Version: Thelia 3.0

Creating a theme from scratch

A Thelia 3 front-office theme is a Symfony bundle. The Flexy theme ships as FlexyBundle: a class extending AbstractBundle that auto-loads its own services, Twig/Live components, controllers and assets. Template files alone are not enough. A real theme needs its Bundle class so Symfony can wire everything together.

This guide walks through the pieces of a theme, using Flexy as the reference, and shows how to build your own.

Prerequisites

A working Thelia 3 installation (see Installation).
Familiarity with Twig basics in Thelia and data access.

A front-office theme served through AssetMapper needs no Node.js and no bundler. Flexy is one, and the guide below follows it.

A theme is a bundle

The Flexy theme registers itself as a Symfony bundle. Services and controllers are autowired from src/, components from components/, and both directories are declared as PSR-4 roots in the theme's composer.json:

{
    "autoload": {
        "psr-4": {
            "FlexyBundle\\": "src/",
            "FlexyBundle\\Components\\": "components/"
        }
    }
}

// templates/frontOffice/flexy/src/FlexyBundle.php
namespace FlexyBundle;

use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
use Symfony\Component\HttpKernel\Bundle\AbstractBundle;

class FlexyBundle extends AbstractBundle
{
    public function loadExtension(array $config, ContainerConfigurator $container, ContainerBuilder $builder): void
    {
        $container->import('../config/services.yaml');

        $container->services()
            ->defaults()
            ->autowire()
            ->autoconfigure();
    }

    public function prependExtension(ContainerConfigurator $container, ContainerBuilder $builder): void
    {
        $builder->prependExtensionConfig('twig', [
            'paths' => [
                \dirname(__DIR__).'/components' => 'Flexy',
                \dirname(__DIR__).'/form' => 'FlexyForm',
            ],
            'globals' => [
                'flexy_form_themes' => ['@FlexyForm/flexy_form_theme.html.twig'],
            ],
        ]);

        $builder->prependExtensionConfig('twig_component', [
            'anonymous_template_directory' => 'frontOffice/%thelia_front_template%/components/',
            'defaults' => [
                'FlexyBundle\\Components\\' => [
                    'template_directory' => '@Flexy',
                    'name_prefix' => '',
                ],
            ],
        ]);

        // AssetMapper, UX Icons, Tailwind and Stimulus are configured the same way.
    }
}

What this does:

loadExtension() imports config/services.yaml, which registers both PSR-4 roots as autowired, autoconfigured services. autoconfigure() is what makes #[Route] controllers, #[AsTwigComponent] and #[AsLiveComponent] classes work without any XML.
prependExtension() configures the framework for the theme: Twig namespaces and globals, the TwigComponent defaults, AssetMapper, UX Icons, Tailwind and the Stimulus controller paths. name_prefix: '' is what makes component names carry no prefix.
Keys that must follow the active front-office template are written with the %thelia_front_template% parameter, so a theme that is installed but not active does not register its own paths.

The bundle is enabled in config/bundles.php:

// config/bundles.php
return [
    // ...
    FlexyBundle\FlexyBundle::class => ['all' => true],
];

note

For your own theme, create a MyThemeBundle class following this pattern (adjust the namespaces and the two psr-4 entries in composer.json), register it in config/bundles.php, and point its Twig and component paths at your theme directory. Without a Bundle class, controllers, Twig components and Live components in your theme will never be discovered.

Directory structure

The Flexy theme lives in templates/frontOffice/flexy/. A theme combines flat page templates at the root, a components/ tree, a src/ PHP tree (the bundle code) and an assets/ pipeline:

