I've a model listen on the vent for a event update:TotalCost, which is triggered from (unrelated) Collection C when any model M belonging to collection C changes.
This event is coded in the initialize method as below. On receiving the event I get the following error:
TypeError: this.set is not a function
this.set({ "totalsale": value});
CostModel = Backbone.Model.extend({
defaults: {
totalSale: 0,
totalTax: 0
},
initialize: function(attrs, options) {
if(options) {
if(options.vent) {
this.vent = options.vent;
}
}
this.vent.on("update:TotalCost", function(value) {
this.set({ "totalSale": value}); **//ERROR HERE**
});
}
});
It is highly possible you've forgot to add the new keyword before your model for example you have:
var user = UserModel();
// instead of
var user = new UserModel();
Have you tried using a closure?
CostModel = Backbone.Model.extend({
defaults: {
totalSale: 0,
totalTax: 0
},
initialize: function(attrs, options) {
var self = this;
if(options) {
if(options.vent) {
this.vent = options.vent;
}
}
this.vent.on("update:TotalCost", function(value) {
self.set({ "totalSale": value});
});
}
});
Perhaps you want this to refer to current CostModel instance, to do so you need to pass this to this.vent.on call so event callback will be executed in context of model:
this.vent.on("update:TotalCost", function(value) {
this.set({ "totalSale": value});
}, this);
it may be due to 'set' works on model not on object. so you can, first convert your object in to model then try..
in example:
new Backbone.Model(your_object).set('val', var);
Another cause of this error can be if you try to create a new model without using the "new" keyword
I was getting this mysterious error when using it with Parse. I had:
Parse.User().current().escape("facebookID")
... when I should have had:
Parse.User.current().escape("facebookID")
Removed the extra () and it works fine now.
Another cause:
// render() method in view object
setInterval(this.model.showName, 3000);
// showName() method in model object
showName: function(){
console.log(this.get('name')); // this.get is not a function
}
Related
Afternoon all, I'm relatively new to backbone and have been stumped for 3 days with this error which I have not seen before.
I have a collection 'TestCollection' which defines it's model as a function. When the collection is loaded I get an error the first time it attempts to make a model with class 'TestModel'.
The error I get is:
Uncaught TypeError: TestModel is not a constructor
at new model (testCollection.js:14)
at child._prepareModel (backbone.js:913)
at child.set (backbone.js:700)
at child.add (backbone.js:632)
at child.reset (backbone.js:764)
at Object.options.success (backbone.js:860)
at fire (jquery.js:3143)
at Object.fireWith [as resolveWith] (jquery.js:3255)
at done (jquery.js:9309)
at XMLHttpRequest.callback (jquery.js:9713)
I believe I have given both the collection and the model all of the code they should need to work. It feels like something has gone wrong with the loading, but when I put a console.log at the top of the model file I could see that it is definitely being loaded before the collection attempts to use it.
Any help would be massively appreciated.
TestCollection:
define([
'backbone',
'models/testModel'
], function(Backbone, TestModel) {
var TestCollection = Backbone.Collection.extend({
model: function(attrs) {
switch (attrs._type) {
case 'test':
console.log('making a test model')
return new TestModel();
}
},
initialize : function(models, options){
this.url = options.url;
this._type = options._type;
this.fetch({reset:true});
}
});
return TestCollection;
});
TestModel:
require([
'./testParentModel'
], function(TestParentModel) {
var TestModel = TestParentModel.extend({
urlRoot: 'root/url',
initialize: function() {
console.log('making test model')
}
});
return TestModel;
});
File where TestCollection is made:
define(function(require) {
var MyProjectCollection = require('collections/myProjectCollection');
var TestCollection = require('collections/testCollection');
Origin.on('router:dashboard', function(location, subLocation, action) {
Origin.on('dashboard:loaded', function (options) {
switch (options.type) {
case 'all':
var myProjectCollection = new MyProjectCollection;
myProjectCollection.fetch({
success: function() {
myProjectCollection.each(function(project) {
this.project[project.id] = {};
this.project[project.id].testObjects = new TestCollection([], {
url: 'url/' + project.id,
_type: 'test'
});
});
}
});
}
});
});
I've had a look around stack overflow, it does not appear to be the issue below (which seems to be the most common issue).
Model is not a constructor-Backbone
I also do not think I have any circular dependencies.
Any help would be massively appreciated as I am completely stumped. I've tried to include only the relevant code, please let me know if additional code would be useful.
