Multiple copies of React in my Application - reactjs

I am using react-treelist component and inside that i am using office-ui-fabric callout(its like a tooltip) component to have a tooltip on elements in tree structure when i am running this program it runs correctly but when i am bundling and using the bundle file in my project as a module it gives error:-
Exception in Layer.componentDidUpdate(): Invariant Violation: addComponentAsRefTo(...): Only a ReactOwner can have refs. You might be adding a ref to a component that was not created inside a component's render method, or you have multiple copies of React loaded
I have tried many solutions from diff forum but none of them worked.I am sure problem is of multiple copies of react.
Details of what i did
I cloned react-treelist from github then i installed office-ui-fabric module then i changed some code to make callout component work with react-treelist, i did npm start it worked fine the i did npm run dist and copied the bundle file to my project directory inside a folder named react-treelist and then imported that file as module in my code and ran the code it gave me the above error.
Can anybody suggest me how to accomplish the above task without having multiple copies of react in my application

If you use webpack to build your application, you can use the resolve.alias configuration option to make sure that all modules refer to the same react library:
resolve: {
alias: {
'react': fs.realpathSync('node_modules/react'),
'react-dom': fs.realpathSync('node_modules/react-dom')
}
}

If you use web pack then you can fix it by adding the following to Webpack config
externals: {
'react': 'React',
'react-dom': 'ReactDOM'
}

Related

Using components from an external directory in a Electron project with Webpack

I am trying to do this as simple as possible, I studied Yarn Workspaces for a while, but that's a solution that's currently doesn't work with Electron, there were simply too many issues.
I have am Electron project here: ./electron/
I have a directory with components here: ./common/
The components are developed in React/JSX, there is nothing really fancy about them. That said, I am using hooks (useXXX).
I tried many ways to include those components (ideally, I wanted to use Yarn Workspaces, but it only multiplied the number of issues), but they all failed. Which is why I would like to avoid using yarn link or workspaces or making the common a library, etc. I just want my Electron project to behave as if the files were under ./electron. That's it.
The closest I came to a solution is by using electron-webpack, and overriding it with this config:
module.exports = function(config) {
config = merge.smart(config, {
module: {
rules: [
{
test: /\.jsx?$/,
//include: /node_modules/,
include: Path.resolve(__dirname, '../common'),
loaders: ['react-hot-loader/webpack', 'babel-loader?presets[]=#babel/preset-react']
},
]
},
resolve: {
alias: {
'#common': Path.resolve(__dirname, '../common')
}
}
})
return config
}
I can import modules, and they work... except if I use hooks. And I am getting the "Invalid Hook Call Warning": https://reactjs.org/warnings/invalid-hook-call-warning.html.
I feel like that /common folder is not being compiled properly by babel, but the reality is that I have no idea where to look or what to try. I guess there is a solution for this, through that webpack config.
Thanks in advance for your help :)
I found the solution. That happens because the instance of React is different between /common and /electron.
The idea is to add an alias, like this:
'react': Path.resolve('./node_modules/react')
Of course, the same can be done for other modules which need to be exactly on the same instance. Don't hesitate to comment this if this answer it not perfectly right.
I wrestled more than a day with a similar problem. My project has a dependency on a module A that is itself bundled by Webpack (one that I authored myself). I externalised React from A (declaring it to be a commonjs2 module). This will exclude the React files from the library bundle.
My main program, running in the Electron Renderer process, uses React as well. I had Webpack include React into the bundle (no special configuration).
However, this produced the 'hooks' problem because of two instances of React in the runtime environment.
This is caused by these facts:
module A 'requires' React and this is resolved by the module system of Electron. So Electron takes React from node_modules;
the main program relies on the Webpack runtime to 'load' React from the bundle itself.
both Electron and the Webpack runtime have their own module cache...
My solution was to externalise React from the main program as well. This way, both the main program and module A get their React from Electron - a single instance in memory.
I tried any number of aliases, but that does not solve the problem as an alias only gives direction to the question of where to find the module code. It does nothing with respect to the problem of multiple module caches!
If you run into this problem with a module that you cannot control, find out if and how React is externalised. If it is not externalised, I think you cannot solve this problem in the context of Electron. If it is externalised as a global, put React into your .html file and make your main program depend on that as well.

Element ref was specified as a string. Backward compatibility with react-dom as external library,

I have defined externals inside of my webpack configuration like:
externals: [
'react-dom-16',
{ 'react-dom': 'react-dom-16' }
],
react-dom-16 is a bundled react-dom with its own name.
And when I run application I got error and nothing is shown:
Element ref was specified as a string (value0) but no owner was set. You may have multiple copies of React loaded.
But the funniest thing is when I remove externals from webpack and put react-dom from dev-dependencies to dependencies and build everything on it. Then magicali everything works.
Probably I'm using ref as a string. But there are too many cases where should I change it, also there are old libraries I'm using and I can't access their code.
So I would like to use react 16.4.1 with backward compatibility but I got that kind of error and have no idea where to go next.
The problem was with circular dependencies of our externals.
It is react-dom was using react inside of it.
So we had duplication of react.
Solution was exposing react-dom without react.

