Find a knowledge base article by words from different fields

plugins/knowledgebase/api/routes.py

@@ -43,6 +43,39 @@ def _visible_articles():
                KnowledgeBase.appid.notin_(retired)))
 
 
+def _search_clause(search):
+    """Articles containing EVERY word of the search, each word in the title, the
+    keywords, or the topic's name, in any order.
+
+    A single `ilike('%CMM Community%')` needs the whole phrase contiguous in ONE
+    field. An article tagged 'community' under the CMM topic has 'CMM' only in
+    its topic's name and 'Community' only in its keywords, so it matched nothing
+    and the search came back empty. Splitting the query and requiring each word
+    somewhere is what people mean when they type two words.
+
+    Kept in step with `_word_match` in shopdb/core/api/search.py, which does the
+    same job for global search. Two copies because the core helper is internal
+    and not on the plugin contract surface (ADR-001).
+
+    Active applications only for the topic. A retired application is not a topic
+    anyone should be offered: matching its name surfaced its articles and printed
+    the retired app as their subject, which reads as though it were still in
+    service.
+    """
+    words = [w for w in search.split() if w] or ['']
+    return db.and_(*[
+        db.or_(
+            KnowledgeBase.shortdescription.ilike(f'%{w}%'),
+            KnowledgeBase.keywords.ilike(f'%{w}%'),
+            KnowledgeBase.appid.in_(
+                db.session.query(Application.appid).filter(
+                    Application.appname.ilike(f'%{w}%'),
+                    Application.isactive.is_(True))),
+        )
+        for w in words
+    ])
+
+
 @knowledgebase_bp.route('', methods=['GET'])
 @jwt_required(optional=True)
 def list_articles():
@@ -51,26 +84,11 @@ def list_articles():
 
     query = _visible_articles()
 
-    # Search: title, keywords, and the topic (its Application's name). The topic
-    # is matched via an appid subquery instead of a join so it does not collide
-    # with the sort=='topic' join below; articles with no app just miss that
-    # clause and still match on title/keywords.
+    # The topic is matched via an appid subquery instead of a join so it does not
+    # collide with the sort=='topic' join below; articles with no app just miss
+    # that clause and still match on title/keywords.
     if search := request.args.get('search'):
-        like = f'%{search}%'
-        # Active applications only. A retired application is not a topic anyone
-        # should be offered: matching its name surfaced its articles and printed
-        # the retired app as their subject, which reads as though it were still
-        # in service.
-        topic_appids = db.session.query(Application.appid).filter(
-            Application.appname.ilike(like),
-            Application.isactive.is_(True))
-        query = query.filter(
-            db.or_(
-                KnowledgeBase.shortdescription.ilike(like),
-                KnowledgeBase.keywords.ilike(like),
-                KnowledgeBase.appid.in_(topic_appids)
-            )
-        )
+        query = query.filter(_search_clause(search))
 
     # Filter by topic/application
     if appid := request.args.get('appid'):