Templates (Twig)

Templates define the way the tree of layout blocks is rendered on the page.

We use Twig as a templating engine. Twig enables you to write concise, readable templates that are more friendly to web designers, and, in several ways, more powerful than PHP templates.

Twig Blocks & Block Themes

Each layout block is rendered with a Twig block, as in:

{% block _header_widget %}
    <header{{ block('block_attributes') }}>
        {{ block_widget(block) }}
    </header>
{% endblock %}

Twig blocks are organized to Twig files named block themes.

For instance, this block theme is used as a theme for the product display page.

Twig Block Names

You can define Twig block for a single layout block or for all the layout blocks of the same block type.

Layout engine will try to find Twig block by layout block ID first, then by the block type, then by the parent block type if it is defined and so on. The Twig block found first will be used for rendering:

  1. {% block _<block_id>_widget %}
  2. {% block <block_type>_widget %}
  3. {% block <parent_block_type>_widget %}

Twig block names are build with the following rules:

  • Names always end with the _widget suffix.
  • Names for block IDs start with the underscore (_) character, then goes the block ID, then the _widget suffix.
  • Names for block types start with a block type name, then the _widget suffix.

For instance, to define a layout block named header with the container block type, you need:

layout:
    actions:
        - '@add':
            id: header
            parentId: head
            blockType: container

The layout engine will look for:

  1. {% block _header_widget %} - starts with an underscore, then the block ID and the _widget suffix.
  2. {% block container_widget %} - a block type name with the _widget suffix.

If _header_widget is found, it will be used, if not, container_widget will be used for rendering the header layout block.

Apply a Block Theme

To use a block theme on a page, you have to add the setBlockTheme instruction to the layout update yaml file.

layout:
    actions:
        - '@setBlockTheme':
            themes: 'profile.html.twig'

Where profile.html.twig is the relative path to the template, from the layout update file where setBlockTheme instruction is defined.

You can pass multiple block themes to the instruction:

layout:
    actions:
        - '@setBlockTheme':
            themes: ['profile.html.twig', 'sidebar.html.twig']

To reference the template from another bundle, you can use standard Symfony syntax with the bundle name and folder name inside the Resources/views folder:

layout:
    actions:
        - '@setBlockTheme':
            themes: '@AcmeLayout/layouts/default/base.html.twig'

Note: Form themes are managed separately from the layout block themes, see Form Themes for more details. To apply the form theme, use the @setFormTheme action.

Locate Block Themes

To find the block theme Twig file and the Twig block that is used for rendering a specific block of content, you can use Twig Inspector that enables you to navigate instantly from a Browser to the Twig template which opens automatically in a PhpStorm.

Dump Block Variables

To discover variables available in a block, you can use the snippets below:

  • To dump all variables

    {{ dump(_context) }}
    
  • To dump all variables to the Symfony Profiler

    {% dump(_context) %}
    
  • To dump a single variable

    {{ dump(variableName) }}
    

Pass Variables to the Twig Block

Block Type Options

You can pass variables from layout update yaml files to Twig blocks with options that are defined by block type.

For example:

layout:
    actions:
        - '@add':
            id: call_button
            parentId: profile
            blockType: button
            options:
                action: submit
                text: 'Call Client'
                icon: 'phone'

Now, you can use the action, text, and icon options in a block theme:

{% block _call_button_widget %}
    <button
        type="{{ action in ['submit', 'reset'] ? action : 'button' }}"
        {%- if action in ['submit', 'reset'] %} type="{{ action }}"{% endif %}
        {{ block('icon_block') }}
        {{ text|trans }}
    </button>
{% endblock %}

HTML Attributes

To pass HTML attributes to the Twig block, use the attr option.

For example:

  layout:
      actions:
          - '@add':
              id: call_button
              parentId: profile
              blockType: button
              options:
                  action: submit
                  text: 'Call Client'
                  icon: 'phone'
+                 attr:
+                    class: btn
+                    id: call-button

In block themes, HTML attributes are rendered with {{ block('block_attributes') }}:

  {% block _call_button_widget %}
-      <button
+      <button {{ block('block_attributes') }}
          type="{{ action in ['submit', 'reset'] ? action : 'button' }}"
          {%- if action in ['submit', 'reset'] %} type="{{ action }}"{% endif %}
          {{ block('icon_block') }}
          {{ text|trans }}
      </button>
  {% endblock %}

Custom Variables

To pass custom variables that are not defined in the layout block type, use the vars options. For example:

  layout:
      actions:
          - '@add':
              id: call_button
              parentId: profile
              blockType: button
              options:
                  action: submit
                  text: 'Call %username%'
                  icon: 'phone'
+                 vars:
+                     userName: John Doe

Now, you can use an additional userName variable in a block theme for the call_button block:

  {% block _call_button_widget %}
      <button {{ block('block_attributes') }}
          type="{{ action in ['submit', 'reset'] ? action : 'button' }}"
          {%- if action in ['submit', 'reset'] %} type="{{ action }}"{% endif %}
          {{ block('icon_block') }}{% endif %}
-         {{ text|trans }}
+         {{ text|trans({'%userName%': userName}) }}
      </button>
  {% endblock %}

Twig Filters and Functions

Oro defines a lot of additional filters and functions. To get the full list, run:

bin/console debug:twig

Render List of Items with the Same Template

Iteration over an array or a collection of data can be implemented in a block template of a block theme file, for instance:

{% block _attributes_container_widget %}
    <div class="attributes-container">
        {% for attribute in attributes %}
            {% do block|merge_context({'attribute': attribute}) %}
            {{ block('container_widget') }}
        {% endfor %}
    </div>
{% endblock %}

This block will iterate over all values from the attributes collection, pass the attribute variable with the appropriate value to all children blocks, and render all children blocks for every existing attribute.

Provide Defaults for Block Attributes

To simplify block attribute configuration, use the layout_attr_defaults(attr, default_attr) Twig function :

{% set attr = layout_attr_defaults(attr, {
    required: 'required',
    autofocus: true,
    '~class': " input input--full input--size-m {{ class_prefix }}--another-modifier"
}) %}

If you use prefix ~ value attr, concatenate the default_attr value with this prefix.

Access Layout Block by ID

You can access any layout block from a different block using its ID and modify the template based on the existing block or any of its properties.

{% block root_widget %}
    <!DOCTYPE {{ doctype|default('html') }}>
    {% if blocks.sidebar is defined and blocks.sidebar.children|length > 0 %}
        {% set attr = attr|merge({'class': 'layout-with-sidebar'}) %}
    {% endif %}
    <html{{ block('block_attributes') }}>
    {{ block_widget(block) }}
    </html>
{% endblock %}

Override Templates

Layout blocks are rendered with Twig blocks. To override the block in Twig, you can define the new block with the same name in another block theme file and load it with setBlockTheme in layout update Yaml file:

  1. First, you need to locate the block that is used for rendering the content you want to override.

  2. Then, find the name for a new block. If the original block name starts with the underscore character (_), than you can use the same block name. Otherwise, the Twig block is used for rendering multiple layout blocks, and you should select the content you want to override.

    • To override all the places where the found template is used, use the same block name as the original one.
    • To override only the single place, use block name for block ID instead.

    You can read the Symfony Profiler Layout Section to find out how to name the corresponding twig blocks naming logic.

  3. Find the folder, where to locate a layout update yaml file.

  4. If no folder found in step 3, create a new block theme Twig file and place a new block with the name you found in step 2 into this folder.

  5. Create a layout update yaml file with the setBlockTheme instruction that will apply block theme Twig file from step 4.