fix(forms): do not reset the value of the input when it came from the view

modules/angular2/src/change_detection/change_detection_util.ts

@@ -9,6 +9,8 @@ export var uninitialized = new Object();
 
 export class SimpleChange {
   constructor(public previousValue: any, public currentValue: any) {}
+
+  isFirstChange(): boolean { return this.previousValue === uninitialized; }
 }
 
 var _simpleChangesIndex = 0;

modules/angular2/src/forms/directives/checkbox_value_accessor.ts

@@ -21,7 +21,6 @@ import {setProperty} from './shared';
   host: {
     '(change)': 'onChange($event.target.checked)',
     '(blur)': 'onTouched()',
-    '[checked]': 'checked',
     '[class.ng-untouched]': 'ngClassUntouched',
     '[class.ng-touched]': 'ngClassTouched',
     '[class.ng-pristine]': 'ngClassPristine',
@@ -31,7 +30,6 @@ import {setProperty} from './shared';
   }
 })
 export class CheckboxControlValueAccessor implements ControlValueAccessor {
-  checked: boolean;
   onChange = (_) => {};
   onTouched = () => {};
 
@@ -39,12 +37,7 @@ export class CheckboxControlValueAccessor implements ControlValueAccessor {
     cd.valueAccessor = this;
   }
 
-  writeValue(value) {
-    // both this.checked and setProperty are required at the moment
-    // remove when a proper imperative API is provided
-    this.checked = value;
-    setProperty(this.renderer, this.elementRef, "checked", value);
-  }
+  writeValue(value) { setProperty(this.renderer, this.elementRef, "checked", value); }
 
   get ngClassUntouched(): boolean {
     return isPresent(this.cd.control) ? this.cd.control.untouched : false;

modules/angular2/src/forms/directives/default_value_accessor.ts

@@ -22,7 +22,6 @@ import {setProperty} from './shared';
     '(change)': 'onChange($event.target.value)',
     '(input)': 'onChange($event.target.value)',
     '(blur)': 'onTouched()',
-    '[value]': 'value',
     '[class.ng-untouched]': 'ngClassUntouched',
     '[class.ng-touched]': 'ngClassTouched',
     '[class.ng-pristine]': 'ngClassPristine',
@@ -32,8 +31,6 @@ import {setProperty} from './shared';
   }
 })
 export class DefaultValueAccessor implements ControlValueAccessor {
-  value: string = null;
-
   onChange = (_) => {};
   onTouched = () => {};
 
@@ -44,8 +41,8 @@ export class DefaultValueAccessor implements ControlValueAccessor {
   writeValue(value) {
     // both this.value and setProperty are required at the moment
     // remove when a proper imperative API is provided
-    this.value = isBlank(value) ? '' : value;
-    setProperty(this.renderer, this.elementRef, 'value', this.value);
+    var normalizedValue = isBlank(value) ? '' : value;
+    setProperty(this.renderer, this.elementRef, 'value', normalizedValue);
   }
 
   get ngClassUntouched(): boolean {

modules/angular2/src/forms/directives/ng_control_name.ts

@@ -1,6 +1,6 @@
 import {CONST_EXPR} from 'angular2/src/facade/lang';
 import {EventEmitter, ObservableWrapper} from 'angular2/src/facade/async';
-import {List, StringMapWrapper, StringMap} from 'angular2/src/facade/collection';
+import {List, StringMap} from 'angular2/src/facade/collection';
 
 import {Directive, LifecycleEvent, Query, QueryList} from 'angular2/angular2';
 import {forwardRef, Ancestor, Binding, Inject} from 'angular2/di';
@@ -8,7 +8,7 @@ import {forwardRef, Ancestor, Binding, Inject} from 'angular2/di';
 import {ControlContainer} from './control_container';
 import {NgControl} from './ng_control';
 import {NgValidator} from './validators';
-import {controlPath, composeNgValidator} from './shared';
+import {controlPath, composeNgValidator, isPropertyUpdated} from './shared';
 import {Control} from '../model';
 
 const controlNameBinding =
@@ -82,6 +82,7 @@ export class NgControlName extends NgControl {
   _parent: ControlContainer;
   update = new EventEmitter();
   model: any;
+  viewModel: any;
   ngValidators: QueryList<NgValidator>;
   _added = false;
 
@@ -98,14 +99,18 @@ export class NgControlName extends NgControl {
       this.formDirective.addControl(this);
       this._added = true;
     }
-    if (StringMapWrapper.contains(c, "model")) {
+    if (isPropertyUpdated(c, this.viewModel)) {
+      this.viewModel = this.model;
       this.formDirective.updateModel(this, this.model);
     }
   }
 
   onDestroy() { this.formDirective.removeControl(this); }
 
-  viewToModelUpdate(newValue: any): void { ObservableWrapper.callNext(this.update, newValue); }
+  viewToModelUpdate(newValue: any): void {
+    this.viewModel = newValue;
+    ObservableWrapper.callNext(this.update, newValue);
+  }
 
   get path(): List<string> { return controlPath(this.name, this._parent); }
 

modules/angular2/src/forms/directives/ng_form_control.ts

@@ -1,5 +1,4 @@
 import {CONST_EXPR} from 'angular2/src/facade/lang';
-import {StringMapWrapper} from 'angular2/src/facade/collection';
 import {EventEmitter, ObservableWrapper} from 'angular2/src/facade/async';
 
 import {Directive, LifecycleEvent, Query, QueryList} from 'angular2/angular2';
@@ -8,7 +7,7 @@ import {forwardRef, Ancestor, Binding} from 'angular2/di';
 import {NgControl} from './ng_control';
 import {Control} from '../model';
 import {NgValidator} from './validators';
-import {setUpControl, composeNgValidator} from './shared';
+import {setUpControl, composeNgValidator, isPropertyUpdated} from './shared';
 
 const formControlBinding =
     CONST_EXPR(new Binding(NgControl, {toAlias: forwardRef(() => NgFormControl)}));
@@ -71,6 +70,7 @@ export class NgFormControl extends NgControl {
   update = new EventEmitter();
   _added = false;
   model: any;
+  viewModel: any;
   ngValidators: QueryList<NgValidator>;
 
   // Scope the query once https://github.com/angular/angular/issues/2603 is fixed
@@ -85,7 +85,7 @@ export class NgFormControl extends NgControl {
       this.form.updateValidity();
       this._added = true;
     }
-    if (StringMapWrapper.contains(c, "model")) {
+    if (isPropertyUpdated(c, this.viewModel)) {
       this.form.updateValue(this.model);
     }
   }
@@ -96,5 +96,8 @@ export class NgFormControl extends NgControl {
 
   get validator(): Function { return composeNgValidator(this.ngValidators); }
 
-  viewToModelUpdate(newValue: any): void { ObservableWrapper.callNext(this.update, newValue); }
+  viewToModelUpdate(newValue: any): void {
+    this.viewModel = newValue;
+    ObservableWrapper.callNext(this.update, newValue);
+  }
 }

modules/angular2/src/forms/directives/ng_model.ts

@@ -1,6 +1,5 @@
 import {CONST_EXPR} from 'angular2/src/facade/lang';
 import {EventEmitter, ObservableWrapper} from 'angular2/src/facade/async';
-import {StringMapWrapper} from 'angular2/src/facade/collection';
 
 import {Directive, LifecycleEvent, QueryList, Query} from 'angular2/angular2';
 import {forwardRef, Ancestor, Binding} from 'angular2/di';
@@ -8,7 +7,7 @@ import {forwardRef, Ancestor, Binding} from 'angular2/di';
 import {NgControl} from './ng_control';
 import {Control} from '../model';
 import {NgValidator} from './validators';
-import {setUpControl, composeNgValidator} from './shared';
+import {setUpControl, composeNgValidator, isPropertyUpdated} from './shared';
 
 const formControlBinding = CONST_EXPR(new Binding(NgControl, {toAlias: forwardRef(() => NgModel)}));
 
@@ -41,6 +40,7 @@ export class NgModel extends NgControl {
   _added = false;
   update = new EventEmitter();
   model: any;
+  viewModel: any;
   ngValidators: QueryList<NgValidator>;
 
   // Scope the query once https://github.com/angular/angular/issues/2603 is fixed
@@ -56,7 +56,7 @@ export class NgModel extends NgControl {
       this._added = true;
     }
 
-    if (StringMapWrapper.contains(c, "model")) {
+    if (isPropertyUpdated(c, this.viewModel)) {
       this._control.updateValue(this.model);
     }
   }
@@ -67,5 +67,8 @@ export class NgModel extends NgControl {
 
   get validator(): Function { return composeNgValidator(this.ngValidators); }
 
-  viewToModelUpdate(newValue: any): void { ObservableWrapper.callNext(this.update, newValue); }
+  viewToModelUpdate(newValue: any): void {
+    this.viewModel = newValue;
+    ObservableWrapper.callNext(this.update, newValue);
+  }
 }

modules/angular2/src/forms/directives/select_control_value_accessor.ts

@@ -29,7 +29,6 @@ export class NgSelectOption {
     '(change)': 'onChange($event.target.value)',
     '(input)': 'onChange($event.target.value)',
     '(blur)': 'onTouched()',
-    '[value]': 'value',
     '[class.ng-untouched]': 'ngClassUntouched',
     '[class.ng-touched]': 'ngClassTouched',
     '[class.ng-pristine]': 'ngClassPristine',
@@ -39,7 +38,7 @@ export class NgSelectOption {
   }
 })
 export class SelectControlValueAccessor implements ControlValueAccessor {
-  value = '';
+  value: string;
   onChange = (_) => {};
   onTouched = () => {};
 
