Migrate paragraphs into node with entity_generate

In case anyone comes across this like I did, looking for a way to to use entity_generate with entity_reference_revisions, here's how you can do it just with some process magic. In the example below I have a phone field from a D7 field source (field_contact_phone) and I'm using that to generate a custom multi_field entity which has separate label and phone fields. The important part is the last bit which looks up the revision ID using an entity_value plugin.

  field_phone:
    - plugin: sub_process
      source: field_contact_phone
      process:
        _linklabel: linklabel
        target_id:
          plugin: entity_generate
          source: phonenumber
          entity_type: multi_field
          bundle: labelled_phone
          value_key: field_phone_number
          bundle_key: bundle
          values:
            label: '@_linklabel'
            field_phone_number/0/value: phonenumber
        _revision_id_value:
          plugin: entity_value
          source: '@target_id'
          entity_type: multi_field
          field_name: revision_id
        target_revision_id: '@_revision_id_value/0/value'

Thanks for that @very_random_man. I was doing something more simple with a entity reference field for media, and didn't know that I needed to use target_id as the attribute of the field to assign the generated entity to it, but your code showed me that's what I was missing:

process:
  youtube_1/url: youtube1
  youtube_2/url: youtube2
  youtube_3/url: youtube3
  vimeo_1/url: vimeo

  videos:
    - plugin: get
      source:
        - '@youtube_1'
        - '@youtube_2'
        - '@youtube_3'
        - '@vimeo_1'

  field_videos:
    plugin: sub_process
    source: '@videos'
    process:
      target_id:
        - plugin: skip_on_empty
          source: url
          method: process
        - plugin: entity_generate
          source: url
          entity_type: media
          bundle: remote_video
          bundle_key: bundle
          value_key: field_media_oembed_video
          values:
            field_media_oembed_video: url

@very_random_man - you saved my day!! I were able to migrate paragraphs with your method without any problems ;-)
Thanx so much!!

My paragraph (colorscheme) has 5 input fields:

• id (unique identifiere)
• hex
• type
• color (name)
• menu (to be used within the menu)

  field_colorscheme:
    - plugin: skip_on_empty
      method: process
      source: colorscheme
    -
      plugin: sub_process
      process:
        _menu: menu
        _hex: hex
        _type: type
        _color: color
        target_id:
          plugin: entity_generate
          source: id
          entity_type: paragraph
          bundle: color_set
          value_key: field_remote_id
          bundle_key: type
          values:
            field_remote_id/0/value: id
            field_color_menu/0/value: '@_menu'
            field_color_value/0/color:  '@_hex'
            field_title/0/value:  '@_type'
            field_color_type/0/value:  '@_color'
        _revision_id_value:
          plugin: entity_value
          source: '@target_id'
          entity_type: paragraph
          field_name: revision_id
        target_revision_id: '@_revision_id_value/0/value'

Another handy way of using entity_generate, granted not paragraphs here, but might help someone (or Future-Me)

  _imageLookup:
    plugin: migration_lookup
    migration: migrate_file_managed
    source: field_image/0/fid

  field_media_image:
    plugin: entity_generate
    access_check: false
    entity_type: media
    source: '@_imageLookup'
    value_key: name
    ignore_case: true
    default_values:
      bundle: 'image'
    values:
      name: '@_imageLookup/filename'
      field_media_image: '@_imageLookup'

This creates an entity:image during a node migrate.

Anybody an idea on how to use entity_generate to add NON existing files to media items?
I am in trouble with source and destination ...

The entity_value plugin here was the key for me - thanks @very_random_man!

I have successfully generated paragraphs using entity_generate. However, when I executed migrate:rollback, the nodes were removed, while the paragraphs generated by the migration remained in the database.
Consequently, there is a risk of having numerous orphan paragraphs, which may be related to this issue: https://www.drupal.org/project/paragraphs/issues/3056819 🐛 Remove orphan paragraphs when host entity is removed Closed: duplicate . Please correct me if I'm wrong.

@Bohdan that's correct, things created using entity_generate won't have a migrate_map table created for them, so they won't get rolled back naturally.

You'll have to snapshot/create restore points for your DB while doing these things I found.