Because Storybook controls the component rendering dynamically from the web application, templates are generated at runtime depending on the args, loaders, decorators, etc. Then the template is sent in an HTTP POST request, with a JSON body containing the story template and its args.
To render stories, the bundle configures Twig to use a dedicated loader and cache. This way, the main Twig environment is kept unchanged and the bundle features don't interfere with the original application functionalities.
sequenceDiagram
title Symfony Renderer
Storybook Manager->>Storybook Preview: Render story "my-story"
activate Storybook Preview
Storybook Preview->>Storybook Preview: Generate Twig template and args
Storybook Preview->>Symfony App: POST /_storybook/render/my-story
activate Symfony App
Note over Storybook Preview,Symfony App: Body: <br/>template: "<twig:Button :btnType="btnType"/>"<br/>args: { "btnType: "primary" }
Symfony App-->>Storybook Preview: HTML for "my-story"
deactivate Symfony App
Storybook Preview->>Storybook Preview: Merge rendered HTML in viewport
Storybook Preview-->>Storybook Manager: Simulate page load
deactivate Storybook Preview
Story templates are rendered in a sandboxed environment. Because the bundle turns the Symfony application into a remote Twig renderer, it also takes care of what is being asked to render.
The sandbox works exactly like the built-in Twig sandbox, except it only applies to the code sent by Storybook, and not to the code owned by the Symfony application. The latter is considered trusted.
By default, the following Twig elements are allowed in stories:
- The
componentfunction - The
componenttag - The
escapefilter
You can configure the sandbox to allow more elements in the bundle configuration:
# config/packages/storybook.yaml
storybook:
sandbox:
allowedTags:
- if
allowedFilters:
- length
when@dev:
storybook:
sandbox:
allowedFunctions:
- dumpWhen Storybook compiles your stories, it also prepares an HTML document where stories will be rendered. This document is displayed in the Storybook UI with an iframe, and contains all needed materials for Storybook to run its features.
To customize the iframe, you can override the preview template provided by the bundle:
{# templates/bundles/@StorybookBundle/preview.html.twig #}
{% extends '@!Storybook/preview.html.twig' %}
{% block previewHead %}
{# render additional tags to <head> #}
{% endblock %}
{% block previewBody %}
{# render additional tags to <body> #}
{% endblock %}The rendered content of these blocks will be injected in the preview iframe, similarly to the previewHead and previewBody configurations.
To make Live Components work in Storybook, you have to enable proxy for live component requests in the
Storybook main.ts|js configuration:
// .storybook/main.ts
// ...
const config: StorybookConfig = {
framework: {
name: "@sensiolabs/storybook-symfony-webpack5",
options: {
// ...
symfony: {
proxyPaths: [
// ...
// 👇 This is the live component route prefix usually set in config/routes/ux_live_component.yaml
'_components/',
],
},
},
},
};Thanks to this configuration, all requests made by live components to re-render themselves will be sent to the Symfony application.
To use Storybook with a project that uses the AssetMapper component, you need to render your importmap in the preview template:
{# templates/bundles/@StorybookBundle/preview.html.twig #}
{% extends '@!Storybook/preview.html.twig' %}
{% block previewHead %}
{{ importmap('app') }}
{% endblock %}Though, standard HMR will not work properly with AssetMapper. To register additional paths to watch and re-trigger the iframe compilation on change, update your main.ts|js configuration:
// .storybook/main.ts
// ...
const config: StorybookConfig = {
framework: {
name: "@sensiolabs/storybook-symfony-webpack5",
options: {
// ...
symfony: {
// 👇 Add more paths to watch
additionalWatchPaths: [
'assets', // Directories
'assets/app.js', // Files
'assets/**/*.js' // Glob patterns
],
},
},
},
};Stimulus controllers are automatically imported with AssetMapper and the importmap directive. They will be loaded in the preview iframe thanks to the AssetMapper configuration described above.
To enable HMR for Stimulus controllers, ensure they are watched in your additionalWatchPaths config key.
If you use TailwindBundle to manage your CSS, you need to tell Storybook to watch the built CSS file, so the preview is refreshed with HMR on change:
// .storybook/main.ts
// ...
const config: StorybookConfig = {
framework: {
name: "@sensiolabs/storybook-symfony-webpack5",
options: {
// ...
symfony: {
additionalWatchPaths: [
// ...
'var/tailwind/tailwind.built.css'
],
},
},
},
};# config/packages/storybook.yaml
storybook:
# Cache base directory for story rendering.
# Set false to disable caching.
cache: '%kernel.cache_dir%/storybook/twig'
# Configure the sandbox for Twig rendering.
sandbox:
# Functions that are allowed in stories.
allowedFunctions: []
# Tags that are allowed in stories.
allowedTags: []
# Filters that are allowed in stories.
allowedFilters: []
# Properties that are allowed in stories.
allowedProperties: {}
# Example:
# App\MyVariable: ['foo', 'bar']
# Methods that are allowed in stories.
allowedMethods: {}
# Example:
# App\MyVariable: ['someMethod', 'getBaz'] // .storybook/main.ts
import type { StorybookConfig } from "@sensiolabs/storybook-symfony-webpack5";
/**
* Main Storybook configuration.
*/
const config: StorybookConfig = {
/**
* Stories specifier.
*
* @see https://storybook.js.org/docs/configure#configure-your-storybook-project
*/
stories: [
"../templates/components/**/*.mdx",
"../templates/components/**/*.stories.[tj]s",
],
/**
* Addons configuration.
*
* @see https://storybook.js.org/docs/configure#configure-your-storybook-project
*/
addons: [
// 👇 This is required for TypeScript config files
"@storybook/addon-webpack5-compiler-swc",
// Other addons...
],
framework: {
// 👇 Tell Storybook to use the Symfony framework
name: "@sensiolabs/storybook-symfony-webpack5",
options: {
/**
* Symfony framework options.
*
* These options only applies to the dev environment.
*/
symfony: {
/**
* Mandatory, the URL of the Symfony development server.
*
* @var string
*/
server: 'http://localhost',
/**
* URLs that should be proxied to the Symfony server.
*
* Useful to resolve assets and re-render LiveComponents.
*
* @var string[]
*/
proxyPaths: [
'/assets',
'/_components'
],
/**
* Additional paths where changes should re-trigger compilation.
*
* Use this if your stories depends on modules that are not part
* of the JavaScript compilation (e.g. with AssetMapper and TailwindBundle).
*
* @var string[]
*/
additionalWatchPaths: [
'assets',
'var/tailwind/tailwind.built.css'
]
}
},
},
};
export default config;