Using expose-loader with webpack 2 to load a module - javascript

I have jwplayer in my lib/ folder because no node_module exists. I tried to use expose-loader in order to be able to import it. In my webpack, I have the following basic setup in order to get this to work:
const path = require('path');
module.exports = {
// ...
module: {
rules: [{
test: /\.jwplayer\.js$/,
use: {
loader: 'expose-loader',
options: 'jwplayer', // have also tried `options: { name: 'jwplayer' }`
},
}]
},
resolve: {
alias: {
jwplayer: path.join(__dirname, './lib/jwplayer-7.7.4/jwplayer.js'),
}
},
externals: {
window: 'Window',
}
};
The strange thing is, jwplayer is exposed on the window object, but it is not available as a module.
import jwplayer from 'jwplayer';
console.log(jwplayer); // Object {} (not jwplayer)
console.log(window.jwplayer); // function jwplayer() {}
Am I loading it incorrectly? How should I load in jwplayer with webpack 2?

That's not how you use the expose loader. The expose loader tells to webpack to expose something to the global context when the bundle is loaded. My understanding is that you want to use jwplayer inside the bundle itself.
You can use the script-loader, that's how I usually import scripts (analytics, for instance)

Actually you can use
externals: ['jwplayer'],
Because externals is for passing global variables inside the bundle to be able to use them as a dependency and then you can import your library as any other
import jwplayer from 'jwplayer';
webpack documentation

Related

Public file is missing from build/public in Webpack [duplicate]

