Add a formatter to choose a different formatter per bundle

We have some similar issues in DER as well #2381993: Allow view mode or formatter to be selected per item in the widget and #2729463: List of view_modes is empty in dynamic_entity_reference_entity_view formatter but those are related to view mode.

This looks great and very useful!

1. +++ b/config/schema/field_formatter.schema.yml
   @@ -24,6 +24,20 @@ field.formatter.settings.field_formatter_with_inline_settings:
   +field.formatter.settings.field_formatter__per_bundle:
   +  type: ignore
   +#  type: mapping
   +#  mapping:
   +#    formatter:
   +#      type: sequence
   +#      sequence:
   +#        type: mapping
   +#        mapping:
   +#          type:
   +#            type: string
   +#          settings:
   +#            type: any
   

   Can we have something better for schema?

2. +++ b/src/Plugin/Field/FieldFormatter/FieldFormatterPerBundle.php
   @@ -0,0 +1,347 @@
   +      $build[$delta] = $this->getViewDisplay($entity->bundle())->build($fake_entity);
   

   Would it make sense to use just the first item? I am not sure but I suspect that we might be able to get rid of a div in that case.

3. +++ b/src/Plugin/Field/FieldFormatter/FieldFormatterPerBundle.php
   @@ -0,0 +1,347 @@
   +    $settings[$bundle_id] += [
   +      'settings' => [],
   +    ];
   +    if (isset($settings[$bundle_id])) {
   +      return $settings[$bundle_id];
   +    }
   

   What will happen if !isset($settings[$bundle_id]) and we set this?

   I tried in Psy shell and got segmentation fault back into my face...

4. +++ b/src/Plugin/Field/FieldFormatter/FieldFormatterPerBundle.php
   @@ -0,0 +1,347 @@
   +  protected static function getChangedFieldAndBundle(FormStateInterface $form_state) {
   

   Comment missing for this function.

5. +++ b/src/Plugin/Field/FieldFormatter/FieldFormatterPerBundle.php
   @@ -0,0 +1,347 @@
   +    // Determine on which bundle this change was.
   +    // We look at the #name of the submitted formatter. In case there are better
   +    // ways, please let us know.
   

   Could you use #parents?

   Also use all 80 characters.

6. +++ b/src/Plugin/Field/FieldFormatter/FieldFormatterPerBundle.php
   @@ -0,0 +1,347 @@
   +    $handler_settings = $this->fieldDefinition->getSetting('handler_settings');
   +    if (empty($handler_settings['target_bundles'])) {
   +      return $form;
   +    }
   +
   +    foreach ($handler_settings['target_bundles'] as $bundle) {
   

   Should we use similar approach as in #2813913: Support Entity reference selection configuration without any target bundles?

7. +++ b/src/Plugin/Field/FieldFormatter/FieldFormatterPerBundle.php
   @@ -0,0 +1,347 @@
   +  protected function getSettingFromFormState(FormStateInterface $form_state, $bundle, $setting) {
   

   Missing comment block.

8. +++ b/src/Plugin/Field/FieldFormatter/FieldFormatterPerBundle.php
   @@ -0,0 +1,347 @@
   +    if ($setting == 'settings') {
   +      return [];
   +    }
   

   In which case this happens? Maybe add a comment?

Almost there :).

Well, can't the entity reference contains multiple entities in the first place?

That code hunk is always rendering a single entity. Doesn't this mean that we're adding an additional wrapper for each of them?

So the current solution is okay?

I don't think so. It is current solution that segfaulted on me when testing it.

> 3 years old. This issue now needs a reroll against latest 1.x-dev. Otherwise please close as outdated.

Switched to 3.x!

@dawehner still interested to reroll this?

And could someone please prepare this as MR? Furthermore it needs tests.

@dawehner & @slashrsm still interested to implement this?
If yes, please use a MR.

Ok let's close this outdated then. If anyone needs it, I'd vote to put it into an optional submodule, so we don't blow up complexity for regular cases.