Merge pull request #1096 from sarhugo/model-events

Model events

Documentation/Books/Users/Foxx/FoxxModel.mdpp

@@ -55,6 +55,47 @@ person.attributes // => { name: "Pete", admin: true, active: true }
 person.errors // => {admin: [ValidationError: value is not allowed]}
 ```
 
+The following events are emitted by a model:
+
+- beforeCreate
+- afterCreate
+- beforeSave
+- afterSave
+- beforeUpdate
+- afterUpdate
+- beforeRemove
+- afterRemove
+
+Model lifecycle:
+
+```js
+var person = new PersonModel();
+person.on('beforeCreate', function() {
+  var model = this;
+  model.fancyMethod(); // Do something fancy with the model
+});
+var people = new Repository(appContext.collection("people"), { model: PersonModel });
+
+people.save(person);
+// beforeCreate()
+// beforeSave()
+// The model is created at db
+// afterSave()
+// afterCreate()
+
+people.update(person, data);
+// beforeUpdate(data)
+// beforeSave(data)
+// The model is updated at db
+// afterSave(data)
+// afterUpdate(data)
+
+people.remove(person);
+// beforeRemove()
+// The model is deleted at db
+// afterRemove()
+```
+
 !SUBSECTION Extend
 <!-- js/server/modules/org/arangodb/foxx/model.js -->
 @startDocuBlock JSF_foxx_model_extend

js/server/modules/org/arangodb/foxx/model.js

@@ -32,6 +32,8 @@ var Model,
   joi = require("joi"),
   is = require("org/arangodb/is"),
   extend = require('org/arangodb/extend').extend,
+  EventEmitter = require('events').EventEmitter,
+  util = require('util'),
   excludeExtraAttributes,
   metadataSchema = {
     _id: joi.string().optional(),
@@ -142,8 +144,11 @@ Model = function (attributes) {
   } else if (attributes) {
     instance.attributes = _.clone(attributes);
   }
+  EventEmitter.call(instance);
 };
 
+util.inherits(Model, EventEmitter);
+
 Model.fromClient = function (attributes) {
   'use strict';
   return new this(excludeExtraAttributes(attributes, this));

js/server/modules/org/arangodb/foxx/repository.js

@@ -130,8 +130,12 @@ _.extend(Repository.prototype, {
 ////////////////////////////////////////////////////////////////////////////////
   save: function (model) {
     'use strict';
+    model.emit('beforeCreate');
+    model.emit('beforeSave');
     var id_and_rev = this.collection.save(model.forDB());
     model.set(id_and_rev);
+    model.emit('afterSave');
+    model.emit('afterCreate');
     return model;
   },
 
@@ -262,8 +266,11 @@ _.extend(Repository.prototype, {
 ////////////////////////////////////////////////////////////////////////////////
   remove: function (model) {
     'use strict';
-    var id = model.get('_id');
+    model.emit('beforeRemove');
-    return this.collection.remove(id);
+    var id = model.get('_id'),
+      result = this.collection.remove(id);
+    model.emit('afterRemove');
+    return result;
   },
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -398,10 +405,14 @@ _.extend(Repository.prototype, {
 ////////////////////////////////////////////////////////////////////////////////
   update: function (model, data) {
     'use strict';
+    model.emit('beforeUpdate', data);
+    model.emit('beforeSave', data);
     var id = model.get("_id") || model.get("_key"),
       id_and_rev = this.collection.update(id, data);
     model.set(data);
     model.set(id_and_rev);
+    model.emit('afterSave', data);
+    model.emit('afterUpdate', data);
     return model;
   },
 

js/server/tests/shell-foxx-model-events-spec.js

@@ -0,0 +1,83 @@
+/*global require, describe, expect, it, beforeEach, createSpyObj */
+
+var FoxxRepository = require("org/arangodb/foxx/repository").Repository,
+  Model = require("org/arangodb/foxx/model").Model;
+
+describe('Model Events', function () {
+  'use strict';
+
+  var collection, instance, repository;
+
+  beforeEach(function () {
+    collection = createSpyObj('collection', [
+      'update',
+      'save',
+      'remove'
+    ]);
+    instance = new Model({ random: '', beforeCalled: false, afterCalled: false });
+    repository = new FoxxRepository(collection, {model: Model});
+  });
+
+  it('should be possible to subscribe and emit events', function () {
+    expect(instance.on).toBeDefined();
+    expect(instance.emit).toBeDefined();
+  });
+
+  it('should emit beforeCreate and afterCreate events when creating the model', function () {
+    addHooks(instance, 'Create');
+    expect(repository.save(instance)).toEqual(instance);
+    expect(instance.get('beforeCalled')).toBe(true);
+    expect(instance.get('afterCalled')).toBe(true);
+  });
+
+  it('should emit beforeSave and afterSave events when creating the model', function () {
+    addHooks(instance, 'Save');
+    expect(repository.save(instance)).toEqual(instance);
+    expect(instance.get('beforeCalled')).toBe(true);
+    expect(instance.get('afterCalled')).toBe(true);
+  });
+
+  it('should emit beforeUpdate and afterUpdate events when updating the model', function () {
+    var newData = { newAttribute: 'test' };
+    addHooks(instance, 'Update', newData);
+    expect(repository.update(instance, newData)).toEqual(instance);
+    expect(instance.get('beforeCalled')).toBe(true);
+    expect(instance.get('afterCalled')).toBe(true);
+  });
+
+  it('should emit beforeSave and afterSave events when updating the model', function () {
+    var newData = { newAttribute: 'test' };
+    addHooks(instance, 'Save', newData);
+    expect(repository.update(instance, newData)).toEqual(instance);
+    expect(instance.get('beforeCalled')).toBe(true);
+    expect(instance.get('afterCalled')).toBe(true);
+  });
+
+  it('should emit beforeRemove and afterRemove events when removing the model', function () {
+    addHooks(instance, 'Remove');
+    repository.remove(instance);
+    expect(instance.get('beforeCalled')).toBe(true);
+    expect(instance.get('afterCalled')).toBe(true);
+  });
+
+});
+
+function addHooks(model, ev, dataToReceive) {
+  'use strict';
+
+  var random = String(Math.floor(Math.random() * 1000));
+
+  model.on('before' + ev, function (data) {
+    expect(this).toEqual(model);
+    expect(data).toEqual(dataToReceive);
+    this.set('random', random);
+    this.set('beforeCalled', true);
+  });
+  model.on('after' + ev, function (data) {
+    expect(this).toEqual(model);
+    expect(data).toEqual(dataToReceive);
+    this.set('afterCalled', true);
+    expect(this.get('beforeCalled')).toBe(true);
+    expect(this.get('random')).toEqual(random);
+  });
+}