Thanks
I can't say for other parts of the code but an obvious problem you have is misunderstanding what data is passed to the model creator function.
var TestCollection = Backbone.Collection.extend({
model: function(attrs) {
switch (attrs._type) { // attrs._type does exist here
console.log( attrs ); // Will print { foo: 'bar' }
case 'test': // This will always be false since attrs._type does not exist
console.log('making a test model')
return new TestModel();
default:
return new Backbone.Model(); // Or return some other model instance,
// you MUST have this function return
// some kind of a Backbone.Model
}
},
initialize : function(models, options){
this.url = options.url;
this._type = options._type;
this.fetch({reset:true});
}
});
new TestCollection([ { foo: 'bar' }], {
url: 'url/' + project.id,
_type: 'test' // This will NOT be passed to the model attrs, these are
// options used for creating the Collection instance.
})
To re-iterate. When you instantiate a Collection you pass an array of plain objects [{ foo: 'bar'}, { foo: 'baz'}] ( or you get them via fetch like you're doing ). That object will be passed as the attrs parameter in the model function, and the model function MUST return at least some kind of a Backbone.Model instance so you need a fallback for your switch statement.
Seems like this should be obvious, but there seem to be so many different examples out there, most of which cause errors for me, making me think they are out of date. The basic situation is that I have a MessageModel linked to a MessageView which extends ItemView, MessageCollection linked to a MessageCollectionView (itemView: MessageView). I have a slightly unusual scenario in that the MessageCollection is populated asynchronously, so when the page first renders, it is empty and a "Loading" icon would be displayed. Maybe I have things structured incorrectly (see here for the history), but right now, I've encapsulated the code that makes the initial request to the server and receives the initial list of messages in the MessageCollection object such that it updates itself. However, I'm not clear, given this, how to trigger displaying the view. Obviously, the model shouldn't tell the view to render, but none of my attempts to instantiate a view and have it listen for modelChange events and call "render" have worked.
I have tried:
No loading element, just display the CollectionView with no elements on load, but then it doesn't refresh after the underlying Collection is refreshed.
Adding modelEvents { 'change': 'render' } to the view --> Uncaught TypeError: Object function () { return parent.apply(this, arguments); } has no method 'on'
I also tried this.bindTo(this.collection..) but "this" did not nave a bindTo method
Finally, I tried, in the view.initialize: _.bindAll(this); this.model.on('change': this.render); --> Uncaught TypeError: Object function () { [native code] } has no method 'on'
Here is the code
Entities.MessageCollection = Backbone.Collection.extend({
defaults: {
questionId: null
},
model: Entities.Message,
initialize: function (models, options) {
options || (options = {});
if (options.title) {
this.title = options.title;
}
if (options.id) {
this.questionId = options.id;
}
},
subscribe: function () {
var self = this; //needed for proper scope
QaApp.Lightstreamer.Do('subscribeUpdate', {
adapterName: 'QaAdapter',
parameterValue: this.questionId,
otherStuff: 'otherstuff',
onUpdate: function (data, options) {
console.log("calling sync");
var obj = JSON.parse(data.jsonString);
self.set(obj.Messages, options);
self.trigger('sync', self, obj.Messages, options);
}
});
},
});
Views.MessageCollectionView = Backbone.Marionette.CollectionView.extend({
itemView: Views.MessageView,
tagName: 'ul',
// modelEvents: {
// 'change': 'render'
// },
onAfterItemAdded: function (itemView) {
this.$el.append(itemView.el);
}
});
var Api = {
subscribe: function (id) {
var question = new QaApp.Entities.Question(null, { id: id });
question.subscribe();
var questionView = new QaApp.Views.QuestionView(question);
QaApp.page.show(questionView);
}
};
I am very grateful for all the help I've received already and thanks in advance for looking.
Try this:
var questionView = new QaApp.Views.QuestionView({
collection: question
});
In this code...
_.each(this.photos, function(element,index,list) {
console.log('element...');
console.log(element);
var photoView = new PhotoView({photo:element});
self.$el.append(photoView.render());
});
element is the entire this.photos collection. Why is not just one photo element of the 10 in the collection?
EDIT: Here is my method that populates the photos collection....
loadPhotos: function(memberId) {
var self = this;
this.photos = new PhotosCollection([]);
this.photos.on('error', this.eventSyncError, this);
this.photos.fetch({
url: this.photos.urlByMember + memberId,
success: function(collection,response,options) {
console.log('Fetch photos success!');
self.render();
}
});
},
The collection loads with models just fine. In the Chrome console, I can see the collection of models. I'm not sure what's wrong. I cannot iterate the collection with any of the methods recommended by posters below.
