a keymap and modifies it to normalize
modifier order and properly recognize multi-stroke bindings. It
will return the keymap itself.
The CodeMirror.keyMap
object associates key maps
with names. User code and key map definitions can assign extra
properties to this object. Anywhere where a key map is expected, a
string can be given, which will be looked up in this object. It
also contains the "default"
key map holding the
default bindings.
The values of properties in key maps can be either functions of
a single argument (the CodeMirror instance), strings, or
false
. Strings refer
to commands, which are described below. If
the property is set to false
, CodeMirror leaves
handling of the key up to the browser. A key handler function may
return CodeMirror.Pass
to indicate that it has
decided not to handle the key, and other handlers (or the default
behavior) should be given a turn.
Keys mapped to command names that start with the
characters "go"
or to functions that have a
truthy motion
property (which should be used for
cursor-movement actions) will be fired even when an
extra Shift
modifier is present (i.e. "Up":
"goLineUp"
matches both up and shift-up). This is used to
easily implement shift-selection.
Key maps can defer to each other by defining
a fallthrough
property. This indicates that when a
key is not found in the map itself, one or more other maps should
be searched. It can hold either a single key map or an array of
key maps.
When a key map needs to set something up when it becomes
active, or tear something down when deactivated, it can
contain attach
and/or detach
properties,
which should hold functions that take the editor instance and the
next or previous keymap. Note that this only works for the
top-level keymap, not for fallthrough
maps or maps added
with extraKeys
or addKeyMap
.
Commands
Commands are parameter-less actions that can be performed on an
editor. Their main use is for key bindings. Commands are defined by
adding properties to the CodeMirror.commands
object.
A number of common commands are defined by the library itself,
most of them used by the default key bindings. The value of a
command property must be a function of one argument (an editor
instance).
Some of the commands below are referenced in the default key map, but not defined by the core library. These are intended to be defined by user code or addons.
Commands can also be run with
the execCommand
method.
selectAll
Ctrl-A (PC), Cmd-A (Mac)- Select the whole content of the editor.
singleSelection
Esc- When multiple selections are present, this deselects all but the primary selection.
killLine
Ctrl-K (Mac)- Emacs-style line killing. Deletes the part of the line after the cursor. If that consists only of whitespace, the newline at the end of the line is also deleted.
deleteLine
Ctrl-D (PC), Cmd-D (Mac)- Deletes the whole line under the cursor, including newline at the end.
delLineLeft
- Delete the part of the line before the cursor.
delWrappedLineLeft
Cmd-Backspace (Mac)- Delete the part of the line from the left side of the visual line the cursor is on to the cursor.
delWrappedLineRight
Cmd-Delete (Mac)- Delete the part of the line from the cursor to the right side of the visual line the cursor is on.
undo
Ctrl-Z (PC), Cmd-Z (Mac)- Undo the last change.
redo
Ctrl-Y (PC), Shift-Cmd-Z (Mac), Cmd-Y (Mac)- Redo the last undone change.
undoSelection
Ctrl-U (PC), Cmd-U (Mac)- Undo the last change to the selection, or if there are no selection-only changes at the top of the history, undo the last change.
redoSelection
Alt-U (PC), Shift-Cmd-U (Mac)- Redo the last change to the selection, or the last text change if no selection changes remain.
goDocStart
Ctrl-Up (PC), Cmd-Up (Mac), Cmd-Home (Mac)- Move the cursor to the start of the document.
goDocEnd
Ctrl-Down (PC), Cmd-End (Mac), Cmd-Down (Mac)- Move the cursor to the end of the document.
goLineStart
Alt-Left (PC), Ctrl-A (Mac)- Move the cursor to the start of the line.
goLineStartSmart
Home- Move to the start of the text on the line, or if we are already there, to the actual start of the line (including whitespace).
goLineEnd
Alt-Right (PC), Ctrl-E (Mac)- Move the cursor to the end of the line.
goLineRight
Cmd-Right (Mac)- Move the cursor to the right side of the visual line it is on.
goLineLeft
Cmd-Left (Mac)- Move the cursor to the left side of the visual line it is on. If this line is wrapped, that may not be the start of the line.
goLineLeftSmart
- Move the cursor to the left side of the visual line it is
on. If that takes it to the start of the line, behave
like
goLineStartSmart
. goLineUp
Up, Ctrl-P (Mac)- Move the cursor up one line.
goLineDown
Down, Ctrl-N (Mac)- Move down one line.
goPageUp
PageUp, Shift-Ctrl-V (Mac)- Move the cursor up one screen, and scroll up by the same distance.
goPageDown
PageDown, Ctrl-V (Mac)- Move the cursor down one screen, and scroll down by the same distance.
goCharLeft
Left, Ctrl-B (Mac)- Move the cursor one character left, going to the previous line when hitting the start of line.
goCharRight
Right, Ctrl-F (Mac)- Move the cursor one character right, going to the next line when hitting the end of line.
goColumnLeft
- Move the cursor one character left, but don't cross line boundaries.
goColumnRight
- Move the cursor one character right, don't cross line boundaries.
goWordLeft
Alt-B (Mac)- Move the cursor to the start of the previous word.
goWordRight
Alt-F (Mac)- Move the cursor to the end of the next word.
goGroupLeft
Ctrl-Left (PC), Alt-Left (Mac)- Move to the left of the group before the cursor. A group is a stretch of word characters, a stretch of punctuation characters, a newline, or a stretch of more than one whitespace character.
goGroupRight
Ctrl-Right (PC), Alt-Right (Mac)- Move to the right of the group after the cursor (see above).
delCharBefore
Shift-Backspace, Ctrl-H (Mac)- Delete the character before the cursor.
delCharAfter
Delete, Ctrl-D (Mac)- Delete the character after the cursor.
delWordBefore
Alt-Backspace (Mac)- Delete up to the start of the word before the cursor.
delWordAfter
Alt-D (Mac)- Delete up to the end of the word after the cursor.
delGroupBefore
Ctrl-Backspace (PC), Alt-Backspace (Mac)- Delete to the left of the group before the cursor.
delGroupAfter
Ctrl-Delete (PC), Ctrl-Alt-Backspace (Mac), Alt-Delete (Mac)- Delete to the start of the group after the cursor.
indentAuto
Shift-Tab- Auto-indent the current line or selection.
indentMore
Ctrl-] (PC), Cmd-] (Mac)- Indent the current line or selection by one indent unit.
indentLess
Ctrl-[ (PC), Cmd-[ (Mac)- Dedent the current line or selection by one indent unit.
insertTab
- Insert a tab character at the cursor.
insertSoftTab
- Insert the amount of spaces that match the width a tab at the cursor position would have.
defaultTab
Tab- If something is selected, indent it by one indent unit. If nothing is selected, insert a tab character.
transposeChars
Ctrl-T (Mac)- Swap the characters before and after the cursor.
newlineAndIndent
Enter- Insert a newline and auto-indent the new line.
toggleOverwrite
Insert- Flip the overwrite flag.
save
Ctrl-S (PC), Cmd-S (Mac)- Not defined by the core library, only referred to in key maps. Intended to provide an easy way for user code to define a save command.
find
Ctrl-F (PC), Cmd-F (Mac)findNext
Ctrl-G (PC), Cmd-G (Mac)findPrev
Shift-Ctrl-G (PC), Shift-Cmd-G (Mac)replace
Shift-Ctrl-F (PC), Cmd-Alt-F (Mac)replaceAll
Shift-Ctrl-R (PC), Shift-Cmd-Alt-F (Mac)- Not defined by the core library, but defined in the search addon (or custom client addons).
Customized Styling
Up to a certain extent, CodeMirror's look can be changed by
modifying style sheet files. The style sheets supplied by modes
simply provide the colors for that mode, and can be adapted in a
very straightforward way. To style the editor itself, it is
possible to alter or override the styles defined
in codemirror.css
.
Some care must be taken there, since a lot of the rules in this file are necessary to have CodeMirror function properly. Adjusting colors should be safe, of course, and with some care a lot of other things can be changed as well. The CSS classes defined in this file serve the following roles:
CodeMirror
- The outer element of the editor. This should be used for the editor width, height, borders and positioning. Can also be used to set styles that should hold for everything inside the editor (such as font and font size), or to set a background.
CodeMirror-scroll
- Whether the editor scrolls (
overflow: auto
+ fixed height). By default, it does. Setting theCodeMirror
class to haveheight: auto
and giving this classoverflow-x: auto; overflow-y: hidden;
will cause the editor to resize to fit its content. CodeMirror-focused
- Whenever the editor is focused, the top element gets this class. This is used to hide the cursor and give the selection a different color when the editor is not focused.
CodeMirror-gutters
- This is the backdrop for all gutters. Use it to set the default gutter background color, and optionally add a border on the right of the gutters.
