Bundle to Integrate Webpack to Symfony

1.0.1 2017-12-13 19:43 UTC


Symfony bundle to help integrating webpack into Symfony project.

What is webpack?

Module bundler and CommonJS / AMD dependency manager.

For me, it replaces both grunt/gulp and RequireJS.

What does this bundle do?

  1. Finds javascript entry points inside your twig templates.
  2. Runs webpack with assets-webpack-plugin.
  3. Saves generated file names, so that twig function returns correct URL to generated asset.

Additionally, for development environment:

  1. Runs webpack-dev-server, which serves and regenerates assets if they are changed.
  2. Watches twig templates for changes, updates entry points and restarts webpack-dev-server if webpack configuration changes.

More goodies:

  1. Lets you configure webpack config as you want, while still providing needed parameters from Symfony, like entry points, aliases, environment and additional parameters.
  2. Lets you define custom entry point providers if you don't use twig or include scripts in any other way.
  3. Works with images and css/less/sass files out-of-the-box, if needed.
  4. Supports both Webpack 2 (by default) and Webpack 1.

Look at Symfony, Webpack and AngularJS Single Page Application Demo for usage examples.

Also look at MabaWebpackMigrationBundle for easier migration from AsseticBundle to webpack.

How does this compare to assetic?

Webpack lets you create components, which know their own dependencies.

With assetic, you must explicitly provide all needed javascript and stylesheet files in your templates. If you split one of your javascript files into two files, you need to update all templates where that new dependency is required. With webpack, you could just require('./newFile.js'); inside the javascript file and you're done.

Moreover, from javascript your can require CSS files as easily as other javascripts - require('./styles.css'); and you're set to go.

If your application is frontend-based, sooner or later you're gonna need to load your assets asynchronously. This comes by default in webpack. Assetic just bundles the assets, you need to use library like RequireJS to do that (for example, you can look at HearsayRequireJSBundle as an alternative).

webpack-dev-server supports hot-reload of your files, sometimes without page refresh (perfect for styling and some JS frameworks, like React).


composer require maba/webpack-bundle

Inside AppKernel:

new Maba\Bundle\WebpackBundle\MabaWebpackBundle(),

Run command:

app/console maba:webpack:setup

It copies default webpack.config.js and package.json files and runs npm install.

If any of the files already exists, you'll be asked if you'd like to overwrite them.

webpack.config.js must export a function that takes options as an argument and returns webpack config.

Feel free to modify this configuration file as you'd like - bundle just provides default one as a starting point.

You should add webpack.config.js and package.json into your repository. You should also add node_modules into .gitignore file and run npm install similarly to composer install (after cloning repository, after package.json is updated and as a task in your deployment). Of course, you could just add it to your repository, too.

git add package.json app/config/webpack.config.js

If you want to use Webpack 1 for some reason, pass --useWebpack1 as a command line option to setup command.


Inside twig templates:

<!DOCTYPE html>
    <meta charset="utf-8">
    {% webpack css '@app/bootstrap.less' '@ApplicationBundle/Resources/assets/script.js' %}
        <link rel="stylesheet" href="{{ asset_url }}"/>
    {% end_webpack %}
    <img src="{{ webpack_asset('@app/funny-kitten.png') }}"/>
    <script src="{{ webpack_asset('@ApplicationBundle/Resources/assets/script.js') }}"></script>

Inside script.js:


function loadScript3() {
    require.ensure([], function() {
setTimeout(loadScript3, 1000);

As part of deployment into production environment, after clearing the cache:

app/console maba:webpack:compile --env=prod

In development environment (this must always run in the background, similar to assetic:watch):

app/console maba:webpack:dev-server

Alternatively, if you are not actively developing your frontend, you can compile once and forget about it, similarly to production environment:

app/console maba:webpack:compile

If you are running functional tests on your app, make sure to compile once for test environment to generate manifest file for test environment:

app/console maba:webpack:compile --env=test

Twig function and tag

You can choose between webpack_asset function and webpack tag.


webpack_asset(resource, type = null)

type is js or css, leave null to guess the type. For css this function could return null if no CSS would be extracted from provided entry point. If you are sure that there will be some CSS, you could just ignore this. Otherwise, you could use webpack tag as it handles this for you (omits the <link/> tag entirely in that case).


{% webpack [js|css] [named] [group=...] resource [resource, ...] %}
    Content that will be repeated for each compiled resource.
    {{ asset_url }} - inside this block this variable holds generated URL for current resource
{% end_webpack %}

As with webpack_asset function, provide js, css or leave it out to guess the type.

See usage with named and group in Using commons chunk section.

Keep in mind that you must provide hard-coded asset paths in both tag and function. This is to find all available assets in compile-time.


By default, ExtractTextPlugin is configured. This means that if you require any file that compiles to CSS (.css, .less, .scss) it is removed from compiled JS file and stored into a separate one. So you have to include it explicitly.

