What's the difference between React App and React Component - reactjs

We will be doing our first project using React.
It will not be a Single Page App, but a Multiple Page App.
What I'm trying to figure out at the moment is : what's the difference between a component and an app.
If I only use components, can I still use Redux to have some state management on the current page ? Or do I need an app for this ?
Thanks for the information you can bring !
THoma

There is no special object called "React App". React Components build an "React App" by coming together.
But React Components are formed like tree structure. That means each component have a parent component so you can create a React Component that named "App" and can put another components inside it.
You don't need redux for state management in React Components.
I hope the answers have helped.

Your app may contains a single component and still it will be a react App. If you are using multiple components in a page you can still use react-redux. Redux is basically a container for your states and let suppose you need some state from one component to be consumed in another, Redux provide you a mechanism to make the communication efficient and predictable.
You can also look at the React Context APIs as an alternate to Redux.

An app is simply a component that holds the root of the work you are trying to do. For example an App may have the navigation menu, testimonials, adverts, content, login avitar etc.
If you are making a single App per page (For example a testimonial) then you would still have a SPA. For example, adding testimonials, searching, editing.
You should only use Redux if you are using a SPA with lots of different parts with data in common. If you are making a one-app-per-page and there is no cross over in data then you can simply using Reacts State/Props to hold your data.
Redux is good, but it forces you into a complex path your should try to avoid. If you find yourself wanting data from different domains (customers address and a list of testimonials) then you should use Redux.
If this is a new applications (green) then I strongly recommend you build the whole thing within a SPA using React-Router to control components. you can use frameworks like Next.JS to ensure the site remains small in size (dynamically loading script only when required).

Related

Slowly implementing redux to an existing React.js project

I want to migrate my project from plain react to react redux, I am not new to React but new to Redux.
I have a fairly big web app written in React, dozens of React.js files.
most of them containing state's + passing variables between them.
including allot of Post/Get requests functions, implemented into at least half of my files.
I want to slowly move from plain react to react redux.
I wanted to ask if anyone have some article or can give an insight about migrating existing react project to react-redux.
I dont want to stop development for the sole purpose of the change but instead to slowly adapt to it.
is it possible ? is there a tool to help me do it ?
I saw some redux examples where entire render of app.js was surrounded by <Provider> </Provider>, does that mean every component inside <Provider> bracelet can not have it's own state ?
can I simply keep my old components as they are and put new ones into <Provider> </Provider> ?
Thanks in advance!
I saw some redux examples where entire render of app.js was surrounded
by , does that mean every component inside
bracelet can not have it's own state ?
The way react-redux works is by exposing a store prop, provided by the Provider. In order to consume it, or extract data from it you must wrap your component by it (not directly necessarily, but one of the parents must be a provider). In general in most apps you would simply wrap the entire application with a Provider, because for the most part, if you've chosen to introduce redux into your application, it is probably because your entire app needs some store.
Using redux does not mean that components can't have state. There is a big difference between global state - something that should be accessible to every component in your app (if the component chooses to "consume" it), and state that is private to a component - e.g. form changes before being sent to the server.
can I simply keep my old components as they are and put new ones into ?
Well, yes. But also - no. As I said earlier, you should probably start from the top and slowly drill down. Wrap your app with a Provider, and start moving your application state from the top-most component to the store. Once you get more comfortable with redux in general, you should start replacing the props you pass down the component tree with props from the state by connecting your inner components.
This way you can do it one component at a time without breaking existing logic.

React Native Navigation - Multiple Instances of a Screen

I have an app (react native/redux/navigation experimental) that has deep flows where a user can navigate to multiple instances of the same screen (think tapping through to multiple profiles).
To avoid each new instance of the screen overwriting data on the screens before it, I’m using a lookup table approach in redux. Each time I push to a new screen, I use a uuid for the route as a key in the lookup table.
Is there a better way to handle this?
I would suggest upgrading the routing framework as React Native Experimental will no longer be supported. You could try either react native router flux or react navigation . I haven't used the latter, so how I would accomplish this in React Native router flux is by: a) utilizing different keys for the same component which you seem to be doing. b) passing the uuid as params to that component upon navigation. E.g.
Actions[routes.currentUser]({ uuid: getUuid() })
where your routes are defined in some other file and you retrieve the uuid.
As explained here
Also, it is generally best practice to separate Navigation State and Application state as explained here

