I'm trying to create a dry search results model and collection for backbone so that no matter what I'm searching for in the app, we use the same model/collection and occasionally might call a different view.
My Model and controller are very simple
Myapp.Models.Search = Backbone.Model.extend();
Myapp.Collections.Search = Backbone.Collection.extend({
model: Myapp.Models.Search
});
I then populate the url value to get the correct requests and parameters in the view
Myapp.Views.SearchResults = Backbone.View.extend({
el: 'div#results',
initialize: function(){
Myapp.results = new Backbone.Collection.Search;
Myapp.results.url = this.model.search_type+'/'+this.model.data; //this holds the search query
Myapp.results.fetch({
success: function(){alert('got result')},
error: function(){alert('that is not good!');}
});
}
without 'fetch', everything is fine, but when I include fetch, the fetch is made, the results are returned, but I get the error
Uncaught TypeError: undefined is not a function in backbone.js:23
I've checked the response, and it is valid JSON. When I output the Myapp.results to the console, I see the collection, but it is still empty. Neither the error not success are getting gtriggered.
----------------update------------------------
as per the comments, I've divided up line 23, and found that the error is being returned in this line
a=new this.model(a,b),
If I am understanding what this line does, could this issue be because the response collection only has one model being returned? I would hope that wouldn't cause the issue, you should be able to have a collection with 1 or less models in it.
--------------update--------------------------
So I remove the reference to model within the collection, and now I don't get the error. So in some ways, this is resolved, but it shouldn't be. Is there a reason why up to now I've always defined the model associated with the collection?
Related
I have a backbone model which has Backbone Collections in it. When I save the model and if it is success then my model object is properly structured as it was. But when error occurs (say validation error), in error callback the model object is modified (Collections inside model object are converted into Array). As a result all my functions defined for that Collections are now "undefined" and gives me error.
save : function() {
this.model.save(_.extend(originalModel.toJSON() || {}, this.model
.toJSON()), {
success : this.onSaveSuccess,
error: this.onSaveError,
include : []
});
},
onSaveSuccess : function(model) {
//Here the model is properly structured
},
onSaveError : function(model, response) {
// Here the model is modified, all collections are now array
//I have to explicitly call my parse method to re structure it.
model = model.parse(model.attributes);
}
I would like to know why is this happening. Am I doing something wrong here ?
For the sake of this example, let's assume the attribute of the model that holds the collection is called "people". It isn't clearly documented, but model.save(attributes) actually behaves like:
model.set(attributes);
model.save();
Here's the relevant annotated source of save(...). What your code is doing is first setting the "people" attribute to the array of people, then attempting to save it. When the save fails, your model has the array, not the collection, as the value of "people".
I suspect your end point is returning the full representation of the model on success, and your model is correctly parsing that representation & re-building the Collection at that point. But your error handler won't do that automatically.
As an aside, in my experience Models that contain Collections are hard to manage & reason about. I've had better luck having a Model that contains an array of data, and then having a method on that Model to build a Collection on the fly. Something like:
var MyModel = Backbone.Model.extend({
// ...
getPeople: function() {
// See if we've previously built this collection
if (!this._peopleCollection) {
var people = this.get('people');
this._peopleCollection = new Backbone.Collection(people);
}
return this._peopleCollection;
}
});
This removes the Collection concept from the server communication (where it's pretty unnecessary), while also providing a smarter data layer of your application (smart Models are a good thing).
The solution for this is passing wait:true in options. This will not modify until and unless server returns a valid response.
save : function() {
this.model.save(_.extend(originalModel.toJSON() || {}, this.model
.toJSON()), {
success : this.onSaveSuccess,
error: this.onSaveError,
**wait:true**
include : []
});
},
I want to grab the length of a collection to use in a random number generator. I want a view that shows one model of the collection, randomly generated. I'm using coffeescript, btw
So far I've tried stuff like
#collection.fetch
data:
id: Math.floor((Math.random()*#length)+1)
which won't work because the length isn't there until after it's fetched... I've tried a couple of other methods, such as grabbing after fetching, but length is always zero.
Anyone give me an idea of how to do this?
edit: javascript for those who can't read coffee
this.collection.fetch({
data: {
'id': Math.floor((Math.random() * length) + 1)
}
});
I had same task in the past. I used underscore _.sample method.
Please try _.sample(collection) it will return random model from collection or even better _.sample(collection, 4) for 4 random models.