Keep in mind that when you are providing entry point - it's still usually .js file (see usage example).

If you want to disable this functionality so that CSS would be loaded together with JS in a single request, disable extract_css:

            extract_css: false

This plugin is also needed if you want to require css/less/sass files directly as an entry point.

ES6, Less and Sass support

ES6, Less and Sass works out of the box:

  • use .js or .jsx extension to compile from ES6 and ES7 to ES5 using Babel;
  • use .less extension to compile Less files;
  • use .scss extension to compile Sass files.

If you need any custom loaders, feel free to install them via npm and modify app/config/webpack.config.js if needed.

Loading images

Images are optimized by default using image-webpack-loader.

You can include images directly into your twig templates by using the same webpack_asset function.

For this to work correctly, loader for image files must remain file in your webpack configuration.

<img src="{{ webpack_asset('@AcmeHelloBundle/Resources/images/cat.png') }}"/>

Of course, you can use them in your CSS, too:

.cat {
    /* cat.png will be optimized and copied to compiled directory with hashed file name */
    /* URL to generated image file will be in the css output  */
    background: url("~@AcmeHelloBundle/Resources/images/cat.png")

If you are providing webpack-compatible asset path in CSS, prefix it with ~. Use relative paths as usual. See css-loader for more information.


Aliases are prefixed with @ and point to some specific path.

Aliases work the same in both twig templates (parameter to webpack_asset function) and Javascript files (parameter to require or similar Webpack provided function).

By default, these aliases are registered:

  • @app, which points to %kernel.root_dir%/Resources/assets
  • @root, which points to %kernel.project_dir% (usually the root of your repository)
  • @templates, which points to %kernel.project_dir%/templates
  • @assets, which points to %kernel.project_dir%/assets
  • @AcmeHelloBundle or similar for each of your bundles. This points to root of the bundle (where Bundle class is), same as when locating resource in Symfony itself
  • @acme_hello or similar for each of your bundles. This points to @AcmeHelloBundle/Resources/assets by default.

You can also register your own aliases, for example @bower or @npm would be great candidates if you use any of those package managers. Or something like @vendor if you use composer to install your frontend assets:

            npm: %kernel.root_dir%/node_modules     # or any other path where assets are installed
            bower: %kernel.root_dir%/bower
            vendor: %kernel.root_dir%/../vendor

Inside your JavaScript files:

var $ = require('@npm/jquery');

Be sure to install dependencies (either npm, bower or any other) on path not directly accessible from web. This is not needed by webpack (it compiles them - they can be anywhere on the system) and could cause a security flaw (some assets contain backend examples, which could be potentially used in your production environment).


See example with explanations.

        - ApplicationBundle
            - %kernel.root_dir%/Resources/partials
        suppress_errors:      true              # whether files not found or twig parse errors should be ignored
                                                # defaults to true in dev environment
                                                # defaults to "ignore_unkwowns" in prod - this option ignores
                                                #     unknown functions etc., but fails on syntax errors
                                                # set to false to always fail on any twig error
        path:                 '%kernel.root_dir%/config/webpack.config.js'
        parameters:           []        # additional parameters passed to webpack config file
                                        # for example, set dev_server_public_path and public_path to overwrite
                                            # //localhost:8080/compiled/ and /compiled/
                                            # see inside your webpack.config.js for more info
        # set location of cached manifests. Useful for deploy, when you don't want to include your cache directory
        manifest_file_path:        '%kernel.cache_dir%/webpack_manifest.php'

    aliases:                            # allows to set aliases inside require() in your JS files
        path_in_bundle:       /Resources/assets     # this means that require('@acme_hello/a.js')
                                                    # will include something like
                                                    # src/Acme/Bundles/AcmeHelloBundle/Resources/assets/a.js
                                                    # see "Aliases" for more information
        additional:           []            # provide any other aliases, prefix (@) is always added automatically
            executable: # how maba:webpack:compile executes webpack
                        # should be array, for example ['/usr/bin/node', 'node_modules/webpack/bin/webpack.js']
                - node_modules/.bin/webpack
            arguments:            []    # additional parameters to pass to webpack
                                        # --config with configuration path is always passed
            executable: # how maba:webpack:dev-server executes webpack-dev-server
                - node_modules/.bin/webpack-dev-server
            arguments:  # additional parameters to pass to webpack-dev-server; these are default ones
                - --hot
                - --history-api-fallback
                - --inline
        disable_tty: false      # disables TTY setting. Defaults to false in dev environment, true in others.
                                # TTY is needed to run dashboard and/or to display colors, but does not work
                                # in some environments like AWS
        working_directory: %kernel.root_dir%/..
    dashboard:                  # configuration for dashboard plugin - only works when TTY available
        enabled: dev_server     # `always` for both compile and dev-server, `false` to disable
            - node_modules/.bin/webpack-dashboard

Configuring dev-server

app/console maba:webpack:dev-server runs webpack-dev-server as a separate process, it listens on localhost:8080. By default, assets in development environment are pointed to //localhost:8080/compiled/*.

