[5.4] Fix OptionsRule validation to support groupedlist fields

[Shauryan0207]

Summary of Changes

Fixed OptionsRule validation to support groupedlist fields by iterating through <group> children to find nested options.

Testing Instructions

Create a groupedlist field with validate="options", submit with valid value, and verify validation passes.

Steps to Test

1. Create a test plugin with a groupedlist field:
   • Go to System → Plugins → Create a test plugin XML file with this field definition:

<field
    name="test_grouped"
    type="groupedlist"
    label="Test Grouped Field"
    validate="options"
>
    <option value="">Select Option</option>
    <group label="Group 1">
        <option value="option1">Option 1</option>
        <option value="option2">Option 2</option>
    </group>
    <group label="Group 2">
        <option value="option3">Option 3</option>
        <option value="option4">Option 4</option>
    </group>
</field>

2. Test the validation:

   • Open the plugin configuration
   • Select a valid option from any group (e.g., "Option 2" or "Option 3")
   • Click Save

3. Verify the result:

   • BEFORE this PR: You would get "Invalid field: test_grouped" error
   • AFTER this PR: The field saves successfully without validation errors

Actual result BEFORE applying this Pull Request

Validation fails with "Invalid field" error even when selecting valid grouped options because OptionsRule only checked direct <option> children and ignored options nested inside <group> elements.

Expected result AFTER applying this Pull Request

Validation passes for valid options within any group. The rule now correctly iterates through both direct options and options nested within group elements.

Link to documentations

• No documentation changes for docs.joomla.org needed
• No documentation changes for manual.joomla.org needed

[Fedik]

Ah no, ignore my comment, I mixed up with the Field, but this is only validation.

Sorry for confusion.

[Shauryan0207]

Ah no, ignore my comment, I mixed up with the Field, but this is only validation.

Sorry for confusion.

No worries 😅

[richard67]

@Fedik As you have labelled this PR as feature: Should it be rebased to 6.1-dev? Ah, I just see you've changed it to bug.

[exlemor]

@Shauryan0207 Hi Shauryan, I tried to create a plugin but for those of us who are not coders, that's not so simple, I didn't succeed (I asked AI, it created me a simple plugin but when I used it to test your PR, I couldn't replicate the BEFORE condition so didn't work and I can't say I trust AI for this purpose) - so that I could gladly test your PR, can you add in the testing instructions a .zip file of the test plugin? (thanks)

[ceford]

I have tested this item ✅ successfully on 705dcaf

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[heelc29]

I have tested this item ✅ successfully on 705dcaf

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_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/46608.}

[richard67]

RTC

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[richard67]

System test failure is not related to this PR.

[muhme]

✅ Final test before merge with JBT

• Created and installed plg_system_groupedlisttest.zip
• Seen error 'Invalid field: Test Grouped Field' before PR
• Applied PR with Patch Tester
• Grouped options can be saved, and the selected parameters are correctly stored in the __extensions table
• Checked Joomla logs

[muhme]

Thank you @Shauryan0207 for your contribution.

Thank you @richard67 and @heelc29 for supporting this PR.

Thank you @ceford and @heelc29 for testing.

@exlemor, plg_system_groupedlisttest.zip has now been added. It's a bit late, but thank you for trying.