Do we really need Redux or @ngrx/store
About this article
If you are writing Angular, Vue or React applications, chances are big that you have used or encountered the Redux pattern. Redux helps us to structure statemanagement in an immutable matter which is great, but in order to use it correctly, we have to write a bunch of boilerplate code. In this article I would like to tackle the question on when to use Redux and why. The referred plugins/code samples are written in an Angular context. But the principles explained in this articles work for other frameworks as well. This also means that we are using the @ngrx/store package instead of the Redux package
To Redux or not to Redux?
First of all it’s important to note that Redux solves certain problems for us. If we are not experiencing those problems, then there is a big chance that the Redux pattern is overkill for our application.
The first question that we might want to ask ourselves is: Does My application have state? State can be the value of a pager that we want to remember, or the fact that a sidebar is collapsed or not. State could be a cached set of data coming from our backend, or user information that we need throughout the whole application. It could be a simple value that we want to remember in memory when we are navigating between pages.
Let’s sum up some examples where the Redux principle might shine in our applications:
- Storing state (like the value of a search filter so it’s still available when the user navigates back to a certain grid)
- Sharing state between components that have their own route, and thus won’t have a parent component to pass them the state through inputs or properties
- Optimistic updates: Check this article
- Real-time updates: Check this article
- When we want undo/redo logic
- When we want to keep track of all the state changes and debug them with awesome tooling (Redux devtools)
- When we want an organised way of handling session storage or localstorage. Check this plugin
When we are writing Angular applications it’s a best-practice to work with immutable data structures. That way we can make use of the OnPush changedetectionstrategy that angular provides us, which results in better performance and less unexpected behavior. In React we could use a Pure component for that. So, for this article let’s assume that immutable datastructures are the way to go and that our application needs it.
While we know that Redux forces you to use immutable datastructures, let’s still challenge the need of Redux shall we? If statemanagement is trivial to our applications and we just want to store values we could work with a state service instead of Redux.
@Injectable()
export class UsersService {
private _users$ = new BehaviorSubject([]);
get users$(): Observable<User[]> {
return this._users$.asObservable();
}
// IMPORTANT: since we use an immutable dataflow
// we have to make sure users is a new instance
setUsers(users: User[]): void {
this._users$.next(...users);
}
}
This example shows how we can set the simple value of an array of users by calling the setUsers()
function. It will store the value into a BehaviorSubject which we will consume as an observable. The spread operator (...
) will create a new instance of the users
array. That way we know that we are working in an immutable manner. This was pretty easy and we don’t need Redux anymore, nor all the boilerplate that we would had to write. So if the state of our application only contains a few simple properties, the Redux pattern might be overkill.
But what if we need to do more then just set the value of users
. What if we want to add and remove users from that stream, and we would have to do it in an immutable manner? Checkout the following example for instance.
@Injectable()
export class UsersService {
private _users$ = new BehaviorSubject([]);
get users$(): Observable<User[]> {
return this._users$.asObservable();
}
setUsers(users: User[]): void {
this._users$.next(...users);
}
addUser(user: User): void {
// We cannot use array.push because we only want to
// pass immutable data to the streame
// for the OnPush strategy remmber?
this._users$.next([...this._users$.getValue(), user])
}
removeUser(id: string) {
// Again, we have to create a new Array instance to not break the
// immutable dataflow
this._users$.next(this._users$.getValue().filter(v => v.id !== id));
}
}
The code above is starting to feel a bit weird, and it seems like we are writing reducer logic inside of this state service to keep it immutable. We have also created our own observable implementation so we could subscribe to the changes of our state service. While it could still be overkill to use redux if this is the only state in our application, it might become complex if we are working with multiple states, nested states, etc.
Another example is caching. People use redux to cache data results. A simple shareReplay
operator might to the trick as well.
fetchUsers(): Observable<User[]> {
...
return this.httpClient.get('').pipe(shareReplay(1));
}
Summary
I would suggest to not use Redux untill we actually need it, and in my experience most applications that I have written in the past did need redux at a certain point. That being said I also wrote a bunch of applications that didn’t need it at all (CRUD applications for instance.
It’s up to you if you want to use Redux or not, but keep your applications immutable at all times. It will save you a lot of energy in debugging and it makes sure that you can optimise the change detection cycle in your applications.


