Twig - HTML Meta / SEO tags # https://github.com/Wolnosciowiec

Example.html.twig

{% import "SEOTags.html.twig" as SEOTags %}

{% block header_meta %}
    {{
        SEOTags.draw({
            'title':       'Hello World',
            'description': 'Hi, this is a test',
            'keywords':    ['first', 'second', 'third'],
            'image':       'http://.../image.jpg'
        })
    }}
{% endblock %}

SEOTags.html.twig

{#
 # Renders meta tags for every page
 # --------------------------------
 #
 #   A part of an anarchist portal - wolnosciowiec.net
 *
 *   Wolnościowiec is a project to integrate the movement
 *   of people who strive to build a society based on
 *   solidarity, freedom, equality with a respect for
 *   individual and cooperation of each other.
 *
 *   We support human rights, animal rights, feminism,
 *   anti-capitalism (taking over the production by workers),
 *   anti-racism, and internationalism. We negate
 *   the political fight and politicians at all.
 *
 *   http://wolnosciowiec.net/free-software
 *
 *   License: LGPLv3
 *   Author: Wolnościowiec team
 #}

{% macro draw(tags) %}

    {# == Generic tags == #}
    <meta property="twitter:site" content="@wolnosciowiec" />
    <meta property="og:site_name" content="Wolnościowiec" />

    {# == Title == #}
    {% if tags.title is defined %}
        <title>{{ tags.title|striptags }}</title>
        <meta property="og:title" content="{{ tags.title|striptags }}" />
    {% endif %}

    {# == URL == #}
    {% if tags.url is defined %}
        <meta property="og:url" content="{{ tags.url }}" />
        <meta property="twitter:url" content="{{ tags.url }}" />
        <link rel="canonical" href="{{ tags.url }}" />
    {% endif %}

    {# == Description == #}
    {% if tags.description is defined %}
        {% set description = tags.description|striptags|truncate(350, true)|striptags|replace({"\n": " "}) %}
        <meta name="description" content="{{ description }}" />
        <meta property="og:description" content="{{ description }}" />
        <meta property="twitter:description" content="{{ description }}" />
    {% endif %}

    {# == Type == #}
    {% if tags.type is defined %}
        <meta property="og:type" content="{{ tags.type }}" />
    {% endif %}

    {# == Section == #}
    {% if tags.section is defined %}
        <meta property="article:section" content="{{ tags.section }}" />
    {% endif %}

    {# == Published time == #}
    {% if tags.published_time is defined %}
        <meta property="article:published_time" content="{{ tags.published_time.format('Y-m-d\TH:i:sO') }}" />
    {% endif %}

    {# == Image == #}
    {% if tags.image is defined %}
        <meta property="og:image" content="{{ tags.image }}" />
        <meta property="twitter:image" content="{{ tags.image }}" />
    {% endif %}

    {# == Keywords == #}
    {% set keywords = "default_keywords"|trans({}, 'main')|split(',') %}
    {% if tags.keywords is defined %}
        {% set keywords = keywords|merge(tags.keywords) %}
    {% endif %}

    {# Search engines are ignoring keywords, but it may be helpful for some web catalogues? #}
    <meta name="keywords" content="{{ keywords|join(', ')|striptags }}" />

{% endmacro %}