OnlyOnce Twig Extension

Twig test which returns true only once per value.

Made to aid in looping through unique values.

    {% for article in articles if article.category is onlyOnce %}
        * {{ article.category }}
    {% endfor %}

Installation

• Install via Composer:

    composer require dpolac/twig-only-once

• Add the extension to Twig:

    $twig->addExtension(new \DPolac\OnlyOnce\OnlyOnceExtension());

---

Usage

Extension provides two tests onlyOnce and onlyOnceWhenOccurs.

###is onlyOnce

    {% if value is onlyOnce %} ... {% endif %}
    {% if value is onlyOnce(space) %} ... {% endif %}

Test returns true only when it's called for the first time with given value and space pair.

Arguments

• value: can be value of any type
  • number - is converted to string, so 12 and '12' are treated as same value,
  • string,
  • object - are compared by reference, so new \stdClass() and new \stdClass() are treated as different value,
  • array - to arrays are treated as same value when have exactly same key-value set; order of keys in hashes is ignored,
• space: can be any string (default: 'default')

###is onlyOnceWhenOccurs

    {% if value is onlyOnceWhenOccurs(n) %} ... {% endif %}
    {% if value is onlyOnceWhenOccurs(n, space) %} ... {% endif %}

Test returns true only when it's called for the n-th time with given value and space pair. Note that onlyOnce is an alias to onlyOnceWhenOccurs(1), so they share internal occurrences' counter.

Arguments

• value: as in onlyOnce,
• n: number of occurrences after which test returns true,
• space: can be any string (default: 'default').

Examples

Check tests in ./Tests/Fixtures/ directory for more examples.