add an afterRollback event (#292)

README.md

@@ -166,6 +166,7 @@ Be sure to call `validate()` on the `changeset` before saving or committing chan
 * Events
   + [`beforeValidation`](#beforevalidation)
   + [`afterValidation`](#aftervalidation)
+  + [`afterRollback`](#afterrollback)
 
 #### `error`
 
@@ -743,6 +744,22 @@ changeset.validate().then(() => {
 
 **[⬆️ back to top](#api)**
 
+#### `afterRollback`
+
+This event is triggered after a rollback of the changeset.
+This can be used for [some advanced use cases](https://github.com/offirgolan/ember-changeset-cp-validations/issues/25#issuecomment-375855834)
+where it is necessary to separately track all changes that are made to the changeset.
+
+```js
+changeset.on('afterRollback', () => {
+  console.log("changeset has rolled back");
+});
+changeset.rollback();
+// console output: changeset has rolled back
+```
+
+**[⬆️ back to top](#api)**
+
 ## Validation signature
 
 To use with your favorite validation library, you should create a custom `validator` action to be passed into the changeset:

addon/index.js

@@ -67,6 +67,7 @@ const OPTIONS = '_options';
 const RUNNING_VALIDATIONS = '_runningValidations';
 const BEFORE_VALIDATION_EVENT = 'beforeValidation';
 const AFTER_VALIDATION_EVENT = 'afterValidation';
+const AFTER_ROLLBACK_EVENT = 'afterRollback';
 const defaultValidatorFn = () => true;
 const defaultOptions = { skipValidate: false };
 
@@ -139,7 +140,7 @@ export type ChangesetDef = {|
   _validateAndSet: <T>(string, T) => (Promise<T> | Promise<ErrLike<T>> | T | ErrLike<T>),
   _setIsValidating: (string, boolean) => void,
   _validate: (string, mixed, mixed) => (ValidationResult | Promise<ValidationResult>),
-  trigger: (string, string) => void,
+  trigger: (string, string | void) => void,
   isValidating: (string | void) => boolean,
   cast: (Array<string>) => ChangesetDef,
   willDestroy: () => void,
@@ -388,14 +389,16 @@ export function changeset(
       for (let key in relayCache) relayCache[key].rollback();
 
       // Get keys before reset.
-      let keys = (this /*: ChangesetDef */)._rollbackKeys();
+      let c /*: ChangesetDef     */ = this;
+      let keys = c._rollbackKeys();
 
       // Reset.
       set(this, RELAY_CACHE, {});
       set(this, CHANGES, {});
       set(this, ERRORS, {});
-      (this /*: ChangesetDef */)._notifyVirtualProperties(keys)
+      c._notifyVirtualProperties(keys)
 
+      c.trigger(AFTER_ROLLBACK_EVENT);
       return this;
     },
 

tests/unit/changeset-test.js

@@ -1243,6 +1243,30 @@ test('afterValidation event is triggered with the key', function(assert) {
   });
 });
 
+/**
+ * afterRollback
+ */
+
+test('afterRollback event is fired after rollback', function(assert) {
+  let dummyChangeset;
+  let _validator = () => resolve(true);
+  let _validations = {
+    reservations() {
+      return _validator();
+    }
+  };
+  let hasFired = false;
+
+  set(dummyModel, 'reservations', 'ABC12345');
+  dummyChangeset = new Changeset(dummyModel, _validator, _validations);
+  dummyChangeset.on('afterRollback', () => { hasFired = true; });
+
+  run(() => {
+    dummyChangeset.rollback();
+    assert.ok(hasFired, 'afterRollback should be triggered');
+  });
+});
+
 /**
  * Behavior.
  */