undocumented #has_garbage_value property of render elements

Thanks for the report! This should be documented on https://api.drupal.org/api/drupal/core!lib!Drupal!Core!Render!Element!Re...
which lists all of the generic properties.

It seems like the documentation should say that it indicates that the #value property of an element should not be used or processed.

I'm rolling a patch for this.

Looks good to me, thanks!

I'm not sure it's correct to document this as being a public API. It's something that's internal to Form API.

        // If the element is a (non-image) button, its name may not identify it
        // uniquely, in which case a match on value is also needed.
        // @see _form_button_was_clicked()
        if (!empty($element['#is_button']) && empty($element['#has_garbage_value'])) {
          $settings['submit']['_triggering_element_value'] = $element['#value'];
        }

+

        // Final catch. If we haven't set a value yet, use the explicit default
        // value. Avoid image buttons (which come with garbage value), so we
        // only get value for the button actually clicked.
        if (!isset($element['#value']) && empty($element['#has_garbage_value'])) {
          $element['#value'] = isset($element['#default_value']) ? $element['#default_value'] : '';
        }

It is being used by at least one or two elements in Core (being set in their form array defaults) -- so not really strictly internal, I think?

Also we are documenting both internal and public properties in the RenderElement and FormElement class. That said, I think you are right that we should add a note to this documentation to say it's internal.

See
https://api.drupal.org/api/drupal/core!lib!Drupal!Core!Render!Element!Re...

The way we are doing this on other properties is changing (bool) to (bool, internal) at the start of the docs line.

so not really strictly internal, I think?

Well, Drupal has internal APIs to work around problems in the API design, I think this is an example of that.

That said, I think you are right that we should add a note to this documentation to say it's internal.

Cool :)

Based on my understanding of the convo above, I updated the description to (bool, internal) and fixed resulting line wrap.

Looks good, thanks!

+1

Stupid Migrate random test failures. I think/hope there is an issue about them.

+++ b/core/lib/Drupal/Core/Render/Element/RenderElement.php
@@ -66,6 +66,8 @@
+ * - #has_garbage_value: (bool, internal) Set to TRUE to indicate that the
+ *   #value property of an element should not be used or processed.

This refers to #value, which is not documented. Also, #value should definitely not be documented on RenderElement, but on FormElement, which makes me think that #has_garbage_value should also be on FormElement, despite RenderElement having code that checks for FAPI-specific properties, which is kind of a shame. I don't want to scope creep this issue too much though, so I'd like to open another issue to delve into these concerns in more detail. Assigning this to myself until I do that.

More accurate status per #15.

Doh! #value should definitely be documented too. It seems to me that #has_garbage_value and #value should both be on FormElement, as I think you are suggesting? Independent of where the code is, that is where they logically should be documented for developers to learn about.

+1 to #17. If you're ok with moving the #has_garbage_value docs to FormElement, despite RenderElement having code that uses it, that certainly works for me, and so this doesn't need to be postponed on moving that code.

Do we want to add #value docs in this issue, or postpone this issue on a separate #value docs issue?

It seems if #has_garbage_value references #value, we should document it in this issue.

Updating summary.

+1 to #19 and the updated IS. Unassigning from myself until it's RTBC again.

- Added #value to above patch

@subhashuyadav, Kindly add full stop at the end of statement.
* - #value: (text or numbers) Sets values that cannot be edited by the user

Thanks @shashikant_chauhan. I have updated the patch. Please review.

Thanks, Looks good now.

@joachim, I think below sentence makes more sense here. Let me know your thoughts on this.

+++ b/core/lib/Drupal/Core/Render/Element/RenderElement.php
@@ -66,6 +66,9 @@
+ * - #value: (text or numbers) Values that cannot be edited by the user.

Changed according to suggestions in #30.

Looks good, thanks

Thanks for picking this up! Does not seem like that #15 or #18 was considered though.

Added documentation FormElement file as well.

+++ b/core/lib/Drupal/Core/Render/Element/FormElement.php
@@ -50,6 +50,9 @@
+ * - #value: (text or numbers) A value that cannot be edited by the user.

+++ b/core/lib/Drupal/Core/Render/Element/RenderElement.php
@@ -66,6 +66,9 @@
+ * - #value: (text or numbers) A value that cannot be edited by the user.

Typically I think we would say 'mixed' instead of 'text or numbers'

Will work on this.

Rerolled the patch in #34 and addressed the changes specified in #42 . Attached an diff file for reference.

Adding a patch with the changes suggested in #45.

Committed and pushed d909b20df7 to 10.0.x and 52fbb19786 to 9.4.x and 6937f0b4e0 to 9.3.x. Thanks!