CodeMirror-linenumbers
- Use this for giving a background or width to the line number gutter.
CodeMirror-linenumber
- Used to style the actual individual line numbers. These
won't be children of the
CodeMirror-linenumbers
(plural) element, but rather will be absolutely positioned to overlay it. Use this to set alignment and text properties for the line numbers. CodeMirror-lines
- The visible lines. This is where you specify vertical padding for the editor content.
CodeMirror-cursor
- The cursor is a block element that is absolutely positioned. You can make it look whichever way you want.
CodeMirror-selected
- The selection is represented by
span
elements with this class. CodeMirror-matchingbracket
,CodeMirror-nonmatchingbracket
- These are used to style matched (or unmatched) brackets.
If your page's style sheets do funky things to
all div
or pre
elements (you probably
shouldn't do that), you'll have to define rules to cancel these
effects out again for elements under the CodeMirror
class.
Themes are also simply CSS files, which define colors for
various syntactic elements. See the files in
the theme
directory.
Programming API
A lot of CodeMirror features are only available through its API. Thus, you need to write code (or use addons) if you want to expose them to your users.
Whenever points in the document are represented, the API uses
objects with line
and ch
properties.
Both are zero-based. CodeMirror makes sure to 'clip' any positions
passed by client code so that they fit inside the document, so you
shouldn't worry too much about sanitizing your coordinates. If you
give ch
a value of null
, or don't
specify it, it will be replaced with the length of the specified
line.
Methods prefixed with doc.
can, unless otherwise
specified, be called both on CodeMirror
(editor)
instances and CodeMirror.Doc
instances. Methods
prefixed with cm.
are only available
on CodeMirror
instances.
Constructor
Constructing an editor instance is done with
the CodeMirror(place: Element|fn(Element),
?option: object)
constructor. If the place
argument is a DOM element, the editor will be appended to it. If
it is a function, it will be called, and is expected to place the
editor into the document. options
may be an element
mapping option names to values. The options
that it doesn't explicitly specify (or all options, if it is not
passed) will be taken
from CodeMirror.defaults
.
Note that the options object passed to the constructor will be mutated when the instance's options are changed, so you shouldn't share such objects between instances.
See CodeMirror.fromTextArea
for another way to construct an editor instance.
Content manipulation methods
doc.getValue(?separator: string) → string
- Get the current editor content. You can pass it an optional
argument to specify the string to be used to separate lines
(defaults to
"\n"
). doc.setValue(content: string)
- Set the editor content.
doc.getRange(from: {line, ch}, to: {line, ch}, ?separator: string) → string
- Get the text between the given points in the editor, which
should be
{line, ch}
objects. An optional third argument can be given to indicate the line separator string to use (defaults to"\n"
). doc.replaceRange(replacement: string, from: {line, ch}, to: {line, ch}, ?origin: string)
- Replace the part of the document between
from
andto
with the given string.from
andto
must be{line, ch}
objects.to
can be left off to simply insert the string at positionfrom
. Whenorigin
is given, it will be passed on to"change"
events, and its first letter will be used to determine whether this change can be merged with previous history events, in the way described for selection origins. doc.getLine(n: integer) → string
- Get the content of line
n
. doc.lineCount() → integer
- Get the number of lines in the editor.
doc.firstLine() → integer
- Get the first line of the editor. This will usually be zero but for linked sub-views, or documents instantiated with a non-zero first line, it might return other values.
doc.lastLine() → integer
- Get the last line of the editor. This will
usually be
doc.lineCount() - 1
, but for linked sub-views, it might return other values. doc.getLineHandle(num: integer) → LineHandle
- Fetches the line handle for the given line number.
doc.getLineNumber(handle: LineHandle) → integer
- Given a line handle, returns the current position of that
line (or
null
when it is no longer in the document). doc.eachLine(f: (line: LineHandle))
doc.eachLine(start: integer, end: integer, f: (line: LineHandle))
- Iterate over the whole document, or if
start
andend
line numbers are given, the range fromstart
up to (not including)end
, and callf
for each line, passing the line handle. This is a faster way to visit a range of line handlers than callinggetLineHandle
for each of them. Note that line handles have atext
property containing the line's content (as a string). doc.markClean()
- Set the editor content as 'clean', a flag that it will
retain until it is edited, and which will be set again when such
an edit is undone again. Useful to track whether the content
needs to be saved. This function is deprecated in favor
of
changeGeneration
, which allows multiple subsystems to track different notions of cleanness without interfering. doc.changeGeneration(?closeEvent: boolean) → integer
- Returns a number that can later be passed
to
isClean
to test whether any edits were made (and not undone) in the meantime. IfcloseEvent
is true, the current history event will be ‘closed’, meaning it can't be combined with further changes (rapid typing or deleting events are typically combined). doc.isClean(?generation: integer) → boolean
- Returns whether the document is currently clean — not
modified since initialization or the last call
to
markClean
if no argument is passed, or since the matching call tochangeGeneration
if a generation value is given.
Cursor and selection methods
doc.getSelection(?lineSep: string) → string
- Get the currently selected code. Optionally pass a line
separator to put between the lines in the output. When multiple
selections are present, they are concatenated with instances
of
lineSep
in between. doc.getSelections(?lineSep: string) → string
- Returns an array containing a string for each selection, representing the content of the selections.
doc.replaceSelection(replacement: string, ?select: string)
- Replace the selection(s) with the given string. By default,
the new selection ends up after the inserted text. The
optional
select
argument can be used to change this—passing"around"
will cause the new text to be selected, passing"start"
will collapse the selection to the start of the inserted text. doc.replaceSelections(replacements: array<string>, ?select: string)
- The length of the given array should be the same as the
number of active selections. Replaces the content of the
selections with the strings in the array.
The
select
argument works the same as inreplaceSelection
. doc.getCursor(?start: string) → {line, ch}
- Retrieve one end of the primary
selection.
start
is a an optional string indicating which end of the selection to return. It may be"from"
,"to"
,"head"
(the side of the selection that moves when you press shift+arrow), or"anchor"
(the fixed side of the selection). Omitting the argument is the same as passing"head"
. A{line, ch}
object will be returned. doc.listSelections() → array<{anchor, head}>
- Retrieves a list of all current selections. These will
always be sorted, and never overlap (overlapping selections are
merged). Each object in the array contains
anchor
andhead
properties referring to{line, ch}
objects. doc.somethingSelected() → boolean
- Return true if any text is selected.
doc.setCursor(pos: {line, ch}|number, ?ch: number, ?options: object)
- Set the cursor position. You can either pass a
single
{line, ch}
object, or the line and the character as two separate parameters. Will replace all selections with a single, empty selection at the given position. The supported options are the same as forsetSelection
. doc.setSelection(anchor: {line, ch}, ?head: {line, ch}, ?options: object)
- Set a single selection range.
anchor
andhead
should be{line, ch}
objects.head
defaults toanchor
when not given. These options are supported:scroll: boolean
- Determines whether the selection head should be scrolled into view. Defaults to true.
origin: string
- Detemines whether the selection history event may be
merged with the previous one. When an origin starts with the
character
+
, and the last recorded selection had the same origin and was similar (close in time, both collapsed or both non-collapsed), the new one will replace the old one. When it starts with*
, it will always replace the previous event (if that had the same origin). Built-in motion uses the"+move"
origin. bias: number
- Determine the direction into which the selection endpoints should be adjusted when they fall inside an atomic range. Can be either -1 (backward) or 1 (forward). When not given, the bias will be based on the relative position of the old selection—the editor will try to move further away from that, to prevent getting stuck.
doc.setSelections(ranges: array<{anchor, head}>, ?primary: integer, ?options: object)
- Sets a new set of selections. There must be at least one
selection in the given array. When
primary
is a number, it determines which selection is the primary one. When it is not given, the primary index is taken from the previous selection, or set to the last range if the previous selection had less ranges than the new one. Supports the same options assetSelection
. doc.addSelection(anchor: {line, ch}, ?head: {line, ch})
- Adds a new selection to the existing set of selections, and makes it the primary selection.
doc.extendSelection(from: {line, ch}, ?to: {line, ch}, ?options: object)
- Similar
to
setSelection
, but will, if shift is held or the extending flag is set, move the head of the selection while leaving the anchor at its current place.to
is optional, and can be passed to ensure a region (for example a word or paragraph) will end up selected (in addition to whatever lies between that region and the current anchor). When multiple selections are present, all but the primary selection will be dropped by this method. Supports the same options assetSelection
. doc.extendSelections(heads: array<{line, ch}>, ?options: object)
- An equivalent
of
extendSelection
that acts on all selections at once. doc.extendSelectionsBy(f: function(range: {anchor, head}) → {anchor, head}), ?options: object)
- Applies the given function to all existing selections, and
calls
extendSelections
on the result. doc.setExtending(value: boolean)
- Sets or clears the 'extending' flag, which acts similar to
the shift key, in that it will cause cursor movement and calls
to
extendSelection
to leave the selection anchor in place. doc.getExtending() → boolean
- Get the value of the 'extending' flag.
cm.hasFocus() → boolean
- Tells you whether the editor currently has focus.
cm.findPosH(start: {line, ch}, amount: integer, unit: string, visually: boolean) → {line, ch, ?hitSide: boolean}
- Used to find the target position for horizontal cursor
motion.
start
is a{line, ch}
object,amount
an integer (may be negative), andunit
one of the string"char"
,"column"
, or"word"
. Will return a position that is produced by movingamount
times the distance specified byunit
. Whenvisually
is true, motion in right-to-left text will be visual rather than logical. When the motion was clipped by hitting the end or start of the document, the returned value will have ahitSide
property set to true. cm.findPosV(start: {line, ch}, amount: integer, unit: string) → {line, ch, ?hitSide: boolean}
- Similar to
findPosH
, but used for vertical motion.unit
may be"line"
or"page"
. The other arguments and the returned value have the same interpretation as they have infindPosH
. cm.findWordAt(pos: {line, ch}) → {anchor: {line, ch}, head: {line, ch}}
- Returns the start and end of the 'word' (the stretch of letters, whitespace, or punctuation) at the given position.
