Taxonomy term feed in not showing absolute URL

@wuinfo confirmed that the problem exists in both D8 and D7. Thanks!

Something we definitely need here is an automated test that fails with the bug in HEAD, and passes with the patch applied.

It'd also help to have step-by-step testing instructions and before/after samples of the feed contents (screenshots, whatever). Another thing that's also not clear to me is whether this only affects taxonomy feed items -- can we confirm that the problem does not exist elsehwere? Are there other items in core we should check? Thanks!

Oops, I missed that screenshots are already attached! Embedding them here.

Before

After

@wuinfo, there are definitely gaps in our existing test coverage. However, per our core testing gate, bugfixes need to be accompanied by a test that will prevent the bug from regressing in the future.

Thanks for the screenshot!

Confirmed with @alexpott that a bug fix here would need a test.

I think creating a new formatter is not a good solution. I think we should add absolute option to existing link formatter to show the absolute url.

:/

I thought I had also added the schema changes.

Here is new and simple fix. Updated IS and added BE.

Better title. FWIW I think #19 is much better option then all others.

nice

+++ b/core/modules/taxonomy/src/Plugin/Field/FieldFormatter/LinkFormatter.php
@@ -56,6 +56,10 @@ public function viewElements(FieldItemListInterface $items) {
+        if ($this->viewMode == 'rss') {
+          $elements[$delta]['#url']->setAbsolute();
+        }
+

I don;t think this is the correct fix. There could be other view modes that need absolute urls.

From EntityReferenceTaxonomyTermRssFormatter::viewElements()

  public function viewElements(FieldItemListInterface $items) {
    $parent_entity = $items->getEntity();
    $elements = array();

    foreach ($this->getEntitiesToView($items) as $delta => $entity) {
      $parent_entity->rss_elements[] = array(
        'key' => 'category',
        'value' => $entity->label(),
        'attributes' => array(
          'domain' => $entity->id() ? \Drupal::url('entity.taxonomy_term.canonical', ['taxonomy_term' => $entity->id()], array('absolute' => TRUE)) : '',
        ),
      );
    }

See absolute => true it is fixed in D8 HEAD
Moving back to D7.

The patch in #24 works for us, but it should be modified to match the changes being made in this issue: https://www.drupal.org/node/2128265

I'm including a new patch for review that makes these updates.

FYI, issue #2128265 is postponed, so the patch I created for #31 is no longer valid. Please review patch #24 instead.