templates/frontOffice/my-theme/
├── template.xml               # Theme descriptor (read by Thelia)
├── composer.json              # type: thelia-frontoffice-template
├── importmap.php              # AssetMapper entrypoints and JavaScript dependencies
├── config/
│   ├── views.yaml             # root templates that are not pages of their own
│   └── packages/              # framework configuration the theme ships
├── base.html.twig             # Base layout
├── index.html.twig            # Homepage
├── category.html.twig
├── product.html.twig
├── content.html.twig
├── folder.html.twig
├── search.html.twig
├── login.html.twig
├── customer-register.html.twig
├── account.html.twig
├── account-orders.html.twig
├── account-order.html.twig
├── account-addresses.html.twig
├── address.html.twig
├── address-update.html.twig
├── checkout-cart.html.twig
├── checkout-delivery.html.twig
├── checkout-payment.html.twig
├── checkout-confirm.html.twig
├── checkout-gateway.html.twig
├── checkout-failed.html.twig
├── contact.html.twig
├── contact-success.html.twig
├── password-forgotten.html.twig
├── reset_password.html.twig
├── 404.html.twig
├── error.html.twig
├── maintenance.html.twig
├── components/                # Components, PHP-backed or anonymous (namespace @Flexy)
│   ├── Atoms/
│   ├── Fields/
│   ├── Forms/
│   ├── Layouts/
│   ├── Molecules/
│   └── Organisms/
├── form/                      # Form theme (namespace @FlexyForm)
├── src/                       # The bundle: Bundle class, Controllers, Services, DTOs
│   ├── MyThemeBundle.php
│   └── Controller/
└── assets/
    ├── app.js
    ├── controllers.json
    ├── controllers/
    ├── styles/
    ├── icons/
    └── images/

tip

The exact file list above mirrors the real Flexy theme root. Pages like checkout-gateway, customer-activation, customer-informations, password-forgotten-confirm, reset-password-confirm, faq, page, sitemap and wishlist also exist in Flexy. Browse templates/frontOffice/flexy/ to see the full set, then keep only the pages your shop needs.

Theme descriptor: template.xml

Every theme has a template.xml at its root. This is the only XML a theme needs: a descriptor read by Thelia, not a service or routing configuration. Here is the real Flexy descriptor:

<!-- templates/frontOffice/my-theme/template.xml -->
<?xml version="1.0" encoding="UTF-8"?>
<template xmlns="http://thelia.net/schema/dic/template"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://thelia.net/schema/dic/template http://thelia.net/schema/dic/template/template-1_0.xsd">
    <descriptive locale="en">
        <title>My front office template</title>
    </descriptive>
    <languages>
        <language>en_US</language>
        <language>fr_FR</language>
    </languages>
    <version>1.0.0</version>
    <authors>
        <author>
            <name>Your Name</name>
            <company>your-company</company>
            <email>contact@example.com</email>
            <website>example.com</website>
        </author>
    </authors>
    <thelia>3.0.0</thelia>
    <stability>prod</stability>
</template>

The tags, in order:

<descriptive locale="...">: one block per locale, each with a <title>. Add as many as you need (Flexy ships fr and en).
<languages>: the locales the theme supports.
<version>: the theme version.
<authors>: one or more <author> blocks with <name>, <company>, <email>, <website>.
<thelia>: the minimum core version the theme requires.
<stability>: prod, beta, alpha, etc.
<assets>: optional, the directory holding compiled assets. It only drives the Webpack Encore manifest and its symlink. A theme served through AssetMapper, as Flexy is, declares no <assets> tag: it would point at a dist directory no build ever produces.

caution

There is no <name>, flat <author>, <description>, <parent> or <required_version> tag. The descriptor does not declare theme inheritance. To reuse Flexy from your own theme, render Flexy's components directly (see Using Flexy components) rather than declaring a parent.

Creating the base layout

{# templates/frontOffice/my-theme/base.html.twig #}
<!DOCTYPE html>
<html lang="{{ app.request.locale }}">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">

    <title>{% block title %}My Shop{% endblock %}</title>

    {% block stylesheets %}
        <link rel="stylesheet" href="{{ asset('styles/app.css') }}" blocking="render">
    {% endblock %}

    {% block javascripts %}
        {{ importmap('app') }}
    {% endblock %}
</head>

<body class="{% block body_class %}{% endblock %}">
    {% block header %}
        <twig:Layouts:Header:Base />
    {% endblock %}

    <main {% block main_attributes %}{% endblock %}>
        {% block body %}{% endblock %}
    </main>

    {% block footer %}
        <twig:Layouts:Footer:Base />
    {% endblock %}

    {% block body_js %}{% endblock %}
</body>
</html>

asset() resolves a path inside the theme's assets/ directory, and importmap() renders the app entrypoint declared in the theme's importmap.php. Both come from AssetMapper.

note

Flexy registers exactly two Twig namespaces from its bundle class: @Flexy for components/ and @FlexyForm for form/. Components are usually rendered by name (<twig:Layouts:Header:Base />), and the namespace is used when one component template references another ({% extends '@Flexy/Organisms/AddressCard/Base.html.twig' %}).

