Migrating Media

Media is a wonderful tool and it is now quite mature and part of Drupal core. It allows easier handling of all media types (file attachments, videos, images etc). Migrations can also import files into the media library easily. The only thing is that you need to execute two separate migrations.

Example: migrating first to files and then to media

• First we migrate the files to Drupal (as managed files) using the entity:file destination plugin.
• Then a second migration is executed, with the same source data, this time to create media entities with the entity:media destination plugin.
• The second migration does a migration_lookup to the first one.
• The UID in the second migration will do nothing in this example, but it is there to demonstrate how you can assign the media entities to a user.

This example works the same for files or other media types as long as you change the migration names accordingly (don't forget the two look ups) and the media bundle to suit your needs, from default_bundle: image to default_bundle: file for example.

images_example.yml

id: images_example
migration_tags:
  - images
label: 'Import images (as files)'
source:
  plugin: embedded_data
  data_rows:
    -
      id: 1
      image: 'https://upload.wikimedia.org/wikipedia/en/a/a9/Example.jpg'
    -
      id: 2
      image: 'https://upload.wikimedia.org/wikipedia/commons/a/a3/Patras_from_the_fortress.jpg'
  ids:
    id:
      type: integer
  constants:
    DRUPAL_FILE_DIRECTORY: 'public://images/'
process:
  pseudo_destination_filename:
    -
      plugin: callback
      callable: basename
      source: image
    -
      plugin: skip_on_empty
      method: row
      message: 'Cannot import empty image filename.'
  pseudo_destination_path:
    -
      plugin: concat
      source:
        - constants/DRUPAL_FILE_DIRECTORY
        - '@pseudo_destination_filename'
  uri:
    -
      plugin: skip_on_empty
      method: process
      source: image
    -
      plugin: file_copy
      source:
        - image
        - '@pseudo_destination_path'
      file_exists: rename
      move: false
destination:
  plugin: 'entity:file'
migration_dependencies: null

images_to_media_example.yml

id: images_to_media_example
migration_tags:
  - images
label: 'Migrate images to media'
source:
  plugin: embedded_data
  data_rows:
    -
      id: 1
      image: 'https://upload.wikimedia.org/wikipedia/en/a/a9/Example.jpg'
    -
      id: 2
      image: 'https://upload.wikimedia.org/wikipedia/commons/a/a3/Patras_from_the_fortress.jpg'
  ids:
    id:
      type: integer
process:
  pseudo_destination_filename:
    -
      plugin: callback
      callable: basename
      source: image
    -
      plugin: skip_on_empty
      method: row
      message: 'Cannot import empty filename.'
  pseudo_destination_path:
    -
      plugin: concat
      source:
        - '@pseudo_destination_filename'
  name: '@pseudo_destination_filename'
  field_media_image/target_id:
    plugin: migration_lookup
    migration: images_example
    source: id
  thumbnail/target_id:
    plugin: migration_lookup
    migration: images_example
    source: id
  uid:
    -
      plugin: skip_on_empty
      method: process
      message: 'No user for this file.'
    -
      plugin: migration_lookup
      migration: users
      source: author
destination:
  plugin: 'entity:media'
  default_bundle: image
migration_dependencies:
  required:
    - images_example

Execute with Drush

To execute these migrations with Drush, save them into one of two places in your module (mymodule).

mymodule/config/install/migrate_plus.migration.images_example.yml
mymodule/config/install/migrate_plus.migration.images_to_media_example.yml

or

mymodule/migrations/images_example.yml
mymodule/migrations/images_to_media_example.yml

Migrate Tools, with dependencies, must be enabled. When you enable mymodule, the migration configuration entities will be installed, and you can run them with drush migrate:import images_example,images_to_media_example (no space after the comma).