Contrib process plugin: entity_generate

The entity_generate plugin, provided by the contributed Migrate Plus module, is used to match existing entities (by entity type, bundle type, and value_key) and generate entities that don't yet exist.

The most common use is for taxonomy term reference fields.

Taxonomy Terms Example with Documentation

Here's a taxonomy term example using all of the possible configuration parameters (spacing and commenting only for documentation purposes):

process:
  # Field to populate
  field_tags:
    # Plugin to use.
    plugin: entity_generate

    # Field from source configuration.
    source: 'Tag'

    # Name of the value in the entity to use for look-up.
    # Values in this field are compared against values from the 
    # source field specified above for "source".
    value_key: name

    # For entities that support bundles: Name of the key that contains the bundle type.
    bundle_key: vid

    # For entities that support bundles: Machine name of the bundle.
    bundle: tags

    # Type of entity.
    entity_type: taxonomy_term

    # Set to true to ignore case when looking up values through value_key.
    ignore_case: true

    default_values:
      # Default values to apply to newly created entities.
      # This is ignored if the target entity already exists.
      # Each key is a machine name of a field in the target entity, and
      # the value is a constant that is used as a default value for that
      # field. The value specified here is only used if the value is not
      # populated by a value from the source (e.g., via "values" below).
      status: 1

    values:
      # Values to populate in newly created entities based on source fields.
      # This is ignored if the target entity already exists.
      # Each key is a machine name of a field in the target entity, and
      # the value is the name of the source field from which the value is
      # sourced.
      description: 'Tag description'

Example of Generating Multiple Taxonomy Terms

If you have multiple terms in you source, for example "tags": "great;helpful;awesome" you can split them up with the Migrate plugin Explode, where the data is separated before being piped on to entity_generate and get created:

process:
  field_tags:
    - plugin: explode
      source: tags
      delimiter: ';'
    - plugin: entity_generate
      value_key: name
      bundle_key: vid
      bundle: tags
      entity_type: taxonomy_term

A single term import can be done like this:

process:
  field_photo_category:
    plugin: entity_generate
    source: photo_category
    value_key: name
    bundle_key: vid
    bundle: image_category
    entity_type: taxonomy_term

Create terms and insert custom field values at the same time

Vocabulary terms can have extra fields, and it's possible to generate a non-existing term, while at the same time inserting a value into another field. This example shows how to loop over a nested JSON-file, create a non-existing term, and populate a multi-value field.

JSON source:

[{
  "companies": [
  {
    "company_name": "Company INC.",
    "company_link": "https://example.org/"
  },
  {
    "company_name": "ABC Company",
    "company_link": "https://example.com/"
  }],
[...]

Combining sub_process and entity_generate:

process:
  taxonomy_vocabulary_4:
    plugin: sub_process
    source: companies
    process:
      target_id:
        plugin: entity_generate
        source: company_name
        value_key: name
        bundle_key: vid
        bundle: vocabulary_4
        entity_type: taxonomy_term
        values:
          field_link/value: company_link

Example of Generating/Looking Up Nodes by Title

Node generation is similar to taxonomy terms, but the bundle_key for nodes is "type" (for the content type of the node):

process:
  field_related_articles:
    plugin: entity_generate
    source: 'title'
    entity_type: node
    bundle: article
    value_key: title
    bundle_key: type
    default_values:
      title: 'Title missing'
    values:
      title: 'title'

process:
  uid:
    - plugin: skip_on_empty
      method: row
      source: 'Author email'
      message: 'Author email is required but missing.'
    - plugin: entity_generate
      entity_type: user
      value_key: mail
      values:
        name: 'Author email'