You are using the _.each method incorrectly. The underscore methods needs to called directly on the collection:
this.photos.each(function(element,index,list) {
console.log('element...');
console.log(element);
var photoView = new PhotoView({photo:element});
self.$el.append(photoView.render());
});
Or you if want to use the _.each from you need to pass in the models property and not the collection object itself as the list:
_.each(this.photos.models, function(element,index,list) {
console.log('element...');
console.log(element);
var photoView = new PhotoView({photo:element});
self.$el.append(photoView.render());
});
One should use this.photos.each(function(elt, index, list){...}) instead of _.each(this.photos,...) because this.photos is not an underscorejs _.chain object.
Thank you for your suggestions! I would never have figured this out without all your advice above. So here was the problem...
In the parent view, this loads up photo records for a particular member...
loadPhotos: function(memberId) {
var self = this;
this.photos = new PhotosCollection([]);
this.photos.on('error',this.eventSyncError,this);
this.photos.fetch({
url: this.photos.urlByMember + memberId,
success: function(collection,response,options) {
self.render();
}
});
},
Still in the parent view, Backbone.Subviews uses this to call each child view when it renders. Note how I'm passing this.photos to the subvw-photos...
subviewCreators: {
"subvw-profile": function() {
var options = {member: this.member};
// do any logic required to create initialization options, etc.,
// then instantiate and return new subview object
return new ProfileView( options );
},
"subvw-photos": function() {
var options = {photos: this.photos};
return new PhotosView( options );
},
"subvw-comments": function() {
var options = {};
return new CommentsView( options );
}
},
This is in the subvw-photos child view. Note how the intialize is accepting the collection as a parameter. See this problem?...
initialize: function(photos) {
Backbone.Courier.add(this);
this.photos = photos;
},
render: function() {
console.log('rendering photosview now...');
var self = this;
this.photos.each(function(element,index,list) {
var photoView = new PhotoView({photo:element});
$(self.el).append(photoView.render());
});
return this;
},
I was passing an object wrapping the photos collection in to initalize but then treating it like it was just a ref to the photos collection. I had to change the subvw-photos initialize to the following...
initialize: function(args) {
Backbone.Courier.add(this);
this.photos = args.photos;
},
Then of course all the other code magically began working :-/
Thank you again for your tips! You definitely kept me on track :-)
I am having problems including an additional model into my view which is based on a collection. I have a list of comments which is created by a parent view. Its need that I have the current user name when rendering the comments to show delete button and to highlight if its his own comment. The problem is now that I cant access in CommentListView the model session, so this.session in initialize or a call from a method like addAllCommentTo list is undefinied. What I am doing wrong here? I thought its easily possible to add another object to an view appart from the model.
CommentListView:
window.CommentListView = Backbone.View.extend({
el: $("#comments"),
initialize: function () {
this.model.bind('reset', this.addAllCommentToList, this);
this.model.bind('add', this.refresh, this);
this.model.bind('remove', this.refresh, this);
},
refresh: function(){
this.model.fetch();
},
addCommentToList : function(comment) {
console.log("comment added to dom");
//need to check why el reference is not working
$("#comments").append(new CommentView({model:comment, sessionModel: this.session}).render().el);
},
addAllCommentToList: function() {
$("#comments").empty();
this.model.each(this.addCommentToList);
}
});
Call from parent list in initialize method:
window.UserDetailView = Backbone.View.extend({
events: {
"click #newComment" : "newComment"
},
initialize: function () {
this.commentText = $("#commentText", this.el);
new CommentListView({ model: this.model.comments, session: this.model.session });
new LikeView({ model: this.model.like });
this.model.comments.fetch();
},
newComment : function() {
console.log("new comment");
this.model.comments.create(
new Comment({text: this.commentText.val()}), {wait: true}
);
this.commentText.val('');
}
});
Model:
window.UserDetail = Backbone.Model.extend({
urlRoot:'/api/details',
initialize:function () {
this.comments = new Comments();
this.comments.url = "/api/details/" + this.id + "/comments";
this.like = new Like();
this.like.url = "/api/details/" + this.id + "/likes";
this.session = new Session();
},
...
});
I see one problem, but can there be others.
You are initializing the View like this:
new CommentListView({ model: this.model.comments, session: this.model.session });
And you are expecting into your View to have a reference like this this.session.
This is not gonna happen. All the hash you send to the View constructor will be stored into this.options, from Backbone View constructor docs:
When creating a new View, the options you pass are attached to the view as this.options, for future reference.
