Allow multiple instances of the same exposed filter form on a single page

+++ b/core/modules/views/src/Form/ViewsExposedForm.php
@@ -115,7 +115,7 @@ public function buildForm(array $form, FormStateInterface $form_state) {
-    $form['#id'] = Html::cleanCssIdentifier('views_exposed_form-' . $view->storage->id() . '-' . $display['id']);
+    $form['#id'] = Html::cleanCssIdentifier('views_exposed_form-' . $view->storage->id() . '-' . $display['id'] . '-' . $view->dom_id);

I'm curious whether we could add the dom ID as data attribute? This way existing HTML ID doesn't change, and as result the risk of breaking things is reduced. Does this make sense?

@Daniel Korte
Thank you for implementing my suggestion.

In order to ensure we don't cause a regression again I am wondering whether we could add some tests for this issue.

NW based on #9.

Patch from #6 does not apply against 8.6.x anymore. Updated it to work with 8.6.x

Great guys, thank you! Patch #12 works form me!

Re-rolled the patch for 8.7.6, strange, but it seems to be the same as for 8.6.x, but somehow #12 doesn't apply to 8.7.5.

UPDATE: Sorry, my bad, the patch applied to 8.7.5.

The above patches are not working on Ajax enabled views. It reloads the page on button click.
Also attached the screenshot showing JS errors on view forms.

#14 is working for me. Also, I looked for AJAX errors but didn't see any.

Need to check for 9.0 and 9.1

Rerolled patch for 9.1.x, please review.

The patch from #12 worked for 8.9.5. Thanks all!

There is another solution to this in #3163299: Ajax exposed filters not working for multiple instances of the same Views block placed on one page, including tests. I don't know which is the better solution.

The above is the patch from #22 as a merge request against 9.2.x.

Patch #22 working! Thank you.

Using Drupal 9.2.9. After applying the patch #22. I still get the console error - Found 2 elements with non-unique id. I am printing out a solr search exposed view form. I am printing the view twice in the twig. 1 for desktop display and another that displays only for mobile display.

Re-rolled for 9.3.x

We tried patch #32 and seems to work disabling the caches, but when we enabled the drupal caches, the form has the ids duplicated.
So seems to be also related to cache.

Rerolled patch for 9.5.x

#38 does not get applied to 10.1x so i made it compatible so now it can applies cleany. creating interdiff giving some error so i couldn’t able to update it here!

Reroll for 9.5.x

The MR seems outdated. Patches #39 and #40 looks fine.

Previously tagged for tests that are still needed.

Also issue summary could use some love.

Re-rolled 10.1.x / 11.x

Patch on #39 was already meant for 10.1.x and 11.x and it applies and passes the tests. However, as said in #43, we still need new tests.

Hi all!
I'm sorry, I've messed around with 11.x branch. I don't understand why, but I was not able to rebase it to 11.3.x.
After messing around I've reset the branch to the initial commit from october and force pushed the initial version back to 11.x.
.. sorry for the confusion.

After messing around with 11.x I've created a new branch (drupal-2968207-11.x) and MR for the 11.3.x version. I hope that's fine?