Configuration methods
cm.setOption(option: string, value: any)
- Change the configuration of the editor.
option
should the name of an option, andvalue
should be a valid value for that option. cm.getOption(option: string) → any
- Retrieves the current value of the given option for this editor instance.
cm.addKeyMap(map: object, bottom: boolean)
- Attach an additional key map to the
editor. This is mostly useful for addons that need to register
some key handlers without trampling on
the
extraKeys
option. Maps added in this way have a higher precedence than theextraKeys
andkeyMap
options, and between them, the maps added earlier have a lower precedence than those added later, unless thebottom
argument was passed, in which case they end up below other key maps added with this method. cm.removeKeyMap(map: object)
- Disable a keymap added
with
addKeyMap
. Either pass in the key map object itself, or a string, which will be compared against thename
property of the active key maps. cm.addOverlay(mode: string|object, ?options: object)
- Enable a highlighting overlay. This is a stateless mini-mode
that can be used to add extra highlighting. For example,
the search addon uses it to
highlight the term that's currently being
searched.
mode
can be a mode spec or a mode object (an object with atoken
method). Theoptions
parameter is optional. If given, it should be an object. Currently, only theopaque
option is recognized. This defaults to off, but can be given to allow the overlay styling, when notnull
, to override the styling of the base mode entirely, instead of the two being applied together. cm.removeOverlay(mode: string|object)
- Pass this the exact value passed for the
mode
parameter toaddOverlay
, or a string that corresponds to thename
propery of that value, to remove an overlay again. cm.on(type: string, func: (...args))
- Register an event handler for the given event type (a
string) on the editor instance. There is also
a
CodeMirror.on(object, type, func)
version that allows registering of events on any object. cm.off(type: string, func: (...args))
- Remove an event handler on the editor instance. An
equivalent
CodeMirror.off(object, type, func)
also exists.
Document management methods
Each editor is associated with an instance
of CodeMirror.Doc
, its document. A document
represents the editor content, plus a selection, an undo history,
and a mode. A document can only be
associated with a single editor at a time. You can create new
documents by calling the CodeMirror.Doc(text, mode,
firstLineNumber)
constructor. The last two arguments are
optional and can be used to set a mode for the document and make
it start at a line number other than 0, respectively.
cm.getDoc() → Doc
- Retrieve the currently active document from an editor.
doc.getEditor() → CodeMirror
- Retrieve the editor associated with a document. May
return
null
. cm.swapDoc(doc: CodeMirror.Doc) → Doc
- Attach a new document to the editor. Returns the old document, which is now no longer associated with an editor.
doc.copy(copyHistory: boolean) → Doc
- Create an identical copy of the given doc.
When
copyHistory
is true, the history will also be copied. Can not be called directly on an editor. doc.linkedDoc(options: object) → Doc
- Create a new document that's linked to the target document.
Linked documents will stay in sync (changes to one are also
applied to the other) until unlinked.
These are the options that are supported:
- When turned on, the linked copy will share an undo history with the original. Thus, something done in one of the two can be undone in the other, and vice versa.
from: integer
to: integer
- Can be given to make the new document a subview of the original. Subviews only show a given range of lines. Note that line coordinates inside the subview will be consistent with those of the parent, so that for example a subview starting at line 10 will refer to its first line as line 10, not 0.
mode: string|object
- By default, the new document inherits the mode of the parent. This option can be set to a mode spec to give it a different mode.
doc.unlinkDoc(doc: CodeMirror.Doc)
- Break the link between two documents. After calling this, changes will no longer propagate between the documents, and, if they had a shared history, the history will become separate.
doc.iterLinkedDocs(function: (doc: CodeMirror.Doc, sharedHist: boolean))
- Will call the given function for all documents linked to the target document. It will be passed two arguments, the linked document and a boolean indicating whether that document shares history with the target.
History-related methods
doc.undo()
- Undo one edit (if any undo events are stored).
doc.redo()
- Redo one undone edit.
doc.undoSelection()
- Undo one edit or selection change.
doc.redoSelection()
- Redo one undone edit or selection change.
doc.historySize() → {undo: integer, redo: integer}
- Returns an object with
{undo, redo}
properties, both of which hold integers, indicating the amount of stored undo and redo operations. doc.clearHistory()
- Clears the editor's undo history.
doc.getHistory() → object
- Get a (JSON-serializeable) representation of the undo history.
doc.setHistory(history: object)
- Replace the editor's undo history with the one provided,
which must be a value as returned
by
getHistory
. Note that this will have entirely undefined results if the editor content isn't also the same as it was whengetHistory
was called.
Text-marking methods
doc.markText(from: {line, ch}, to: {line, ch}, ?options: object) → TextMarker
- Can be used to mark a range of text with a specific CSS
class name.
from
andto
should be{line, ch}
objects. Theoptions
parameter is optional. When given, it should be an object that may contain the following configuration options:className: string
- Assigns a CSS class to the marked stretch of text.
inclusiveLeft: boolean
- Determines whether text inserted on the left of the marker will end up inside or outside of it.
inclusiveRight: boolean
- Like
inclusiveLeft
, but for the right side. atomic: boolean
- Atomic ranges act as a single unit when cursor movement is
concerned—i.e. it is impossible to place the cursor inside of
them. In atomic ranges,
inclusiveLeft
andinclusiveRight
have a different meaning—they will prevent the cursor from being placed respectively directly before and directly after the range. collapsed: boolean
- Collapsed ranges do not show up in the display. Setting a range to be collapsed will automatically make it atomic.
clearOnEnter: boolean
- When enabled, will cause the mark to clear itself whenever
the cursor enters its range. This is mostly useful for
text-replacement widgets that need to 'snap open' when the
user tries to edit them. The
"clear"
event fired on the range handle can be used to be notified when this happens. clearWhenEmpty: boolean
- Determines whether the mark is automatically cleared when it becomes empty. Default is true.
replacedWith: Element
- Use a given node to display this range. Implies both collapsed and atomic. The given DOM node must be an inline element (as opposed to a block element).
handleMouseEvents: boolean
- When
replacedWith
is given, this determines whether the editor will capture mouse and drag events occurring in this widget. Default is false—the events will be left alone for the default browser handler, or specific handlers on the widget, to capture. readOnly: boolean
- A read-only span can, as long as it is not cleared, not be
modified except by
calling
setValue
to reset the whole document. Note: adding a read-only span currently clears the undo history of the editor, because existing undo events being partially nullified by read-only spans would corrupt the history (in the current implementation). addToHistory: boolean
- When set to true (default is false), adding this marker will create an event in the undo history that can be individually undone (clearing the marker).
startStyle: string
- Can be used to specify an extra CSS class to be applied to the leftmost span that is part of the marker.
endStyle: string
- Equivalent
to
startStyle
, but for the rightmost span. title: string
- When given, will give the nodes created
for this span a HTML
title
attribute with the given value. - When the
target document is linked to other
documents, you can set
shared
to true to make the marker appear in all documents. By default, a marker appears only in its target document.
