Merge pull request #2409 from Polymer/2408-multiple-linkPath

Allow multiple paths to be linked using linkPath. Fixes #2048

Author: Steve Orvell

src/standard/notify-path.html

@@ -278,7 +278,7 @@
           this._boundPaths[to] = from;
           // this.set(to, this.get(from));
         } else {
-          this.unbindPath(to);
+          this.unlinkPaths(to);
           // this.set(to, from);
         }
       },
@@ -299,23 +299,13 @@
       },
 
       _notifyBoundPaths: function(path, value) {
-        var from, to;
         for (var a in this._boundPaths) {
           var b = this._boundPaths[a];
           if (path.indexOf(a + '.') == 0) {
-            from = a;
-            to = b;
-            break;
+            this.notifyPath(this._fixPath(b, a, path), value);
+          } else if (path.indexOf(b + '.') == 0) {
+            this.notifyPath(this._fixPath(a, b, path), value);
           }
-          if (path.indexOf(b + '.') == 0) {
-            from = b;
-            to = a;
-            break;
-          }
-        }
-        if (from && to) {
-          var p = this._fixPath(to, from, path);
-          this.notifyPath(p, value);
         }
       },
 

test/unit/notify-path-elements.html

@@ -125,7 +125,10 @@
         'multiplePathsChanged(a, nested.b, nested.obj.c)',
         'arrayChanged(array.splices)',
         'arrayNoCollChanged(arrayNoColl.splices)',
-        'arrayOrPropChanged(prop, array.splices)'
+        'arrayOrPropChanged(prop, array.splices)',
+        'aChanged(a.*)',
+        'bChanged(b.*)',
+        'cChanged(c.*)'
       ],
       created: function() {
         this.observerCounts = {
@@ -219,7 +222,10 @@
       arrayOrPropChanged: function(prop, splices) {
         this.observerCounts.arrayOrPropChanged++;
         assert.equal(prop, this.prop);
-      }
+      },
+      aChanged: function() {},
+      bChanged: function() {},
+      cChanged: function() {}
     });
   </script>
 </dom-module>

test/unit/notify-path.html

@@ -1153,6 +1153,82 @@
     assert.strictEqual(el.array[3], 'orig3');
   });
 
+  test('link two objects', function() {
+    var aChanged = 0;
+    var bChanged = 0;
+    el.a = el.b = {};
+    el.linkPaths('b', 'a');
+    el.aChanged = function() { aChanged++; };
+    el.bChanged = function() { bChanged++; };
+    el.set('a.foo', 1);
+    assert.equal(aChanged, 1);
+    assert.equal(bChanged, 1);
+    el.unlinkPaths('b');
+    el.set('a.foo', 2);
+    assert.equal(aChanged, 2);
+    assert.equal(bChanged, 1);
+  });
+
+  test('link three objects', function() {
+    var aChanged = 0;
+    var bChanged = 0;
+    var cChanged = 0;
+    el.a = el.b = el.c = {};
+    el.linkPaths('b', 'a');
+    el.linkPaths('c', 'a');
+    el.aChanged = function() { aChanged++; };
+    el.bChanged = function() { bChanged++; };
+    el.cChanged = function() { cChanged++; };
+    el.set('a.foo', 1);
+    assert.equal(aChanged, 1);
+    assert.equal(bChanged, 1);
+    assert.equal(cChanged, 1);
+    el.unlinkPaths('b');
+    el.set('a.foo', 2);
+    assert.equal(aChanged, 2);
+    assert.equal(bChanged, 1);
+    assert.equal(cChanged, 2);
+  });
+
+  test('link two arrays', function() {
+    var aChanged = 0;
+    var bChanged = 0;
+    el.a = el.b = [];
+    el.linkPaths('b', 'a');
+    el.aChanged = function() { aChanged++; };
+    el.bChanged = function() { bChanged++; };
+    el.push('a', {});
+    // 2 changes for arrays (splices & length)
+    assert.equal(aChanged, 2);
+    assert.equal(bChanged, 2);
+    el.unlinkPaths('b');
+    el.push('a', {});
+    assert.equal(aChanged, 4);
+    assert.equal(bChanged, 2);
+  });
+
+  test('link three arrays', function() {
+    var aChanged = 0;
+    var bChanged = 0;
+    var cChanged = 0;
+    el.a = el.b = el.c = [];
+    el.linkPaths('b', 'a');
+    el.linkPaths('c', 'a');
+    el.aChanged = function() { aChanged++; };
+    el.bChanged = function() { bChanged++; };
+    el.cChanged = function() { cChanged++; };
+    el.push('a', {});
+    // 2 changes for arrays (splices & length)
+    assert.equal(aChanged, 2);
+    assert.equal(bChanged, 2);
+    assert.equal(cChanged, 2);
+    el.unlinkPaths('b');
+    el.push('a', {});
+    assert.equal(aChanged, 4);
+    assert.equal(bChanged, 2);
+    assert.equal(cChanged, 4);
+  });
+
 });
 
 </script>