This bundle allows you to use the splitEntryChunks() feature from Webpack Encore by reading an entrypoints.json file and helping you render all of the dynamic script and link tags needed.

Install the bundle with:

composer require symfony/webpack-encore-bundle

If you're using Symfony Flex, you're done! The recipe will pre-configure everything you need in the config/packages/webpack_encore.yaml file:

# config/packages/webpack_encore.yaml
webpack_encore:
    # The path where Encore is building the assets - i.e. Encore.setOutputPath()
    # if you customize this, you will also need to change framework.assets.json_manifest_path (it usually lives in assets.yaml)
    output_path: '%kernel.project_dir%/public/build'
    # If multiple builds are defined (as shown below), you can disable the default build:
    # output_path: false

    # Set attributes that will be rendered on all script and link tags
    script_attributes:
        defer: true
        # referrerpolicy: origin
    # link_attributes:
    #     referrerpolicy: origin
    
    # if using Encore.enableIntegrityHashes() and need the crossorigin attribute (default: false, or use 'anonymous' or 'use-credentials')
    # crossorigin: 'anonymous'

    # preload all rendered script and link tags automatically via the http2 Link header
    # preload: true

    # Throw an exception if the entrypoints.json file is missing or an entry is missing from the data
    # strict_mode: false
    
    # if you have multiple builds:
    # builds:
        # pass "frontend" as the 3rg arg to the Twig functions
        # {{ encore_entry_script_tags('entry1', null, 'frontend') }}

        # frontend: '%kernel.project_dir%/public/frontend/build'

    # Cache the entrypoints.json (rebuild Symfony's cache when entrypoints.json changes)
    # Available in version 1.2
    # Put in config/packages/prod/webpack_encore.yaml
    # cache: true

The "Split Chunks" functionality in Webpack Encore is enabled by default with the recipe if you install this bundle using Symfony Flex. Otherwise, enable it manually:

// webpack.config.js
// ...
    .setOutputPath('public/build/')
    .setPublicPath('/build')
    .setManifestKeyPrefix('build/')

    .addEntry('entry1', './assets/some_file.js')

+   .splitEntryChunks()
// ...

When you enable splitEntryChunks(), instead of just needing 1 script tag for entry1.js and 1 link tag for entry1.css, you may now need multiple script and link tags. This is because Webpack "splits" your files into smaller pieces for greater optimization.

To help with this, Encore writes an entrypoints.json file that contains all of the files needed for each "entry".

For example, to render all of the script and link tags for a specific "entry" (e.g. entry1), you can:

{# any template or base layout where you need to include a JavaScript entry #}

{% block javascripts %}
    {{ parent() }}

    {{ encore_entry_script_tags('entry1') }}

    {# or render a custom attribute #}
    {#
    {{ encore_entry_script_tags('entry1', attributes={
        defer: true
    }) }}
    #}
{% endblock %}

{% block stylesheets %}
    {{ parent() }}

    {{ encore_entry_link_tags('entry1') }}
{% endblock %}

Assuming that entry1 required two files to be included - build/vendor~entry1~entry2.js and build/entry1.js, then encore_entry_script_tags() is equivalent to:

<script src="{{ asset('build/vendor~entry1~entry2.js') }}"></script>
<script src="{{ asset('build/entry1.js') }}"></script>

If you want more control, you can use the encore_entry_js_files() and encore_entry_css_files() methods to get the list of files needed, then loop and create the script and link tags manually.

When you render your script or link tags, the bundle is smart enough not to repeat the same JavaScript or CSS file within the same request. This prevents you from having duplicate <link> or <script> tags if you render multiple entries that both rely on the same file.

In some cases, however, you may want to render the script & link tags for the same entry multiple times in a request. For example, if you render multiple Twig templates to create multiple PDF files during a single request.

In that case, before each render, you'll need to "reset" the internal cache so that the bundle re-renders CSS or JS files that it previously rendered. For example, in a controller:

// src/Controller/SomeController.php

use Symfony\WebpackEncoreBundle\Asset\EntrypointLookupInterface;

class SomeController
{
    public function index(EntrypointLookupInterface $entrypointLookup)
    {
        $entrypointLookup->reset();
        // render a template

        $entrypointLookup->reset();
        // render another template

        // ...
    }
}

If you have multiple builds, you can also autowire Symfony\WebpackEncoreBundle\Asset\EntrypointLookupCollectionInterface and use it to get the EntrypointLookupInterface object for any build.

Custom attributes can be added to rendered script or link in 3 different ways:

1. Via global config (script_attributes and link_attributes) - see the config example above.

2. When rendering in Twig - see the attributes option in the docs above.

3. By listening to the Symfony\WebpackEncoreBundle\Event\RenderAssetTagEvent event. For example:

<?php

namespace App\EventSubscriber;

use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\WebpackEncoreBundle\Event\RenderAssetTagEvent;

class ScriptNonceSubscriber implements EventSubscriberInterface
{
    public static function getSubscribedEvents()
    {
        return [
            RenderAssetTagEvent::class => 'onRenderAssetTag'
        ];
    }

    public function onRenderAssetTag(RenderAssetTagEvent $event)
    {
        if ($event->isScriptTag()) {
            $event->setAttribute('nonce', 'lookup nonce');
        }
    }
}

This bundle also ships with a special stimulus_controller() Twig function that can be used to render Stimulus Controllers & Values. See stimulus-bridge for more details.

For example:

<div {{ stimulus_controller('chart', { 'name': 'Likes', 'data': [1, 2, 3, 4] }) }}>
    Hello
</div>

<!-- would render -->
<div
   data-controller="chart"
   data-chart-name-value="Likes"
   data-chart-data-value="&#x5B;1,2,3,4&#x5D;"
>
   Hello
</div>

Any non-scalar values (like data: [1, 2, 3, 4]) are JSON-encoded. And all values are properly escaped (the string [ is an escaped [ character, so the attribute is really [1,2,3,4]).

If you have multiple controllers on the same element, pass them all as an associative array in the first argument:

<div {{ stimulus_controller({
    'chart': { 'name': 'Likes' },
    'other-controller': { },
) }}>
    Hello
</div>

Ok, have fun!