helper function to build the recursive list of broader keywords (#4570)

src/collective/dms/thesaurus/dmskeyword.py

@@ -76,6 +76,16 @@ class DmsKeyword(Item):
                 words.append(keyword.get_words_for_indexation(limit=limit-1))
         return ' '.join(words)
 
+    def get_keyword_tree(self, limit=5):
+        thesaurus = aq_parent(self)
+        l = [self.id]
+        for broader_keyword in self.broader or []:
+            try:
+                keyword = thesaurus[broader_keyword]
+            except KeyError:
+                continue
+            l.extend(keyword.get_keyword_tree(limit=limit-1))
+        return l
 
 
 class DmsKeywordSchemaPolicy(DexteritySchemaPolicy):