how to automatically create other entities when creating an entity

Question

I have 4 entity types. All types have a relation to each other. For now let's call them A, B, C and D. How can I allow a user (let's say userA) to create an entity of type A so that entities for B, C and D are also created at the same moment. UserA has the permission to create A entity types and is not the author of the automatically created entities of type B, C and D. Is there a way to automatically create these related entities?

Answer 1

If you were looking for a code solution, you can use hook_entity_insert() to trigger the creation of the other entities.

Your custom module code would look something like this:

function mymodule_entity_insert($entity, $type) {
  if ($type == 'typeA') {
    // entity type A is being inserted
    global $user;

    // now create type B
    $entity_b = entity_create('type_b', array(
          'uid' => $user->uid,
          'type' => 'type_b', //bundle
          'field_my_field_c' => array(
            LANGUAGE_NONE => array(
              0 => array(
                'value' => 'foo!',
              ),
            ),
          ),
        ))->save();

    // now create type C
    $entity_c = entity_create('type_c', array(
          'uid' => $user->uid,
          'type' => 'type_c', //bundle
          'field_my_field_c' => array(
            LANGUAGE_NONE => array(
              0 => array(
                'value' => 'foo!',
              ),
            ),
          ),
        ))->save();

    // now create type D, etc...
    }
}

I've borrowed from the code sample posted in the comment from Mołot and for simplicity sake, I made the author of A to be the same as B, C and D.

One more thing, the entity_create() function is in the contrib module Entity API. Your custom module would have a dependency on Entity API.

Answer 2

Create 4 content types or your own entities. Create a field for each of the other three entities on the parent entity using the entity reference module. Use the inline entity form module to allow users to create the other three entities directly in the parent entity. Limit it to just one allowed value. If you are also limiting which entity can be created by role then use the field permission module to show/ hide accordingly.

Answer 3

Okay, I've worked it out with Rules and it works like a charm without the need for additional modules or additional php code.

Here's how to:

Step 1: create 1 generic user (fictitious author) for each content type

Step 2: create an empty (or prefilled) node for each of the 3 content types which need to be referenced and set the author to the generic user specific for that entity

Now in Rules create a new rule which acts on the event of creating a node of content type A and then add the following actions

Step 3: add an action: create a new entity for content type B where you set the title of the new entity with replacement patterns (as you like) and where you set the author to be the generic user of that content type B (use the direct input method: uid = "x") and provide a "created entity" variable label and name

Step 4: add an action: save the entity

Step 5: add an action: set the data value of the reference field on the node of content type A to that "created entity"

Repeat steps 3 to 5 for the content type C and D. You'll end up with 3 new nodes which all have a generic author and are immediately tied to the reference fields in the content of type A.