Prevent reference self

Yes, that's by design, because there is no general reason to prevent it. Let's make this a feature request.

IMO, it should prevent from self referring. this is error happen when self referring:

EntityMalformedException: Kehilangan sifat berkas pada entiti jenis taxonomy_term. in entity_extract_ids() (line 7633 of /var/www/portal/includes/common.inc).

most probable there is no problem unless if the content has node_access capability. and I'm sure it would replicate the error message when some one using back references module, extending entity references module it self.

IMO it should be an option to "allow" self reference, and keep it disabled by default.

I agree with Amitaibu that 99% of the time it won't be needed.

Hello,

it would be nice to have a sitewide and/or per-widget checkbox setting to allow for self-entityreferenceing, and have that self-referencing prevented by default.

Currently, you can prevent self-references by using a View for the reference field entity selection.

You have to create the View as normal, just add a Contextual filter: Node ID and default value taken from Node URL. In the filter settings, there is an option:

Exclude
If selected, the numbers entered for the filter will be excluded rather than limiting the view.

...coming from #2132215: Validation for not allowing adding an issue relation to itself.

Here is a patch. I've added checkbox "Allow self reference" disabled by default on Views and Generic handlers. It adds condition <> $entity_id if checkbox is unchecked and handler instance has attached entity.

Added simpletest coverage for UI and Generic handler. I would like to add full test coverage for Views handler, but wondering if it's possible without dependencies[] = views for whole module?

Just a minor nitpicks,

1. +++ b/plugins/selection/EntityReference_SelectionHandler_Generic.class.php
   @@ -149,6 +150,13 @@ class EntityReference_SelectionHandler_Generic implements EntityReference_Select
   +    );
   +    ¶
   

   trailing white-space

2. +++ b/plugins/selection/EntityReference_SelectionHandler_Views.class.php
   @@ -9,12 +9,14 @@ class EntityReference_SelectionHandler_Views implements EntityReference_Selectio
   +  protected function __construct($field, $instance, $entity_type = NULL, $entity = NULL) {
   

   it awesome to make this inline with getInstance(), otoh does this breaks other contrib modules?

3. +++ b/plugins/selection/EntityReference_SelectionHandler_Views.class.php
   @@ -76,6 +86,11 @@ class EntityReference_SelectionHandler_Views implements EntityReference_Selectio
   +    $allow_self_reference = $this->field['settings']['handler_settings']['allow_self_reference'];
   ...
   +    if (!$allow_self_reference && isset($this->entity)) {
   

   suppose better
   if (isset($this->entity) && empty($this->field[....])

   because setting could not exist in fields that saved before this version

4. +++ b/tests/entityreference.admin.test
   @@ -73,8 +77,10 @@ class EntityReferenceAdminTestCase extends DrupalWebTestCase {
   +    $this->assertNoFieldChecked('edit-field-settings-handler-settings-allow-self-reference');
   

   check for default value! ++

5. +++ b/tests/entityreference.handlers.test
   @@ -594,4 +599,175 @@ class EntityReferenceHandlersTestCase extends DrupalWebTestCase {
   +      'node_1' => (object) array(
   +          'type' => 'article',
   +          'status' => 1,
   +          'title' => 'First node',
   +          'uid' => 1,
   ...
   +      'node_2' => (object) array(
   +          'type' => 'article',
   +          'status' => 1,
   +          'title' => 'Second node',
   +          'uid' => 1,
   

   wrong indent

1. +++ b/plugins/selection/EntityReference_SelectionHandler_Generic.class.php
   @@ -269,6 +277,12 @@ class EntityReference_SelectionHandler_Generic implements EntityReference_Select
   +    // Exclude self reference
   

   missing dot at the end

2. +++ b/plugins/selection/EntityReference_SelectionHandler_Views.class.php
   @@ -68,6 +70,14 @@ class EntityReference_SelectionHandler_Views implements EntityReference_Selectio
   +      '#title' => t('Allow to choose self reference.'),
   +      '#description' => t('If checked you will be able to set reference to self entity. Disabled by default'),
   

   titles mostly have no dots at the end, use dot for descriptions, please

Here is new patch with interdiff for #9

Great!

Thanks everyone!

I think the default value should be TRUE here (and it should be a boolean, not an int):

+      'allow_self_reference' => 0,

The way the current patch is built is also going to change the behavior for existing fields, which is not acceptable.

and it should be a boolean, not an int

The standard in core is that field settings exposed as checkboxes use int default, since checkboxes save a '0' or '1' value, and not booleans. See text_field_info() and the 'text_processing' setting for an example.