CodeMirror.TextMarker
), which exposes three methods:clear()
, to remove the mark,find()
, which returns a{from, to}
object (both holding document positions), indicating the current position of the marked range, orundefined
if the marker is no longer in the document, and finallychanged()
, which you can call if you've done something that might change the size of the marker (for example changing the content of areplacedWith
node), and want to cheaply update the display. doc.setBookmark(pos: {line, ch}, ?options: object) → TextMarker
- Inserts a bookmark, a handle that follows the text around it
as it is being edited, at the given position. A bookmark has two
methods
find()
andclear()
. The first returns the current position of the bookmark, if it is still in the document, and the second explicitly removes the bookmark. The options argument is optional. If given, the following properties are recognized:widget: Element
- Can be used to display a DOM
node at the current location of the bookmark (analogous to
the
replacedWith
option tomarkText
). insertLeft: boolean
- By default, text typed when the cursor is on top of the bookmark will end up to the right of the bookmark. Set this option to true to make it go to the left instead.
shared: boolean
- See
the corresponding option
to
markText
.
doc.findMarks(from: {line, ch}, to: {line, ch}) → array<TextMarker>
- Returns an array of all the bookmarks and marked ranges found between the given positions.
doc.findMarksAt(pos: {line, ch}) → array<TextMarker>
- Returns an array of all the bookmarks and marked ranges present at the given position.
doc.getAllMarks() → array<TextMarker>
- Returns an array containing all marked ranges in the document.
Widget, gutter, and decoration methods
cm.setGutterMarker(line: integer|LineHandle, gutterID: string, value: Element) → LineHandle
- Sets the gutter marker for the given gutter (identified by
its CSS class, see
the
gutters
option) to the given value. Value can be eithernull
, to clear the marker, or a DOM element, to set it. The DOM element will be shown in the specified gutter next to the specified line. cm.clearGutter(gutterID: string)
- Remove all gutter markers in the gutter with the given ID.
doc.addLineClass(line: integer|LineHandle, where: string, class: string) → LineHandle
- Set a CSS class name for the given line.
line
can be a number or a line handle.where
determines to which element this class should be applied, can can be one of"text"
(the text element, which lies in front of the selection),"background"
(a background element that will be behind the selection),"gutter"
(the line's gutter space), or"wrap"
(the wrapper node that wraps all of the line's elements, including gutter elements).class
should be the name of the class to apply. doc.removeLineClass(line: integer|LineHandle, where: string, class: string) → LineHandle
- Remove a CSS class from a line.
line
can be a line handle or number.where
should be one of"text"
,"background"
, or"wrap"
(seeaddLineClass
).class
can be left off to remove all classes for the specified node, or be a string to remove only a specific class. cm.lineInfo(line: integer|LineHandle) → object
- Returns the line number, text content, and marker status of
the given line, which can be either a number or a line handle.
The returned object has the structure
{line, handle, text, gutterMarkers, textClass, bgClass, wrapClass, widgets}
, wheregutterMarkers
is an object mapping gutter IDs to marker elements, andwidgets
is an array of line widgets attached to this line, and the various class properties refer to classes added withaddLineClass
. cm.addWidget(pos: {line, ch}, node: Element, scrollIntoView: boolean)
- Puts
node
, which should be an absolutely positioned DOM node, into the editor, positioned right below the given{line, ch}
position. WhenscrollIntoView
is true, the editor will ensure that the entire node is visible (if possible). To remove the widget again, simply use DOM methods (move it somewhere else, or callremoveChild
on its parent). cm.addLineWidget(line: integer|LineHandle, node: Element, ?options: object) → LineWidget
- Adds a line widget, an element shown below a line, spanning
the whole of the editor's width, and moving the lines below it
downwards.
line
should be either an integer or a line handle, andnode
should be a DOM node, which will be displayed below the given line.options
, when given, should be an object that configures the behavior of the widget. The following options are supported (all default to false):coverGutter: boolean
- Whether the widget should cover the gutter.
noHScroll: boolean
- Whether the widget should stay fixed in the face of horizontal scrolling.
above: boolean
- Causes the widget to be placed above instead of below the text of the line.
handleMouseEvents: boolean
- Determines whether the editor will capture mouse and drag events occurring in this widget. Default is false—the events will be left alone for the default browser handler, or specific handlers on the widget, to capture.
insertAt: integer
- By default, the widget is added below other widgets for the line. This option can be used to place it at a different position (zero for the top, N to put it after the Nth other widget). Note that this only has effect once, when the widget is created.
line
property pointing at the line handle that it is associated with, and the following methods:clear()
- Removes the widget.
changed()
- Call this if you made some change to the widget's DOM node that might affect its height. It'll force CodeMirror to update the height of the line that contains the widget.
Sizing, scrolling and positioning methods
cm.setSize(width: number|string, height: number|string)
- Programatically set the size of the editor (overriding the
applicable CSS
rules).
width
andheight
can be either numbers (interpreted as pixels) or CSS units ("100%"
, for example). You can passnull
for either of them to indicate that that dimension should not be changed. cm.scrollTo(x: number, y: number)
- Scroll the editor to a given (pixel) position. Both
arguments may be left as
null
orundefined
to have no effect. cm.getScrollInfo() → {left, top, width, height, clientWidth, clientHeight}
- Get an
{left, top, width, height, clientWidth, clientHeight}
object that represents the current scroll position, the size of the scrollable area, and the size of the visible area (minus scrollbars). cm.scrollIntoView(what: {line, ch}|{left, top, right, bottom}|{from, to}|null, ?margin: number)
- Scrolls the given position into view.
what
may benull
to scroll the cursor into view, a{line, ch}
position to scroll a character into view, a{left, top, right, bottom}
pixel range (in editor-local coordinates), or a range{from, to}
containing either two character positions or two pixel squares. Themargin
parameter is optional. When given, it indicates the amount of vertical pixels around the given area that should be made visible as well. cm.cursorCoords(where: boolean|{line, ch}, mode: string) → {left, top, bottom}
- Returns an
{left, top, bottom}
object containing the coordinates of the cursor position. Ifmode
is"local"
, they will be relative to the top-left corner of the editable document. If it is"page"
or not given, they are relative to the top-left corner of the page.where
can be a boolean indicating whether you want the start (true
) or the end (false
) of the selection, or, if a{line, ch}
object is given, it specifies the precise position at which you want to measure. cm.charCoords(pos: {line, ch}, ?mode: string) → {left, right, top, bottom}
- Returns the position and dimensions of an arbitrary
character.
pos
should be a{line, ch}
object. This differs fromcursorCoords
in that it'll give the size of the whole character, rather than just the position that the cursor would have when it would sit at that position. cm.coordsChar(object: {left, top}, ?mode: string) → {line, ch}
- Given an
{left, top}
object, returns the{line, ch}
position that corresponds to it. The optionalmode
parameter determines relative to what the coordinates are interpreted. It may be"window"
,"page"
(the default), or"local"
. cm.lineAtHeight(height: number, ?mode: string) → number
- Computes the line at the given pixel
height.
mode
can be one of the same strings thatcoordsChar
accepts. cm.heightAtLine(line: number, ?mode: string) → number
- Computes the height of the top of a line, in the coordinate
system specified by
mode
(seecoordsChar
), which defaults to"page"
. When a line below the bottom of the document is specified, the returned value is the bottom of the last line in the document. cm.defaultTextHeight() → number
- Returns the line height of the default font for the editor.
cm.defaultCharWidth() → number
- Returns the pixel width of an 'x' in the default font for the editor. (Note that for non-monospace fonts, this is mostly useless, and even for monospace fonts, non-ascii characters might have a different width).
cm.getViewport() → {from: number, to: number}
- Returns a
{from, to}
object indicating the start (inclusive) and end (exclusive) of the currently rendered part of the document. In big documents, when most content is scrolled out of view, CodeMirror will only render the visible part, and a margin around it. See also theviewportChange
event. cm.refresh()
- If your code does something to change the size of the editor element (window resizes are already listened for), or unhides it, you should probably follow up by calling this method to ensure CodeMirror is still looking as intended.
