Provide a custom diff plugin

The plugin for diff module since there is no field type for paragraphs the plugin is based on the field type entity_reference_revisions.
Created the issue #2459237: Services for diff plugin for adding the services for the plugin

Adding screens.

+++ b/src/Plugin/diff/EntityReferenceRevisionsFIeldBuilder.php
@@ -0,0 +1,49 @@
+              //$result_text[$id] = 'Field id :' . $field_id . '. Entity id: ' . $id . '. Text:' . $text[0];

Removed this line.

Now that the entity parser service is injected in the base plugin class we should definitely use it :)

The entity parser service used from the injected config.
Needs test coverage for this.

Added the tests.

Separated the test and added a field for text only.

+++ b/src/Tests/ParagraphsAdministrationTest.php
@@ -186,6 +189,109 @@ class ParagraphsAdministrationTest extends WebTestBase {
+
+  public function testParagraphsDiff() {
+
+    $this->drupalGet('admin/structure/paragraphs_type');

It should be a separate test *class*, not just method. With a @dependencies diff annotation.

It also needs a test_dependencies entry in the info file for the diff module. Please upload that as a separate patch, as that needs to be committed first, then we need to wait for testbot dependencies to rebuild, then it should work.

Separated the test into a new class and added the @dependencies.

@miro_dietiker, seems like the dependency is working now?

[1] => Array
                        (
                            [repository] => Array
                                (
                                    [type] => git
                                    [url] => git://git.drupal.org/project/diff.git
                                )

                            [vcs_identifier] => 8.x-1.x
                        )

Locally the tests pass, and the revisions are correctly shown. Only one slight issue which might not be related to paragraphs: Under the revisions tab the operations look rather strange, some radio buttons are there which mess up the whole formatting, plus some empty padding between the two operations columns. I don't know where the revisions page is built. A screenshot of the weird formatting on /node/{ID}/revisions.

Rebased the patch #23.

What are you doing, testbot?

Reproduced the issue on simplytest.me:

Probably a missing dependency. Here is a patch to try out.

Thanks to miro_dietiker we found the cause for the test fails: Missing capitalisation of one folder name (diff -> DIff). Now the plugin should be found on the linux test bot as well.

1. index 0000000..d17778a
   --- /dev/null
   
   --- /dev/null
   +++ b/src/Plugin/Diff/EntityReferenceRevisionsFIeldBuilder.php
   
   +++ b/src/Plugin/Diff/EntityReferenceRevisionsFIeldBuilder.php
   @@ -0,0 +1,47 @@
   
   @@ -0,0 +1,47 @@
   +<?php
   +
   +/**
   + * @file
   + * Contains \Drupal\paragraphs\Plugin\Diff\EntityReferenceRevisionsFieldBuilder
   

   There's still a case mismatch here (FIeld)

2. +++ b/src/Plugin/Diff/EntityReferenceRevisionsFIeldBuilder.php
   @@ -0,0 +1,47 @@
   +    // Every item from $field_items is of type FieldItemInterface.
   +    foreach ($field_items as $field_key => $field_item) {
   

   The use @var to document that, so that phpstorm actually understands it :)

3. +++ b/src/Plugin/Diff/EntityReferenceRevisionsFIeldBuilder.php
   @@ -0,0 +1,47 @@
   +        $parsed_text = $this->entityParser->parseEntity($field_item->entity);
   +        if (is_array($parsed_text)) {
   +          foreach ($parsed_text as $field_id => $field) {
   +            foreach ($field as $id => $text) {
   +              $result_text[$item_counter + $id] = $text[0];
   +            }
   +            $item_counter = $id + 1;
   

   The problem is that this is kind of paragraph specific or to be more specific, inline entity specific. So we should name the class and plugin in a way that makes that clear.. something like "Entity Reference Revisions Inline Diff" or so.

   Or maybe we should actually just name it Paragraphs Diff or something since it's in this module, otherwise we'd need to move it to that?

4. +++ b/src/Tests/ParagraphsAdministrationTest.php
   @@ -33,6 +33,8 @@ class ParagraphsAdministrationTest extends WebTestBase {
        'block',
   +    'diff',
   +    'diff_test',
      );
   

   Those shouldn't be needed anymore.

5. +++ b/src/Tests/ParagraphsAdministrationTest.php
   @@ -129,29 +132,27 @@ class ParagraphsAdministrationTest extends WebTestBase {
      public function testParagraphsCreation() {
        $admin_user = $this->drupalCreateUser(array(
   -      'administer site configuration',
   -      'administer nodes',
   -      'create article content',
   -      'create paragraphs content',
   -      'administer content types',
   -      'administer node fields',
   -      'administer node display',
   -      'administer paragraphs types',
   -      'administer paragraph fields',
   -      'administer paragraph display',
   -      'administer paragraph form display',
   -      'administer node form display',
   -      'edit any article content',
   -      'delete any article content'
   -    ));
   +        'administer site configuration',
   +        'administer nodes',
   +        'create article content',
   

   Unrelated change, let's remove all changes in this file.

6. +++ b/src/Tests/ParagraphsDiffTest.php
   @@ -0,0 +1,175 @@
   +class ParagraphsDiffTest extends WebTestBase {
   

   Would it make sense to use the demo module for the test, and automatically configure it in there? The demo module would then create a paragraph node with revisions and the test could be very, very simple.

It does much more, but it does so through the API. I'd expect that actually isn't much slower than the current test which has a lot of UI interaction.

Here is an updated version which uses the paragraphs_demo module. The other feedback should be implemented as well (file renaming, adding comment for @var, removing unrelated changes).

The demo is committed now, here is a rebased version of the patch.

I'll set it on postponed for now, waiting for #2540556: Translated paragraphs is not displayed in the correct translation to be fixed before I expand the tests.

I can also open a follow up to expand the tests to cover translated paragraphs diffs in case someone wants to commit this patch.

Unblocked because #2540556: Translated paragraphs is not displayed in the correct translation is fixed, so...

This patch does not work for me. When applied, the diff is empty. See attachment.

Hmm, I should probably configure it on admin/config/content/diff/fields first :) But that form currently doesn't save for me...

Yep, diff needs a patch first. I can't change any options (with a blank install of d8 and diff). I created an issue #2601180: Field settings are not changed on saving and postpone this one (again... :D).

#2612158: Field type form doesn't save settings / #2601180: Field settings are not changed on saving are fixed, can we continue on this?

Rebased, did some cleanup and fixed a failing test.
I reviewed the work and the tests and seems enough covered for now.

Ups, I deleted to much.
Now should be fine.

Shouldn't have too many changes.

Added a working version for testing, tested manually but still need to write tests.

Screenshot about a manual test.

Added tests. :)

Sorry it seems we need to add the test dependencies. Also improved the code a bit, fixed comments.

This should go first right? :)

And the patch without the dependency.

Followup will be covered here; #2708601: Allow per-field diff configuration