Add a new test to check if a block exists

[hason]

Suggested names:

• block name
• block
• defined block

{% if "content" is block name %}
<div>{{ block("content") }}</div>
{% endif %}

[ninsuo]

is block looks fair enough

[fabpot]

I would use is block as well. Can you tell us a bit more about the use case? It is mainly useful for dynamic uses?

[hason]

I want to use it in combination with tag embed:

{# header.html.twig #}
<h{{ level|default(2) }} class="ui{% if 'icon' is block %} icon{% endif %} header">
  {{ block('icon') }}
  {% if 'subheader' is block %}
    <div class="content">
      {{ block('header') }}
      <div class="sub header">{{ block('subheader') }}</div>
    </div>
  {% else %}
    {{ block('header') }}
  {% endif %}
</h{{ level|default(2) }}>

Example of use:

{# index.html.twig #}
{% embed 'header.html.twig' with { level: 3 } %}
    {% block header %}My settings{% endblock %}
    {% block icon %}<i class="settings icon"></i>{% endblock %}
{% endembed %}
{# <h3 class="ui icon header"><i class="settings icon"></i>My setting</h3> #}

{% embed 'header.html.twig' with { level: 4 } %}
    {% block header %}My header{% endblock %}
{% endembed %}
{# <h4 class="ui header">My setting</h4> #}

{% embed 'header.html.twig' with { level: 2 } %}
    {% block header %}My header{% endblock %}
    {% block subheader %}My subheader{% endblock %}
{% endembed %}
{# <h2 class="ui header"><div class="content">My setting<div class="sub header">My subheader</div></div></h2> #}

[fabpot]

ok, can you submit a PR?