Fixed missing layout parameter when choosing widget page group

[ma4nn]

Description (*)

This PR fixes the issue that the layout parameter is missing in some cases when choosing the page group on the widget instance page in backend.
As a result not all available block references will be shown in the select field.

This has already been tried to fix in #802, but the implementation does only work when choosing "Specified Page" in the page group select. For all other options like category or product pages (where no additional "Page" select is available) only the default layout handle will be used (instead of e.g. catalog_product_view) and therewith not all available blocks will be shown in "Block Reference".

Related Pull Requests

Fixed Issues (if relevant)

Manual testing scenarios (*)

1. In Backend go to CMS > Widgets and create a new Widget instance
2. In the form section "Layout Updates" verify that all combinations of "Display On", "Page" and "Block Reference" produce the correct behaviour, i.e. the contents of the "Block Reference" select matches the chosen page
3. Verify step 2. especially for product pages vs. home page (as mentioned in Fix widgets layout handle on edit #802)

Questions or comments

Contribution checklist (*)

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All automated tests passed successfully (all builds are green)
• Add yourself to contributors list

[fballiano]

@ma4nn I can't seem to replicate the issue or I didn't understand it correctly

it seems to me that the layout parameter is always passed

[ma4nn]

@fballiano thanks for your feedback. As mentioned in the ticket description for "Display On = Specified Page" the layout parameter is correctly passed. But if you choose something else like "All Product Types" the layout parameter is empty and as a result the "Block Reference" select field is missing values like "Bottom Block Options Wrapper" which are only available for catalog_product_view layout handle.

[fballiano]

select#layout_handle doesn't even exist in the DOM, interesting, I'm trying to think of why nobody noticed before but this PR seems to work fine.

[fballiano]

before PR

after PR

I can't find any problem with this PR so I'm approving it

[ma4nn]

What about this mini-bugfix? Is any other reviewer able to verify and approve?

[fballiano]

@addison74 @kiatng @Flyingmana I think this one should be approved, I've tested it and it works

[kiatng]

Following the testing steps outlined: after creating a widget, and select it for editing, and set Display On to All Product Types, the dropdown options for Block References increases as shown by the screenshots captured by @fballiano: