feat(forms): add support for validations

modules/angular2/src/forms/model.js

@@ -1,18 +1,56 @@
-import {StringMapWrapper, StringMap} from 'angular2/src/facade/collection';
+import {isPresent} from 'angular2/src/facade/lang';
+import {StringMap, StringMapWrapper} from 'angular2/src/facade/collection';
+import {nullValidator, controlGroupValidator} from './validators';
+
+export const VALID = "VALID";
+export const INVALID = "INVALID";
 
 export class Control {
   value:any;
+  validator:Function;
+  status:string;
+  errors;
+  _parent:ControlGroup;
 
-  constructor(value:any) {
+  constructor(value:any, validator:Function = nullValidator) {
     this.value = value;
+    this.validator = validator;
+    this._updateStatus();
+  }
+
+  updateValue(value:any) {
+    this.value = value;
+    this._updateStatus();
+    this._updateParent();
+  }
+
+  get valid() {
+    return this.status === VALID;
+  }
+
+  _updateStatus() {
+    this.errors = this.validator(this);
+    this.status = isPresent(this.errors) ? INVALID : VALID;
+  }
+
+  _updateParent() {
+    if (isPresent(this._parent)){
+      this._parent._controlChanged();
+    }
   }
 }
 
 export class ControlGroup {
-  controls: StringMap;
+  controls;
+  validator:Function;
+  status:string;
+  errors;
 
-  constructor(controls:StringMap) {
+  constructor(controls, validator:Function = controlGroupValidator) {
     this.controls = controls;
+    this.validator = validator;
+    this._setParentForControls();
+    this._updateStatus();
   }
 
   get value() {
@@ -22,4 +60,23 @@ export class ControlGroup {
     });
     return res;
   }
+
+  get valid() {
+    return this.status === VALID;
+  }
+
+  _setParentForControls() {
+    StringMapWrapper.forEach(this.controls, (control, name) => {
+      control._parent = this;
+    });
+  }
+
+  _updateStatus() {
+    this.errors = this.validator(this);
+    this.status = isPresent(this.errors) ? INVALID : VALID;
+  }
+
+  _controlChanged() {
+    this._updateStatus();
+  }
 }