Essential pages

Homepage (index.html.twig)

The homepage is served at / by the route named index. Fetch data with resources() (see Data access). Product and category URLs are rewritten, so link with the resource's publicUrl field. There is no product_show or category route to call.

{# templates/frontOffice/my-theme/index.html.twig #}
{% extends 'base.html.twig' %}

{% block body %}
    <section class="featured-categories container">
        <h2>Shop by Category</h2>

        {% set categories = resources('/api/front/categories', {
            parent: 0,
            visible: 1,
            itemsPerPage: 6
        }) %}

        <div class="category-grid">
            {% for category in categories %}
                {# publicUrl is the rewritten, SEO-friendly category URL #}
                <a href="{{ category.publicUrl }}" class="category-card">
                    <h3>{{ category.i18ns.title }}</h3>
                </a>
            {% endfor %}
        </div>
    </section>

    <section class="featured-products container">
        <h2>Featured Products</h2>

        {% set products = resources('/api/front/products', {
            visible: 1,
            itemsPerPage: 8
        }) %}

        <div class="product-grid">
            {% for product in products %}
                <twig:Molecules:ProductCard:Base :product="product" />
            {% endfor %}
        </div>
    </section>
{% endblock %}

Category page (category.html.twig)

The current category id is read from the request attributes with attr(). The title comes from the resource's i18ns collection.

{# templates/frontOffice/my-theme/category.html.twig #}
{% extends 'base.html.twig' %}

{% set categoryId = attr('category', 'id') %}
{% set category = resources('/api/front/categories/' ~ categoryId) %}

{% block title %}
    {{ category.i18ns.title }} - {{ parent() }}
{% endblock %}

{% block body %}
    <div class="category-page container">
        <header class="category-header">
            <h1>{{ category.i18ns.title }}</h1>
            {% if category.i18ns.chapo %}
                <p class="lead">{{ category.i18ns.chapo|raw }}</p>
            {% endif %}
        </header>

        {# Delegate product listing + filters + pagination to a LiveComponent #}
        <twig:Layouts:ProductListing:Base :categoryId="categoryId" />
    </div>
{% endblock %}

tip

Filtering, sorting and paginating a product grid is stateful work. Flexy delegates it to the Layouts:ProductListing:Base LiveComponent rather than rebuilding pagination by hand in the template. See LiveComponents.

Product page (product.html.twig)

{# templates/frontOffice/my-theme/product.html.twig #}
{% extends 'base.html.twig' %}

{% set productId = attr('product', 'id') %}
{% set product = resources('/api/front/products/' ~ productId) %}

{% block title %}
    {{ product.i18ns.title }} - {{ parent() }}
{% endblock %}

{% block body %}
    <div class="product-page container">
        <h1>{{ product.i18ns.title }}</h1>

        {# The add-to-cart UI (price, PSE selection, quantity) is a LiveComponent #}
        <twig:Layouts:ProductDetails:Base :product="product" />

        {% if product.i18ns.description %}
            <section class="product-description">
                <h2>Description</h2>
                <div class="wysiwyg">{{ product.i18ns.description|raw }}</div>
            </section>
        {% endif %}
    </div>
{% endblock %}

caution

Adding to the cart is handled by the Layouts:ProductDetails:Base LiveComponent, not by a plain HTML <form> posting to a cart_add route. No such route exists. If you build your own add-to-cart UI, model it on the Flexy Live component in components/Layouts/ProductDetails/.

Creating components

Flexy splits its UI in two places:

Everything lives in components/, organized with Atomic Design (Atoms/, Molecules/, Organisms/, Layouts/, Fields/, Forms/). A component is a directory:

an anonymous component is a .html.twig file on its own;
a PHP-backed one adds a class next to its template, carrying a bare #[AsTwigComponent] or #[AsLiveComponent].

Either way the component is named after its path: components/Organisms/ProductCard/Base.php is rendered as <twig:Organisms:ProductCard:Base />. Flexy's own product card is one of these, and it fetches its own price and image data.

