> For the complete documentation index, see [llms.txt](https://stack.sylius.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://stack.sylius.com/twig-hooks/getting-started.md).

# Getting started

Twig Hooks are a robust and powerful alternative to the Sonata Block Events and the old Sylius Template Events systems.

### Main features

* built-in support for *Twig templates*, *Twig Components* and *Symfony Live Components*
* adjustability
* autoprefixing hooks
* configurable hookables
* priority mechanism
* easy enable/disable mechanism for each hook

### Installation

Install the package using Composer and Symfony Flex:

```bash
composer require sylius/twig-hooks
```

### Your first hook & hookable

Once Twig Hooks is installed, you can open **any** Twig file and define your first hook.

{% code title="some.html.twig" %}

```twig
{% hook 'my_first_hook' %}
```

{% endcode %}

This way, `my_first_hook` becomes a unique name which we can use to hook into that specific spot.

{% hint style="success" %}
The ideal hook name:

* is lowercase
* has its logical parts separated with dots (`.`)
* when there is more than one word, they are separated by underscores (`_`)

<mark style="color:green;">Recommended:</mark>

* `index`
* `index.sidebar`
* `index.top_menu`

<mark style="color:red;">Not recommended:</mark>

* index
* indextopmenu
  {% endhint %}

**Hooking into a hook**

For the purpose of this example, let's consider we want to render the `some_block.html.twig` template inside the `my_first_hook` hook. First step is to create a `twig_hooks.yaml` file (or any other format you use) under the `config/packages/` directory (if you don't have one already, of course).

Now, we can define our first hookable with the following configuration:

{% code title="config/packages/twig\_hooks.yaml" lineNumbers="true" %}

```yaml
sylius_twig_hooks:
    hooks:
        'my_first_hook':
            some_block:
                template: 'some_block.html.twig'
```

{% endcode %}

Decomposing the example above we can notice that:

1. `sylius_twig_hooks` is the main key for Twig Hooks configuration
2. `hooks` is a configuration key for defining hookables for all hooks
3. `my_first_hook` is our hook name, defined on the Twig file level
4. `some_block` is the name of our hookable, it can be any string, but it should be unique for a given hook unless you want to override the existing hookable (if you want to read more about overriding hookables check the overriding-hookables.md section)
5. finally we have a `template` key that defines which template should be rendered inside the `my_first_hook` hook

**Possible hookable configuration options**

Depending on the hookable template, we can pass different configuration options while defining hookables:

{% tabs %}
{% tab title="Hookable Template" %}
{% code lineNumbers="true" %}

```yaml
sylius_twig_hooks:
    hooks:
        'my_first_hook':
            some_block:
                template: 'some_block.html.twig'
                enabled: true # whether the hookable is enabled
                context: [] # key-value pair that will be passed to the context bag
                configuration: [] # key-value pair that will be passed to the configuration bag
                condition: '@=user != null' # expression evaluated at runtime; the hookable is rendered only when it returns true
                priority: 0 # priority, the higher the number, the earlier the hookable will be hooked
```

{% endcode %}
{% endtab %}

{% tab title="Hookable Component" %}
{% code title="" %}

```yaml
sylius_twig_hooks:
    hooks:
        'my_first_hook':
            some_block:
                component: 'app:block' # component key
                enabled: true # whether the hookable is enabled
                context: [] # key-value pair that will be passed to the context bag
                props: [] # key-value pair that will be passed to our component as props
                configuration: [] # key-value pair that will be passed to the configuration bag
                condition: '@=user != null' # expression evaluated at runtime; the hookable is rendered only when it returns true
                priority: 0 # priority, the higher the number, the earlier the hookable will be hooked
```

{% endcode %}
{% endtab %}
{% endtabs %}

**Conditions in hookables**

Unlike the `enabled` flag — which is evaluated statically during the application boot — the `condition` option is an [Expression Language](https://symfony.com/doc/current/expression_language.html) expression that is evaluated at runtime, each time the hook is rendered. The hookable is rendered only when the expression returns `true`. Both the whole hook context and the `_context` variable are available within the expression, so both of these work:

```yaml
condition: '@=user != null'
condition: '@=_context.user != null'
```

The `user` variable is provided from Symfony's current security token, as in Symfony security expressions. To refer to a `user` value passed explicitly in the hook context, use `_context.user`. For context keys, `_context` behaves like [Twig's `defined`](https://twig.symfony.com/doc/3.x/tests/defined.html)-style check: `@=_context.product` returns `null` when the variable is absent from the context. Referencing a missing variable directly (e.g. `@=product ...`) throws a clear `InvalidExpressionException` instead, which makes invalid conditions fail fast during development.

Conditions can also use Symfony's `is_granted()` authorization check. Pass the required role or attribute, and optionally a subject:

```yaml
condition: '@=is_granted("ROLE_ADMIN")'
condition: '@=is_granted("EDIT", _context.product)'
```

The check uses Symfony's authorization checker, so voters and access decision rules apply as they do in Twig templates.

{% hint style="info" %}
On Symfony 7.1 and newer, conditions are validated at the application boot: an invalid expression is reported as soon as the container is compiled. On older versions, errors are only reported at runtime, when the hook is rendered.
{% endhint %}


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.

Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:

```
GET https://stack.sylius.com/twig-hooks/getting-started.md?ask=<question>&goal=<user_goal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.