EntityFieldQuery with Workflow

Question

I need to filter an EntityFieldQuery with a given workflow state, let's say workflow it is state 21 (sid = 21). Below, the query I am using

$query_formularios_completos = new EntityFieldQuery();
  $query_formularios_completos
    ->entityCondition('entity_type', 'node')
    ->propertyCondition('type', array(
        'evento_agencia',
        'evento_energia'
      )
    )
    ->propertyCondition('workflow', 21)
    ->fieldCondition('field_e_expositor', 'target_id', $node_expositor_nid);
  $result_formularios_completos = $query_formularios_completos->execute();

When using DEVEL to inspect my node, I can see there is a property ->workflow, side by side with ordinary properties like ->title or ->created. Although I can see it there and I expected to filter only items with workflow state 21, I get a horrid database error when trying to execute the code above. Here is more or less the message I get:

Column not found: 1054 Column 'node.workflow' unknown in 'where clause'

Any ideas on how I should filter an entity query using a workflow state as filter? Maybe what I am trying to do isn'tpossible and I have to actually run a query using db_query and applying the appropriate joins.

Answer 1

As described in EntityFieldQuery::propertyCondition(), you can use that method for every database field defined in the hook_schema() implementation for the base database table used from the entity.

$column: A column defined in the hook_schema() of the base table of the entity.

The code that effectively handle that is in EntityFieldQuery::propertyQuery() which contains the following code.

  $entity_type = $this->entityConditions['entity_type']['value'];
  $entity_info = entity_get_info($entity_type);
  if (empty($entity_info['base table'])) {
    throw new EntityFieldQueryException(t('Entity %entity has no base table.', array('%entity' => $entity_type)));
  }
  $base_table = $entity_info['base table'];
  $base_table_schema = drupal_get_schema($base_table);
  $select_query = db_select($base_table);
  $select_query->addExpression(':entity_type', 'entity_type', array(':entity_type' => $entity_type));
  // Process the property conditions.
  foreach ($this->propertyConditions as $property_condition) {
    $this->addCondition($select_query, $base_table . '.' . $property_condition['column'], $property_condition);
  }

You could implement hook_entity_query_alter(), which is invoked before EntityFieldQuery::propertyQuery() is called, and which (by default) it's the EntityFieldQuery::executeCallback callback, the same callback hook_entity_query_alter() is suggested to change. Using your own callback, you could make a join with the tables the Workflow module is using.