title: Twig block calling with parameters
body: <p>I am kinda new to Symfony and Twig. I am trying to override default Twig form template in vendor\symfony\symfony\src\Symfony\Bridge\Twig\Resources\views\Form\form_div_layout.html.twig (Symfony 3.2.6)</p>
  
  <p>As far as I know, block can be defined and then used in other part of template</p>
  
  <pre><code>{% block fooBlock %}
  // the block body
  {% endblock %}
  </code></pre>
  
  <p>When parameters are to be passed into, a macro should be rather used</p>
  
  <pre><code>{% macro barMarco(param1, param2, param3) %}
  // macro body using param1, param2, param3 etc,
  {% endmacro %}
  </code></pre>
  
  <p>In mentioned above file i found something like. this 
  The definition of block:</p>
  
  <pre><code>{%- block form_errors -%}
      {%- if errors|length &gt; 0 -%}
      &lt;ul&gt;
          {%- for error in errors -%}
              &lt;li&gt;{{ error.message }}&lt;/li&gt;
          {%- endfor -%}
      &lt;/ul&gt;
      {%- endif -%}
  {%- endblock form_errors -%}
  </code></pre>
  
  <p>And usage:</p>
  
  <pre><code>{%- block form_row -%}
      &lt;div&gt;
          {{- form_label(form) -}}
          {{- form_errors(form) -}}
          {{- form_widget(form) -}}
      &lt;/div&gt;
  {%- endblock form_row -%}
  </code></pre>
  
  <p>And here's the question: why this block it called with param <code>(form)</code>. I thought a macro should be invoked like this?</p>