diff --git a/modules/angular2/forms.js b/modules/angular2/forms.js
index c6b0c5d325..e943dd2d96 100644
--- a/modules/angular2/forms.js
+++ b/modules/angular2/forms.js
@@ -1,3 +1,4 @@
 export * from './src/forms/model';
 export * from './src/forms/directives';
-export * from './src/forms/validators';
\ No newline at end of file
+export * from './src/forms/validators';
+export * from './src/forms/validator_directives';
\ No newline at end of file
diff --git a/modules/angular2/src/forms/directives.js b/modules/angular2/src/forms/directives.js
index 9ca80e38a4..66c4d4ad89 100644
--- a/modules/angular2/src/forms/directives.js
+++ b/modules/angular2/src/forms/directives.js
@@ -88,14 +88,13 @@ export class ControlDirective {
   _initialize() {
     this._groupDecorator.addDirective(this);
 
-    if (isPresent(this.validator)) {
-      var c = this._control();
-      c.validator = validators.compose([c.validator, this.validator]);
-    }
+    var c = this._control();
+    c.validator = validators.compose([c.validator, this.validator]);
 
     if (isBlank(this.valueAccessor)) {
       this.valueAccessor = controlValueAccessorFor(this.type);
     }
+
     this._updateDomValue();
     DOM.on(this._el.domElement, "change", (_) => this._updateControlValue());
   }
diff --git a/modules/angular2/src/forms/model.js b/modules/angular2/src/forms/model.js
index c714f20471..982b21e659 100644
--- a/modules/angular2/src/forms/model.js
+++ b/modules/angular2/src/forms/model.js
@@ -5,32 +5,69 @@ import {nullValidator, controlGroupValidator} from './validators';
 export const VALID = "VALID";
 export const INVALID = "INVALID";
 
+//interface IControl {
+//  get value():any;
+//  validator:Function;
+//  get status():string;
+//  get errors():Map;
+//  get active():boolean {}
+//  updateValue(value:any){}
+//  setParent(parent){}
+//}
+
 export class Control {
-  value:any;
-  validator:Function;
-  status:string;
-  errors;
+  _value:any;
+  _status:string;
+  _errors;
+  _updated:boolean;
   _parent:ControlGroup;
+  validator:Function;
 
   constructor(value:any, validator:Function = nullValidator) {
-    this.value = value;
+    this._value = value;
     this.validator = validator;
-    this._updateStatus();
+    this._updated = true;
   }
 
   updateValue(value:any) {
-    this.value = value;
-    this._updateStatus();
+    this._value = value;
+    this._updated = true;
     this._updateParent();
   }
 
-  get valid() {
-    return this.status === VALID;
+  get active():boolean {
+    return true;
   }
 
-  _updateStatus() {
-    this.errors = this.validator(this);
-    this.status = isPresent(this.errors) ? INVALID : VALID;
+  get value() {
+    return this._value;
+  }
+
+  get status() {
+    this._updateIfNeeded();
+    return this._status;
+  }
+
+  get valid() {
+    this._updateIfNeeded();
+    return this._status === VALID;
+  }
+
+  get errors() {
+    this._updateIfNeeded();
+    return this._errors;
+  }
+
+  setParent(parent){
+    this._parent = parent;
+  }
+
+  _updateIfNeeded() {
+    if (this._updated) {
+      this._updated = false;
+      this._errors = this.validator(this);
+      this._status = isPresent(this._errors) ? INVALID : VALID;
+    }
   }
 
   _updateParent() {
@@ -41,42 +78,118 @@ export class Control {
 }
 
 export class ControlGroup {
-  controls;
+  _value:any;
+  _status:string;
+  _errors;
+  _updated:boolean;
   validator:Function;
-  status:string;
-  errors;
+  controls;
 
   constructor(controls, validator:Function = controlGroupValidator) {
     this.controls = controls;
     this.validator = validator;
+    this._updated = true;
     this._setParentForControls();
-    this._updateStatus();
   }
 
   get value() {
-    var res = {};
-    StringMapWrapper.forEach(this.controls, (control, name) => {
-      res[name] = control.value;
-    });
-    return res;
+    this._updateIfNeeded();
+    return this._value;
+  }
+
+  get status() {
+    this._updateIfNeeded();
+    return this._status;
   }
 
   get valid() {
-    return this.status === VALID;
+    this._updateIfNeeded();
+    return this._status === VALID;
+  }
+
+  get errors() {
+    this._updateIfNeeded();
+    return this._errors;
   }
 