Mode, state, and token-related methods
When writing language-aware functionality, it can often be useful to hook into the knowledge that the CodeMirror language mode has. See the section on modes for a more detailed description of how these work.
doc.getMode() → object
- Gets the (outer) mode object for the editor. Note that this
is distinct from
getOption("mode")
, which gives you the mode specification, rather than the resolved, instantiated mode object. doc.getModeAt(pos: {line, ch}) → object
- Gets the inner mode at a given position. This will return
the same as
getMode
for simple modes, but will return an inner mode for nesting modes (such ashtmlmixed
). cm.getTokenAt(pos: {line, ch}, ?precise: boolean) → object
- Retrieves information about the token the current mode found
before the given position (a
{line, ch}
object). The returned object has the following properties:start
- The character (on the given line) at which the token starts.
end
- The character at which the token ends.
string
- The token's string.
type
- The token type the mode assigned
to the token, such as
"keyword"
or"comment"
(may also be null). state
- The mode's state at the end of this token.
precise
is true, the token will be guaranteed to be accurate based on recent edits. If false or not specified, the token will use cached state information, which will be faster but might not be accurate if edits were recently made and highlighting has not yet completed. cm.getLineTokens(line: integer, ?precise: boolean) → array<{start, end, string, type, state}>
- This is similar
to
getTokenAt
, but collects all tokens for a given line into an array. It is much cheaper than repeatedly callinggetTokenAt
, which re-parses the part of the line before the token for every call. cm.getTokenTypeAt(pos: {line, ch}) → string
- This is a (much) cheaper version
of
getTokenAt
useful for when you just need the type of the token at a given position, and no other information. Will returnnull
for unstyled tokens, and a string, potentially containing multiple space-separated style names, otherwise. cm.getHelpers(pos: {line, ch}, type: string) → array<helper>
- Fetch the set of applicable helper values for the given
position. Helpers provide a way to look up functionality
appropriate for a mode. The
type
argument provides the helper namespace (seeregisterHelper
), in which the values will be looked up. When the mode itself has a property that corresponds to thetype
, that directly determines the keys that are used to look up the helper values (it may be either a single string, or an array of strings). Failing that, the mode'shelperType
property and finally the mode's name are used. - For example, the JavaScript mode has a
property
fold
containing"brace"
. When thebrace-fold
addon is loaded, that defines a helper namedbrace
in thefold
namespace. This is then used by thefoldcode
addon to figure out that it can use that folding function to fold JavaScript code. - When any 'global' helpers are defined for the given namespace, their predicates are called on the current mode and editor, and all those that declare they are applicable will also be added to the array that is returned.
cm.getHelper(pos: {line, ch}, type: string) → helper
- Returns the first applicable helper value.
See
getHelpers
. cm.getStateAfter(?line: integer, ?precise: boolean) → object
- Returns the mode's parser state, if any, at the end of the
given line number. If no line number is given, the state at the
end of the document is returned. This can be useful for storing
parsing errors in the state, or getting other kinds of
contextual information for a line.
precise
is defined as ingetTokenAt()
.
Miscellaneous methods
cm.operation(func: () → any) → any
- CodeMirror internally buffers changes and only updates its DOM structure after it has finished performing some operation. If you need to perform a lot of operations on a CodeMirror instance, you can call this method with a function argument. It will call the function, buffering up all changes, and only doing the expensive update after the function returns. This can be a lot faster. The return value from this method will be the return value of your function.
cm.indentLine(line: integer, ?dir: string|integer)
- Adjust the indentation of the given line. The second
argument (which defaults to
"smart"
) may be one of:"prev"
- Base indentation on the indentation of the previous line.
"smart"
- Use the mode's smart indentation if available, behave
like
"prev"
otherwise. "add"
- Increase the indentation of the line by one indent unit.
"subtract"
- Reduce the indentation of the line.
<integer>
- Add (positive number) or reduce (negative number) the indentation by the given amount of spaces.
cm.toggleOverwrite(?value: bool)
- Switches between overwrite and normal insert mode (when not given an argument), or sets the overwrite mode to a specific state (when given an argument).
cm.execCommand(name: string)
- Runs the command with the given name on the editor.
doc.posFromIndex(index: integer) → {line, ch}
- Calculates and returns a
{line, ch}
object for a zero-basedindex
who's value is relative to the start of the editor's text. If theindex
is out of range of the text then the returned object is clipped to start or end of the text respectively. doc.indexFromPos(object: {line, ch}) → integer
- The reverse of
posFromIndex
. cm.focus()
- Give the editor focus.
cm.getInputField() → TextAreaElement
- Returns the hidden textarea used to read input.
cm.getWrapperElement() → Element
- Returns the DOM node that represents the editor, and controls its size. Remove this from your tree to delete an editor instance.
cm.getScrollerElement() → Element
- Returns the DOM node that is responsible for the scrolling of the editor.
cm.getGutterElement() → Element
- Fetches the DOM node that contains the editor gutters.
Static properties
The CodeMirror
object itself provides
several useful properties.
CodeMirror.version: string
- It contains a string that indicates the version of the
library. This is a triple of
integers
"major.minor.patch"
, wherepatch
is zero for releases, and something else (usually one) for dev snapshots. CodeMirror.fromTextArea(textArea: TextAreaElement, ?config: object)
-
The method provides another way to initialize an editor. It
takes a textarea DOM node as first argument and an optional
configuration object as second. It will replace the textarea
with a CodeMirror instance, and wire up the form of that
textarea (if any) to make sure the editor contents are put
into the textarea when the form is submitted. The text in the
textarea will provide the content for the editor. A CodeMirror
instance created this way has three additional methods:
cm.save()
- Copy the content of the editor into the textarea.
cm.toTextArea()
- Remove the editor, and restore the original textarea (with the editor's current content).
cm.getTextArea() → TextAreaElement
- Returns the textarea that the instance was based on.
CodeMirror.defaults: object
- An object containing default values for all options. You can assign to its properties to modify defaults (though this won't affect editors that have already been created).
CodeMirror.defineExtension(name: string, value: any)
- If you want to define extra methods in terms of the
CodeMirror API, it is possible to
use
defineExtension
. This will cause the given value (usually a method) to be added to all CodeMirror instances created from then on. CodeMirror.defineDocExtension(name: string, value: any)
- Like
defineExtension
, but the method will be added to the interface forDoc
objects instead. CodeMirror.defineOption(name: string, default: any, updateFunc: function)
- Similarly,
defineOption
can be used to define new options for CodeMirror. TheupdateFunc
will be called with the editor instance and the new value when an editor is initialized, and whenever the option is modified throughsetOption
. CodeMirror.defineInitHook(func: function)
- If your extention just needs to run some
code whenever a CodeMirror instance is initialized,
use
CodeMirror.defineInitHook
. Give it a function as its only argument, and from then on, that function will be called (with the instance as argument) whenever a new CodeMirror instance is initialized. CodeMirror.registerHelper(type: string, name: string, value: helper)
- Registers a helper value with the given
name
in the given namespace (type
). This is used to define functionality that may be looked up by mode. Will create (if it doesn't already exist) a property on theCodeMirror
object for the giventype
, pointing to an object that maps names to values. I.e. after doingCodeMirror.registerHelper("hint", "foo", myFoo)
, the valueCodeMirror.hint.foo
will point tomyFoo
. CodeMirror.registerGlobalHelper(type: string, name: string, predicate: fn(mode, CodeMirror), value: helper)
- Acts
like
registerHelper
, but also registers this helper as 'global', meaning that it will be included bygetHelpers
whenever the givenpredicate
returns true when called with the local mode and editor. CodeMirror.Pos(line: integer, ?ch: integer)
- A constructor for the
{line, ch}
objects that are used to represent positions in editor documents. CodeMirror.changeEnd(change: object) → {line, ch}
- Utility function that computes an end position from a change
(an object with
from
,to
, andtext
properties, as passed to various event handlers). The returned position will be the end of the changed range, after the change is applied.
Addons
The addon
directory in the distribution contains a
number of reusable components that implement extra editor
functionality (on top of extension functions
like defineOption
, defineExtension
,
and registerHelper
). In
brief, they are:
dialog/dialog.js
- Provides a very simple way to query users for text input.
Adds the
openDialog(template, callback, options) → closeFunction
method to CodeMirror instances, which can be called with an HTML fragment or a detached DOM node that provides the prompt (should include aninput
orbutton
tag), and a callback function that is called when the user presses enter. It returns a functioncloseFunction
which, if called, will close the dialog immediately.openDialog
takes the following options:closeOnEnter
:- If true, the dialog will be closed when the user presses
enter in the input. Defaults to
true
. onKeyDown
:- An event handler of the signature
(event, value, closeFunction)
that will be called wheneverkeydown
fires in the dialog's input. If your callback returnstrue
, the dialog will not do any further processing of the event. onKeyUp
:- Same as
onKeyDown
but for thekeyup
event. onInput
:- Same as
onKeyDown
but for theinput
event. onClose
:- A callback of the signature
(dialogInstance)
that will be called after the dialog has been closed and removed from the DOM. No return value.
Also adds an
openNotification(template, options) → closeFunction
function that simply shows an HTML fragment as a notification at the top of the editor. It takes a single option:duration
, the amount of time after which the notification will be automatically closed. Ifduration
is zero, the dialog will not be closed automatically.Depends on
addon/dialog/dialog.css
. search/searchcursor.js
- Adds the
getSearchCursor(query, start, caseFold) → cursor
method to CodeMirror instances, which can be used to implement search/replace functionality.query
can be a regular expression or a string (only strings will match across lines—if they contain newlines).start
provides the starting position of the search. It can be a{line, ch}
object, or can be left off to default to the start of the document.caseFold
is only relevant when matching a string. It will cause the search to be case-insensitive. A search cursor has the following methods:findNext() → boolean
findPrevious() → boolean
- Search forward or backward from the current position.
