feat(forms): provide support for controls and state flags

lib/directive/module.dart

@@ -72,6 +72,6 @@ class NgDirectiveModule extends Module {
     value(NgStyleDirective, null);
     value(NgNonBindableDirective, null);
     value(NgTemplateDirective, null);
-    value(NgForm, null);
+    value(NgForm, new NgNullForm());
   }
 }

lib/directive/ng_form.dart

@@ -8,15 +8,129 @@ part of angular.directive;
 @NgDirective(
     selector: 'form',
     visibility: NgDirective.CHILDREN_VISIBILITY)
-class NgForm {
-  dom.Element _element;
-  Scope _scope;
+@NgDirective(
+    selector: '.ng-form',
+    visibility: NgDirective.CHILDREN_VISIBILITY)
+@NgDirective(
+    selector: '[ng-form]',
+    visibility: NgDirective.CHILDREN_VISIBILITY)
+class NgForm extends NgDetachAware {
+  static const String NG_VALID_CLASS    = "ng-valid";
+  static const String NG_INVALID_CLASS  = "ng-invalid";
+  static const String NG_PRISTINE_CLASS = "ng-pristine";
+  static const String NG_DIRTY_CLASS    = "ng-dirty";
+
+  final dom.Element _element;
+  final Scope _scope;
+
+  String _name;
+
+  bool _dirty;
+  bool _pristine;
+  bool _valid;
+  bool _invalid;
+
+  final List<NgModel> _controls = new List<NgModel>();
+  final Map<String, NgModel> _controlByName = new Map<String, NgModel>();
 
   NgForm(this._scope, this._element) {
     if(!this._element.attributes.containsKey('action')) {
       this._element.onSubmit.listen((event) {
         event.preventDefault();
       });
     }
+
+    this.pristine = true;
   }
+
+  detach() {
+    for (int i = _controls.length - 1; i >= 0; --i) {
+      removeControl(_controls[i]);
+    }
+  }
+
+  @NgAttr('name')
+  get name => _name;
+  set name(name) {
+    _name = name;
+    _scope[name] = this;
+  }
+
+  get pristine => _pristine;
+  set pristine(value) {
+    _pristine = true;
+    _dirty = false;
+
+    _element.classes.remove(NG_DIRTY_CLASS);
+    _element.classes.add(NG_PRISTINE_CLASS);
+  }
+
+  get dirty => _dirty;
+  set dirty(value) {
+    _dirty = true;
+    _pristine = false;
+
+    _element.classes.remove(NG_PRISTINE_CLASS);
+    _element.classes.add(NG_DIRTY_CLASS);
+  }
+
+  get valid => _valid;
+  set valid(value) {
+    _invalid = false;
+    _valid = true;
+
+    _element.classes.remove(NG_INVALID_CLASS);
+    _element.classes.add(NG_VALID_CLASS);
+  }
+
+  get invalid => _invalid;
+  set invalid(value) {
+    _valid = false;
+    _invalid = true;
+
+    _element.classes.remove(NG_VALID_CLASS);
+    _element.classes.add(NG_INVALID_CLASS);
+  }
+
+  operator[](name) {
+    return _controlByName[name];
+  }
+
+  addControl(NgModel control) {
+    _controls.add(control);
+    if(control.name != null) {
+      _controlByName[control.name] = control;
+    }
+  }
+
+  removeControl(NgModel control) {
+    _controls.remove(control);
+    if(control.name != null) {
+      _controlByName.remove(control.name);
+    }
+  }
+}
+
+class NgNullForm implements NgForm {
+  NgNullForm() {}
+  operator[](name) {}
+  operator []=(String name, value) {}
+  addControl(control) {}
+  removeControl(control) {}
+  setValidity(control, String errorType, bool isValid) {}
+
+  get name => null;
+  set name(name) {}
+
+  get pristine => null;
+  set pristine(value) {}
+
+  get dirty => null;
+  set dirty(value) {}
+
+  get valid => null;
+  set valid(value) {}
+
+  get invalid => null;
+  set invalid(value) {}
 }

lib/directive/ng_model.dart

@@ -11,24 +11,41 @@ part of angular.directive;
  * (to be implemented)
  */
 @NgDirective(
-    selector: '[ng-model]',
-    map: const {'ng-model': '&model'})
+    selector: '[ng-model]')
 class NgModel {
+  final NgForm _form;
+  final dom.Element _element;
   final Scope _scope;
 
   Getter getter = ([_]) => null;
   Setter setter = (_, [__]) => null;
+
   String _exp;
+  String _name;
 
+  bool _dirty;
+  bool _pristine;
+  bool _valid;
+  bool _invalid;
 
   Function _removeWatch = () => null;
   bool _watchCollection;
 
   Function render = (value) => null;
 
-  NgModel(this._scope, NodeAttrs attrs) {
+  NgModel(this._scope, NodeAttrs attrs, [dom.Element this._element, NgForm this._form]) {
     _exp = 'ng-model=${attrs["ng-model"]}';
     watchCollection = false;
+
+    _form.addControl(this);
+    pristine = true;
+  }
+
+  @NgAttr('name')
+  get name => _name;
+  set name(value) {
+    _name = value;
+    _form.addControl(this);
   }
 
   get watchCollection => _watchCollection;
@@ -43,6 +60,7 @@ class NgModel {
     }
   }
 
+  @NgCallback('ng-model')
   set model(BoundExpression boundExpression) {
     getter = boundExpression;
     setter = boundExpression.assign;
@@ -55,6 +73,43 @@ class NgModel {
 
   get modelValue        => getter();
   set modelValue(value) => setter(value);
+
+  get pristine => _pristine;
+  set pristine(value) {
+    _pristine = true;
+    _dirty = false;
+    _element.classes.remove(NgForm.NG_DIRTY_CLASS);
+    _element.classes.add(NgForm.NG_PRISTINE_CLASS);
+  }
+
+  get dirty => _dirty;
+  set dirty(value) {
+    _dirty = true;
+    _pristine = false;
+    _element.classes.remove(NgForm.NG_PRISTINE_CLASS);
+    _element.classes.add(NgForm.NG_DIRTY_CLASS);
+  }
+
+  get valid => _valid;
+  set valid(value) {
+    _invalid = false;
+    _valid = true;
+    _element.classes.remove(NgForm.NG_INVALID_CLASS);
+    _element.classes.add(NgForm.NG_VALID_CLASS);
+  }
+
+  get invalid => _invalid;
+  set invalid(value) {
+    _valid = false;
+    _invalid = true;
+    _element.classes.remove(NgForm.NG_VALID_CLASS);
+    _element.classes.add(NgForm.NG_INVALID_CLASS);
+  }
+
+
+  destroy() {
+    _form.removeControl(this);
+  }
 }
 
 /**