   _setParentForControls() {
     StringMapWrapper.forEach(this.controls, (control, name) => {
-      control._parent = this;
+      control.setParent(this);
     });
   }
 
-  _updateStatus() {
-    this.errors = this.validator(this);
-    this.status = isPresent(this.errors) ? INVALID : VALID;
+  _updateIfNeeded() {
+    if (this._updated) {
+      this._updated = false;
+      this._value = this._reduceValue();
+      this._errors = this.validator(this);
+      this._status = isPresent(this._errors) ? INVALID : VALID;
+    }
+  }
+
+  _reduceValue() {
+    var newValue = {};
+    StringMapWrapper.forEach(this.controls, (control, name) => {
+      if (control.active) {
+        newValue[name] = control.value;
+      }
+    });
+    return newValue;
   }
 
   _controlChanged() {
-    this._updateStatus();
+    this._updated = true;
   }
 }
+
+export class OptionalControl {
+  _control:Control;
+  _cond:boolean;
+
+  constructor(control:Control, cond:boolean) {
+    super();
+    this._control = control;
+    this._cond = cond;
+  }
+
+  get active():boolean {
+    return this._cond;
+  }
+
+  get value() {
+    return this._control.value;
+  }
+
+  get status() {
+    return this._control.status;
+  }
+
+  get errors() {
+    return this._control.errors;
+  }
+
+  set validator(v) {
+    this._control.validator = v;
+  }
+
+  get validator() {
+    return this._control.validator;
+  }
+
+  set cond(value:boolean){
+    this._cond = value;
+    this._control._updateParent();
+  }
+
+  get cond():boolean{
+    return this._cond;
+  }
+
+  updateValue(value:any){
+    this._control.updateValue(value);
+  }
+
+  setParent(parent){
+    this._control.setParent(parent);
+  }
+}
\ No newline at end of file
diff --git a/modules/angular2/src/forms/validators.js b/modules/angular2/src/forms/validators.js
index ec43010b0e..f49a75a58d 100644
--- a/modules/angular2/src/forms/validators.js
+++ b/modules/angular2/src/forms/validators.js
@@ -4,7 +4,7 @@ import {List, ListWrapper, StringMapWrapper} from 'angular2/src/facade/collectio
 import {ControlGroup, Control} from 'angular2/forms';
 
 export function required(c:Control) {
-  return isBlank(c.value) || c.value === "" ? {"required" : true} : null;
+  return isBlank(c.value) || c.value == "" ? {"required" : true} : null;
 }
 
 export function nullValidator(c:Control) {
@@ -13,17 +13,18 @@ export function nullValidator(c:Control) {
 
 export function compose(validators:List<Function>):Function {
   return function(c:Control) {
-    return ListWrapper.reduce(validators, (res, validator) => {
+    var res = ListWrapper.reduce(validators, (res, validator) => {
       var errors = validator(c);
       return isPresent(errors) ? StringMapWrapper.merge(res, errors) : res;
     }, {});
+    return StringMapWrapper.isEmpty(res) ? null : res;
   }
 }
 
 export function controlGroupValidator(c:ControlGroup) {
   var res = {};
   StringMapWrapper.forEach(c.controls, (control, name) => {
-    if (isPresent(control.errors)) {
+    if (control.active && isPresent(control.errors)) {
       res[name] = control.errors;
     }
   });
diff --git a/modules/angular2/test/forms/integration_spec.js b/modules/angular2/test/forms/integration_spec.js
index b77c4ddc62..27eca06218 100644
--- a/modules/angular2/test/forms/integration_spec.js
+++ b/modules/angular2/test/forms/integration_spec.js
@@ -15,7 +15,7 @@ import {MockTemplateResolver} from 'angular2/src/mock/template_resolver_mock';
 import {Injector} from 'angular2/di';
 
 import {Component, Decorator, Template} from 'angular2/core';
-import {ControlGroupDirective, ControlDirective, Control, ControlGroup,
+import {ControlGroupDirective, ControlDirective, Control, ControlGroup, OptionalControl,
   ControlValueAccessor, RequiredValidatorDirective} from 'angular2/forms';
 
 import * as validators from 'angular2/src/forms/validators';
@@ -42,7 +42,7 @@ export function main() {
 