The return value indicates whether a match was found. If
matching a regular expression, the return value will be the
array returned by the
match
method, in case you want to extract matched groups. from() → {line, ch}
to() → {line, ch}
- These are only valid when the last call
to
findNext
orfindPrevious
did not return false. They will return{line, ch}
objects pointing at the start and end of the match. replace(text: string)
- Replaces the currently found match with the given text and adjusts the cursor position to reflect the replacement.
search/search.js
- Implements the search commands. CodeMirror has keys bound to
these by default, but will not do anything with them unless an
implementation is provided. Depends
on
searchcursor.js
, and will make use ofopenDialog
when available to make prompting for search queries less ugly. edit/matchbrackets.js
- Defines an option
matchBrackets
which, when set to true, causes matching brackets to be highlighted whenever the cursor is next to them. It also adds a methodmatchBrackets
that forces this to happen once, and a methodfindMatchingBracket
that can be used to run the bracket-finding algorithm that this uses internally. edit/closebrackets.js
- Defines an option
autoCloseBrackets
that will auto-close brackets and quotes when typed. By default, it'll auto-close()[]{}''""
, but you can pass it a string similar to that (containing pairs of matching characters), or an object withpairs
and optionallyexplode
properties to customize it.explode
should be a similar string that gives the pairs of characters that, when enter is pressed between them, should have the second character also moved to its own line. Demo here. - Defines an option
matchTags
that, when enabled, will cause the tags around the cursor to be highlighted (using theCodeMirror-matchingtag
class). Also defines a commandtoMatchingTag
, which you can bind a key to in order to jump to the tag mathing the one under the cursor. Depends on theaddon/fold/xml-fold.js
addon. Demo here. edit/trailingspace.js
- Adds an option
showTrailingSpace
which, when enabled, adds the CSS classcm-trailingspace
to stretches of whitespace at the end of lines. The demo has a nice squiggly underline style for this class. edit/closetag.js
- Provides utility functions for adding automatic tag closing to XML modes. See the demo.
edit/continuelist.js
- Markdown specific. Defines
a
"newlineAndIndentContinueMarkdownList"
command command that can be bound toenter
to automatically insert the leading characters for continuing a list. See the Markdown mode demo. comment/comment.js
- Addon for commenting and uncommenting code. Adds three
methods to CodeMirror instances:
lineComment(from: {line, ch}, to: {line, ch}, ?options: object)
- Set the lines in the given range to be line comments. Will
fall back to
blockComment
when no line comment style is defined for the mode. blockComment(from: {line, ch}, to: {line, ch}, ?options: object)
- Wrap the code in the given range in a block comment. Will
fall back to
lineComment
when no block comment style is defined for the mode. uncomment(from: {line, ch}, to: {line, ch}, ?options: object) → boolean
- Try to uncomment the given range.
Returns
true
if a comment range was found and removed,false
otherwise.
options
object accepted by these methods may have the following properties:blockCommentStart, blockCommentEnd, blockCommentLead, lineComment: string
- Override the comment string properties of the mode with custom comment strings.
padding: string
- A string that will be inserted after opening and leading markers, and before closing comment markers. Defaults to a single space.
commentBlankLines: boolean
- Whether, when adding line comments, to also comment lines that contain only whitespace.
indent: boolean
- When adding line comments and this is turned on, it will align the comment block to the current indentation of the first line of the block.
fullLines: boolean
- When block commenting, this controls whether the whole
lines are indented, or only the precise range that is given.
Defaults to
true
.
toggleComment
command, which will try to uncomment the current selection, and if that fails, line-comments it. fold/foldcode.js
- Helps with code folding. Adds a
foldCode
method to editor instances, which will try to do a code fold starting at the given line, or unfold the fold that is already present. The method takes as first argument the position that should be folded (may be a line number or aPos
), and as second optional argument either a range-finder function, or an options object, supporting the following properties:rangeFinder: fn(CodeMirror, Pos)
- The function that is used to find
foldable ranges. If this is not directly passed, it will
default to
CodeMirror.fold.auto
, which usesgetHelpers
with a"fold"
type to find folding functions appropriate for the local mode. There are files in theaddon/fold/
directory providingCodeMirror.fold.brace
, which finds blocks in brace languages (JavaScript, C, Java, etc),CodeMirror.fold.indent
, for languages where indentation determines block structure (Python, Haskell), andCodeMirror.fold.xml
, for XML-style languages, andCodeMirror.fold.comment
, for folding comment blocks. widget: string|Element
- The widget to show for folded ranges. Can be either a
string, in which case it'll become a span with
class
CodeMirror-foldmarker
, or a DOM node. scanUp: boolean
- When true (default is false), the addon will try to find foldable ranges on the lines above the current one if there isn't an eligible one on the given line.
minFoldSize: integer
- The minimum amount of lines that a fold should span to be accepted. Defaults to 0, which also allows single-line folds.
fold/foldgutter.js
- Provides an option
foldGutter
, which can be used to create a gutter with markers indicating the blocks that can be folded. Create a gutter using thegutters
option, giving it the classCodeMirror-foldgutter
or something else if you configure the addon to use a different class, and this addon will show markers next to folded and foldable blocks, and handle clicks in this gutter. Note that CSS styles should be applied to make the gutter, and the fold markers within it, visible. A default set of CSS styles are available in:addon/fold/foldgutter.css
. The option can be either set totrue
, or an object containing the following optional option fields:gutter: string
- The CSS class of the gutter. Defaults
to
"CodeMirror-foldgutter"
. You will have to style this yourself to give it a width (and possibly a background). See the default gutter style rules above. indicatorOpen: string | Element
- A CSS class or DOM element to be used as the marker for
open, foldable blocks. Defaults
to
"CodeMirror-foldgutter-open"
. indicatorFolded: string | Element
- A CSS class or DOM element to be used as the marker for
folded blocks. Defaults to
"CodeMirror-foldgutter-folded"
. rangeFinder: fn(CodeMirror, Pos)
- The range-finder function to use when determining whether
something can be folded. When not
given,
CodeMirror.fold.auto
will be used as default.
foldOptions
editor option can be set to an object to provide an editor-wide default configuration. Demo here. runmode/runmode.js
- Can be used to run a CodeMirror mode over text without actually opening an editor instance. See the demo for an example. There are alternate versions of the file avaible for running stand-alone (without including all of CodeMirror) and for running under node.js.
runmode/colorize.js
- Provides a convenient way to syntax-highlight code snippets
in a webpage. Depends on
the
runmode
addon (or its standalone variant). Provides aCodeMirror.colorize
function that can be called with an array (or other array-ish collection) of DOM nodes that represent the code snippets. By default, it'll get allpre
tags. Will read thedata-lang
attribute of these nodes to figure out their language, and syntax-color their content using the relevant CodeMirror mode (you'll have to load the scripts for the relevant modes yourself). A second argument may be provided to give a default mode, used when no language attribute is found for a node. Used in this manual to highlight example code. mode/overlay.js
- Mode combinator that can be used to extend a mode with an
'overlay' — a secondary mode is run over the stream, along with
the base mode, and can color specific pieces of text without
interfering with the base mode.
Defines
CodeMirror.overlayMode
, which is used to create such a mode. See this demo for a detailed example. mode/multiplex.js
- Mode combinator that can be used to easily 'multiplex'
between several modes.
Defines
CodeMirror.multiplexingMode
which, when given as first argument a mode object, and as other arguments any number of{open, close, mode [, delimStyle, innerStyle]}
objects, will return a mode object that starts parsing using the mode passed as first argument, but will switch to another mode as soon as it encounters a string that occurs in one of theopen
fields of the passed objects. When in a sub-mode, it will go back to the top mode again when theclose
string is encountered. Pass"\n"
foropen
orclose
if you want to switch on a blank line.- When
delimStyle
is specified, it will be the token style returned for the delimiter tokens. - When
innerStyle
is specified, it will be the token style added for each inner mode token.
- When
hint/show-hint.js
- Provides a framework for showing autocompletion hints.
