The 'entity_reference_autocomplete' widget doesn't handle multiple values correctly

proper component

So just extend one of existing tests to multple items, it's not clear how to reproduce bug

I can confirm the issue described and the patch provided by likin in comment 3 fixed the issue.

1. +++ b/core/modules/entity_reference/lib/Drupal/entity_reference/Plugin/Field/FieldWidget/AutocompleteWidget.php
   @@ -41,14 +41,15 @@ class AutocompleteWidget extends AutocompleteWidgetBase {
   +    $item = clone $items;
   

   If this clone is really required you should at least explain why

2. +++ b/core/modules/entity_reference/lib/Drupal/entity_reference/Tests/EntityReferenceWidgetTest.php
   @@ -0,0 +1,113 @@
   +      } else {
   

   The codestyle of drupal adds a linebreak here.

3. +++ b/core/modules/entity_reference/lib/Drupal/entity_reference/Tests/EntityReferenceWidgetTest.php
   @@ -0,0 +1,113 @@
   +    // Checks.
   

   It would be maybe helpful to exlain what is checked...

4. +++ b/core/modules/entity_reference/lib/Drupal/entity_reference/Tests/EntityReferenceWidgetTest.php
   @@ -0,0 +1,113 @@
   +class EntityReferenceWidgetTest extends EntityUnitTestBase {
   

   A kind of unit test is certainly great here, but I wonder whether having a webtest would be kind of helpful here, given that this is some actual high level user problem.

Patch at #12 applies to D8 alpha 7, and fixes a problem where only the first field value is loaded when editing a node with a multiple-value entity reference field, and saving the node destroys subsequent field values.

Here's another approach which doesn't mess with the $items object anymore by moving that piece of functionality to a separate helper method.

I also brought in the complete tests from #2160575-27: Option widgets integration is broken for the entity reference field which covers multiple values properly.

+++ b/core/modules/entity_reference/lib/Drupal/entity_reference/Plugin/Field/FieldWidget/AutocompleteTagsWidget.php
@@ -49,6 +49,9 @@ public function elementValidate($element, &$form_state, $form) {
+        elseif (preg_match("/.+\(([\w.]+)\)/", $input, $matches)) {
+          $match = $matches[1];
+        }

Is there a reason why this should be part of this patch?

That's because the new tests expose a bug in the 'tags' widget so I needed to bring in the fix as well to get them to pass.

Mh I wonder whether we could document this new regex, these are just always hard to understand.

Fair enough :)

I manually stopped the testbot since we have a backlog of 150 (!!!) patches and the last patch is just about some new comments (and the one from #17 passed).

Thanks, this should be ready then, nice clean-up and comes with tests :)

Committed/pushed to 8.x, thanks!

Oops, this patch needed a small update after #2164827: Rename the entityInfo() and entityType() methods on EntityInterface and EntityStorageControllerInterface.

Committed by @catch: 60fb1aa.

I don't really understand the logic of
getEntityIds($items, $delta)
getLabels($items, $delta)

- If they're supposed to work on a specific $delta, why would they return an *array* of ids / labels ?
- AutocompleteWidgetBase::getEntityIds($items, $delta) receives a $delta but doesn't use it, instead it iterates on all $items ?
- The override in AutocompleteWidget returns only the id for the specific $delta ?

Related : I would really welcome anyone able to work on #2175343: Pass a FieldItem instead of FieldItemListInterface in WidgetInterface::formElements :-)

That's because entity reference has two different autocomplete widgets, one with a text field per item and one that lists all. This dates back to 7.x code, we just switched to a less crazy override for that use case.

Well, then it seems the two implementations of getEntityIds() are actually different use cases that cannot really live in the same method under the same contract / phpdoc ?

Well, the use case to get entity IDs from the $items array, one widget needs all of them and the other needs just the one matching a delta. I'm not sure why this is so different..