For a custom theme you can either reuse Organisms:ProductCard:Base or build your own. The hand-built version below links to the product with product.publicUrl and resolves the image the same way the real one does:

{# templates/frontOffice/my-theme/components/Molecules/ProductCard/Base.html.twig #}
<article class="product-card">
    <a href="{{ product.publicUrl }}">
        <div class="product-card-image">
            {# Product images are a separate resource. The collection endpoint returns ids,
               so build the image URL from the id (the front-single read group carries fileUrl). #}
            {% set images = resources('/api/front/product_images', {
                'product.id': product.id,
                position: 'ASC',
                itemsPerPage: 1
            }) %}
            {% if images %}
                <img src="/legacy-image-library/product_image_{{ images|first.id }}/full/%5E*!386,280/0/default.webp"
                     alt="{{ product.i18ns.title }}"
                     loading="lazy">
            {% endif %}
        </div>

        <div class="product-card-info">
            <h3 class="product-card-title">{{ product.i18ns.title }}</h3>
        </div>
    </a>
</article>

The header links to real, named routes (the back-office and the Flexy controllers register them via #[Route] attributes):

{# templates/frontOffice/my-theme/components/Layouts/Header/Base.html.twig #}
<header class="site-header">
    <div class="container">
        {# Homepage route is named "index" #}
        <a href="{{ path('index') }}" class="logo">
            <img src="{{ asset('images/logo.svg') }}" alt="My Shop">
        </a>

        <nav class="main-nav">
            {% set categories = resources('/api/front/categories', {parent: 0, visible: 1}) %}
            <ul>
                {% for category in categories %}
                    {# Rewritten URL, not a route #}
                    <li><a href="{{ category.publicUrl }}">{{ category.i18ns.title }}</a></li>
                {% endfor %}
            </ul>
        </nav>

        <div class="header-actions">
            {% if app.user %}
                {# Account index route is "account_index" #}
                <a href="{{ path('account_index') }}">My Account</a>
            {% else %}
                <a href="{{ path('customer_login') }}">Login</a>
            {% endif %}

            {# Cart link. Flexy renders this with its Molecules:HeaderButton:Base
               TwigComponent, which takes `text` and usually `href` and `icon`. #}
            <a href="{{ path('checkout_cart') }}" class="cart-link">Cart</a>
        </div>
    </div>
</header>

Route names

The Flexy controllers prefix their routes. Use path('index') for the homepage, path('customer_login') to log in, path('account_index') for the account dashboard, path('checkout_cart') for the cart. Do not use homepage, account, product_show or category: those route names do not exist.

Serving the pages

A theme carries the routes of the front office. The one that makes a shop work is the catch-all: it reads the last segment of a URL as the name of a view and hands it to the core.

// templates/frontOffice/my-theme/src/Controller/ViewController.php
namespace MyThemeBundle\Controller;

use Symfony\Component\Routing\Attribute\Route;
use Thelia\Controller\Front\DefaultController;
use Thelia\Core\HttpFoundation\Request;

class ViewController extends DefaultController
{
    #[Route(
        '/{_view}',
        name: 'my_theme_view',
        requirements: ['_view' => '^(?!admin|api)[^/]+'],
        defaults: ['_view' => 'index'],
        priority: -1000,
    )]
    public function view(Request $request): void
    {
        $this->noAction($request);
    }
}

Category, product, content and folder pages all arrive here, either named directly or through the rewriting router, which resolves a SEO URL and hands over the view it points at. Without this route the shop serves none of them.

Two details are not optional. The negative priority puts the route last, because the pattern swallows any single segment and would otherwise hide every route declared after it. The requirement excludes admin and api, which are served by routers that only run once this one has been tried.

The rendering itself stays in the core: DefaultController::noAction() does the work, and the controller above only carries the route to it. No module is involved. A theme that expects the thelia/front-module package to declare this route is a Thelia 2 theme.

Downloading a virtual product

A theme that sells virtual products needs a route to serve the file, and it must not read that file itself. Flexy exposes /account/order/download/{orderProductId}: it checks that the order line belongs to the logged-in customer and that the order is paid, dispatches an event, and returns whatever a listener puts on it.

#[Route('/order/download/{orderProductId}', name: 'order_download', requirements: ['orderProductId' => '\d+'], methods: ['GET'])]
public function downloadVirtualProduct(EventDispatcherInterface $eventDispatcher, int $orderProductId): Response
{
    // ... resolve $orderProduct for the current customer, 404 otherwise

    $event = new VirtualProductOrderDownloadResponseEvent($orderProduct);
    $eventDispatcher->dispatch($event, TheliaEvents::VIRTUAL_PRODUCT_ORDER_DOWNLOAD_RESPONSE);

    if (!$event->getResponse() instanceof Response) {
        // No module answered, so there is no file to serve
        throw new NotFoundHttpException();
    }

    return $event->getResponse();
}

The module storing the file answers the event, VirtualProductDelivery being the usual one. A shop with no such module gets a 404 here, not a 500. An unknown id, an order line belonging to someone else and an unpaid order return that same 404: none of them tells whether the file exists.

