MacroTwigExtension - Autoloading macro in templates for symfony 2.3+

action.html.twig

{# app/Resources/views/Bundle/Controller/action.html.twig #}

{{ macro_list_ol(['un', 'deux', 'trois']) }}

{% set hash = { 'one': 'un', 'two': 2, 'posts': posts } %}
{{ macro_list_ul(hash) }}

{% macro article(art) %}
    <article>
        <h3>{{ art.title }}</h3>
        <p>{{ art.content }}</p>
        <div class="comments">{{ macro_list_ol(art.comments) }}</div> {# autoloaded from macro #}
    <article>
{% endmacro %}

{% import _self as macro %}
{{ macro.article(post) }} {# needs to be imported as current "_self" is not in autoloaded library #}

list.twig

{# app/Resources/views/_includes/macros/list.twig #}
{% macro ol(array) %}
{% if array is iterable %}
    <ol>
    {% for item in array %}
        <li>
        {% if item is iterable %}
            {% for sub_item in item %}{{ macro_list_ul(sub_item) }}{% endfor %}
        {% else %}{{ item }}{% endif %}
        </li>
    {% endfor %}
    </ol>
{% else %}
    <ol><li>{{ array }}</li></ol>
{% endif %}
{% endmacro %}

{% macro ul(array) %}
{% if array is iterable %}
    <ul>
        {% for key, item in array %}
        <li>{{ key }}:
            {% if item is iterable %}
                {% for sub_item in item %}{{ macro_list_ol(item) }}{% endfor %}
            {% else %}
                {{ item }}
            {% endif %}
        </li>
    {% endfor %}
    </ul>
{% else %}
    <ul><li>{{ array }}</li></ul>
{% endif %}
{% endmacro %}

MacroAutoloadTwigExtension.php

<?php

// src/AppBundle/Twig/MacroTwigExtension.php

namespace AppBundle\Twig;

class MacroAutoloadTwigExtension extends \Twig_Extension
{
    public function getFunctions()
    {
        return array(
            // "*"" is used to get "template_macro" as $macro as third argument
            new \Twig_SimpleFunction('macro_*', array($this, 'twig_render_macro'), array(
                'needs_environment' => true, // $env first argument will render the macro
                'needs_context' => true,     // $context second argument an array of view vars
                'is_safe' => array('html'),  // function returns escaped html
                'is_variadic' => true,       // and takes any number of arguments
            ))
        );
    }

    public function twig_render_macro(\Twig_Environment $env, array $context, $macro, array $vars = array())
    {
        list($name, $func) = explode('_', $macro);

        $notInContext = 0; // helps generate a unique context key

        $varToContextKey = function ($var) use (&$context, $name, $func, &$notInContext) {
            if (false !== $idx = array_search($var, $context, true)) {
                return $idx;
            }

            // else the var does not belong to context
            $key = '_'.$name.'_'.$func.'_'.++$notInContext;
            $context[$key] = $var;

            return $key;
        };

        $args = implode(', ', array_map($varToContextKey, $vars));

        $twig = <<<EOT
{% import '_includes/macros/$name.twig' as $name %}
{{ $name.$func($args) }}
EOT;
        try {
            $html = $env->createTemplate($twig)->render($context);
        } catch (\Twig_Error $e) {
            $e->setTemplateFile(sprintf('_includes/macros/%s.twig', $name));
            
            throw $e;
        }
        
        return $html;
    }

    public function getName()
    {
        return 'macro_autoload_extension';
    }
}

services.yml

# app/config/sevices.yml
services:
    app.macro_autoload_extension:
        class: AppBundle\Twig\MacroAutoloadExtension
        public: false
        tags:
            - { name: twig.extension }