     tplResolver.setTemplate(componentType, new Template({
       inline: template,
-      directives: [ControlGroupDirective, ControlDirective, WrappedValue]
+      directives: [ControlGroupDirective, ControlDirective, WrappedValue, RequiredValidatorDirective]
     }));
 
     compiler.compile(componentType).then((pv) => {
diff --git a/modules/angular2/test/forms/model_spec.js b/modules/angular2/test/forms/model_spec.js
index 700b50a23a..8ef2f7bc21 100644
--- a/modules/angular2/test/forms/model_spec.js
+++ b/modules/angular2/test/forms/model_spec.js
@@ -1,5 +1,5 @@
 import {ddescribe, describe, it, iit, xit, expect, beforeEach, afterEach, el} from 'angular2/test_lib';
-import {ControlGroup, Control} from 'angular2/forms';
+import {ControlGroup, Control, OptionalControl} from 'angular2/forms';
 import * as validations from 'angular2/forms';
 
 export function main() {
@@ -40,7 +40,17 @@ export function main() {
     });
 
     describe("validator", () => {
-      it("should run the validator with the initial value", () => {
+      it("should run the validator with the initial value (valid)", () => {
+        var g = new ControlGroup({
+          "one": new Control('value', validations.required)
+        });
+
+        expect(g.valid).toEqual(true);
+
+        expect(g.errors).toEqual(null);
+      });
+
+      it("should run the validator with the initial value (invalid)", () => {
         var g = new ControlGroup({
           "one": new Control(null, validations.required)
         });
@@ -61,4 +71,54 @@ export function main() {
       });
     });
   });
+
+  describe("OptionalControl", () => {
+    it("should read properties from the wrapped component", () => {
+      var wrapperControl = new Control("value", validations.required);
+      var c = new OptionalControl(wrapperControl, true);
+
+      expect(c.value).toEqual('value');
+      expect(c.status).toEqual('VALID');
+      expect(c.validator).toEqual(validations.required);
+    });
+
+    it("should update the wrapped component", () => {
+      var wrappedControl = new Control("value");
+      var c = new OptionalControl(wrappedControl, true);
+
+      c.validator = validations.required;
+      c.updateValue("newValue");
+
+
+      expect(wrappedControl.validator).toEqual(validations.required);
+      expect(wrappedControl.value).toEqual('newValue');
+    });
+
+    it("should not include an inactive component into the group value", () => {
+      var group = new ControlGroup({
+        "required" : new Control("requiredValue"),
+        "optional" : new OptionalControl(new Control("optionalValue"), false)
+      });
+
+      expect(group.value).toEqual({"required" : "requiredValue"});
+
+      group.controls["optional"].cond = true;
+
+      expect(group.value).toEqual({"required" : "requiredValue", "optional" : "optionalValue"});
+    });
+
+    it("should not run validations on an inactive component", () => {
+      var group = new ControlGroup({
+        "required" : new Control("requiredValue", validations.required),
+        "optional" : new OptionalControl(new Control("", validations.required), false)
+      });
+
+      expect(group.valid).toEqual(true);
+
+      group.controls["optional"].cond = true;
+
+      expect(group.valid).toEqual(false);
+    });
+  });
+
 }
\ No newline at end of file
diff --git a/modules/angular2/test/forms/validators_spec.js b/modules/angular2/test/forms/validators_spec.js
index db3e8d7bcd..be3ccbb865 100644
--- a/modules/angular2/test/forms/validators_spec.js
+++ b/modules/angular2/test/forms/validators_spec.js
@@ -1,5 +1,5 @@
 import {ddescribe, describe, it, iit, xit, expect, beforeEach, afterEach, el} from 'angular2/test_lib';
-import {ControlGroup, Control, required, compose, controlGroupValidator} from 'angular2/forms';
+import {ControlGroup, Control, required, compose, controlGroupValidator, nullValidator} from 'angular2/forms';
 
 export function main() {
   function validator(key:string, error:any){
@@ -35,6 +35,11 @@ export function main() {
         var c = compose([validator("a", 1), validator("a", 2)]);
         expect(c(new Control(""))).toEqual({"a" : 2});
       });
+
+      it("should return null when no errors", () => {
+        var c = compose([nullValidator, nullValidator]);
+        expect(c(new Control(""))).toEqual(null);
+      });
     });
 
     describe("controlGroupValidator", () => {