Render multiple value fields in node template

Regarding Gagarin's answer, here is the code of the Twig filter that I simply put in a custom module.

mymodule/mymodule.services.yml

services:
  mymodule.twig_extension:
    arguments: ['@renderer']
    class: Drupal\mymodule\TwigExtension\Children
    tags:
      - { name: twig.extension }

mymodule/src/TwigExtension/Children.php

namespace Drupal\mymodule\TwigExtension;


class Children extends \Twig_Extension
{

  /**
   * Generates a list of all Twig filters that this extension defines.
   */
  public function getFilters()
  {
    return [
      new \Twig_SimpleFilter('children', array($this, 'children')),
    ];
  }


  /**
   * Gets a unique identifier for this Twig extension.
   */
  public function getName()
  {
    return 'mymodule.twig_extension';
  }


  /**
   * Get the children of a field (FieldItemList)
   */
  public static function Children($variable)
  {
    if (!empty($variable['#items'])
      && $variable['#items']->count() > 0
    ) {
      return $variable['#items']->getIterator();
    }

    return null;
  }

}

in the Twig template (it will result a plain-text output):

  {% for item in content.field_tags|children %}
    {{ item.get('value').getValue() }}
  {% endfor %}

As a front guy I can say, I already needed and still need this! Don't know how much time I already wasted on workarounds...

As a first step it would be nice to add this to https://www.drupal.org/project/twig_extensions or https://www.drupal.org/project/twig_tweak
Allowing people to have access to it as soon is possible is a nice feature.

Yes this would be very useful in core or first in one of these helper modules. We're having that problems with paragraphs... ugly workaround.

We can find the solution to this problem by different types of approaches:

1. I am explaining this an example. Like if we are having an array named testArray from the controller to a twig template and want to print every element.

{% for element in testArray %}
        {{ element.someString }}, 
    {% endfor %} 

    <!--  output: 'test1, test2, test3, ' -->

2.

{{ myArray|join(', ') }}

    <!--  output: 'test1, test2, test3, ' -->

3. Another option to do it by this code

    {% for role in user.roles %}
        {{ role.name }}
        {% if not loop.last %},{% endif %}
    {% endfor %}

Hope this helps you.

The patch attached adds a twig filter based on the code in the twig_extender module.

https://cgit.drupalcode.org/twig_extender/tree/modules/twig_extender_ext...

+++ b/core/lib/Drupal/Core/Template/TwigExtension.php
@@ -110,6 +111,7 @@ public function getFilters() {
+      new \Twig_SimpleFilter('children', [$this, 'children']),

Twig_SimpleFilter is deprecated. We should replace this with TwigFunction.

Update TwigFunction.

I’m sorry, i meant TwigFilter..

Also remove the leading backslash.

Applied patch #27 changes made in TwigExtension.php

Added test coverage.

I was about to point out the redundant is_array check but it looks like it disappeared from #31 which was added while I was typing :D

The Needs Review Queue Bot tested this issue. It either no longer applies to Drupal core, or fails the Drupal core commit checks. Therefore, this issue status is now "Needs work".

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Re-rolled #31

Happy to see there are tests in there.

The issue summary should be updated with what is being added, The "why" is there. Would recommend using default issue template.

If we are adding a new twig function or way to render it will need a change record.

=====

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Wow, this gets the award for the simplest patch I didn't know i needed. Very neat.

Re-roll #37 against 11.2.x