Meteor - webpack and ecmascript are both trying to handle *.jsx

So I'm trying to install and use react-wavesurfer in Meteor which is a react component wrapper for an existing js library (wavesurfer.js). It requires that the wavesurfer.js file (which has to be installed separately) is made available as a global variable.
The suggestion is to use webpack for this as below :
// provide WaveSurfer as a globally accessible variable
plugins: [
new webpack.ProvidePlugin({
WaveSurfer: 'wavesurfer.js'
})
],
// Alias `wavesurfer` to the correct wavesurfer package.
// (wavesurfer.js has some non-standard naming convention)
resolve: {
alias: {
wavesurfer: require.resolve('wavesurfer.js')
}
},
I've never used Webpack (not entirely sure what it does) and I'm a Meteor / React newbie.
So I installed :
meteor add webpack:webpack
And now I'm getting the following error in the console :
While determining active plugins:
error: conflict: two packages included in the app (webpack:webpack and ecmascript) are both trying to handle *.js
error: conflict: two packages included in the app (webpack:webpack and ecmascript) are both trying to handle *.jsx
From the error I assume that ecmascript (again something I know nothing about) is doing a similar job to webpack already which is causing the clash?
So, my question... How do I set this up using ecmascript instead? I literally have no idea!
Try to use new package that I still maintain
https://github.com/ardatan/meteor-webpack

React with Webpack - package a module for use in Dynamic loading in another site

I'm using Webpack as our build/bundler for an application using a standard React/Redux/etc.
We have a requirement to build out custom components that can be loaded dynamically into the main application. This would require that the component is created OUTSIDE the main development so would not be involved in the main app build. The ideal solution would be to build out the components in their own side projects, bundle up (since they will have imports/require, etc) and spit out a bundle.js file that is only that component (could be multiple components merged together). Then we'd like to be able to take that file and dynamically load it in the main application dynamically.
I understand how code splitting works with webpack to a certain degree which we use in our main project. I've also been able to successfully import SIMPLE components externally I built out externally. The problem is that these external components can get pretty hefty so using a build/bundler to put it all together in one package would be ideal. I have no idea how to go about building components externally from the main project, bundle up using webpack to merge in all of the goodies into one package and inject that new bundled component which is typically wrapped in webpackjsonp and all the other runtime stuff.
Has anybody else been able to do something crazy like this?
Thanks!
EDIT
I've been able to successfully build a silo component in it's own project using webpack and dynamically loading that into a different running application bundled with webpack by using the Output.Library options as described here
Below is the sample config I used for testing a custom react component called TestMe located inside the index.js file of the test folder.
module.exports = {
entry: {
developer: "./test"
},
output: {
path: path.join(__dirname, "dist", "static", "developer"),
filename: "MyLibrary.[name].js",
library: ["MyLibrary", "[name]"],
libraryTarget: "var"
},
externals: {
'react': 'React'
, 'react-dom': 'ReactDOM'
, 'react-dom/server': 'ReactDOMServer'
, 'react/lisb/ReactTransitionGroup': 'React.addons.TransitionGroup'
, 'react/lib/ReactCSSTransitionGroup': 'React.addons.CSSTransitionGroup'
}, ...
When imported in you will have access to the TestMe component as a global variable MyLibrary.developer.TestMe (or MyLibrary.developer.default depending on how you exported the component). The externals are there to keep Webpack from including those in the final bundle which was already included in the main application. Otherwise you're going to get a really big nasty bundle file. Check out LibraryTarget if you rather have UMD, etc.
Moral of the story here is "when all else fails, read the docs again".

Prevent web pack from bundling react

How do I prevent webpack from bundling react?
Currently I am writing a library that causes a You've loaded two copies of React on the page. error after distribution. I suspect that webpack starts bundling all dependencies, including devDependencies.
Is there any way around that?
In my case it should be possible for the library to get React out of node_modules.
So what I basicly want is, instead of webpack resolving the require('React), it should just leave require('React) untouched.
You can use webpack externals.
externals: {
// Use external version of React
"react": "React"
}
UPD Detailed docs on the resulting code generated for externals.
To make webpack "leave require('React) untouched" you need the following config
{
output: { libraryTarget: 'commonjs' },
externals: { react: true }
...
}
Moelalez, just like Yury Tarabanko stated, externals option allows you import an existing API into applications. For context, say you want to use React from a CDN via a separate tag and still declare it as a dependency via require("react") in your application, you would use externals option to specify that.

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