So you can start changing this line:
$("#comments").append(new CommentView({model:comment, sessionModel: this.session}).render().el);
by this other:
$("#comments").append(new CommentView({model:comment, sessionModel: this.options.session}).render().el);
Try and tell us.
Updated
Also change this line:
this.model.each(this.addCommentToList);
by this:
this.model.each(this.addCommentToList, this);
The second argument is the context, in other words: what you want to be this in the called handler.
When the view is initialized, how can I bind the model to the specific View that is created? The view is current initialized at the start of the application. Also, how can I bind the model to the collection?
(function ($) { //loads at the dom everything
//Creation, Edit, Deletion, Date
var Note = Backbone.Model.extend({
defaults: {
text: "write here...",
done: false
},
initialize: function (){
if(!this.get("text")){
this.set({"text": this.default.text});
}
},
edit: function (){
this.save({done: !this.get("done")});
},
clear: function (){
this.destroy();
}
});
var NoteList = Backbone.Collection.extend({
model:Note
});
var NoteView = Backbone.View.extend ({
el: "body",
initialize: function(){
alert("initialized");
var list = new NoteList;
return list;
},
events: {
"click #lol" : "createNote"
},
createNote : function(){
var note = new Note;
this.push(note);
alert("noted");
}
});
var ninja = new NoteView;
})(jQuery);
Update
I just took a look at #James Woodruff's answer, and that prompted me to take another look at your code. I didn't look closely enough the first time, but I'm still not sure what you're asking. If you're asking how to have a model or view listen for and handle events triggered on the other, then check out James's example of calling bind() to have the view listen for change (or change:attr) events on the model (although I'd recommend using on() instead of bind(), depending what version of Backbone you're using).
But based on looking at your code again, I've revised my answer, because I see some things you're trying to do in ways that don't make sense, so maybe that's what you're asking about.
New Answer
Here's the code from your question, with comments added by me:
var NoteView = Backbone.View.extend ({
// JMM: This doesn't make sense. You wouldn't normally pass `el`
// to extend(). I think what you really mean here is
// passing el : $( "body" )[0] to your constructor when you
// instantiate the view, as there can only be one BODY element.
el: "body",
initialize: function(){
alert("initialized");
// JMM: the next 2 lines of code won't accomplish anything.
// Your NoteList object will just disappear into thin air.
// Probably what you want is one of the following:
// this.collection = new NoteList;
// this.list = new NoteList;
// this.options.list = new NoteList;
var list = new NoteList;
// Returning something from initialize() won't normally
// have any effect.
return list;
},
events: {
"click #lol" : "createNote"
},
createNote : function(){
var note = new Note;
// JMM: the way you have your code setup, `this` will be
// your view object when createNote() is called. Depending
// what variable you store the NoteList object in (see above),
// you want something here like:
// this.collection.push( note ).
this.push(note);
alert("noted");
}
});
Here is a revised version of your code incorporating changes to the things I commented on:
var NoteView = Backbone.View.extend( {
initialize : function () {
this.collection = new NoteList;
},
// initialize
events : {
"click #lol" : "createNote"
},
// events
createNote : function () {
this.collection.push( new Note );
// Or, because you've set the `model` property of your
// collection class, you can just pass in attrs.
this.collection.push( {} );
}
// createNote
} );
var note = new NoteView( { el : $( "body" )[0] } );
You have to bind views to models so when a model updates [triggers an event], all of the corresponding views that are bound to the model update as well. A collection is a container for like models... for example: Comments Collection holds models of type Comment.
In order to bind a view to a model they both have to be instantiated. Example:
var Note = Backbone.Model.extend({
defaults: {
text: "write here..."
},
initialize: function(){
},
// More code here...
});
var NoteView = Backbone.View.extend({
initialize: function(){
// Listen for a change in the model's text attribute
// and render the change in the DOM.
this.model.bind("change:text", this.render, this);
},
render: function(){
// Render the note in the DOM
// This is called anytime a 'Change' event
// from the model is fired.
return this;
},
// More code here...
});
Now comes the Collection.
var NoteList = Backbone.Collection.extend({
model: Note,
// More code here...
});
Now it is time to instantiate everything.
var Collection_NoteList = new NoteList();
var Model_Note = new Note();
var View_Note = new NoteView({el: $("Some Element"), model: Model_Note});
// Now add the model to the collection
Collection_NoteList.add(Model_Note);
I hope this answers your question(s) and or leads you in the right direction.