feat(form): add ability to reset a form to pristine state

Retting a form to pristine state will cause all of the nested
form and form controls to be recursively reset as well.

Closes #856

1 files changed, 31 insertions, 2 deletions

diff --git a/src/ng/directive/form.js b/src/ng/directive/form.js
index 4f06f093..b4d500c6 100644
--- a/src/ng/directive/form.js
+++ b/src/ng/directive/form.js
@@ -5,7 +5,8 @@ var nullFormCtrl = {
   $addControl: noop,
   $removeControl: noop,
   $setValidity: noop,
-  $setDirty: noop
+  $setDirty: noop,
+  $setPristine: noop
 };
 
 /**
@@ -37,7 +38,8 @@ function FormController(element, attrs) {
   var form = this,
       parentForm = element.parent().controller('form') || nullFormCtrl,
       invalidCount = 0, // used to easily determine if we are valid
-      errors = form.$error = {};
+      errors = form.$error = {},
+      controls = [];
 
   // init state
   form.$name = attrs.name;
@@ -61,6 +63,8 @@ function FormController(element, attrs) {
   }
 
   form.$addControl = function(control) {
+    controls.push(control);
+
     if (control.$name && !form.hasOwnProperty(control.$name)) {
       form[control.$name] = control;
     }
@@ -73,6 +77,8 @@ function FormController(element, attrs) {
     forEach(errors, function(queue, validationToken) {
       form.$setValidity(validationToken, true, control);
     });
+
+    arrayRemove(controls, control);
   };
 
   form.$setValidity = function(validationToken, isValid, control) {
@@ -120,6 +126,29 @@ function FormController(element, attrs) {
     parentForm.$setDirty();
   };
 
+  /**
+   * @ngdoc function
+   * @name ng.directive:form.FormController#$setPristine
+   * @methodOf ng.directive:form.FormController
+   *
+   * @description
+   * Sets the form to its pristine state.
+   *
+   * This method can be called to remove the 'ng-dirty' class and set the form to its pristine
+   * state (ng-pristine class). This method will also propagate to all the controls contained
+   * in this form.
+   *
+   * Setting a form back to a pristine state is often useful when we want to 'reuse' a form after
+   * saving or resetting it.
+   */
+  form.$setPristine = function () {
+    element.removeClass(DIRTY_CLASS).addClass(PRISTINE_CLASS);
+    form.$dirty = false;
+    form.$pristine = true;
+    forEach(controls, function(control) {
+      control.$setPristine();
+    });
+  };
 }