Tag - Add a Tag.merge API action and SearchKit "Merge Tags" bulk task

[mattwire]

Overview

Adds a Tag.merge API4 action and wires it up as a SearchKit bulk task, so merging duplicate/overlapping tags can be done by selecting rows in a Tag listing instead of only through the dedicated CRM_Tag_Form_Merge popup.

Before

Tag merging was only reachable via civicrm/tag/merge, a standalone form outside of any SearchKit-driven listing. There was no API action wrapping the merge logic, so it couldn't be exposed as a bulk task on a Tag SearchDisplay.

After

A new Tag.merge action takes a targetId, a list of tagIds to merge into it, and an optional new label. Any Tag SearchDisplay with update and delete actions gets a "Merge Tags" bulk task once 2+ rows are selected, opening a dialog to pick the merge target and label.

Technical Details

• Civi\Api4\Action\Tag\Merge wraps the existing CRM_Core_BAO_EntityTag::mergeTags() logic (already handles child reparenting, used_for union, and de-duping EntityTag rows) — it isn't reimplemented, just exposed through a proper API4 action.
• Reserved tags require administer reserved tags to merge, mirroring the existing form's permission check.
• GetSearchTasks.php registers the merge task for Tag displays; crmSearchTaskTagMerge.ctrl.js/.html is a new, purpose-built controller (not the generic apiBatch mechanism — merge needs to pick one selected row as the target, which apiBatch's one-call-per-row model can't express) for choosing the target tag and label.
• Test coverage in TagTest.php covers a normal merge and the reserved-tag permission check.

Comments

Manually verified in the browser: selecting 3 tags in a Tag listing, merging into one with a new label, correctly reparents children and unions used_for.

[civibot]

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