Change notice: Allow Views handlers to be optional

Updated issue summary.

Not using the broken handler results in an even more wonky UI. We should definitely go in the direction of the first patch.

However, we can go one step further in simplifying the DX for callers. The tests look a bit more awkward, but that's not who we're optimizing for.

+++ b/core/modules/views/lib/Drupal/views/Plugin/views/exposed_form/InputRequired.phpundefined
@@ -82,8 +82,9 @@ function pre_render($values) {
+        'optional' => FALSE,

There is no need to have this marked as not optional.

+++ b/core/modules/views/views.moduleundefined
@@ -877,21 +877,25 @@ function views_library_info() {
+ *   - optional: (optional) Whether or not this handler is optional. If a
+ *     handler is missing and not optional, a debug message will be displayed.

This should explain that optional is defaulted to FALSE.

Addressed the comments in #3 (thanks) and fixed two calls to this in tests I missed.

Still needs dedicated tests.

I will either write tests tomorrow morning or in the evening, if noone else stepped forward in the meantime.

Added some test coverage for that.

@dawehner++

+++ b/core/modules/views/lib/Drupal/views/Tests/ModuleTest.phpundefined
@@ -21,6 +22,15 @@ class ModuleTest extends ViewUnitTestBase {
+  public $lastErrorMessage;

Could be protected, I guess. Doesn't really matter.

+++ b/core/modules/views/lib/Drupal/views/Tests/ModuleTest.phpundefined
@@ -67,7 +77,59 @@ function testviews_get_handler() {
+    // Test non existing tables/fields.

non-existant

+++ b/core/modules/views/lib/Drupal/views/Tests/ModuleTest.phpundefined
@@ -67,7 +77,59 @@ function testviews_get_handler() {
+    set_error_handler(array($this, 'customErrorHandler'));

Nice!

+++ b/core/modules/views/lib/Drupal/views/Tests/ModuleTest.phpundefined
@@ -67,7 +77,59 @@ function testviews_get_handler() {
+    $item = array(
+    'table' => 'views_test_data',
+    'field' => 'field_invalid',
+  );
+    views_get_handler($item, 'field');

Weird indentation

#10 is correct.

Is it worth us also just adding a quick test that an actual handler with optional = TRUE doesn't throw a debug. I know it won't but you never know what'll happen in the future

Isn't that what assertFalse() is doing? Added a test for explicit 'optional' => FALSE.

This is awesome! Yay team.

This blocks #1851086: Replace admin/people with a View, so it is also major

This actually looks like nice code clean-up, in addition to providing that capability.

Committed and pushed to 8.x. Thanks!

Probably merits a change notice?

So should we expose this bit in the UI?

@dawehner, maybe a followup to discuss the possibility of the UI would be good? My gut reaction is no, because it adds another whole layer of complexity to the view, but not sure.

Well, there are already a lot of different levels of configuration the normal user would never need. Additional I don't think changing config files by hand is recommended at all?

Updated issue summary.

For more information as to why this issue was moved to the Drupal core project, please see issue #3030347: Plan to clean process issue queue

Moving back to the contributed Views issue queue and closing as outdated per https://www.drupal.org/project/views/issues/3030347#comment-13023447