If you run this command inside VM, docker container etc., configure maba_webpack.config.parameters.dev_server_public_path to use correct host. Also, as dev-server listens only to localhost connections by default, add this to configuration:

                - --hot                     # these are default options - leave them if needed
                - --history-api-fallback
                - --inline
                - --host                    # let's add host option
                -                   # each line is escaped, so option comes in it's own line
                - --public                  # this is also needed from webpack-dev-server 2.4.3
                -  # change to whatever host you are using
        parameters:                         # this is where the assets will be loaded from
            dev_server_public_path: //
            dev_server: {}                  # any additional parameters to pass to `devServer` configuration

If you need to provide different port, be sure to put --port and the port itself into separate lines.

When compiling assets with webpack-dev-server, webpack-dashboard is used for more user-friendly experience. You can disable it by setting tty_prefix option to []. You can also remove DashboardPlugin in such case from webpack.config.js.

Configuring memory for Node.js

If you are experiencing "heap out of memory" error when running maba:webpack:compile and/or maba:webpack:dev-server, try to give more memory for Node.js process:

        webpack:        # same with dev_server
                - node
                - "--max-old-space-size=4096"   # 4GB
                - node_modules/webpack/bin/webpack.js

Using commons chunk

This bundle supports both single and several commons chunks, but you have to configure this explicitly.

In your webpack.config.js:

    new webpack.optimize.CommonsChunkPlugin({
        name: 'commons'

In your base template:

{% webpack named css 'commons' %}
    <link rel="stylesheet" href="{{ asset_url }}"/>
{% end_webpack %}
{# ... #}
{% webpack named js 'commons' %}
    <script src="{{ asset_url }}"></script>
{% end_webpack %}

You can also use webpack_named_asset twig function instead of webpack tags.

Grouped commons chunks

webpack tag supports group option:

{% webpack js '@app/admin-init.js' group='admin' %}
    <script src="{{ asset_url }}"></script>
{% end_webpack %}

Name of assets are given in options.groups, which is passed to your webpack.config.js. Assets without group set are assigned to default group. Configuration example:

config.plugins.push(new webpack.optimize.CommonsChunkPlugin({
    name: 'admin_commons_chunk',
    chunks: options.groups['admin']
config.plugins.push(new webpack.optimize.CommonsChunkPlugin({
    name: 'front_commons_chunk',
    chunks: options.groups['default']

Keep in mind that currently the same entry point cannot belong to several groups, even if it's used in different places. This means that you must provide the same group for JavaScript and CSS versions of the same asset.

Note on bundle inheritance

If you use bundles with inheritance, keep in mind, that the assets themselves are usually resolved in different context (in webpack itself), assets pointing to parent bundle (by it's aliases) will actually point to child bundle. This allows you to override any of the assets in the parent bundle, but requires to copy all of them, as they will not be looked in parent bundle's directory at all.

Semantic versioning

This bundle follows semantic versioning.

Public API of this bundle (in other words, you should only use these features if you want to easily update to new versions):

  • only services that are not marked as public="false"
  • only classes, interfaces and class methods that are marked with @api
  • twig functions and tags
  • console commands
  • supported DIC tags

For example, if only class method is marked with @api, you should not extend that class, as constructor could change in any release.

See Symfony BC rules for basic information about what can be changed and what not in the API. Keep in mind, that in this bundle everything is @internal by default.

After updating this bundle, you should re-run maba:webpack:setup command and review changes in files, merge them with any of your own. This bundle might make an assumption that all the needed dependencies are installed. As compiling is made beforehand as a deployment step, you should notice any errors in your staging environment if there would be any.


There are a few alternatives out there for integrating webpack.

Plain simple webpack commands

I would really recommend this approach - just split your frontend code (HTML, CSS, JS) from backend code (PHP + some HTTP API).

Especially if you have single-page application, there is really not much point in integrating your webpack workflow with Symfony.

In this case you could use html-webpack-plugin to generate HTML with correct URL to your bundled javascript file.


This is minimal bundle to provide compiled file names into your twig templates. It also uses assets-webpack-plugin.

What it's missing when compared to this bundle - gathering all entry points. You must manually set them inside your webpack config. If there are only few of them, this is usually not that hard to maintain.

Webpack config is completely manual and does not integrate with your Symfony application.


This bundle gathers all entry points, but does not provide generated URLs to use inside your twig templates. It does solve this problem by appending modification timestamp for cache busting.

Webpack config is completely integrated into your Symfony application and requires custom PHP code for any custom configuration changes.

In development environment, it generates assets on request. This can be more convenient than having to run specific command in the background, but is usually slower. Also at this point it's kind of hard to integrate it with webpack-dev-server.

It has more tags for twig, like inline scripts. One example is inline splitpoint generation which allows you to generate simple splitpoints per file.

Running tests

Travis status

composer install
vendor/bin/codecept run