binding check dir/subs count before queueing, rename instances -> dirs

Author: yyx990803

src/binding.js

@@ -16,7 +16,7 @@ function Binding (compiler, key, isExp, isFn) {
     this.root = !this.isExp && key.indexOf('.') === -1
     this.compiler = compiler
     this.key = key
-    this.instances = []
+    this.dirs = []
     this.subs = []
     this.deps = []
     this.unbound = false
@@ -31,17 +31,19 @@ BindingProto.update = function (value) {
     if (!this.isComputed || this.isFn) {
         this.value = value
     }
-    batcher.queue(this)
+    if (this.dirs.length || this.subs.length) {
+        batcher.queue(this)
+    }
 }
 
 /**
- *  Actually update the instances.
+ *  Actually update the directives.
  */
 BindingProto._update = function () {
-    var i = this.instances.length,
+    var i = this.dirs.length,
         value = this.val()
     while (i--) {
-        this.instances[i].update(value)
+        this.dirs[i].update(value)
     }
     this.pub()
 }
@@ -76,9 +78,9 @@ BindingProto.unbind = function () {
     // the batcher's flush queue when its owner
     // compiler has already been destroyed.
     this.unbound = true
-    var i = this.instances.length
+    var i = this.dirs.length
     while (i--) {
-        this.instances[i].unbind()
+        this.dirs[i].unbind()
     }
     i = this.deps.length
     var subs

src/compiler.js

@@ -490,7 +490,7 @@ CompilerProto.bindDirective = function (directive) {
         compiler = compiler || this
         binding = compiler.bindings[key] || compiler.createBinding(key)
     }
-    binding.instances.push(directive)
+    binding.dirs.push(directive)
     directive.binding = binding
 
     // invoke bind hook if exists
@@ -672,7 +672,7 @@ CompilerProto.destroy = function () {
     if (this.destroyed) return
 
     var compiler = this,
-        i, key, dir, instances, binding,
+        i, key, dir, dirs, binding,
         vm          = compiler.vm,
         el          = compiler.el,
         directives  = compiler.dirs,
@@ -690,11 +690,11 @@ CompilerProto.destroy = function () {
         dir = directives[i]
         // if this directive is an instance of an external binding
         // e.g. a directive that refers to a variable on the parent VM
-        // we need to remove it from that binding's instances
+        // we need to remove it from that binding's directives
         // * empty and literal bindings do not have binding.
         if (dir.binding && dir.binding.compiler !== compiler) {
-            instances = dir.binding.instances
-            if (instances) instances.splice(instances.indexOf(dir), 1)
+            dirs = dir.binding.dirs
+            if (dirs) dirs.splice(dirs.indexOf(dir), 1)
         }
         dir.unbind()
     }

test/unit/specs/binding.js

@@ -20,9 +20,9 @@ describe('UNIT: Binding', function () {
             assert.ok(!b.root)
         })
 
-        it('should have instances, subs and deps as Arrays', function () {
+        it('should have dirs, subs and deps as Arrays', function () {
             var b = new Binding(null, 'test')
-            assert.ok(Array.isArray(b.instances), 'instances')
+            assert.ok(Array.isArray(b.dirs), 'dirs')
             assert.ok(Array.isArray(b.subs), 'subs')
             assert.ok(Array.isArray(b.deps), 'deps')
         })
@@ -42,7 +42,7 @@ describe('UNIT: Binding', function () {
                 }
             }
         for (var i = 0; i < numInstances; i++) {
-            b.instances.push(instance)
+            b.dirs.push(instance)
         }
         b.pub = function () {
             pubbed = true
@@ -59,7 +59,7 @@ describe('UNIT: Binding', function () {
             assert.strictEqual(b.value, val)
         })
 
-        it('should update the binding\'s instances', function () {
+        it('should update the binding\'s directives', function () {
             assert.strictEqual(updated, val * numInstances)
         })
 
@@ -140,7 +140,7 @@ describe('UNIT: Binding', function () {
                 }
             }
         for (var i = 0; i < numInstances; i++) {
-            b.instances.push(instance)
+            b.dirs.push(instance)
         }
 
         // mock deps
@@ -150,7 +150,7 @@ describe('UNIT: Binding', function () {
 
         b.unbind()
 
-        it('should call unbind() of all instances', function () {
+        it('should call unbind() of all directives', function () {
             assert.strictEqual(unbound, numInstances)
         })
 

test/unit/specs/viewmodel.js

@@ -376,13 +376,13 @@ describe('UNIT: ViewModel', function () {
         var dirMock = {
             binding: {
                 compiler: null,
-                instances: []
+                dirs: []
             },
             unbind: function () {
                 dirUnbindCalled = true
             }
         }
-        dirMock.binding.instances.push(dirMock)
+        dirMock.binding.dirs.push(dirMock)
 
         var bindingsMock = {
             test: {
@@ -474,7 +474,7 @@ describe('UNIT: ViewModel', function () {
         })
 
         it('should remove directives from external bindings', function () {
-            assert.strictEqual(dirMock.binding.instances.indexOf(dirMock), -1)
+            assert.strictEqual(dirMock.binding.dirs.indexOf(dirMock), -1)
         })
 
         it('should unbind all expressions', function () {