From what I have been researching, ReactJS is the new craze in the world of front-end development. I can find few articles that are able to provide a bias free look on ReactJS. There is only praise for it, but should it be used everywhere? I know an html.erb file with javascript can accomplish what ReactJS can do. Everything has its place. Where does ReactJS and React Native fit in? Specifically when should they be used? I know JavaScript can handle a lot, but of those things it probably shouldn't handle, or there is a better solution.
I would greatly appreciate guidance on these questions.
React has many cool features and is one of the best libraries for using for building UI apps
it utilizes something called the virtual dom to enhance performance in applications
it has a really intuitive pattern with storing state in local components which can be passed down to children components as props.
it integrates well with state management frameworks like Redux (there is a helper package called react-redux which makes the integration seamless) but it also has it's own context API which can be used for wider ranging state
it recently introduced the concept of hooks. these replaced lifecycle methods which were popular in previous versions and are now a cool way to "hook" into components and utilise functionality whilst the component mounts and unmount
of course, like with everything, there are alternatives. you can just use plain old vanilla which has it's own benefits or you can choose a popular alternative such as Vue.js.
There is no hard and fast rule specifically when it should be used. the ball is in your court
I was done one small web application using ReactJS. It's easy to maintain and understandable. Now I learned Redux and plan to implement on it.
Its need some more stuff and extra things to do (To create store, Reducers etc.). I personally thought without redux the react is fine and easy to understand and maintain the states. Then why we need extra stuff (Redux)?
Reasons to use Redux:
Same piece of application state needs to be mapped to multiple
container components.
A good example of this is session state. When the app first loads, often information about the user needs to be shared with various components in the titlebar and each page. It’s likely these components don’t have any direct relationship so Redux provides a convenient way to share state.
Global strong textcomponents that can be accessed from anywhere.
It’s common to have components that live for the life of the application (for a single-page app this is every time the entry point is reloaded) that do things like show notifications, snackbars, tooltips, modals, interactive tutorials, etc. With Redux, you can create actions that dispatch commands to these components so, for example, if the code makes a asynchronous request to the backend it can dispatch a show snackbar action if the request fails. Without Redux, you would need some other event system or have to instantiate the snackbar component every time it gets used.
Too many props are being passed through multiple hierarchies of
components.
If a higher-level component is provided with a dozen props and uses only two of them, and the rest are passed down to a lower-level component, then consider refactoring with Redux. This scenario happens a lot with wrapper components that just provide layout styles, but don’t require a lot of data or configuration. It’s more practical to side-chain Redux directly into a lower-level component in this case.
State management using setState is bloating the component.
This is pretty subjective, but components that are over several hundred lines of code start to become harder to reason and maintain. Separating out the state management into a reducer breaks up the code and makes it more readable.
Caching page state.
When the user does some stuff to a page, then goes to another page and comes back, the expectation usually is to have the page in the same state. Some of this can be addressed by saving the page state in the backend and recalling it on page load. But, often things like search input values and expanded/collapsed accordions are just overkill to store in the backend. Since reducers typically initialize and live throughout the session, they can cache the page state so things remain the same.
Managing the state can be complex. Although react provides us with the state property but passing the state from component A to component B can be quite complex when the application grows. Here is a simple example which shows why do we need redux.
Consider an application with two functionalities "Users" and "Products".
Users have authentication implemented where they can sign-up and sign-in and the users can view the dashboard only when they are authenticated.
The other functionality "Products" also require user authentication information because the "Cart" operations will be accessible when the user is authenticated/signed-in. To get user authentication information at this part will require alot of state/props passing from "Users" component to a different section of the application "Products".
This is when Redux comes in picture, it provides a central store (stores entire application state) which is then available to the entire application.
TL;DR: Because you've done "one small web application". Not all web applications are small.
The most trivial examples of why you might need it include:
Sometimes unrelated components need to share state.
Sometimes state needs to be updated by things other than components.
Is it always necessary? Absolutely not. But breaking up state handling may confer advantages to non-small web applications, or complex interactions.
If all you have is a simple hierarchy of components, and things very low in that hierarchy never need to modify state that higher-level components need, then it brings in complexity that might not be necessary.
(Although even in those cases, it may be helpful; as always, "it depends".)
If you're building a house, you probably don't need a jackhammer even if you've learned how to use it.