Declaring internal views

Not every root template is a page. Layouts exist to be extended, error pages are rendered by the error handler, and checkout or account templates render only with the context their controller prepares. The catch-all above cannot tell them apart from a real page, so a theme says which is which in config/views.yaml:

# templates/frontOffice/my-theme/config/views.yaml
internal:
    - base
    - checkout-base
    - error
    # Quoted: unquoted, YAML reads it as an integer and the core rejects a non-string entry
    - '404'
    - account
    - checkout-cart
    - checkout-delivery

A request naming one of these views gets a 404. A controller rendering the same template is unaffected, since only requests that name a view go through the check.

The file is optional. A theme that ships none keeps every root template reachable by its own name, which was the behaviour of every theme until Thelia 3.0.0-beta3. The nearest declaration wins: an inherited list only applies while the theme itself declares nothing.

An unreadable or malformed file is a packaging error and is reported as one, so a typo does not pass silently.

Asset pipeline

A theme served through AssetMapper ships its assets as they are. There is no bundler, no package.json and no dist/ directory.

importmap.php at the theme root declares the JavaScript entrypoints and dependencies.
assets/ holds styles, icons, images and Stimulus controllers.
assets/styles/app.css is the single input Tailwind compiles.

The theme points the framework at those directories from its bundle class:

// templates/frontOffice/my-theme/src/MyThemeBundle.php
public function prependExtension(ContainerConfigurator $container, ContainerBuilder $builder): void
{
    $builder->prependExtensionConfig('framework', [
        'asset_mapper' => [
            // Listed first so AssetMapper searches the theme before the project
            'paths' => [
                \dirname(__DIR__).'/assets',
                \dirname(__DIR__).'/assets/styles',
                \dirname(__DIR__).'/components',
            ],
            'vendor_dir' => '%kernel.project_dir%/templates/frontOffice/%thelia_front_template%/assets/vendor',
            'importmap_path' => '%kernel.project_dir%/templates/frontOffice/%thelia_front_template%/importmap.php',
            'public_prefix' => '/assets/frontOffice/%thelia_front_template%/',
            'excluded_patterns' => ['*/*.html.twig'],
        ],
    ]);
}

Keys that must follow the active theme are written with the %thelia_front_template% parameter. paths is the exception: those entries designate this bundle's own directories, so they stay on dirname(__DIR__).

Build the assets:

php Thelia importmap:install
php Thelia tailwind:build

bin/install runs both at the end of an install, so a fresh project has nothing to do. Run them again after a composer update, which reinstalls the theme package.

Using Flexy components

A custom theme can reuse Flexy's components instead of declaring inheritance in template.xml. Render them by name with the component() Twig function:

{# In your custom theme #}
{% extends 'base.html.twig' %}

{% block body %}
    <twig:Layouts:ProductDetails:Base :product="product" />
    <twig:Layouts:ProductListing:Base :categoryId="categoryId" />
    <twig:Molecules:HeaderButton:Base href="{{ path('checkout_cart') }}" icon="cart" text="{{ 'Cart'|trans }}" />
{% endblock %}

This works because Flexy's bundle registers those components as services; as long as FlexyBundle is enabled in config/bundles.php, their names are available to any active theme.

Activating the theme

Activate a theme from the command line with the template:set command (type then name):

php Thelia template:set frontOffice my-theme

Or from the back office: Configuration → Templates, select your theme for the front office, and save.

tip

bin/install accepts --frontoffice_theme=my-theme to set the active front-office template during installation. See Installation.

Learn more

Customizing Flexy: override specific parts of the Flexy theme
LiveComponents: build interactive, server-rendered components
TwigComponents: reusable Twig component classes
Data access: fetch data with resources() and attr()
Stimulus: add behavior to your assets

Prerequisites​

A theme is a bundle​

Directory structure​

Theme descriptor: template.xml​

Creating the base layout​

Essential pages​

Homepage (index.html.twig)​

Category page (category.html.twig)​

Product page (product.html.twig)​

Creating components​

Serving the pages​

Downloading a virtual product​

Declaring internal views​

Asset pipeline​

Using Flexy components​

Activating the theme​

Learn more​