Switch default value

Small test correction

+++ b/plugins/selection/EntityReference_SelectionHandler_Views.class.php
@@ -75,7 +75,8 @@ class EntityReference_SelectionHandler_Views implements EntityReference_Selectio
-      '#default_value' => empty($field['settings']['handler_settings']['allow_self_reference']) ? 0 : 1,
+      '#default_value' => empty($field['settings']['handler_settings']['allow_self_reference'])
+        ? 1 : $field['settings']['handler_settings']['allow_self_reference'],

makes no sense!

should be if !empty then no need to change test!

Yeh, my bad.
But we still should change test to make him expects Allowed self reference by default.

I found this functionality is useful/musthave when CER is configured.

For those who applied non-commited patch #2010898: Use tokens for entity selection view arguments may get error while patching EntityReference_SelectionHandler_Views.class.php file. So applying patch manually is must until that patch/this get committed.
Observations:

1. This patch only works at form level and doesn't prevent referencing self when value is submitted manually.
2. Either checkbox should be off or change the
   

   If checked you will be able to set reference to self entity. Disabled by default

   to
   

   If checked you will be able to set reference to self entity. Enabled by default.

3. following notice is showing on node create/edit pages when entity views selection is used.
   

   Notice: Undefined index: allow_self_reference in EntityReference_SelectionHandler_Views->initializeView() (line 111 of /public/sites/all/modules/entityreference/plugins/selection/EntityReference_SelectionHandler_Views.class.php).

What more needs to happen for this feature to be committed?

I had a bug with #24 where when creating a new content, the entity reference list was empty. However it worked fine when editing an existing node.

I solved that by editing EntityReference_SelectionHandler_Generic.class.php (line 280) :

$entity_id was empty ($this->entity was the current user, for some reason), so I added a check on $entity_id.

from :

    // Exclude self reference.
    if (empty($this->field['settings']['handler_settings']['allow_self_reference']) && isset($this->entity)) {
      list($entity_id,,) = entity_extract_ids($this->entity_type, $this->entity);
      $query->entityCondition('entity_id', $entity_id, '<>');
    }

to :

    // Exclude self reference.
    if (empty($this->field['settings']['handler_settings']['allow_self_reference']) && isset($this->entity)) {
      list($entity_id, ,) = entity_extract_ids($this->entity_type, $this->entity);

      if (!empty($entity_id)) {
        $query->entityCondition('entity_id', $entity_id, '<>');
      }
    }

I'm sorry I don't have enough time right now to issue a patch but if anyone experiences the same bug, that's how I fixed it.

I've taken @m1r1k patch at #24 and applied it to the latest 7.x-1.x-dev (2017-May-16). Added @bernig's suggestion to catch empty entity ID for new entities to be created.

I hope this helps.

Adding a new patch that fixes the Test fails.

Thanks! Tests passed. This needs review. Sadly, I don't have bandwidth to do it now. Hopefully someone will have a chance.

Meanwhile, does anyone know if this issue affects the version of entity_reference in D8 core? I searched the core issue queue and didn't find anything relevant. If there's an open issue, it'd be great to link it as a related or even the parent issue for this. And/or confirming if D8 already handles this or not. If not, we should open a separate issue in the core queue and cross link it here instead of moving this issue between projects as it moves through the porting/backporting hoops.

Thanks,
-Derek

Unassigned m1r1k

1. +++ b/plugins/selection/EntityReference_SelectionHandler_Generic.class.php
   @@ -149,6 +150,13 @@ class EntityReference_SelectionHandler_Generic implements EntityReference_Select
   +    $form['allow_self_reference'] = array(
   

   tested - works as designed

2. +++ b/plugins/selection/EntityReference_SelectionHandler_Generic.class.php
   @@ -273,6 +281,15 @@ class EntityReference_SelectionHandler_Generic implements EntityReference_Select
   +    // Exclude self reference.
   

   tested - works as designed

3. +++ b/plugins/selection/EntityReference_SelectionHandler_Views.class.php
   @@ -88,6 +88,15 @@ class EntityReference_SelectionHandler_Views implements EntityReference_Selectio
   +    $form['allow_self_reference'] = array(
   

   tested - this is the form that appears when you select "Views: Filter by an entity reference view" in the entity reference field's "Entity selection" section. Works as designed

4. +++ b/plugins/selection/EntityReference_SelectionHandler_Views.class.php
   @@ -96,6 +105,11 @@ class EntityReference_SelectionHandler_Views implements EntityReference_Selectio
   +    $entity_id_to_exclude = FALSE;
   

   tested - works as designed

Results of running simpletests is attached. All green.

above patch rerolled.

Oops, this is much closer to patch 31

ok there's a core bug that is exposed by this patch.

I'm going to hold off merging this until the core bug is resolved.

There is a patch available for core.

Core patch fixes issue when using PHP 7.4, 8.0, 8.1, 8.2
#3314719-5: Notice: Trying to access array offset on value of type null in _field_write_instance()

postponed on related core bug affecting PHP 7.4, 8.0, 8.1, 8.2+