added querying by relation's properties

src/services/search/expressions/relation_where.js

@@ -0,0 +1,41 @@
+"use strict";
+
+const Expression = require('./expression');
+const NoteSet = require('../note_set');
+const noteCache = require('../../note_cache/note_cache');
+
+class RelationWhereExp extends Expression {
+    constructor(relationName, subExpression) {
+        super();
+
+        this.relationName = relationName;
+        this.subExpression = subExpression;
+    }
+
+    execute(inputNoteSet, searchContext) {
+        const candidateNoteSet = new NoteSet();
+
+        for (const attr of noteCache.findAttributes('relation', this.relationName)) {
+            const note = attr.note;
+
+            if (inputNoteSet.hasNoteId(note.noteId)) {
+                const subInputNoteSet = new NoteSet([attr.targetNote]);
+                const subResNoteSet = this.subExpression.execute(subInputNoteSet, searchContext);
+
+                if (subResNoteSet.hasNote(attr.targetNote)) {
+                    if (attr.isInheritable) {
+                        candidateNoteSet.addAll(note.subtreeNotesIncludingTemplated);
+                    } else if (note.isTemplate) {
+                        candidateNoteSet.addAll(note.templatedNotes);
+                    } else {
+                        candidateNoteSet.add(note);
+                    }
+                }
+            }
+        }
+
+        return candidateNoteSet.intersection(inputNoteSet);
+    }
+}
+
+module.exports = RelationWhereExp;