Defines
editor.showHint
, which takes an optional options object, and pops up a widget that allows the user to select a completion. Finding hints is done with a hinting functions (thehint
option), which is a function that take an editor instance and options object, and return a{list, from, to}
object, wherelist
is an array of strings or objects (the completions), andfrom
andto
give the start and end of the token that is being completed as{line, ch}
objects. - If no hinting function is given, the addon will
use
CodeMirror.hint.auto
, which callsgetHelpers
with the"hint"
type to find applicable hinting functions, and tries them one by one. If that fails, it looks for a"hintWords"
helper to fetch a list of completable words for the mode, and usesCodeMirror.hint.fromList
to complete from those. - When completions aren't simple strings, they should be
objects with the following properties:
text: string
- The completion text. This is the only required property.
displayText: string
- The text that should be displayed in the menu.
className: string
- A CSS class name to apply to the completion's line in the menu.
render: fn(Element, self, data)
- A method used to create the DOM structure for showing the completion by appending it to its first argument.
hint: fn(CodeMirror, self, data)
- A method used to actually apply the completion, instead of the default behavior.
from: {line, ch}
- Optional
from
position that will be used bypick()
instead of the global one passed with the full list of completions. to: {line, ch}
- Optional
to
position that will be used bypick()
instead of the global one passed with the full list of completions.
hint: function
- A hinting function, as specified above. It is possible to
set the
async
property on a hinting function to true, in which case it will be called with arguments(cm, callback, ?options)
, and the completion interface will only be popped up when the hinting function calls the callback, passing it the object holding the completions. completeSingle: boolean
- Determines whether, when only a single completion is available, it is completed without showing the dialog. Defaults to true.
alignWithWord: boolean
- Whether the pop-up should be horizontally aligned with the start of the word (true, default), or with the cursor (false).
closeOnUnfocus: boolean
- When enabled (which is the default), the pop-up will close when the editor is unfocused.
customKeys: keymap
- Allows you to provide a custom key map of keys to be active
when the pop-up is active. The handlers will be called with an
extra argument, a handle to the completion menu, which
has
moveFocus(n)
,setFocus(n)
,pick()
, andclose()
methods (see the source for details), that can be used to change the focused element, pick the current element or close the menu. AdditionnalymenuSize()
can give you access to the size of the current dropdown menu,length
give you the number of availlable completions, anddata
give you full access to the completion returned by the hinting function. extraKeys: keymap
- Like
customKeys
above, but the bindings will be added to the set of default bindings, instead of replacing them.
"shown" ()
- Fired when the pop-up is shown.
"select" (completion, Element)
- Fired when a completion is selected. Passed the completion value (string or object) and the DOM node that represents it in the menu.
"pick" (completion)
- Fired when a completion is picked. Passed the completion value (string or object).
"close" ()
- Fired when the completion is finished.
addon/hint/show-hint.css
. Check out the demo for an example. hint/javascript-hint.js
- Defines a simple hinting function for JavaScript
(
CodeMirror.hint.javascript
) and CoffeeScript (CodeMirror.hint.coffeescript
) code. This will simply use the JavaScript environment that the editor runs in as a source of information about objects and their properties. hint/xml-hint.js
- Defines
CodeMirror.hint.xml
, which produces hints for XML tagnames, attribute names, and attribute values, guided by aschemaInfo
option (a property of the second argument passed to the hinting function, or the third argument passed toCodeMirror.showHint
).
The schema info should be an object mapping tag names to information about these tags, with optionally a"!top"
property containing a list of the names of valid top-level tags. The values of the properties should be objects with optional propertieschildren
(an array of valid child element names, omit to simply allow all tags to appear) andattrs
(an object mapping attribute names tonull
for free-form attributes, and an array of valid values for restricted attributes). Demo here. hint/html-hint.js
- Provides schema info to
the xml-hint addon for HTML
documents. Defines a schema
object
CodeMirror.htmlSchema
that you can pass to as aschemaInfo
option, and aCodeMirror.hint.html
hinting function that automatically callsCodeMirror.hint.xml
with this schema data. See the demo. hint/css-hint.js
- A hinting function for CSS, SCSS, or LESS code.
Defines
CodeMirror.hint.css
. hint/python-hint.js
- A very simple hinting function for Python code.
Defines
CodeMirror.hint.python
. hint/anyword-hint.js
- A very simple hinting function
(
CodeMirror.hint.anyword
) that simply looks for words in the nearby code and completes to those. Takes two optional options,word
, a regular expression that matches words (sequences of one or more character), andrange
, which defines how many lines the addon should scan when completing (defaults to 500). hint/sql-hint.js
- A simple SQL hinter. Defines
CodeMirror.hint.sql
. Takes two optional options,tables
, a object with table names as keys and array of respective column names as values, anddefaultTable
, a string corresponding to a table name intables
for autocompletion. search/match-highlighter.js
- Adds a
highlightSelectionMatches
option that can be enabled to highlight all instances of a currently selected word. Can be set either to true or to an object containing the following options:minChars
, for the minimum amount of selected characters that triggers a highlight (default 2),style
, for the style to be used to highlight the matches (default"matchhighlight"
, which will correspond to CSS classcm-matchhighlight
), andshowToken
which can be set totrue
or to a regexp matching the characters that make up a word. When enabled, it causes the current word to be highlighted when nothing is selected (defaults to off). Demo here. lint/lint.js
- Defines an interface component for showing linting warnings,
with pluggable warning sources
(see
json-lint.js
,javascript-lint.js
, andcss-lint.js
in the same directory). Defines alint
option that can be set to a warning source (for exampleCodeMirror.lint.javascript
), or totrue
, in which casegetHelper
with type"lint"
is used to determined a validator function. Depends onaddon/lint/lint.css
. A demo can be found here. selection/mark-selection.js
- Causes the selected text to be marked with the CSS class
CodeMirror-selectedtext
when thestyleSelectedText
option is enabled. Useful to change the colour of the selection (in addition to the background), like in this demo. selection/active-line.js
- Defines a
styleActiveLine
option that, when enabled, gives the wrapper of the active line the classCodeMirror-activeline
, and adds a background with the classCodeMirror-activeline-background
. is enabled. See the demo. mode/loadmode.js
- Defines a
CodeMirror.requireMode(modename, callback)
function that will try to load a given mode and call the callback when it succeeded. You'll have to setCodeMirror.modeURL
to a string that mode paths can be constructed from, for example"mode/%N/%N.js"
—the%N
's will be replaced with the mode name. Also definesCodeMirror.autoLoadMode(instance, mode)
, which will ensure the given mode is loaded and cause the given editor instance to refresh its mode when the loading succeeded. See the demo. mode/meta.js
- Provides meta-information about all the modes in the
distribution in a single file.
Defines
CodeMirror.modeInfo
, an array of objects with{name, mime, mode}
properties, wherename
is the human-readable name,mime
the MIME type, andmode
the name of the mode file that defines this MIME. There are optional propertiesmimes
, which holds an array of MIME types for modes with multiple MIMEs associated, andext
, which holds an array of file extensions associated with this mode. Three convenience functions,CodeMirror.findModeByMIME
, andCodeMirror.findModeByExtension
, andCodeMirror.findModeByName
are provided, which return such an object given a MIME or extension string. Note that, for historical reasons, this file resides in the top-levelmode
directory, not underaddon
. Demo. comment/continuecomment.js
- Adds a
continueComments
option, which sets whether the editor will make the next line continue a comment when you press Enter inside a comment block. Can be set to a boolean to enable/disable this functionality. Set to a string, it will continue comments using a custom shortcut. Set to an object, it will use thekey
property for a custom shortcut and the booleancontinueLineComment
property to determine whether single-line comments should be continued (defaulting totrue
). display/placeholder.js
- Adds a
placeholder
option that can be used to make text appear in the editor when it is empty and not focused. Also gives the editor aCodeMirror-empty
CSS class whenever it doesn't contain any text. See the demo. display/fullscreen.js
- Defines an option
fullScreen
that, when set totrue
, will make the editor full-screen (as in, taking up the whole browser window). Depends onfullscreen.css
. Demo here. display/rulers.js
- Adds a
rulers
option, which can be used to show one or more vertical rulers in the editor. The option, if defined, should be given an array of{column [, className, color, lineStyle, width]}
objects or numbers (wich indicate a column). The ruler will be displayed at the column indicated by the number or thecolumn
property. TheclassName
property can be used to assign a custom style to a ruler. Demo here. wrap/hardwrap.js
- Addon to perform hard line wrapping/breaking for paragraphs
of text. Adds these methods to editor instances:
wrapParagraph(?pos: {line, ch}, ?options: object)
- Wraps the paragraph at the given position.
If
pos
is not given, it defaults to the cursor position. wrapRange(from: {line, ch}, to: {line, ch}, ?options: object)
- Wraps the given range as one big paragraph.
wrapParagraphsInRange(from: {line, ch}, to: {line, ch}, ?options: object)
- Wrapps the paragraphs in (and overlapping with) the given range individually.
paragraphStart, paragraphEnd: RegExp
- Blank lines are always considered paragraph boundaries. These options can be used to specify a pattern that causes lines to be considered the start or end of a paragraph.
column: number
- The column to wrap at. Defaults to 80.
wrapOn: RegExp
- A regular expression that matches only those two-character strings that allow wrapping. By default, the addon wraps on whitespace and after dash characters.
killTrailingSpace: boolean
- Whether trailing space caused by wrapping should be preserved, or deleted. Defaults to true.
merge/merge.js
- Implements an interface for merging changes, using either a
2-way or a 3-way view. The
CodeMirror.MergeView
constructor takes arguments similar to theCodeMirror
constructor, first a node to append the interface to, and then an options object. Two extra optional options are recognized,origLeft
andorigRight
, which may be strings that provide original versions of the document, which will be shown to the left and right of the editor in non-editable CodeMirror instances. The merge interface will highlight changes between the editable document and the original(s), and, unless arevertButtons
option offalse
is given, show buttons that allow the user to revert changes (demo). tern/tern.js
- Provides integration with the Tern JavaScript analysis engine, for completion, definition finding, and minor refactoring help. See the demo for a very simple integration. For more involved scenarios, see the comments at the top of the addon and the implementation of the (multi-file) demonstration on the Tern website.
