I am creating a webapp where user creates an inventory of items and he uses folders to categorize them. Now suppose I have two folders like this:
All items (route: /)
Closet items (route: #get/closet/id)
When I navigate between these routes, I want to dispose of the models rendered in the previous route. How and where should I do that? Is there an event which is triggered when I navigate to a new route where may be I can perform this operation?
There are lots of ways to approach this, and it really depends on how you're doing the navigation. If you're changing routes with actual links, or by using router.navigate(), your router will dispatch a route:<route name> event that you can listen to, passing the same arguments to the handler as it passes to the route function.
In what turned out to be a demonstration of just how long it takes to set up test case code with Backbone, I made you a jsFiddle to illustrate this approach: http://jsfiddle.net/nrabinowitz/ZrgJF/7/
A lot of this is just setup code; the important parts for this question are the router:
var MyRouter = Backbone.Router.extend({
routes: {
'view/:id' : 'openView'
},
openView: function(id) {
app.openView(id)
}
});
router = new MyRouter();
And the view, which binds removal to the route:
var MyView = Backbone.View.extend({
initialize: function(opts) {
this.id = opts.id;
router.bind('route:openView', this.dispose, this);
},
// id is the same as the route argument
dispose: function(id) {
if (id != this.id) {
this.remove();
}
}
// etc
});
Related
I'm trying to use Backbone with REST API:
Here the code
My model:
var PagesModel = Backbone.Model.extend({
idAttribute: 'Guid',
initialize: function () {
this.on('remove', this.destroy);
},
urlRoot: '/api/pages'
});
Collection:
var PagesCollection = Backbone.Collection.extend({
model: PagesModel,
url: '/api/pages'
});
View:
var PagesView = Backbone.View.extend({
el: '#pages',
events: {
'click .removePage': 'remove',
},
initialize: function (collection) {
this.collection = collection;
this.collection.fetch();
this.template = $('#pages-template').html();
this.collection.bind('change reset', this.render, this);
},
render: function () {
var template = _.template(this.template);
$(this.el).html(template({ pages: this.collection.toJSON() }));
return this;
},
remove: function (e) {
e.preventDefault();
var id = $(e.currentTarget).closest('ul').data("id");
var item = this.collection.get(id);
this.collection.remove(item);
$(e.currentTarget).closest('ul').fadeOut(300, function () {
$(this).remove();
});
}
});
And here I'm starting up application:
$(function () {
var pagesCollection = new PagesCollection();
var pagesView = new PagesView(pagesCollection);
});
I'm clicking or Remove and in Network inspector see this link
http://localhost:54286/backbone/function%20()%20%7B%20%20%20%20%20%20var%20base%20=%20getValue(this,%20'urlRoot')%20%7C%7C%20getValue(this.collection,%20'url')%20%7C%7C%20urlError();%20%20%20%20%20%20if%20(this.isNew())%20return%20base;%20%20%20%20%20%20return%20base%20+%20(base.charAt(base.length%20-%201)%20==%20'/'%20?%20''%20:%20'/')%20+%20encodeURIComponent(this.id);%20%20%20%20}
instead of /api/pages/{guid}.
What I'm doing wrong?
I still haven't figured fully why, but you can make it work by destroying your model after the end of its removal (Backbone does one last thing after triggering the remove event: destroy the collection's reference in the model).
But what's even better, is using directly the destroy function on the model, it will remove it from the collection automatically (use {wait: true} if needed).
Edit:
Finally managed to locate the source of the problem. It's rather simple in fact. To override the model's url (calculated with urlRoot but that doesn't matter), you can pass Model#destroy a url option when calling Backbone.sync (or something that'll call it).
Now you're thinking "but I don't!". But you do. The listener (Model#destroy in your case) is given 3 arguments. Model#destroy will take the first one (the model itself) as options.
And here's the fail (I think Backbone needs a patch to this): giving an url option to Backbone.sync is the only time _.result in not used to calculate the url. So you find yourself having as url the url property of your model, which is the function you see in your call.
Now, for a quickfix:
this.on('remove', this.destroy.bind(this, {}));
This will ensure the first argument of your Model#destroy call is {} (as well as binding the context).
Bear with me a little longer.
Now, if you're still willing to call Collection#remove before destroying your model, here's a little hack: because (as I stated above) the remove event is triggered before Backbone makes sure to remove the collection's reference in your model, you don't need the urlRoot property in your model. Indeed, the model won't be in the collection anymore, but Backbone will still take the collection's url into account to get the model's url (as the reference is still there).
Not a definitive answer, but just going by the code in your question and the backbone.js documentation, the problem may be that you named your method remove and this is getting in the way of the remove method in Backbone.View.
http://backbonejs.org/#View-remove
Update:
It also looks like the output you see in the network inspector is that the definition of the Backbone.Model.url function is being appended. Meaning url is not being properly called (Maybe the () is missing by the caller?). Are you overriding Backbone.sync anywhere in your application?
