How do I get a field value in another field's template on a paragraph?

Question

I have a Paragraphs bundle that has 2 fields. I want to have the value of the first field in the second field's template so I can combine it with {{ loop.index }} to make unique classes for a grid layout.

Is this possible using a preprocess function and a theme template?

Answer 1

For non-paragraph fields, there is a node object available in the variables of the field template, so you can put this in a field.html.twig file:

{{ element['#object'].machine_name_of_other_field.value }}

Answer 2

Here is a solution that I came up with to solve this in the Paragraph template (paragraph--PARAGRAPH-NAME.html.twig), but I still think there is a better way using a preprocess.

{# Renders Grid Style field. #}
{% if content.field_grid_style|render %}
  {% set grid_style = content.field_grid_style['#items'].getString() %}
{% endif %}

{#
  Loops through the Column field here instead of the field template so we can
  set the grid_style class and add the loop index (key + 1)
#}
{% for key, item in content.field_column_content if key|first != '#' %}
  <div class="{{ grid_style }}--{{ key + 1 }}">{{ item }}</div>
{% endfor %}

Answer 3

Here is the solution for rendering one field inside second's field template.

Get the first field value from hook_preprocess_field.

function teachervision_preprocess_file_field(&$variables) {
  if ($variables['field_name'] == 'second_field_machine_name') {
    $node = \Drupal::routeMatch()->getParameter('node');
    $variables['first_field'] = '';
    if ($node && isset($node->first_field_machine_name->value)) {
      $variables['first_field'] = $node->first_field_machine_name->value;
    }
  }
}

Inside field template of second field, you can get this variable 'first_field' and do something like that

{% for item in items %}
  <div{{ attributes.addClass(classes, 'field__first_item') }}>{{ first_field }}</div>
  <div{{ attributes.addClass(classes, 'field__second_item') }}>{{ item.content }}</div>
{% endfor %}

Hope, it makes sense to you.

Answer 4

Another option that worked for me. Enable view() in twig templates. See this Drupal 8 tutorial:

• Whitelist view in your settings.php file.
• {{ element['#object'].machine_name_of_other_field.view }}

Answer 5

This worked for me within my field.twig where field_column_classes is my custom field name.

{% set paragraph_parent = paragraph.getParentEntity() %}
{% set column_classes = paragraph_parent.field_column_classes.value %}
{{ element['#object'].field_column_classes.value }}

Answer 6

I use this in my .theme file:

function HOOK_preprocess_field(&$variables) {
  if ($variables['element']['#field_name'] === 'field_name_to_add_the_var_to' && $variables['element']['#object']->hasField('field_name_to_get_the_value_from')) {
    $paragraph_value = $variables['element']['#object']->get('field_name_to_get_the_value_from')->value;

    $variables['custom_value'] = $paragraph_value;
  }
}

Then in the template field_name_to_add_the_var_to.twig.html I can use:

{{ custom_value }}