You don't need Redux if your application's state is easy to manage without it.
As said in redux motivation page:
As the requirements for JavaScript single-page applications have
become increasingly complicated, our code must manage more state than
ever before. This state can include server responses and cached data,
as well as locally created data that has not yet been persisted to the
server. UI state is also increasing in complexity, as we need to
manage active routes, selected tabs, spinners, pagination controls,
and so on.
Managing this ever-changing state is hard. If a model can update
another model, then a view can update a model, which updates another
model, and this, in turn, might cause another view to update. At some
point, you no longer understand what happens in your app as you have
lost control over the when, why, and how of its state. When a system
is opaque and non-deterministic, it's hard to reproduce bugs or add
new features.
As if this wasn't bad enough, consider the new requirements becoming
common in front-end product development. As developers, we are
expected to handle optimistic updates, server-side rendering, fetching
data before performing route transitions, and so on. We find ourselves
trying to manage a complexity that we have never had to deal with
before, and we inevitably ask the question: is it time to give up? The
answer is no.
This complexity is difficult to handle as we're mixing two concepts
that are very hard for the human mind to reason about: mutation and
asynchronicity. I call them Mentos and Coke. Both can be great in
separation, but together they create a mess. Libraries like React
attempt to solve this problem in the view layer by removing both
asynchrony and direct DOM manipulation. However, managing the state of
your data is left up to you. This is where Redux enters.
Following in the steps of Flux, CQRS, and Event Sourcing, Redux
attempts to make state mutations predictable by imposing certain
restrictions on how and when updates can happen. These restrictions are reflected in the three principles of Redux.
But there are many cases where you won't need redux, it's important to understand what it does, and why you would need it.
I personally didn't use Redux in any of project I started over the last couple of year or so. I don't expect to use it in future either. Here's why.
Redux was revolutionary when it appeared in 2015. It brought two big ideas to React:
It combined action-based model of Flux with a concept of Reducer (It is in its name: "Red" "ux" = "Red"ucer + Fl"ux"). That Action - Reducer pattern instantly gained traction among React programmers.
It solved an application-wide state. Let's say we had certain data that we wanted to make available throughout the app. Before Redux the only reliable way to do that was to pass that data through props to child components... and then to their child components, and so on. Redux changed that. It allowed pieces of data to transcend the entire component hierarchy of an application without passing that data through props from one component to another. It also provided a convenient way to access and manipulate that application state from anywhere in the application.
Redux used a context API under the hood, which at the time was intended for React internal use only and was cumbersome to use.
Fast forward to 2019. A lot has changed. We now have hooks and the stable public context API which is ready for the prime time. An action - reducer pattern is now readily available via useReducer hook. We don't need Redux for that any more.
The modern React context API is simpler, more efficient than before and comes with hooks support. In most cases, wrapping your application state in a context is all you need to access it anywhere in your app.
So what about Redux?
My point of view that in a vast majority of cases you don't need Redux any more. Contexts and hooks get the job done most of the time. If you still think that contexts are not very friendly you may have a look at unstated-next library which is just a thin wrapper on top of the context API. That whole library is just 200 bytes!
However, plugging Redux into your project may be warranted if:
you want to take advantage of Redux middlewares such as redux-thunk
or you love Redux developer tools with their time-travelling ability.
In that case, make sure you know what you are doing. Redux magic comes with a price.
Redux is a complicated beast. It will bring a lot of complexity into your app. Some of that complexity is obvious while many other unobvious gotchas are hidden and waiting for you to trip on it. Think twice if you want to deal with that. Even then it is worth checking out alternatives such as MobX or react-sweet-state.
origin: You may not need redux
React ships with all the features you need to handle your state without a single additional library. Most of your application's states should not be global as they live just fine in a useState or useReducer or custom hook next to your components.
So before you dive into the world of advanced state management (e.g. Redux), consider using the tools React ships with out of the box.
If you are interested in learning a bit more about this, I'd recommend this article by Andy Fernandez: https://www.scalablepath.com/react/context-api-vs-redux
What are the pro and cons of using either pure Redux or ngrx with Angular2/4?
I have been using both in differenet projects but am still wondering which one is the most efficient and fastest.
It ends up that ngrx and Redux follows mostly the same ideas and help solving pretty much the same issues.