Note: I'm a total ignoramus regarding javascript.
I've broken my ExtJS 4.1 MVC app out into several controllers like:
/app/controller/Auth
| |Quiz
| |Result
| |Blah...
|model/...
I want to respond to an "event", not a DOM Event, rather a Ext.form.action.Submit.success event by calling functions in both my Auth and Quiz controllers. The summarized code for the first part is here:
// File: app/controller/Auth.js
attemptLogin : function() {
var form = Ext.ComponentQuery.query('#loginpanel')[0].form;
if (form.isValid()) {
form.submit({
success : function(form, action) {
// THIS IS THE FUNCTION FROM THE CURRENT CONTROLLER
Assessor.controller.Auth.prototype.finishLogin();
// THIS IS THE FUNCTION FROM THE OTHER CONTROLLER
Assessor.controller.Quiz.prototype.setupAssessment();
},
This works but feels wrong. Is there a proper way to do this? It seems like I should fire a unique event that is listened to by both controllers, but I can't understand how to do that with Ext.Event. Any guidance?
Thanks! I'm really grateful for all the great ideas and advice.
It makes sense to me to fire a custom event from the form and simply listen to it in both your controllers, like what you said here:
It seems like I should fire a unique event that is listened to by both
controllers
// File: app/controller/Auth.js
attemptLogin : function() {
var form = Ext.ComponentQuery.down('#loginpanel').form;
if (form.isValid()) {
form.submit({
success : function(form, action) {
// fire the event from the form panel
form.owner.fireEvent('loginsuccess', form.owner);
},
Then in each of your controllers you can listen to it with Controller#control, like this:
Ext.define('YourApp.controller.Auth', {
extend: 'Ext.app.Controller',
init: function() {
var me = this;
me.control({
'#loginpanel': {
loginsuccess: me.someHandler
}
});
},
someHandler: function(form) {
//whatever needs to be done
console.log(form);
}
}
And then add the same thing to your Quiz controller:
Ext.define('YourApp.controller.Quiz', {
extend: 'Ext.app.Controller',
init: function() {
var me = this;
me.control({
'#loginpanel': {
loginsuccess: me.someOtherHandler
}
});
},
someOtherHandler: function(form) {
//whatever needs to be done
console.log(form);
}
}
I've used this approach successfully in 4.1.0 and 4.1.1
It really should be
Assessor.controller.Auth.prototype.finishLogin.apply(this, arguments)
or something along these lines (in order to have a correct this reference that points to the 'owner' of the method, the controller object)
However, why do you use this unorthodox way to call the current controller's method. Just set the scope for the success callback, then call this.finishLogin().
form.submit({
success : function(form, action) {
// THIS IS THE FUNCTION FROM THE CURRENT CONTROLLER
this.finishLogin();
...
},
scope: this
});
Also, you can retrieve another controller instance using Controller#getController.
this.getController('Assessor.controller.quiz').setupAssignment();
Then, if your controller methods are not depending on each other, you could make them both listen to the same event.
Another solution is to fire a custom event once the login is finished. You could do that on the application object
this.application.fireEvent('logincomplete');
and in your controller's init method:
this.application.mon('logincomplete', this.setupAssignment, this);
Please note that you cannot listen to those events via Controller#control - see Alexander Tokarev's blog post for a patch to Ext to achieve this.
There is no standard way to fire events between controllers, but it's possible with some custom hacks. See my recent blog post.
I have also been looking for this and all you need is Asanda.app.getController('quiz').setupAssignment();, where Asanda is the name of your app
You should use a MessageBus if you have to send events between controllers:
Ext.define('MyApp.utils.MessageBus', {
extend : 'Ext.util.Observable'
});
store the message bus in a global var
MsgBus = Ext.create('MyApp.utils.MessageBus');
Where you have to send events:
MsgBus.fireEvent('eventName',eventArg_1,eventArg_2);
Where you have to receive events:
MsgBus.on('eventName', functionHandler,scope); //scope is not mandatory
...
functionHandler:function(eventArg_1,eventArg_2){
...
//do whatever you want
...
