Can hook_field_extra_fields be used with field collections? I have a field collection view that I have to manipulate some data on before it gets displayed, so I was going to use hook_field_extra_fields with the extrafield_views_integration module.  This worked great for me on nodes, but I'm not seeing the extra field get displayed on field collections.  Is there any way to get around this?

function my_module_field_extra_fields() {
  $extra['field_collection']['my_field_collection']['display'] = array(
    'some_extra_field' =&gt; array(
      'label' =&gt; 'TESTING FIELD 123',
      'description' =&gt; 'This is a test of hook_field_extra_fields on FCs',
      'weight' =&gt; 100
    ),
  );

  return $extra;
}
The entity name for a Field Collection is actually field_collection_item and not field_collection (if you run var_dump(entity_get_info()) you'll see this).

This means your implementation should actually look as follows:

/**
 *  Implementation of hook_fields_extra_fields().
 */
function my_module_field_extra_fields() {
  $extra = array();

  $extra['field_collection_item']['my_field_collection']['display'] = array(
    'some_extra_field' =&gt; array(
      'label' =&gt; t('TESTING FIELD 123'),
      'description' =&gt; t('This is a test of hook_field_extra_fields on FCs'),
      'weight' =&gt; 100,
    ),
  );

  return $extra;
}


Also, dont forget your t()'s ;-)