The ultimate productivity hack is saying no. Not doing something will always be faster than doing it. This statement reminds me of the old computer programming saying, “Remember that there is no code faster than no code.” The same philosophy applies in other areas of life. For example, there is no meeting that goes faster than not having a meeting at all.
This is not to say you should never attend another meeting, but the truth is that we say yes to many things we don't actually want to do. There are many meetings held that don't need to be held. There is a lot of code written that could be deleted. How often do people ask you to do something and you just reply, “Sure thing.” Three days later, you're overwhelmed by how much is on your to-do list. We become frustrated by our obligations even though we were the ones who said yes to them in the first place. It's worth asking if things are necessary. Many of them are not, and a simple “no” will be more productive than whatever work the most efficient person can muster. But if the benefits of saying no are so obvious, then why do we say yes so often? (CHECK COMMENTS)
Why We Say Yes
We agree to many requests not because we want to do them, but because we don't want to be seen as rude, arrogant, or unhelpful. Often, you have to consider saying no to someone you will interact with again in the future—your co-worker, your spouse, your family and friends.
Saying no to these people can be particularly difficult because we like them and want to support them. (Not to mention, we often need their help too.) Collaborating with others is an important element of life. The thought of straining the relationship outweighs the commitment of our time and energy
For this reason, it can be helpful to be gracious in your response. Do whatever favors you can, and be warm-hearted and direct when you have to say no.
But even after we have accounted for these social considerations, many of us still seem to do a poor job of managing the tradeoff between yes and no. We find ourselves over-committed to things that don't meaningfully improve or support those around us, and certainly don't improve our own lives.
Perhaps one issue is how we think about the meaning of yes and no.


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AVGPRICE - Average Price
real = AVGPRICE(open, high, low, close)
Learn more about the Average Price at tadoc.org.
MEDPRICE - Median Price
real = MEDPRICE(high, low)
Learn more about the Median Price at tadoc.org.
TYPPRICE - Typical Price
real = TYPPRICE(high, low, close)
Learn more about the Typical Price at tadoc.org.
WCLPRICE - Weighted Close Price
real = WCLPRICE(high, low, close)
Learn more about the Weighted Close Price at tadoc.org.


?THE
NEW
YORK
BOTANICAL
GARDEN
Plants
of
Hispaniola
Dominican
Republic
No.
11213
^umelia
cubensis
Griseb.
Det.
Alain
H.
Liogier,
Feb.
1970.
Shrub,
2
m
high,
flowers
wldte.
On
exposed
rocks,
on
top
of
the
ridge.
Cordillera
de
Yaroa,
limestone
ridge,
facing
the
Yaroa
valley,
Puerto
Flat?
Prov.
Alt.
800-850
m.
Bro,
Alain
H.
Liogier
U
May
I969
g
Supported
by
funds
from
the
National
Science
Foundation.
NEW
YORK
BOTANICAL
GARDEN
01443336
01443336
Legend -
Level of confidence that token is an accurately-transcribed word
extremely low
very low
low
undetermined
medium
high
very high