}
There's a addPost function in my router. I don't want to re-create the postAddView every time the function is invoked:
addPost: function () {
var that = this;
if (!this.postAddView) {
this.postAddView = new PostAddView({
model: new Post()
});
this.postAddView.on('back', function () {
that.navigate('#/post/list', { trigger: true });
});
}
this.elms['page-content'].html(this.postAddView.render().el);
}
Here's the PostAddView:
PostAddView = backbone.View.extend({
events: {
'click #post-add-back': 'back'
}
, back: function (e) {
e.preventDefault();
this.trigger('back');
}
});
The first time the postAddView is rendered, the event trigger works well. However, after rendering other views to page-content and render postAddView back, the event trigger won't be trigger anymore. The following version of addPost works well, though.
addPost: function () {
var that = this, view;
view = new PostAddView({
model: new Post()
});
this.elms['page-content'].html(view.render().el);
view.on('back', function () {
delete view;
that.navigate('#/post/list', { trigger: true });
});
}
Somewhere you are calling jQuery's remove and that
In addition to the elements themselves, all bound events and jQuery data associated with the elements are removed.
so the delegate call that Backbone uses to bind events to your postAddView.el will be lost. Then, when you re-add your postAddView.el, there are is no delegate attached anymore and no events are triggered. Note that Backbone.View's standard remove method calls jQuery's remove; a few other things in jQuery, just as empty will do similar things to event handlers. So the actual function call that is killing your delegate could be hidden deep inside something else.
You could try calling delegateEvents manually:
this.elms['page-content'].html(this.postAddView.render().el);
this.postAddView.delegateEvents();
or better, just throw the view away and create a new one every time you need it. Your view objects should be pretty light weight so creating new ones should be cheap and a lot less hassle than trying to keep track of the existing views by hand.
If you really want to reuse the current DOM and View you do not need to set again and again the element as you are doing, everything that you call .html() you are destroying the DOM of the View and generating again and losing events. Also I prefer always to add the "el" in the DOM before render the View. I will have your function in this way:
addPost: function () {
if (!this.postAddView) {
this.postAddView = new PostAddView({
model: new Post()
});
this.postAddView.on('back', this.onBack);
this.elms['page-content'].html(this.postAddView.el);
}
this.postAddView.render();
},
onBack : function () {
this.navigate('#/post/list', { trigger: true });
}
I'm not fan of the use of local variables to refer to "this". If all of your Views uses _.bindAll(this) in the initialize method you could bind your events to your view and could use this(check how I transformed onBack).
With my code there is not a need to manually call this.delegateEvents()
Can't figure out what's wrong. When I click on a model title, it fetches all models in collection at once rather than fetch one model. If I move this event from logView to logsView it works properly but doesn't have access to model, well I can find this model using index or ant other model's ID but don't think this is a nice way.
var Log = Backbone.Model.extend({});
window.LogsList = Backbone.Collection.extend({
model:Log,
url:function (tag) {
this.url = '/logs/' + tag;
return this;
}
});
window.colList = new LogsList();
window.logView = Backbone.View.extend({
el:$('.accordion'),
template:_.template($('#log').html()),
initialize:function () {
this.model.bind('add', this.render, this);
},
events:{
"click .accordion-toggle" :"getLogBody"
},
render:function () {
return this.template(this.model.toJSON());
},
getLogBody:function () {
this.model.fetch();
}
});
window.LogsView = Backbone.View.extend({
el:$("#content"),
initialize:function (options) {
colList.bind('reset', this.addAll, this);
colList.url(options.data).fetch();
},
addOne:function (model) {
var view = new logView({model:model});
$("#accordion").append(view.render());
},
addAll:function () {
colList.each(this.addOne);
}
});
window.listView = new LogsView({data:"Visa_Cl"});
The problem is caused by your el in the LogView: el:$('.accordion')
Backbone's view events are scope to the view's el. In this case, you've specified the view's el as ALL HTML elements with a class of "accordion". Therefore, when you click on any of your HTML elements with this class, the code runs for all of them, which is why you are seeing this behavior.
This article will show you a few options for doing what you want, correctly:
Backbone.js: Getting The Model For A Clicked Element
I would also recommend reading this one, to better understand the use of el in Backbone, and a few of the tricks and traps of it:
Backbone.js: Object Literals, Views Events, jQuery, and el
I have a multiple files uploadify setting with:
'onComplete' : function(event, ID, fileObj, response, data) {
myCollection.add({params parsed from response json});
}
which triggers (trough this.collection.bind('add', this.add)) this collection view method:
add: function(obj) {
var view = new MyModelView({model: obj});
this.$('.insert-models-here').append(view.render().el);
return this;
},
The new MyModelView call triggers: MyModelView::initialize() which is here:
initialize: function() {
var t = $('#photo-template').html();
this.template = _.template(t);
this.model.view = this;
},
And every _.template() calls jumps inside __flash__toXML() method from which all thread is stopped.
The result is no model added inside my collection from any uploadify event.
Does anyone knows why and how to avoid this?
Ok, I found solution.
Problem was in using underscore in uploadify events so I replace underscore _.templates with icanhaz and rewrite my add() collection view method this way to workaround any underscore functionality:
add: function(obj) {
var view = new MyModelView({model: obj});
$('.insert-models-here').first().append(view.render().el);
return this;
},
Hope someone will call my name in future..