Views cannot be filtered by language of translation

Added link to related issue #2218025: Field language filter/sort/etc. for Views do not work and are not needed (this took me two tries because I forgot the # the first time and I forgot to add a comment the first time too, sorry for the noise).

RE #1 - yes, good idea. That's the db column "default_langcode" in node_field_data, which is TRUE for the row that is the default language translation.

It seems that several other issues need this to be done.

I just discussed it with Gabor in IRC... some thoughts:

(a) I guess people will understand that they are getting each translation of each node when they see what Views gives them, so we probably do not need to clarify this further.

(c) Adding a filter that lets you actually filter the translations by language is needed by many issues and must be done.

We probably do not need (b) in that case, which would make each node filter to its own default language -- probably the main use case is to show Views in one language only, either that or to (as it is now) show all languages. If we do want to add a filter for (b), we can file a new issue to do that.

(d) is just a label change, so might as well do that too, to avoid confusion.

In the absence of anyone else wanting to do this (it's been sitting for 4 months), I'll take it on.

OK, here's a patch.

I confess: I slipped in one unrelated change in there. I was scanning through the list of Content and Content Revision filters and the one remaining use of "node" jumped out at me (the others have all been changed, except NID, which I didn't mess with, and that one was missed). If that is terrible I can take it out of the patch.

Anyway, here's a patch, with tests and everything. The test passes locally. Let's see if this breaks anything else... but it shouldn't, since it's only adding a new filter to Views.

The filter, sorting, field display, and arguments all work fine, as long as you do not try to display fields (see related issues) other than title, language anyway.

As a note, language sorting is by language code, not by displayed language name, but that is not a function of this patch (exists on other language filters already).

Apparently, between when I did a git pull to start working on this, and when I made the patch, FieldConfig became FieldStorage Config... this might fix the broken test, hopefully!

OK, the tests passed this time. Let the reviews begin!

By the way, I'm unlikely to be back to this before Monday. If someone has a review and someone else besides me wants to revise the patch, I will not be offended in any way -- feel free to reassign, I was just trying to move this forward.

We also do need to fix the "related" issues. Views is really broken for multilingual nodes right now...

OK, I've made some small tweaks here, as suggested in #2/#3.

On #1... I think there is a bit of confusion here. Here's what node module's hook_views_data() is adding for this field/filter/sort (in this new patch I'm about to upload):

   $data['node_field_data']['langcode'] = array(
      'title' => t('Translation language'),
      'help' => t('The language of the content or translation.'),
      'field' => array(
        'id' => 'node_language',
      ),
      'filter' => array(
        'id' => 'language',
      ),
      'argument' => array(
        'id' => 'language',
      ),
      'sort' => array(
        'id' => 'standard',
      ),
    );

The 'id' values here are the string IDs of the handler plugin that is being used for the field, filter, or sort. Those IDs do not have to be unique within the data table -- what has to be unique is the field key, which here is "langcode" in $data['node_field_data']['langcode']. Right?

So I think this is OK? Maybe I didn't understand the comment?

Anyway, here's a new patch.

Follow-up on the confusion around 'id' in hook_views_data: #2308505: hook_views_data() does not document the very confusingly named 'id' key

Thanks for the typo nitpick fixes. :)

These are just fake translations for a test. They do not need to be correct French. Gabor: See, that comment was necessary!

Follow-up issue #2320521: Follow-up: Node language views filters need label adjustments needs a review...

Hi mahpari -- this issue was resolved in Drupal 8.0.x, and is now closed. Please open a new issue to resolve your problem.

Hi! I am not currently working on Views or multilingual support in Drupal Core, so hopefully someone else will help resolve it.

Your other issue could receive quicker action if you provided a set of steps that can be taken to reproduce your issue in a minimal way, such as:

1. Install Drupal in English.
2. Turn on the 4 multilingual modules.
3. Add Spanish as a second language.
4. Go to the content translation settings page and make Page content items translatable.
5. Create a Page content item in Spanish. ...