isoverlapping documentation
The isoverlapping function determines whether geographic boundingboxes overlap.
Back to Climate Data Tools Contents.
Contents
Syntax
tf = isoverlapping(S,S0) tf = isoverlapping(BoundingBoxes,BoundingBox)
Description
tf = isoverlapping(S,S0) returns true for any of the BoundingBoxes in the shapefile structure S that overlap with the BoundingBox identified by the shapefile structure S0.
tf = isoverlapping(BoundingBoxes,BoundingBox) returns true for any of the BoundingBoxes that overlap with BoundingBox. Here, BoundingBoxes must have the dimensions 2x2xN, which can be obtained by cat(3,S.BoundingBox). The reference BoundingBox must have the dimensions 2x2.
Example
Start by loading these example shapefiles (requires Matlab's Mapping Toolbox):
Sr = shaperead('concord_roads.shp'); Sa = shaperead('concord_hydro_area.shp'); % Convert Sa to a polyshape (for no particular reason, except that we can): P = polyshape([Sa.X],[Sa.Y]);
Plot the data for context
% Plot the hydo areas as blue water: figure plot(P,'facecolor',rgb('water blue'),'edgecolor','none') axis image % Add roads: hold on plot([Sr.X],[Sr.Y],'color',rgb('gray'))
Now consider this section of water:
plot(Sa(98).X,Sa(98).Y,'r','linewidth',2)
Which sections of road have bounding box coordinates that overlap with the bounding box of that section of water?
tf = isoverlapping(Sr,Sa(98)); plot([Sr(tf).X],[Sr(tf).Y],'color',rgb('orange'),'linewidth',2)
Author Info
This function is part of the Climate Data Toolbox for Matlab. The function and supporting documentation were written by Chad A. Greene of NASA's Jet Propulsion Laboratory.


Bill to ban production, sale of e-cigarettes in Lok Sabha
The Prohibition of Electronic Cigarettes (Production, Manufacture, Import, Export, Transport, Sale, Distribution, Storage and Advertisement) Bill, 2019 seeks to replace an ordinance issued recently.
by PTIA bill to ban production, import and sale of e-cigarettes and similar products was introduced in Lok Sabha on Friday.
The Prohibition of Electronic Cigarettes (Production, Manufacture, Import, Export, Transport, Sale, Distribution, Storage and Advertisement) Bill, 2019 seeks to replace an ordinance issued recently.
The government had cited health risk to people, especially youth and issued an ordinance to ban such products. It seeks jail term of up to three years as well as fine for those violating the law.


The Registry SPI may be used by infrastructure modules which handle
persistence of settings.
Normal modules should not need to use this SPI.
Registry SPI in detail
(TBD)
The heart of the Registry SPI is BasicContext interface. Any client
implementing the SPI must implement this interface. The
ResettableContext is optional extension of the BasicContext capable to
revert modifications to their default state. The RootContext is special
extension of context which describes root of the registry hierarchy and
several of its special capabilities like searching over the whole
registry hierarchy, making pending registry modifications permanent, provides one mutex for all synchronization
Each root context must implement the RootContext.
At the moment it is not expected that some other
implementations of backend storage would exist or would be needed. The
default one provided by NetBeans (currently known as SystemFilesystem)
will be documented in separate document. It will implement
ResettableContext; it will document how defaults can be declared; it
will document how it persist binded objects (eg. first the convertor is
searched; if failed "implements Serializable" is tested; if failed
throw exceptions and reject the object); etc.
The SpiUtils class has several helper methods for creating misc Objects, Contexts, etc.
Threading Model
(TBD)
Threading model is very simple. SPI clients do not have to synchronize
anything. They must only correctly implement RootContext.getMutex()
method. The implementation of Registry APIs synchronizes all its
methods calls on this mutex. That makes API thread save and it can be
accessed from arbitrary threads without the need of client
synchronization and that SPI will be always accessed only under the
read or write lock of the SPI mutex. That also means that one client
owning exlusive write lock and modifying a context blocks the whole
registry or more precisely the root context and its hierarchy of
context descendants to which the modified context belongs.


This is a website about my frogs, Alex, and Sam.
My frogs like to climb to the highest point in their terrerium, to get the most amount of "sun" possible.
They are easily spooked, once I was bringing their crickets into their terrarium and they jumped off of their peice of wood and hid behind it.
Here are some reasons why I like them:
Which name do you like better?
Want to learn about my dog? Click Here!
Want to learn about my cousins dogs? Click here