WW-3624 feat(tags): allow regex matching of field names on fielderror tag

[lukaszlenart]

Fixes WW-3624

Summary

Adds a regex attribute (default false) to <s:fielderror>. When enabled, fieldName and nested <s:param> values are regular expressions matched against the whole field error name, e.g. all errors of one iterated row:

<s:fielderror regex="true">
    <s:param>ledger\.records\[<s:property value="#row.index"/>\]\..*</s:param>
</s:fielderror>

• simple and html5 fielderror.ftl: in regex mode the template first collects the matching error keys, then renders them through the existing loop. The exact-match path is unchanged.
• javatemplates FieldErrorHandler: same matching via Pattern.matcher(...).matches().
• A field error matched by several patterns is rendered once; errors keep the order in which validation recorded them.
• regex is reset in clearTagStateForTagPoolingServers.

This follows the design of the patch attached to the ticket, ported to the current templates (it only covered simple). Prefix matching without escaping is tracked separately in WW-5784.

Notes

• Pre-existing difference, left as is: when no listed name matches, FieldErrorHandler writes an empty <ul class="errorMessage"></ul> while the FreeMarker themes write nothing. Regex mode follows each renderer's existing behaviour.
• The fielderror tag page in struts-site needs the new attribute.

Test plan

• New FieldErrorTagTest cases for simple and html5 (row match, no match, whole-name match, no duplicates, literal match without regex, tag-pooling reset); the matching cases failed before the template change
• New FieldErrorTest cases in javatemplates
• core: 3490 tests, 0 failures; javatemplates: 83 tests, 0 failures

🤖 Generated with Claude Code

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

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