Use {questionName} for question value in conditions. Return false if …

…there is underfined value in an expression: #60

src/conditions.ts

@@ -99,10 +99,24 @@ module Survey {
         }
         private runCondition(condition: Condition): boolean {
             var left = condition.left;
-            if (left && this.values[left]) left = this.values[left];
+            var name = this.getValueName(left);
+            if (name) {
+                if (!(name in this.values)) return false;
+                left = this.values[name];
+            }
             var right = condition.right;
-            if (right && this.values[right]) right = this.values[right];
+            name = this.getValueName(right);
+            if (name) {
+                if (!(name in this.values)) return false;
+                right = this.values[name];
+            }
             return condition.perform(left, right);
         }
+        private getValueName(nodeValue: any) {
+            if (!nodeValue) return null;
+            if (typeof nodeValue !== 'string') return null;
+            if (nodeValue.length < 3 || nodeValue[0] != '{' || nodeValue[nodeValue.length - 1] != '}') return null;
+            return nodeValue.substr(1, nodeValue.length - 2);
+        }
     }
 }

tests/conditionstests.ts

@@ -173,22 +173,25 @@ module Survey.Tests {
         assert.equal(right.children[1].right, 3);
     });
     QUnit.test("Run one condition", function (assert) {
-        var runner = new ConditionRunner("'a' > 5");
+        var runner = new ConditionRunner("{a} > 5");
         var values = { a: 6 };
         assert.equal(runner.run(values), true, "6 > 5");
         values = { a: 5 };
         assert.equal(runner.run(values), false, "5 > 5");
+        var values2 = { b: 5 };
+        assert.equal(runner.run(values2), false, "undefined > 5");
+
     });
     QUnit.test("Run complex condition", function (assert) {
-        var runner = new ConditionRunner("'age' >= 21 and ('sex' = 'male' or 'kids' > 1)");
+        var runner = new ConditionRunner("{age} >= 21 and ({sex} = 'male' or {kids} > 1)");
         var values = { age: 21, sex: 'male', kids: 1 };
         assert.equal(runner.run(values), true, "21 >= 21 and (male = male or 1 > 1");
         var values = { age: 21, sex: 'female', kids: 1 };
-        assert.equal(runner.run(values), false, "21 >= 21 and (male = female or 1 > 1");
+        assert.equal(runner.run(values), false, "21 >= 21 and (male = female or 1 > 1)");
         var values = { age: 21, sex: 'female', kids: 2 };
-        assert.equal(runner.run(values), true, "21 >= 21 and (male = female or 2 > 1");
+        assert.equal(runner.run(values), true, "21 >= 21 and (male = female or 2 > 1)");
         var values = { age: 20, sex: 'male', kids: 2 };
-        assert.equal(runner.run(values), false, "20 >= 21 and (male = male or 2 > 1");
+        assert.equal(runner.run(values), false, "20 >= 21 and (male = male or 2 > 1)");
     });
     QUnit.test("Expression Tree to Text", function (assert) {
         var parser = new ConditionsParser();

tests/surveytests.ts

@@ -624,9 +624,9 @@ module Survey.Tests {
                 questions: [
                     { type: "checkbox", name: "q1", choices: ["yes", "no"] },
                     { type: "checkbox", name: "q2", choices: ["yes", "no"] }]
-            }, { name : "page2", visibleIf: "q1 = 'yes' or 'q2' = 'no'",
+            }, { name : "page2", visibleIf: "{q1} = 'yes' or {q2} = 'no'",
                     questions: [
-                        { type: "text", name: "q3", visibleIf: "q1 = 'yes' and 'q2' = 'no'", },
+                        { type: "text", name: "q3", visibleIf: "{q1} = 'yes' and {q2} = 'no'", },
                         { type: "text", name: "q4" }]
                 }
             ]