Develop Reference

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.

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.

How to load images through webpack when using HTMLWebpackPlugin?

I am using HTMLWebpackPlugin and in my template I have an img tag:
<img src="./images/logo/png">
If you notice, here I am using a relative path thinking webpack will trigger the file loader that's configured in my webpack.config.js file but after compilation I get the exact same src attribute in my html:
<img src="./images/logo/png">
How can I trigger webpack to dynamically replace these relative paths with, well whatever I've configured in my webpack configuration?

I'm not a webpack expert, but i got it to work by doing this:
<img src="<%=require('./src/assets/logo.png')%>">
Plugin config
new HtmlWebpackPlugin({
filename: 'index.html',
template: 'index.html'
}),
According to the docs: https://github.com/jantimon/html-webpack-plugin/blob/master/docs/template-option.md
By default (if you don't specify any loader in any way) a fallback
lodash loader kicks in.
The <%= %> signifies a lodash template
Under the hood it is using a webpack child compilation which inherits
all loaders from your main configuration.
Calling require on your img path will then call the file loader.
You may run into some path issues, but it should work.

Using html-loader with HTML webpack plugin worked for me.
module: {
rules: [
{
test: /\.(html)$/,
use: ['html-loader']
}
]
},
plugins: [
new HtmlWebpackPlugin({
template: './src/index.html'
})
]

You should use the CopyWebpackPlugin.
const CopyWebpackPlugin = require('copy-webpack-plugin');
plugins:[
....
new CopyWebpackPlugin({'patterns': [
{from:'./src/assets/images', to:'images'}
]}),
....
]
This is copy the src/assets/images to your `distfolder/images'.

You could use url-loader in your webpack config to add images below a certain limit encoded as base64 uri's in your final bundle and images above the limit as regular image tags (relative to the publicPath)
module.rules.push({
test: /\.(png|jp(e*)g|gif)$/,
exclude: /node_modules/,
use: [{
loader: 'url-loader',
options: {
limit: 10000,
publicPath: "/"
}
}]
})

I ran into this issue while following the Getting Started guide that Webpack provides. I was using the template code from the guide and bundling images. But then when migrating an existing vanilla html/js/css project to use Webpack, I discovered that in order to use the template HTML loading like I wanted -- with paths to image resource contained in the template -- I had to remove the asset loader usage from my webpack.config.js for the html-loader to properly resolve the new hashed paths it was creating in dist
To use Webpack doc syntax, remove the lines prefixed with "-" and add the lines prefixed with "+"
module: {
rules: [
{
- test: /\.(png|svg|jpg|jpeg|gif)$/i,
- type: 'asset/resource',
+ test: /\.(html)$/,
+ use: ['html-loader'],
}
]
}

Compiling SCSS into CSS and transpiling ES6 to ES5 simultaneously

So I have a SCSS file called style.scss. And I have an ES6 file called script.js. Both these files are in a ./src/ directory.
I want to use Webpack to take the style.scss, convert it to CSS and stick it into a folder called ./dist/ with the filename style.css. I can actually make that happen.
I also want Webpack to take the script.js, transpile to ES5, and put that in to the same ./dist/ folder with a file called script.js. I can also make that happen.
What I cannot do, is make both happen simultaneously. Is this something that Webpack can even do? In this instance I don't want all my styles putting into my JS, I specifically want them to be kept in separate files like a standard website (as that's what this is, really).
The closest I have got is this:
const ExtractTextPlugin = require('extract-text-webpack-plugin');
module.exports = {
entry: {
script: './src/script.js',
style: './src/style.scss'
},
output: {
path: './dist',
filename: '[name].js'
},
module: {
rules: [
{
test: /\.scss$/,
use: ExtractTextPlugin.extract({
fallback: "style-loader",
use: ['css-loader', 'sass-loader']
})
}
]
},
plugins: [
new ExtractTextPlugin('style.css')
] }
But this gives me a script.js file, a style.css file and ALSO a style.js file which is a mess.
Any suggestions?

You don't want to create a separate entry point for the CSS. You can either import the style.scss in your script.js or you can add it to the same entry. An entry can also be an array and webpack will include them in the same bundle, well the CSS is extracted anyway so there won't really be any additional JavaScript. Your entry would be as follows:
entry: {
script: ['./src/script.js', './src/style.scss']
},

Webpack, new chunk is loading in with wrong path

I am trying to chunk my app - attempting to follow webpacks guide on how-to (https://webpack.github.io/docs/code-splitting.html). So I have a seperate chunk set up for my app, I can see that webpack is generating 1.bundle.js in my build folder, however it is pasting it onto my index.html with an incorrect path, and in my console I see the fetch error for the 1.bundle.js file.
So my webpack config looks like so (im just using the webpack:dev for now):
return {
dev: {
entry: {
index: './client/app.jsx'
},
output: {
path: path.join(__dirname, '..', '..', 'dist', 'client'),
publicPath: "/dist/client/",
filename: 'bundle.js'
},
module: {
loaders: [{
test: /\.jsx?$/,
exclude: /node_modules/,
loader: 'babel-loader',
query: {
presets: ['es2015']
}
}, {
test: /\.json$/,
loader: 'json-loader'
}]
},
resolve: {
extensions: ['', '.js', '.jsx']
},
resolveLoader: {
fallback: [path.join(__dirname, 'node_modules')]
},
plugins: [
new webpack.DefinePlugin({
"process.env": {
"NODE_ENV": JSON.stringify("dev")
}
})
]
},
and in my index.html I manually add <script src="bundle.js"></script> and that has been working great. It looks like when this builds now, webpack is applying its own script tag on my index like so
<script type="text/javascript" charset="utf-8" async="" src="/dist/client/1.bundle.js"></script>
However this path is incorrect, it should just be src="1.bundle.js". I have tried tweaking the path and publicPath but nothing seems to work. Is there a way to have webpack add the correct path? Thanks!

You should change publicPath for this snippet:
publicPath: "/"
It will always serve your chunks from root path.

Even though it is answered and accepted, I am providing additional helpful info for others with similar problems.
There are two different purposes for which the 2 parameters are used.
Output:path : The directory the bundle files mentioned in entry section are saved into. For example, the bundle.js for the 'entry' entry you had mentioned. In this case, it will be saved in webconfigfolder+"../../dist/client" folder.
Output: publicPath: The directory prefix that is added to refer to a module when accessed from browser. 0.bundle.js is an unnamed chunk created by code splitting. It will be placed in the output:path mentioned above but will be referred in your html using the public path.
So,if your files as in this case is stored in /dist/client folder, but the index.htm is served in /dist/client, you should give the public path as ./. If htm is served from /dist, the public path should be given as ./client/.
The public path is useful for chunks created for async loading which are called from browser dynamically.

This is because you have given reference to publicPath. So it will try to load the script from this publicPath though the file is not present there.
Removing publicPath can resolve the error