That said, angular uses Rxjs a lot, specially Observables, and as ngrx is also built upon Rxjs, the integration is a little bit easier and smoother
Regarding performance, if there is a component for which the entire state is in store, and the async pipe is used to output data to the view, you may use another change detection strategy for this component and this may lead to a performance improvement, specially on large applications. You may do it by setting changeDetection to ChangeDetectionStrategy.OnPush on #Component decorator. You may find more information on that here.
Also, on this thread you may find a detailed discussion on ngrx/store vs Redux.
ngrx/store was created specifically for Angular2.
The detailed reasons can be found here:
https://github.com/ngrx/store/issues/16
Background
I've been building an application using React Native & Redux to make an assessment over whether to use it for an upcoming project over Swift and going fully native.
I genuinely believe that Dan Abramov's techniques with Redux are a case of solid engineering. Not updating the state and having the view as a function of the state is great, and I'm very much on board with the idea. Where I'm coming somewhat unstuck is with throwing animations into the mix.
Scenario
More complicated animations require state management, for example, fading out a view, replacing the text and fading it back in. I'd only want to update the text halfway through the animation, and this is easy enough to do using local state and leveraging the Animated framework.
Say the text to be displayed is driven by the state, it'd be updated the moment the state is changed via an appropriate action & reducer combo, but for the sake of presentation I need it between these two animations.
An example of this would be selecting a record from a list, where there's an on-screen label showing the name of the selected record. Ideally you'd want to update the global store straight away, but perform a nice transition on the label itself.
My Thoughts
To my mind it makes some amount of sense to use 'local state' inside of components to deal with animations, and the main Redux store for more overall data or architecture state. The problem is this breaks the idea of the view being a function of the global state and I'm not sure that sits right with me.
On the other hand, managing animation sequences etc. by writing heaps of actions, reducers and cluttering up the store also doesn't feel clean.
The Question
I know React Native is in it's infancy, and not everybody is using Redux, but is there a generally accepted way of managing animations in this kind of scenario?
I've been developing React for only 9ish months, and so I'm probably a n00b compared to the likes of you Matt, and I can say without much hesitation that redux is awesome, but that it shouldn't replace internal component state in all circumstances. Especially for things like animations. You asked this yourself, but I ask again: why would this need to be in a global state? Redux is there to allow components across an application to get updated state when things happen throughout your application. That does not mean, however, that there should never be any state anywhere in your application except for in a Redux store.
A man much smarter than me said
If you feel pressured to do things “the Redux way”, it may be a sign that you or your teammates are taking it too seriously. It’s just one of the tools in your toolbox, an experiment gone wild.
Local state is fine....
The tradeoff that Redux offers is to add indirection to decouple “what
happened” from “how things change”. Is it always a good thing to do?
No. It’s a tradeoff.
What is this I'm quoting? What kind of blasphemous React developer could possibly say that Redux shouldn't be used for all things React??
I'll tell you who. The creator of Redux.
https://medium.com/#dan_abramov/you-might-not-need-redux-be46360cf367#.flb8fzjr8
TLDR Use Redux where it is useful and where it makes sense. It's awesome for what it's suppose to do.
But don't try to fit that round peg into a square hole.
I hope this is useful.
I read articles criticizing React for setState being weird when instead the people criticizing it did not understand it properly.
I really like React modularity, and the more I learn it the more I find it intuitive.
Nevertheless, I ran into multiple situations in which I would have liked the states to be cross-component. What I mean is, changing a state in a component could affect another component. It is my understanding that there is no React built in solution to this problem. Of course there are ways around it but there is no fixed protocol.
My question is, why is that? what is the advantage of not providing a simple way to handle such a common scenario? Or if there is and I don't know about it, please enlighten me!
There are at least 4 out-of-the-box ways to share state between closely related (and unrelated) components: props, callbacks, refs, the ctx variable.
I simply think it's built to be as small as possible with the complete intention that if you need an app state manager for a complex project (where unrelated components need to communicate) that you will include one, and they will not force you into any one approach.
If you did want something with more substantial scaffolding to start a project, which many people do, you could refer to react-boilerplate or similar.
But having React itself limited to the minimal, I have the freedom to choose (or not) the best tool for each project without having to override one-size-fits-all defaults.