Twig: Include block of another template

Question

I would like to include only the contents of certain block of another template. Is it possible to access only the contents of a block and not the whole file?

As far as I can see it, embed and include always include and output the whole file. And use imports all blocks and apparently (?) the destination file needs to be hard-coded and cannot be an expression or a variable passed to the template. Is that correct?

Answer 1

Use a macro https://twig.symfony.com/doc/2.x/tags/macro.html

Render a block template (used by web profiler): https://twig.symfony.com/doc/2.x/functions/block.html

{{ block("title", "common_blocks.twig") }}

Symfony WebProfiler - Interesting usage of blocks and templates

The Symfony WebProfiler it is a great example:

vendor/symfony/symfony/src/Symfony/Bundle/WebProfilerBundle/Resources/views/Collector/request.html.twig

Each profiler view template has 3 blocks:

1. Menu
2. Panel
3. Toolbar

Then it renders each block depending on when it is required.

Toolbar example: vendor/symfony/symfony/src/Symfony/Bundle/WebProfilerBundle/Resources/views/Profiler/toolbar.html.twig

<!-- START of Symfony Web Debug Toolbar -->
<div id="sfMiniToolbar-{{ token }}" class="sf-minitoolbar" data-no-turbolink>
    <a href="#" title="Show Symfony toolbar" tabindex="-1" id="sfToolbarMiniToggler-{{ token }}" accesskey="D">
        {{ include('@WebProfiler/Icon/symfony.svg') }}
    </a>
</div>
<div id="sfToolbarClearer-{{ token }}" class="sf-toolbar-clearer"></div>

<div id="sfToolbarMainContent-{{ token }}" class="sf-toolbarreset clear-fix" data-no-turbolink>
    {% for name, template in templates %}
        {% if block('toolbar', template) is defined %}
            {% with {
                collector: profile.getcollector(name),
                profiler_url: profiler_url,
                token: profile.token,
                name: name,
                profiler_markup_version: profiler_markup_version,
                csp_script_nonce: csp_script_nonce,
                csp_style_nonce: csp_style_nonce
              } %}
                {{ block('toolbar', template) }}
            {% endwith %}
        {% endif %}
    {% endfor %}

    <a class="hide-button" id="sfToolbarHideButton-{{ token }}" title="Close Toolbar" tabindex="-1" accesskey="D">
        {{ include('@WebProfiler/Icon/close.svg') }}
    </a>
</div>
<!-- END of Symfony Web Debug Toolbar -->