Difference between react habitat and react router

I just wanted to know the difference between react router and react habitat. From what I have been reading (which is not much) these two solve the same problem of externalizing components of a website. I would like to know why one would consider one above the other if they are even comparable in this manner.
React Habitat does not worry about routes or the application information architecture (IA). It simply lets some other system render HTML pages how ever it likes and will hook up one/or many React apps on the fly when ever it see's targets in the html. If a CMS content author changes the URL of a page, or adds a new page no problem React Habitat doesn't care and will continue to hook up React apps.
React Router use routes (urls) to mount React components, this means it needs to know allot about the IA of the application and cant simply be 'dumb' to it like React Habitat. If a CMS content author changes a URL React Router will no longer render, it will require a developer to update the route in the javascript. You could be fancy and dynamically load routes from the CMS but I would question is this too tightly coupled.
They both solve different problems.
1) If you are building a SPA or PWA and want to hold all the IA in the javascript application then use React Router.
2) If a system (.net/php/java/etc) is rendering your HTML such as a CMS and it holds all the IA then use React Habitat.

React passing state between instances of the same Component

I'm fairly new to React, and I was trying to create an app that functioned thusly:
The app consists of several Pages, with multiple Components on each Page.
One of these Components is stats, which can change as the user interacts with Components on the Page.
When a user clicks on a certain Component, they will be taken to a "different" page, which is really just another Page, with different text, data, etc. This is carried out through the browserHistory.push() method. I would like to be able to carry over the changed 'stats' component from one Page to the next, but I am not sure how to do so. Furthermore, since I set the default value for stats in the Page component, it seems that any attempt at passing the changed values into the new Page would result in the new values being overridden. Can anyone help me?
Thanks.
State should live above the level of all components that need access to that state.
Remember that one of the principles of React is "one-way" data flow down the component hierarchy. Essentially, data/state should live at a high level, getting passed down to child components and consumed as needed.
In your case, you have some "stats" data that needs to be displayed across multiple Pages. So, "stats" needs to be owned by a component above all of your Page components - perhaps at the root component of the app itself. Pages themselves would just take the data in and render it, potentially with some callbacks appropriate for editing the data.
Read a bit more about Facebook's philosophy for React in "Thinking in React" in the official docs: https://facebook.github.io/react/docs/thinking-in-react.html#step-4-identify-where-your-state-should-live
One option to consider is to use React Redux to store the state of your application. You would then use mapStateToProps (See Redux API for details) to map the state into props for your stats component.

Issue with UI event when rendering component inside a web component shadow DOM

I'm facing some issues when rendering a React component into the shadow DOM of a webcomponent.
I wrote a small piece of code to turn a React component into a webcomponent, but I want to render the
React component inside the shadow DOM of the webcomponent. But in that case, it seems that React is not able to catch UI events (click, keyPress, etc ...) anymore.
Let's take an example, let say that I have a first webcomponent <awesome-timer /> that render the React component inside the webcomponent node, and another webcomponent <less-awesome-timer /> that render the React component inside the shadow DOM of the webcomponent.
Both webcomponents use the same React component. However the one rendered inside the shadow DOM does not work, because click events on the button of the timer component does not trigger the bound function.
I guess React is not designed to handle such case, but I'd love to get more details about it.
The code of the example is available here : https://gist.github.com/mathieuancelin/cca14d31184bf4468bc1
Does anyone have an idea about it ?
I know this is kinda late but, I believe your issue when you pass any attributes to a web component they instantly become strings Because that's all you can pass to a web component. Now of course you can convert or cast them back to there original data type, except functions because once stringified they loose there scoping, lexical and all.
Now to your main question, you are were trying to pass you child element through the Main web components slot. Now you have to remember that once you pass anything to a web component you now have to use the webs components methods and return types to manage whatever you pass. So yes passing react into a web component will not work they you expect.
You will need to go back to whatever tool you use to build your web component and deal with the slot logic there. Since this is a very old post as are web components. You might not have had access to the modern web component build tool's we have today. I found Stenicl allows you to build and manage your web components in Typescript.
A good option is to change your pattern a little bit and just return web components from your react app.
Or you can use another really cool to call Lit-HTML or Lit-element. I believe they may have combined there core libraries. Anyway these tool will allow you to combine Reactjs and web components where lit-html gives you access to methods simial to Reactjs's life cycle methods. Anyway some good stuff to check out if your stuck at this point.

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