From 2a7e93d97805efaade915a8884ba97b6c11b419f Mon Sep 17 00:00:00 2001
From: Klaus Zanders <k.zanders@openproject.com>
Date: Thu, 28 May 2026 17:21:10 +0200
Subject: [PATCH] Add compatability for Work Package Queries

---
 app/models/query.rb                           |  9 ++++++++
 lookbook/docs/patterns/11-filter-forms.md.erb | 19 ++++++++++++++++
 spec/models/query_spec.rb                     | 22 +++++++++++++++++++
 3 files changed, 50 insertions(+)

diff --git a/app/models/query.rb b/app/models/query.rb
index ed9b540a515..f8c2e313a1d 100644
--- a/app/models/query.rb
+++ b/app/models/query.rb
@@ -208,6 +208,15 @@ class Query < ApplicationRecord
     filters.delete_if { |f| f.field.to_s == name.to_s }
   end
 
+  # Mirrors `Queries::BaseQuery#find_active_filter` so that consumers built
+  # on top of the modern query API (e.g. `Filters::FilterForm`) can ask any
+  # query — including this legacy work-package one — for its active filter
+  # by name. Signature kept identical to BaseQuery's (symbol arg in, filter
+  # or nil out).
+  def find_active_filter(name)
+    filters.detect { |f| f.name == name }
+  end
+
   def normalized_name
     name.parameterize.underscore
   end
diff --git a/lookbook/docs/patterns/11-filter-forms.md.erb b/lookbook/docs/patterns/11-filter-forms.md.erb
index 706ff10aafc..898163bbdf2 100644
--- a/lookbook/docs/patterns/11-filter-forms.md.erb
+++ b/lookbook/docs/patterns/11-filter-forms.md.erb
@@ -85,3 +85,22 @@ itself — the surrounding `IndexSubHeaderComponent` does, so quick filter
 and advanced form share one. For standalone embeds without a co-located
 quick filter, `FilterForm`'s `wrap_with_controller: true` is the right
 default.
+
+## Compatibility with the legacy `Query` (work packages)
+
+`Filters::FilterForm` reads three things off the query: `available_advanced_filters`,
+`filters`, and `find_active_filter(name)`. The first two come from the
+`Queries::Filters::AvailableFilters` concern, which the legacy work-package
+`Query` model also includes. `find_active_filter` is defined directly on
+`Queries::BaseQuery` and used to live only there — `Query` now mirrors it
+with the same signature, so passing a `Query` (or any of its subclasses)
+to `FilterForm` works exactly like passing a `BaseQuery` subclass.
+
+What `FilterForm` does *not* do for you on the legacy side: parsing the
+form submission back into a `Query#filters` collection. The work-package
+filter pipeline still uses its own serialization (URL `filters=[...]`
+JSON / YAML in the DB), so a controller receiving a `FilterForm` submit
+either needs to use `hidden_input_name:` with a format the existing
+parser understands, or translate the `operator_<name>` / `<name>_value`
+fields by hand. The form renders fine either way; what to do with the
+submitted values is the caller's call.
diff --git a/spec/models/query_spec.rb b/spec/models/query_spec.rb
index 4dcbb49f663..81c47965853 100644
--- a/spec/models/query_spec.rb
+++ b/spec/models/query_spec.rb
@@ -65,6 +65,28 @@ RSpec.describe Query,
     end
   end
 
+  describe "#find_active_filter" do
+    let(:query) { described_class.new }
+
+    it "returns the active filter matching the given name" do
+      query.add_filter("status_id", "=", ["1"])
+
+      expect(query.find_active_filter(:status_id))
+        .to be_a(Queries::WorkPackages::Filter::StatusFilter)
+    end
+
+    it "returns nil when no filter with that name is active" do
+      expect(query.find_active_filter(:status_id)).to be_nil
+    end
+
+    it "matches by symbol, like Queries::BaseQuery#find_active_filter" do
+      query.add_filter("status_id", "=", ["1"])
+
+      expect(query.find_active_filter("status_id")).to be_nil
+      expect(query.find_active_filter(:status_id)).not_to be_nil
+    end
+  end
+
   describe "include_subprojects" do
     let(:query) { described_class.new name: "foo" }