I'm trying to move from Gulp to Webpack. In Gulp I have task which copies all files and folders from /static/ folder to /build/ folder. How to do the same with Webpack? Do I need some plugin?
Requiring assets using the file-loader module is the way webpack is intended to be used (source). However, if you need greater flexibility or want a cleaner interface, you can also copy static files directly using my copy-webpack-plugin (npm, Github). For your static to build example:
const CopyWebpackPlugin = require('copy-webpack-plugin');
module.exports = {
context: path.join(__dirname, 'your-app'),
plugins: [
new CopyWebpackPlugin({
patterns: [
{ from: 'static' }
]
})
]
};
Compatibility note: If you're using an old version of webpack like webpack#4.x.x, use copy-webpack-plugin#6.x.x. Otherwise use latest.
You don't need to copy things around, webpack works different than gulp. Webpack is a module bundler and everything you reference in your files will be included. You just need to specify a loader for that.
So if you write:
var myImage = require("./static/myImage.jpg");
Webpack will first try to parse the referenced file as JavaScript (because that's the default). Of course, that will fail. That's why you need to specify a loader for that file type. The file- or url-loader for instance take the referenced file, put it into webpack's output folder (which should be build in your case) and return the hashed url for that file.
var myImage = require("./static/myImage.jpg");
console.log(myImage); // '/build/12as7f9asfasgasg.jpg'
Usually loaders are applied via the webpack config:
// webpack.config.js
module.exports = {
...
module: {
loaders: [
{ test: /\.(jpe?g|gif|png|svg|woff|ttf|wav|mp3)$/, loader: "file" }
]
}
};
Of course you need to install the file-loader first to make this work.
If you want to copy your static files you can use the file-loader in this way :
for html files :
in webpack.config.js :
module.exports = {
...
module: {
loaders: [
{ test: /\.(html)$/,
loader: "file?name=[path][name].[ext]&context=./app/static"
}
]
}
};
in your js file :
require.context("./static/", true, /^\.\/.*\.html/);
./static/ is relative to where your js file is.
You can do the same with images or whatever.
The context is a powerful method to explore !!
One advantage that the aforementioned copy-webpack-plugin brings that hasn't been explained before is that all the other methods mentioned here still bundle the resources into your bundle files (and require you to "require" or "import" them somewhere). If I just want to move some images around or some template partials, I don't want to clutter up my javascript bundle file with useless references to them, I just want the files emitted in the right place. I haven't found any other way to do this in webpack. Admittedly it's not what webpack originally was designed for, but it's definitely a current use case.
(#BreakDS I hope this answers your question - it's only a benefit if you want it)
Webpack 5 adds Asset Modules which are essentially replacements for common file loaders. I've copied a relevant portion of the documentation below:
asset/resource emits a separate file and exports the URL. Previously achievable by using file-loader.
asset/inline exports a data URI of the asset. Previously achievable by using url-loader.
asset/source exports the source code of the asset. Previously achievable by using raw-loader.
asset automatically chooses between exporting a data URI and emitting a separate file. Previously achievable by using url-loader with asset size limit.
To add one in you can make your config look like so:
// webpack.config.js
module.exports = {
...
module: {
rules: [
{
test: /\.(jpe?g|gif|png|svg|woff|ttf|wav|mp3)$/,
type: "asset/resource"
}
]
}
};
To control how the files get output, you can use templated paths.
In the config you can set the global template here:
// webpack.config.js
module.exports = {
...
output: {
...
assetModuleFilename: '[path][name].[hash][ext][query]'
}
}
To override for a specific set of assets, you can do this:
// webpack.config.js
module.exports = {
...
module: {
rules: [
{
test: /\.(jpe?g|gif|png|svg|woff|ttf|wav|mp3)$/,
type: "asset/resource"
generator: {
filename: '[path][name].[hash][ext][query]'
}
}
]
}
};
The provided templating will result in filenames that look like build/images/img.151cfcfa1bd74779aadb.png. The hash can be useful for cache busting etc. You should modify to your needs.
Above suggestions are good. But to try to answer your question directly I'd suggest using cpy-cli in a script defined in your package.json.
This example expects node to somewhere on your path. Install cpy-cli as a development dependency:
npm install --save-dev cpy-cli
Then create a couple of nodejs files. One to do the copy and the other to display a checkmark and message.
copy.js
#!/usr/bin/env node
var shelljs = require('shelljs');
var addCheckMark = require('./helpers/checkmark');
var path = require('path');
var cpy = path.join(__dirname, '../node_modules/cpy-cli/cli.js');
shelljs.exec(cpy + ' /static/* /build/', addCheckMark.bind(null, callback));
function callback() {
process.stdout.write(' Copied /static/* to the /build/ directory\n\n');
}
checkmark.js
var chalk = require('chalk');
/**
* Adds mark check symbol
*/
function addCheckMark(callback) {
process.stdout.write(chalk.green(' ✓'));
callback();
}
module.exports = addCheckMark;
Add the script in package.json. Assuming scripts are in <project-root>/scripts/
...
"scripts": {
"copy": "node scripts/copy.js",
...
To run the sript:
npm run copy
The way I load static images and fonts:
module: {
rules: [
....
{
test: /\.(jpe?g|png|gif|svg)$/i,
/* Exclude fonts while working with images, e.g. .svg can be both image or font. */
exclude: path.resolve(__dirname, '../src/assets/fonts'),
use: [{
loader: 'file-loader',
options: {
name: '[name].[ext]',
outputPath: 'images/'
}
}]
},
{
test: /\.(woff(2)?|ttf|eot|svg|otf)(\?v=\d+\.\d+\.\d+)?$/,
/* Exclude images while working with fonts, e.g. .svg can be both image or font. */
exclude: path.resolve(__dirname, '../src/assets/images'),
use: [{
loader: 'file-loader',
options: {
name: '[name].[ext]',
outputPath: 'fonts/'
},
}
]
}
Don't forget to install file-loader to have that working.
You can write bash in your package.json:
# package.json
{
"name": ...,
"version": ...,
"scripts": {
"build": "NODE_ENV=production npm run webpack && cp -v <this> <that> && echo ok",
...
}
}
Most likely you should use CopyWebpackPlugin which was mentioned in kevlened answer. Alternativly for some kind of files like .html or .json you can also use raw-loader or json-loader. Install it via npm install -D raw-loader and then what you only need to do is to add another loader to our webpack.config.js file.
Like:
{
test: /\.html/,
loader: 'raw'
}
Note: Restart the webpack-dev-server for any config changes to take effect.
And now you can require html files using relative paths, this makes it much easier to move folders around.
template: require('./nav.html')
I was stuck here too. copy-webpack-plugin worked for me.
However, 'copy-webpack-plugin' was not necessary in my case (i learned later).
webpack ignores root paths
example
<img src="/images/logo.png'>
Hence, to make this work without using 'copy-webpack-plugin'
use '~' in paths
<img src="~images/logo.png'>
'~' tells webpack to consider 'images' as a module
note:
you might have to add the parent directory of images directory in
resolve: {
modules: [
'parent-directory of images',
'node_modules'
]
}
Visit https://vuejs-templates.github.io/webpack/static.html
The webpack config file (in webpack 2) allows you to export a promise chain, so long as the last step returns a webpack config object. See promise configuration docs. From there:
webpack now supports returning a Promise from the configuration file. This allows to do async processing in you configuration file.
You could create a simple recursive copy function that copies your file, and only after that triggers webpack. E.g.:
module.exports = function(){
return copyTheFiles( inpath, outpath).then( result => {
return { entry: "..." } // Etc etc
} )
}
lets say all your static assets are in a folder "static" at the root level and you want copy them to the build folder maintaining the structure of subfolder, then
in your entry file) just put
//index.js or index.jsx
require.context("!!file?name=[path][name].[ext]&context=./static!../static/", true, /^\.\/.*\.*/);
In my case I used webpack for a wordpress plugin to compress js files, where the plugin files are already compressed and need to skip from the process.
optimization: {
minimize: false,
},
externals: {
"jquery": "jQuery",
},
entry: glob.sync('./js/plugin/**.js').reduce(function (obj, el) {
obj[path.parse(el).name] = el;
return obj
}, {}),
output: {
path: path.resolve(__dirname, './js/dist/plugin'),
filename: "[name].js",
clean: true,
},
That used to copy the js file as it is to the build folder. Using any other methods like file-loader and copy-webpack create issues with that.
Hope it will help someone.