Writing CodeMirror Modes
Modes typically consist of a single JavaScript file. This file defines, in the simplest case, a lexer (tokenizer) for your language—a function that takes a character stream as input, advances it past a token, and returns a style for that token. More advanced modes can also handle indentation for the language.
This section describes the low-level mode interface. Many modes are written directly against this, since it offers a lot of control, but for a quick mode definition, you might want to use the simple mode addon.
The mode script should
call CodeMirror.defineMode
to
register itself with CodeMirror. This function takes two
arguments. The first should be the name of the mode, for which you
should use a lowercase string, preferably one that is also the
name of the files that define the mode (i.e. "xml"
is
defined in xml.js
). The second argument should be a
function that, given a CodeMirror configuration object (the thing
passed to the CodeMirror
function) and an optional
mode configuration object (as in
the mode
option), returns
a mode object.
Typically, you should use this second argument
to defineMode
as your module scope function (modes
should not leak anything into the global scope!), i.e. write your
whole mode inside this function.
The main responsibility of a mode script is parsing the content of the editor. Depending on the language and the amount of functionality desired, this can be done in really easy or extremely complicated ways. Some parsers can be stateless, meaning that they look at one element (token) of the code at a time, with no memory of what came before. Most, however, will need to remember something. This is done by using a state object, which is an object that is always passed when reading a token, and which can be mutated by the tokenizer.
Modes that use a state must define
a startState
method on their mode
object. This is a function of no arguments that produces a state
object to be used at the start of a document.
The most important part of a mode object is
its token(stream, state)
method. All
modes must define this method. It should read one token from the
stream it is given as an argument, optionally update its state,
and return a style string, or null
for tokens that do
not have to be styled. For your styles, you are encouraged to use
the 'standard' names defined in the themes (without
the cm-
prefix). If that fails, it is also possible
to come up with your own and write your own CSS theme file.
A typical token string would
be "variable"
or "comment"
. Multiple
styles can be returned (separated by spaces), for
example "string error"
for a thing that looks like a
string but is invalid somehow (say, missing its closing quote).
When a style is prefixed by "line-"
or "line-background-"
, the style will be applied to
the whole line, analogous to what
the addLineClass
method
does—styling the "text"
in the simple case, and
the "background"
element
when "line-background-"
is prefixed.
The stream object that's passed
to token
encapsulates a line of code (tokens may
never span lines) and our current position in that line. It has
the following API:
eol() → boolean
- Returns true only if the stream is at the end of the line.
sol() → boolean
- Returns true only if the stream is at the start of the line.
peek() → string
- Returns the next character in the stream without advancing
it. Will return an
null
at the end of the line. next() → string
- Returns the next character in the stream and advances it.
Also returns
null
when no more characters are available. eat(match: string|regexp|function(char: string) → boolean) → string
match
can be a character, a regular expression, or a function that takes a character and returns a boolean. If the next character in the stream 'matches' the given argument, it is consumed and returned. Otherwise,undefined
is returned.eatWhile(match: string|regexp|function(char: string) → boolean) → boolean
- Repeatedly calls
eat
with the given argument, until it fails. Returns true if any characters were eaten. eatSpace() → boolean
- Shortcut for
eatWhile
when matching white-space. skipToEnd()
- Moves the position to the end of the line.
skipTo(ch: string) → boolean
- Skips to the next occurrence of the given character, if found on the current line (doesn't advance the stream if the character does not occur on the line). Returns true if the character was found.
match(pattern: string, ?consume: boolean, ?caseFold: boolean) → boolean
match(pattern: regexp, ?consume: boolean) → array<string>
- Act like a
multi-character
eat
—ifconsume
is true or not given—or a look-ahead that doesn't update the stream position—if it is false.pattern
can be either a string or a regular expression starting with^
. When it is a string,caseFold
can be set to true to make the match case-insensitive. When successfully matching a regular expression, the returned value will be the array returned bymatch
, in case you need to extract matched groups. backUp(n: integer)
- Backs up the stream
n
characters. Backing it up further than the start of the current token will cause things to break, so be careful. column() → integer
- Returns the column (taking into account tabs) at which the current token starts.
indentation() → integer
- Tells you how far the current line has been indented, in spaces. Corrects for tab characters.
current() → string
- Get the string between the start of the current token and the current stream position.
By default, blank lines are simply skipped when
tokenizing a document. For languages that have significant blank
lines, you can define
a blankLine(state)
method on your
mode that will get called whenever a blank line is passed over, so
that it can update the parser state.
Because state object are mutated, and CodeMirror
needs to keep valid versions of a state around so that it can
restart a parse at any line, copies must be made of state objects.
The default algorithm used is that a new state object is created,
which gets all the properties of the old object. Any properties
which hold arrays get a copy of these arrays (since arrays tend to
be used as mutable stacks). When this is not correct, for example
because a mode mutates non-array properties of its state object, a
mode object should define
a copyState
method, which is given a
state and should return a safe copy of that state.
If you want your mode to provide smart indentation
(through the indentLine
method and the indentAuto
and newlineAndIndent
commands, to which keys can be
bound), you must define
an indent(state, textAfter)
method
on your mode object.
The indentation method should inspect the given state object,
and optionally the textAfter
string, which contains
the text on the line that is being indented, and return an
integer, the amount of spaces to indent. It should usually take
the indentUnit
option into account. An indentation method may
return CodeMirror.Pass
to indicate that it
could not come up with a precise indentation.
To work well with
the commenting addon, a mode may
define lineComment
(string that
starts a line
comment), blockCommentStart
, blockCommentEnd
(strings that start and end block comments),
and blockCommentLead
(a string to put at the start of
continued lines in a block comment). All of these are
optional.
Finally, a mode may define either
an electricChars
or an electricInput
property, which are used to automatically reindent the line when
certain patterns are typed and
the electricChars
option is enabled. electricChars
may be a string, and
will trigger a reindent whenever one of the characters in that
string are typed. Often, it is more appropriate to
use electricInput
, which should hold a regular
expression, and will trigger indentation when the part of the
line before the cursor matches the expression. It should
usually end with a $
character, so that it only
matches when the indentation-changing pattern was just typed, not when something was
typed after the pattern.
So, to summarize, a mode must provide
a token
method, and it may
provide startState
, copyState
,
and indent
methods. For an example of a trivial mode,
see the diff mode, for a more
involved example, see the C-like
mode.
Sometimes, it is useful for modes to nest—to have one
mode delegate work to another mode. An example of this kind of
mode is the mixed-mode HTML
mode. To implement such nesting, it is usually necessary to
create mode objects and copy states yourself. To create a mode
object, there are CodeMirror.getMode(options,
parserConfig)
, where the first argument is a configuration
object as passed to the mode constructor function, and the second
argument is a mode specification as in
the mode
option. To copy a
state object, call CodeMirror.copyState(mode, state)
,
where mode
is the mode that created the given
state.
In a nested mode, it is recommended to add an
extra method, innerMode
which, given
a state object, returns a {state, mode}
object with
the inner mode and its state for the current position. These are
used by utility scripts such as the tag
closer to get context information. Use
the CodeMirror.innerMode
helper function to, starting
from a mode and a state, recursively walk down to the innermost
mode and state.
To make indentation work properly in a nested parser, it is
advisable to give the startState
method of modes that
are intended to be nested an optional argument that provides the
base indentation for the block of code. The JavaScript and CSS
parser do this, for example, to allow JavaScript and CSS code
inside the mixed-mode HTML mode to be properly indented.
It is possible, and encouraged, to associate
your mode, or a certain configuration of your mode, with
a MIME type. For
example, the JavaScript mode associates itself
with text/javascript
, and its JSON variant
with application/json
. To do this,
call CodeMirror.defineMIME(mime,
modeSpec)
, where modeSpec
can be a string or
object specifying a mode, as in
the mode
option.
If a mode specification wants to add some properties to the
resulting mode object, typically for use
with getHelpers
, it may
contain a modeProps
property, which holds an object.
This object's properties will be copied to the actual mode
object.
Sometimes, it is useful to add or override mode
object properties from external code.
The CodeMirror.extendMode
function
can be used to add properties to mode objects produced for a
specific mode. Its first argument is the name of the mode, its
second an object that specifies the properties that should be
added. This is mostly useful to add utilities that can later be
looked up through getMode
.