#680910 by yched and bjaspan: Allow fields to be restricted to entity types.

6 files changed, 59 insertions, 3 deletions

diff --git a/modules/comment/comment.install b/modules/comment/comment.install
index 501252eb0..6865c6b6b 100644
--- a/modules/comment/comment.install
+++ b/modules/comment/comment.install
@@ -55,6 +55,7 @@ function comment_enable() {
     $field = array(
       'field_name' => 'comment_body',
       'type' => 'text_long',
+      'object_types' => array('comment'),
     );
     field_create_field($field);
   }
@@ -254,6 +255,7 @@ function comment_update_7012() {
   $field = array(
     'field_name' => 'comment_body',
     'type' => 'text_long',
+    'object_types' => array('comment'),
   );
   field_create_field($field);
 
diff --git a/modules/field/field.crud.inc b/modules/field/field.crud.inc
index 7b502943f..e8a48008b 100644
--- a/modules/field/field.crud.inc
+++ b/modules/field/field.crud.inc
@@ -45,6 +45,9 @@
  * - type (string)
  *     The type of the field, such as 'text' or 'image'. Field types
  *     are defined by modules that implement hook_field_info().
+ * - object_types (array)
+ *     The array of entity types that can hold instances of this field. If
+ *     empty or not specified, the field can have instances in any entity type.
  * - cardinality (integer)
  *     The number of values the field can hold. Legal values are any
  *     positive integer or FIELD_CARDINALITY_UNLIMITED.
@@ -265,6 +268,7 @@ function field_create_field($field) {
   }
 
   $field += array(
+    'object_types' => array(),
     'cardinality' => 1,
     'translatable' => FALSE,
     'locked' => FALSE,
@@ -396,6 +400,9 @@ function field_update_field($field) {
   if ($field['type'] != $prior_field['type']) {
     throw new FieldException("Cannot change an existing field's type.");
   }
+  if ($field['object_types'] != $prior_field['object_types']) {
+    throw new FieldException("Cannot change an existing field's object_types property.");
+  }
   if ($field['storage']['type'] != $prior_field['storage']['type']) {
     throw new FieldException("Cannot change an existing field's storage type.");
   }
@@ -611,6 +618,10 @@ function field_create_instance($instance) {
   if (empty($instance['bundle'])) {
     throw new FieldException(t('Attempt to create an instance of field @field_name without a bundle.', array('@field_name' => $instance['field_name'])));
   }
+  // Check that the field can be attached to this object type.
+  if (!empty($field['object_types']) && !in_array($instance['object_type'], $field['object_types'])) {
+    throw new FieldException(t('Attempt to create an instance of field @field_name on forbidden object type @obj_type.', array('@field_name' => $instance['field_name'], '@obj_type' => $instance['object_type'])));
+  }
 
   // Set the field id.
   $instance['field_id'] = $field['id'];
diff --git a/modules/field/tests/field.test b/modules/field/tests/field.test
index 3052af9ad..94c94afd7 100644
--- a/modules/field/tests/field.test
+++ b/modules/field/tests/field.test
@@ -2297,7 +2297,6 @@ class FieldInstanceCrudTestCase extends FieldTestCase {
     $this->instance_definition = array(
       'field_name' => $this->field['field_name'],
       'object_type' => 'test_entity',
-      'object_type' => 'test_entity',
       'bundle' => 'test_bundle',
     );
   }
@@ -2355,6 +2354,39 @@ class FieldInstanceCrudTestCase extends FieldTestCase {
       $this->pass(t('Cannot create an instance of a non-existing field.'));
     }
 
+    // Create a field restricted to a specific entity type.
+    $field_restricted = array(
+      'field_name' => drupal_strtolower($this->randomName()),
+      'type' => 'test_field',
+      'object_types' => array('test_cacheable_entity'),
+    );
+    field_create_field($field_restricted);
+
+    // Check that an instance can be added to an object type allowed
+    // by the field.
+    try {
+      $instance = $this->instance_definition;
+      $instance['field_name'] = $field_restricted['field_name'];
+      $instance['object_type'] = 'test_cacheable_entity';
+      field_create_instance($instance);
+      $this->pass(t('Can create an instance on a object type allowed by the field.'));
+    }
+    catch (FieldException $e) {
+      $this->fail(t('Can create an instance on a object type allowed by the field.'));
+    }
+
+    // Check that an instance cannot be added to an object type
+    // forbidden by the field. 
+    try {
+      $instance = $this->instance_definition;
+      $instance['field_name'] = $field_restricted['field_name'];
+      field_create_instance($instance);
+      $this->fail(t('Cannot create an instance on a object type forbidden by the field.'));
+    }
+    catch (FieldException $e) {
+      $this->pass(t('Cannot create an instance on a object type forbidden by the field.'));
+    }
+
     // TODO: test other failures.
   }
 
diff --git a/modules/field_ui/field_ui.admin.inc b/modules/field_ui/field_ui.admin.inc
index eb94ed6c7..4104e04cf 100644
--- a/modules/field_ui/field_ui.admin.inc
+++ b/modules/field_ui/field_ui.admin.inc
@@ -787,8 +787,13 @@ function field_ui_existing_field_options($obj_type, $bundle) {
       if (!($existing_bundle == $bundle && $existing_obj_type == $obj_type)) {
         foreach ($instances as $instance) {
           $field = field_info_field($instance['field_name']);
-          // Don't show locked fields or fields already in the current bundle.
-          if (empty($field['locked']) && !field_info_instance($obj_type, $field['field_name'], $bundle)) {
+          // Don't show
+          // - locked fields,
+          // - fields already in the current bundle,
+          // - field that cannot be added to the object type.
+          if (empty($field['locked'])
+            && !field_info_instance($obj_type, $field['field_name'], $bundle)
+            && (empty($field['object_types']) || in_array($obj_type, $field['object_types']))) {
             $text = t('@type: @field (@label)', array(
               '@type' => $field_types[$field['type']]['label'],
               '@label' => t($instance['label']), '@field' => $instance['field_name'],
diff --git a/modules/field_ui/field_ui.test b/modules/field_ui/field_ui.test
index f14ed11c0..e3f030782 100644
--- a/modules/field_ui/field_ui.test
+++ b/modules/field_ui/field_ui.test
@@ -146,6 +146,11 @@ class FieldUITestCase extends DrupalWebTestCase {
     $this->drupalGet(('admin/structure/types/manage/page/fields'));
     $this->assertRaw(t('Add existing field'), t('"Add existing field" was found.'));
 
+    // Check that the list of options respects object type restrictions on
+    // fields. The 'comment' field is restricted to the 'comment' object type
+    // and should not appear in the list.
+    $this->assertFalse($this->xpath('//select[@id="edit--add-existing-field-field-name"]//option[@value="comment"]'), t('The list of options respects object type restrictions.'));
+
     // Add a new field based on an existing field.
     $edit = array(
       '_add_existing_field[label]' => $this->field_label . '_2',
diff --git a/modules/node/node.module b/modules/node/node.module
index 58a264749..d54f75e0a 100644
--- a/modules/node/node.module
+++ b/modules/node/node.module
@@ -576,6 +576,7 @@ function node_configure_fields($type) {
       $field = array(
         'field_name' => 'body',
         'type' => 'text_with_summary',
+        'object_types' => array('node'),
         'translatable' => TRUE,
       );
       $field = field_create_field($field);