I have created a react app using create-react-app. I'm using react-admin to develop my admin panel. I want to use some environment variables. Here's my .env file:
REACT_APP_API_URL=http://localhost:8000
REACT_APP_BRAND=Guli
REACT_APP_SLOGAN=Financial transactions, redefined
And I also have .env.test and .env.production for staging and production environments, and I only override API URL in those files.
Now I want to use these variables inside my react app. I'm using them inside index.html and DataProvider.js that I use for react-admin.
In index.html I use:
<title>%REACT_APP_BRAND%</title>
and in DataProvider I use:
const apiUrl = process.env.REACT_APP_API_URL;
// using apiUrl in the rest of DataProvider.js
The problem is that none of these variables are read from .env file. In index.html I see the title of my app to be exactly %REACT_APP_BRAND%, and the calls to my API go to undefined/users for example which means that process.env.REACT_APP_API_URL is not loaded.
What sould I do?
When generating a new project using Vue CLI v.4.0.0 everything is bootstrapped nicely with an index.html file, a couple of .vue files, several configuration files and finally a main.js file. But since the HTML-file does not reference main.js I wonder how Vue knows to look for main.js. Is it implicitly understood by Vue or is there a binding somewhere that tells Vue to look for a file named "main.js"?
Vue CLI runs on Webpack.
Webpack requires an entry file.
You can overwrite the entry file by creating a vue.config.js file at the root of your project and adding:
module.exports = {
configureWebpack: {
entry: {
main: './src/overwritten-main-file.js'
}
}
}
See the Vue.js Configuration Reference for more info
I created a jhipster ui only angular 6 app.
I now want to add a script to index.html:
<head>
...
<script src='widgets/widgets.js'></script>
</head>
When I run the index.html is copied to the build/www directory fine, but in the app my script tag or any other changes are not there.
Seems that webpack does not use my new version.
How do I get webpack to use the changed template?
You have to use webpack in order to achieve the script tag injection.
Add your script to the entry points of webpack in the entry property located in webpack.dev.js (or prod) file, then add the related key inside the chunks array of the HtmlWebpackPlugin (it is located in webpack.common file).
This should inject the script tag inside your index.html
I'm doing a webpage with Vue (Vue-bootstrap) and I'm having problems to make it works. I'm uploading the content of the dist folder after using npm run build, the project was started using `vue init bootstrap-vue/webpack my-project. I've tried to add a vue.config.js file with the next information:
module.exports = {
baseUrl: './',
//...
}
I've try several times adding this in different folders before build it but I can't make it work.
The result just show the footer, it is in:
http://thegraph.es/Citython/
and the code without this vue.config.js is in the next link:
https://github.com/MGijon/Citython/tree/master/web
I have a react app , created with create-react-app then I build the app with command: npm run build
It's using serve to run the app after build, if we start the app with development code by running ENV=production npm run start it can read the process.env.ENV variable beacause I'm adding this plugins to webpack dev config
new webpack.DefinePlugin({
'process.env':{
'ENV': JSON.stringify(process.env.ENV),
}
}),
I also add the script above to webpack prod config, but if I try this command after build ENV=prod serve -s build, it cannot read the environment variable
How to fix this?
If you set all the environment variables inside the app.config.js, you can replace them after the build in the main.????????.chunk.js file.
A sample app.config.js could look like:
export default {
SOME_URL: "https://${ENV_VAR_1}"
SOME_CONFIGURATION: "${ENV_VAR_2}",
}
Leave the app.config.js file as is, without replacing the environment variables with their actual values. Then, create the optimized production build:
npm ci # if not already installed
npm run build
If the default webpack configurations are used, the contents of app.config.js will be bundled in build/static/js/main.????????.chunk.js. The values of the environment variables can be be envsubst, with a bash script like this:
main_chunk=$(ls build/static/js/main.*.js)
envsubst <$main_chunk >./main_chunk_temp
cp ./main_chunk_temp $main_chunk
rm ./main_chunk_temp
Note: In the above example, envsubst reads the actual variables set in the environment at runtime and literally replaces ${ENV_VAR_1} and ${ENV_VAR_2} with them. So, you can only run this once as the chunk is being over-written.
The reason why you can not read the ENV var is because:
(1) In development mode webpack watches your files and bundles you app on the fly. It also will read (because of the DefinePlugin) your process.env.ENV and will add it as a global variable. So it is basically piping variables from process.env to your JS app.
(2) After you've build your app (with webpack) everything is already bundled up into one or more files. When you run serve you just start a HTTP server that serves the static build files. So there is no way to pipe the ENV to you app.
Basically what the DefinePlugin does is add a var to the bundle. E.g.
new webpack.DefinePlugin({
'token': '12356234ga5q3aesd'
})
will add a line similar to this:
var token = '12356234ga5q3aesd';
since the JS files is static there is no way to change this variable after you've build/bundled it with webpack. Basically, when you do npm run build you're creating the compiled binary/.dll/.jar/... file and can no longer influence its contents via the plugin.
You can add a .env file to the root of your project and define your environment variables there. That will be your default (production) environment variables definition. But then you can have a local file called .env.local to override values from the default.
When defining your environment variables, make sure they start with REACT_APP_ so your environment variable definitions would look like this:
REACT_APP_SERVER_URL=https://my-awesome-app.herokuapp.com
Also, add this to .gitignore so you don't commit your local overrides:
.env*.local
Reference:
Adding Development Environment Variables In .env (create-react-app)
From create-react-app documentation:
Your project can consume variables declared in your environment as if
they were declared locally in your JS files. By default you will have
NODE_ENV defined for you, and any other environment variables starting
with REACT_APP_.
You can read them from process.env inside your code:
render() {
return (
<div>
<small>You are running this application in <b>{process.env.NODE_ENV}</b> mode.</small>
<form>
<input type="hidden" defaultValue={process.env.REACT_APP_NOT_SECRET_CODE} />
</form>
</div>
);
}