21.05.2026 | Lothar Ferreira Neumann

Aggregate heterogeneous media fields for structured Drupal migration

migration_field_merge.yml

  field_media:
    - plugin: merge
      source:
        - field_image
        - field_images
    - plugin: sub_process
      process:
        target_id:
          - plugin: migration_lookup
            source: fid
            migration:
              - my_migration_media_image

Issue:

You want to combine multiple image fields from a legacy system into a single media field in a new Drupal system during migration.

Solution:

The code uses the migration API of Drupal to merge multiple source image fields into a single media field. It employs the merge plugin to combine the fields and a sub-process to transform the references into media entities using a migration lookup.

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16.07.2026 | Lothar Ferreira Neumann

How to translate the Maxlength Countdown message label globally

A Drupal backend screenshot showing the "Count down message" field

Leave this field empty to allow for translation via Drupal interface translation.

Example configuration created by enabling Maxlength:

core.entity_form_display.node.article_not_translatable.default.yml

# ...
content:
  field_copyright:
    type: text_textarea
    weight: 3
    region: content
    settings:
      rows: 2
      placeholder: ''
    third_party_settings:
      allowed_formats:
        hide_help: '1'
        hide_guidelines: '1'
      maxlength:
        maxlength_js: null
        maxlength_js_label: 'Content limited to @limit characters, remaining: <strong>@remaining</strong>'
        maxlength_js_enforce: false
# ...

However, the module already contains fallback logic for this label in maxlength.module:

maxlength.module

$maxlength_js_label = !empty($thirdPartySettings['maxlength']['maxlength_js_label']) ? $thirdPartySettings['maxlength']['maxlength_js_label'] : t('Content limited to @limit characters, remaining: <strong>@remaining</strong>');
$maxlength_js = $thirdPartySettings['maxlength']['maxlength_js'];

Working configuration: empty the label

core.entity_form_display.node.article_translatable.default.yml

# ...
content:
  field_copyright:
    type: text_textarea
    weight: 3
    region: content
    settings:
      rows: 2
      placeholder: ''
    third_party_settings:
      allowed_formats:
        hide_help: '1'
        hide_guidelines: '1'
      maxlength:
        maxlength_js: null
        maxlength_js_label: ''
        maxlength_js_enforce: false
# ...

With the label empty, the module falls back to its internal t() string, which can then be translated normally via the interface translation system.

yml

module

maxlength

translation

15.01.2026 | Lothar Ferreira Neumann

How to migrate latitude & longitude geodata into a unified geocode field

geofield_migration.yml

field_geofield:
  plugin: geofield_latlon
  source:
    - field_latitude
    - field_longitude

yml

geodata

Migration