cer.api.php in Corresponding Entity References 7.3

File

cer.api.php

<?php

/**
 * In order to create relationships between reference fields, CER needs to know
 * about what reference fields are available, and how to handle them, which is
 * what this hook is for. It should always return an array, even if there are
 * no fields to expose. The ultimate goal of this hook is to define a flattened
 * hierarchy of all the reference-type fields that CER can use.
 *
 * A reference-type field is any type of field that can refer to an entity.
 * This is pretty broadly defined: for example, CER considers field collections
 * to be reference-type fields, since they refer to entities of the
 * field_collection_item type. Even though the field collection may be displayed
 * as an embedded part of its host entity, at heart it's still just a reference
 * to an entity.
 */
function hook_cer_fields() {
  return array(
    // The keys should refer to a single field instance on a single bundle of a single
    // entity type, even for embedded entities like field collections (see below).
    'node:article:field_related_pages' => array(
      // At the very least, each field you return here needs to have a 'class' set,
      // which is the class of the plugin which will handle this field. A CER field
      // plugin must be a sub-class of CerField, and there must be a separate plugin
      // for each *type* of field you want to integrate (CER provides support for
      // most reference-type fields out of the box, though). The class you provide
      // MUST be registered with the autoloader (i.e., you need to mention it in the
      // files[] array in your module's info file).
      'class' => 'CerEntityReferenceField',
    ),
    // A field collection field is a type of reference field, so you can expose these
    // to CER too. If you want to refer to reference fields on field collections, you
    // must define the parent fields too, as in this example.
    'node:page:field_my_field_collection' => array(
      'class' => 'CerFieldCollectionField',
    ),
    'field_collection_item:field_my_field_collection:field_related_articles' => array(
      'class' => 'CerEntityReferenceField',
      // For fields that are embedded in other entities (the prime example being field
      // collections), the possible parents of the field need to be defined. The array
      // of parents should be an array of keys that are present in the aggregated result
      // of hook_cer_fields(). There could be many possible parents for a single field;
      // each parent represents another possible "route" to this field. If you leave
      // this out, CER will try to automatically detect the parents.
      'parents' => array(
        'node:page:field_my_field_collection',
      ),
      // Embedded fields might *require* a parent. At the time of this writing, this
      // really only applies to field collections. The "require parent" flag means that
      // this field MUST have at least one parent, or CER won't use it. You can probably
      // omit this key, and let CER detect the correct value.
      'require parent' => TRUE,
    ),
  );
}

/**
 * Alter the information gathered by hook_cer_fields().
 */
function hook_cer_fields_alter(array &$fields) {

  // Do clever things here.
}

Functions

Name	Description
hook_cer_fields	In order to create relationships between reference fields, CER needs to know about what reference fields are available, and how to handle them, which is what this hook is for. It should always return an array, even if there are no fields to expose.…
hook_cer_fields_alter	Alter the information gathered by hook_cer_fields().