Handle hidden search field entries

[roland-d]

Summary of Changes

When you add a hidden field to the search filters you will see an error message in the console and the searchtools like:

Uncaught TypeError: element.labels is null
    activeFilter http://joomlacms.test/media/system/js/searchtools.js?7039b530192126304eb4d7e43f009e45:330
    checkFilter http://joomlacms.test/media/system/js/searchtools.js?7039b530192126304eb4d7e43f009e45:222
    Searchtools http://joomlacms.test/media/system/js/searchtools.js?7039b530192126304eb4d7e43f009e45:167
    Searchtools http://joomlacms.test/media/system/js/searchtools.js?7039b530192126304eb4d7e43f009e45:166
    onBoot http://joomlacms.test/media/system/js/searchtools.js?7039b530192126304eb4d7e43f009e45:542
    EventListener.handleEvent* http://joomlacms.test/media/system/js/searchtools.js?7039b530192126304eb4d7e43f009e45:563
    <anonymous> http://joomlacms.test/media/system/js/searchtools.js?7039b530192126304eb4d7e43f009e45:564
searchtools.js:330:13

This is caused by a hidden field in the filter_VIEW.xml file. This field has no label field and is not required according to the documentation at https://docs.joomla.org/Hidden_form_field_type

Testing Instructions

1. Open the file administrator/components/com_content/forms/filter_articles.xml
2. After the search field add this field

<field
	name="search_id"
	type="hidden"
	default="abc"
/>

3. Login to your Joomla 4 site
4. Open the browser console page
5. Open the Articles List page
6. See the error in the console page
7. Apply the pull request
8. Compile the JS with npm run build:js
9. Refresh the Articles List
10. Notice there are no more errors in the console

Actual result BEFORE applying this Pull Request

An error is shown in the console

Uncaught TypeError: element.labels is null
    activeFilter http://joomlacms.test/media/system/js/searchtools.js?7039b530192126304eb4d7e43f009e45:330
    checkFilter http://joomlacms.test/media/system/js/searchtools.js?7039b530192126304eb4d7e43f009e45:222
    Searchtools http://joomlacms.test/media/system/js/searchtools.js?7039b530192126304eb4d7e43f009e45:167
    Searchtools http://joomlacms.test/media/system/js/searchtools.js?7039b530192126304eb4d7e43f009e45:166
    onBoot http://joomlacms.test/media/system/js/searchtools.js?7039b530192126304eb4d7e43f009e45:542
    EventListener.handleEvent* http://joomlacms.test/media/system/js/searchtools.js?7039b530192126304eb4d7e43f009e45:563
    <anonymous> http://joomlacms.test/media/system/js/searchtools.js?7039b530192126304eb4d7e43f009e45:564
searchtools.js:330:13

Expected result AFTER applying this Pull Request

There are no errors in the console.

Documentation Changes Required

None

[ceford]

I have tested this item ✅ successfully on 74f0d35

Works as described.

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_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/32511.}

[Quy]

I have tested this item ✅ successfully on 74f0d35

---

_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/32511.}

[Quy]

RTC

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_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/32511.}

[wilsonge]

Thanks!