Get class functions from webpack module

I need to call class function, what writed in webpack module from outside script.
There is webpack config:
entry: {
main: ["./src/js/main.js"],
},
performance: {
hints: false,
},
output: {
filename: "[name].js",
path: path.resolve(__dirname, "dist/js"),
},
optimization: optimization(),
module: {
rules: ifBabel(),
},
In main.js i have
import { finishing } from "./modules/forms/finishing";
var fns = new finishing();
fns.init();
I need to call some function of fns from outside script. But webpack compiling script inside his function and i cant access to it..
You have 2 primary options:
Use Webpack's library to define how your Webpack bundle exposes itself to the page when loaded, and have your main.js export functions to be used by your page via the library, like
import { foo } from "./foo";
export { foo };
with the page then able to use LibraryName.foo()
Have main.js explicitly do something like
import { foo } from "./foo";
window.foo = foo;
to manually expose specific functions on the window or some other location.
I would recommend the first approach, but either is fine.

Keep a ES module outside the bundle

My application has a configuration file
external-config.js
import {constants} from "./constants.js";
export const ExternalConfig = {
title: "My application",
version: "2.0",
constants: constants
list: ["uno", "due", "tre"]
}
I don't want it to be bundled with the application, I want to keep it outside. I tried the IgnorePlugin, but apparently this simply breaks the dependency graph and I get the error ReferenceError: Config is not defined even if the reference to the path of the config file in the budle is correct.
plugins: [
new webpack.IgnorePlugin({
checkResource (resource) {
if (resource === "./conf/external-config.js") return true;
return false;
}
})
]
I cannot even import it in the main html page like
<script type="module" src="./conf/config.js"></script>
because in this way I couldn't access the object outside its own script.
Is there a way to do that?
EDIT: following #raz-nonen advice, I tried null-loader, it seems it could be a solution. The problem with that is the physical position of the configuration file.
rules: [
{
test: path.resolve(__dirname, "src/conf/external-config.js"),
use: "null-loader"
}
...]
And this is the result in the built script
// EXTERNAL MODULE: ./src/conf/external-config.js
var external_config = __webpack_require__(13);
But the actual position of the configuration in the dist folder is ./conf/external-config.js, not ./src/conf/external-config.js
This is the chunk of my app that consumes the external file
import {ExternalConfig} from "./conf/external-config.js";
class MyApp extends LitElement {
constructor() {
super();
console.log(ExternalConfig.list)
}
}
You'll need to make this file available in the dist folder. You can do that with copy-webpack-plugin
Tell webpack that ExternalConfig will be imported from external. It means that you'll have to take care that it'll be available at runtime. You can do it simply by importing your conf/config.js that you copied from a <script> tag in your index.html.
Add:
externals: {
'conf/external-config': 'conf/external-config'
}
In your webpack configuration.

How to change the src attribute of <img> in .vue files with webpack and vue-loader?