@@ -51,8 +50,6 @@ export class SelectControlValueAccessor implements ControlValueAccessor {
   }
 
   writeValue(value) {
-    // both this.value and setProperty are required at the moment
-    // remove when a proper imperative API is provided
     this.value = value;
     setProperty(this.renderer, this.elementRef, "value", value);
   }

modules/angular2/src/forms/directives/shared.ts

@@ -1,5 +1,5 @@
-import {ListWrapper, iterableToList} from 'angular2/src/facade/collection';
-import {isBlank, BaseException} from 'angular2/src/facade/lang';
+import {ListWrapper, iterableToList, StringMapWrapper} from 'angular2/src/facade/collection';
+import {isBlank, BaseException, looseIdentical} from 'angular2/src/facade/lang';
 
 import {ControlContainer} from './control_container';
 import {NgControl} from './ng_control';
@@ -26,7 +26,7 @@ export function setUpControl(c: Control, dir: NgControl) {
   // view -> model
   dir.valueAccessor.registerOnChange(newValue => {
     dir.viewToModelUpdate(newValue);
-    c.updateValue(newValue);
+    c.updateValue(newValue, {emitModelToViewChange: false});
     c.markAsDirty();
   });
 
@@ -52,3 +52,11 @@ export function setProperty(renderer: Renderer, elementRef: ElementRef, propName
                             propValue: any) {
   renderer.setElementProperty(elementRef, propName, propValue);
 }
+
+export function isPropertyUpdated(changes: StringMap<string, any>, viewModel: any): boolean {
+  if (!StringMapWrapper.contains(changes, "model")) return false;
+  var change = changes["model"];
+
+  if (change.isFirstChange()) return true;
+  return !looseIdentical(viewModel, change.currentValue);
+}

modules/angular2/src/forms/model.ts

@@ -151,10 +151,13 @@ export class Control extends AbstractControl {
     this._valueChanges = new EventEmitter();
   }
 
-  updateValue(value: any, {onlySelf, emitEvent}: {onlySelf?: boolean, emitEvent?: boolean} = {}):
+  updateValue(value: any,
+              {onlySelf, emitEvent, emitModelToViewChange}:
+                  {onlySelf?: boolean, emitEvent?: boolean, emitModelToViewChange?: boolean} = {}):
       void {
+    emitModelToViewChange = isPresent(emitModelToViewChange) ? emitModelToViewChange : true;
     this._value = value;
-    if (isPresent(this._onChange)) this._onChange(this._value);
+    if (isPresent(this._onChange) && emitModelToViewChange) this._onChange(this._value);
     this.updateValueAndValidity({onlySelf: onlySelf, emitEvent: emitEvent});
   }
 

modules/angular2/test/forms/integration_spec.ts

@@ -721,6 +721,33 @@ export function main() {
            });
          }));
     });
+
+    describe("ng-model corner cases", () => {
+      it("should not update the view when the value initially came from the view",
+         inject([TestComponentBuilder], fakeAsync((tcb: TestComponentBuilder) => {
+                  var form = new Control("");
+
+                  var t =
+                      `<div><input type="text" [ng-form-control]="form" [(ng-model)]="name"></div>`;
+                  var rootTC;
+                  tcb.overrideTemplate(MyComp, t).createAsync(MyComp).then(
+                      (root) => { rootTC = root; });
+                  tick();
+                  rootTC.componentInstance.form = form;
+                  rootTC.detectChanges();
+
+                  var input = rootTC.query(By.css("input")).nativeElement;
+                  input.value = "aa";
+                  input.selectionStart = 1;
+                  dispatchEvent(input, "change");
+
+                  tick();
+                  rootTC.detectChanges();
+
+                  // selection start has not changed because we did not reset the value
+                  expect(input.selectionStart).toEqual(1);
+                })));
+    });
   });
 }
 

modules/angular2/test/forms/model_spec.ts

@@ -71,6 +71,15 @@ export function main() {
           expect(onChange).toEqual(["invoked", "newValue"]);
         });
 
+        it("should not invoke on change when explicitly specified", () => {
+          var onChange = null;
+          c.registerOnChange((v) => onChange = ["invoked", v]);
+
+          c.updateValue("newValue", {emitModelToViewChange: false});
+
+          expect(onChange).toBeNull();
+        });
+
         it("should update the parent", () => {
           c.updateValue("newValue");
           expect(g.value).toEqual({"one": "newValue"});