I have a vue.js (version 2.4.4) application built with webpack (version 3.6.0) and vue-loader (version 13.0.5).
In the .vue files, I need to modify the url contained in the src attribute of the <img> tags according to the environment of my application.
In the development environment, the images must come from the
application folder, with a relative path: "/src/images/exemple.png"
In the production environment, the images must come from a cdn, with
an absolute path: "https://my-cdn.net/images/exemple.png"
In the "webpack.config.js" file, I already differentiate the different environments using "process.env.NODE_ENV", like this:
const isDev = process.env.NODE_ENV === 'dev';
But I don't know how to modify the src attribute of the img tags in my .vue files with vue-loader (or with something else).
For information, here is the definition of the vue-loader in the "webpack.config.js" file:
{
test: /\.vue$/,
loader: 'vue-loader',
options: {
loaders: {
'scss': [
'vue-style-loader',
'css-loader',
'sass-loader'
]
}
}
}
Is there a simple way to do this?
Piggybacking off of #Michael Levy's answer:
I am currently having this issue with Vue 3, #vue/cli 4.5.10, and webpack. I've solved it after much research.
Webpack configurations go into vue.config.js, where there is a lot of abstraction. To fine tune control, you can use chain webpack configs. To help you, use Vue Inspect when you are trying to access specific loaders via chaining.
$ vue inspect > output.js
That will give you a nice list of all the loaders that vue-cli is using.
For example - to modify webpack image options within vue.config.js, you can use vue inspect > output.js, search the output.js file, and discover the loader that's managing images.
Which is: /* config.module.rule('images').use('url-loader') */
To answer the question - in your vue.config.js
module.exports = {
chainWebpack: (config) => {
config.module
.rule("images")
.use("url-loader")
.tap((options) => {
options.name = "images/[name].[ext]";
options.publicPath = isDev ? __webpack_public_path__ : 'https://my-cdn.net/';
return options;
});
},
};
Vue-loader is preconfigured to handle src attributes in Vue single file components as you can see here. So for example <img src="../image.png"> in the template is transformed into:
createElement('img', {
attrs: {
src: require('../image.png') // this is now a module request
}
})
What Webpack do with this require depends on configured loaders. Usual there is a file-loader configured. It looks like this (from project generated by Vue CLI + simplified):
module: {
rules: [
{
test: /\.(png|jpe?g|gif|webp)(\?.*)?$/,
use: [
{
loader: 'file-loader',
options: {
name: 'img/[name].[hash:8].[ext]'
}
}
]
}
]
}
Loader is responsible for copying your file into dist directory and returning public URI, which will be inserted into src attribute.
So what you want can be configured here, by specifying right options. For example:
options: {
name: 'images/[name].[ext]'
publicPath: isDev ? __webpack_public_path__ : 'https://my-cdn.net/'
}
Just take content of dist/images directory after the build and deploy it so it is accessible by https://my-cdn.net/images and it should work....
You can create an alias for/src/images and alter the url at transpile time based on the environment:
{
//..
resolve: {
alias: {
'/src/images': isDev ? '/src/images' : process.env.IMAGE_CDN + '/images'
}
}
}
Another way to handle this would be to use DefinePlugin to create a global variable that each of your images reference.
module.exports = {
chainWebpack: config => {
console.log('\n')
console.log('Setting global variables:')
console.log(`__YOUR_GLOBAL_CONSTANT__: ${JSON.stringify(process.env.YOUR_GLOBAL_CONSTANT)}`)
console.log('\n')
config
.plugin('provide')
.use(require('webpack').DefinePlugin, [{
__YOUR_GLOBAL_CONSTANT__: JSON.stringify(process.env.YOUR_GLOBAL_CONSTANT)
}])
}
}
The example above is utilizing a vue.config.js file, but the strategy should be pretty similar. Also, if you're using something like eslint, you'll need to specify the variable in the globals section as readonly.

Initializing third-part plugin in webpack bundle.js

One of my module is external plugin (WOW effect), which needs to be initialize in index.html to works properly by using:
<script>
new WOW().init();
</script>
If I use the plugin as a completely external file - it works. But when I compile it with webpack it gives me an error:
Uncaught ReferenceError: wow is not defined.
My config file looks like this:
module.exports = {
entry: './modules/_entry.js',
output: {
filename: 'bundle.js'
}
};
and _entry.js contains:
require("./wow.js");
What I am doing wrong?
There are two possibilities:
Externals The benefit of this one is that you can easly exchange your local script file for example for a CDN one. In this method, the source of the script is an external vendor file.
Have a folder with you vendor scripts, like WOW.
Link to it in your HTML file using <script src="vendors/WOW.js">.
You are free to make the initialization like you indicated above, inside another <script> tag.
Add externals configuration to your webpack config:
var config = {
entry: [...],
output: {...},
externals: {
Wow: 'WOW'
},
module: {...},
plugins: [...]
};
From now on, you have access to an artificial module Wow in all your application modules and you can import or require them (although in case of WOW, I don't think you would need it).
Expose-loader This way lets you move to the global scope modules that you would normally use as... well, modules :) In this method, the source of the script is a module (either yours own, or installed with npm).
Install the plugin: npm install expose-loader --save-dev
Add the expose loader configuration to your webpack config file:
var config = {
entry: [...],
output: {...},
module: {
loaders: [{
...
}, {
test: 'path/to/your/module/wow.min.js',
loader: "expose?WOW"
}]
},
plugins: [...]
};
This should make the WOW a global variable, usable inside <script> tags.

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