According to the Backbone manual :
Backbone.Collection
Collections are ordered sets of models
So what you need in your application is actually a random model from your server database. According to your API, you need to get the count of your records in your server and then get a random model of one of the records. If you are the developer of your Serverside API there is a way to do that with one connection, otherwise you can do something like this :
class randomModel extends Backbone.Model
// Assuming 'GET' /api/model/100 will get record No. 100
urlRoot: '/api/model'
// ... in your document ready
$ () ->
model = null
// Assuming 'GET' /api/count, will return JSON string with your records count
$.getJSON '/api/count', (response) =>
model = new randomModel id: (Math.random()*response.count)+1
model.fetch()
console.log model
Pretty much that's what I would use in your case. Another method is to populate the whole collection and get the random model after it is populated ( you save one request ), by doing :
collection.fetch() // get's all models
collection.get (Math.random()*collection.length)+1
I have this code in my Backbone application:
app.Collections.quotes = new app.Collections.Quotes();
app.Collections.quotes.fetch();
And I can see an array of Objects returned in the network tab but when I expand out the Collection, the Models array inside is 0. Do they get instantiated as Models when fetch() is ran on a new Collection?
This is my Collection:
app.Collections.Quotes = Backbone.Collection.extend({
model: app.Models.Quote,
url: function() {
return app.Settings.apiUrl() + '/quotes';
}
});
EDIT:
app.Collections.quotes.fetch({
success: function(){
app.Utils.ViewManager.swap('section', new app.Views.section({section: 'quotes'}));
}
});
And in my Model:
idAttribute: 'Number',
This was the fix! Thanks for help. Dan kinda pointed me in the right direction amongst the comments...
Calling fetch() on a Collection attempts to populate the JSON response into Models: Collection#fetch.
Is your server definitely returning a valid JSON array of objects?
Do you have any validation on your Quote Model? I'm pretty sure Backbone validates each models before populating the collection, only populating with the models which pass. So if it exists, check that your Model#validate method is working correctly.
You shouldn't need an ID (although it's obviously required if you want to edit them).
I know this error has come up a few times, but I'm still not sure how to make this work appropriately..
My magic begins here :
var list_edit_member_view = new app.views.ListMemberEdit({
el: $("#enterprise_member_list_edit_container"),
list_ids: list_ids
});
list_edit_member_view.render();
And this loads this View (ListMemberEdit.js) which has this in the render() :
this.list_edit_member_view = new app.views.CollectionView({
el: $("#enterprise_member_list_edit_container"),
collection: app.peers,
list_item: app.views.ListMemberEditSelection,
list_item_options: {list_ids: this.options.list_ids}
});
Which loads a CollectionView view that renders its list_item_options as model views.. It is within this file (ListMemberEditSelection.js), that when I perform this.destroy, it will return :
Uncaught Error: A "url" property or function must be specified
So this makes me think that the Model or the Model URL is not being defined.. I'm just not sure where to put this since it works very similar to my other partials that are doing roughly the same thing..
Any thoughts? My apologies for the vagueness. Let me know if there's anything else you would like to look at!
I'm curious if its possible to see where this URL attribute would be written within the Object Model or Collection itself.
This is because destroy() function will call Backbone.sync to update the server too, not only your models in the frontend. http://backbonejs.org/#Model-destroy
So, if you're using REST to sync your data, you'll need to set a url property in your model so Backbone know where to send request:
Backbone.Model.extend({
url: "http://myapi.com/"
})
To allow more flexibility, you can also set a urlRoot: http://backbonejs.org/#Model-urlRoot
I had a similar problem, I removed the "id":"" from my models default values and the problem was solved.
I did receive similar error
Try this: I am just making an assumption what your model might look like
window.MyModel = Backbone.Model.extend({
url: function(){
return this.instanceUrl;
},
initialize: function(props){
this.instanceUrl = props.url;
}
}
Please look at this question that I had posted myself for more details: https://stackoverflow.com/a/11700275/405117
I am providing this reference as the answers here helped me better understand
Hope this helps!
I created my web site having 2 types of users: admin and user. So, I created 3 pages mainpag.html, admin.html, user.html. and separate models, views, collections, routers.js files for each of them. After logging in, as I am sending users to separate HTML pages with different models, I can't automatically get user model. so I did like this:
First, I made AJAX call to server, asking for the _id (username in session, so I can get id)
from the id, I fetched the model, by model.fetch(), then I got my usermodel with all attributes.
then in the success callback of fetch, I did model.save({weight: "somevalue"}). According to me, it should update right, as the model is already available, that attribute weight also available with some old value, but it is sending POST request, also when I tried model.isNew(), it returned true. Where am I wrong? how can I update my model? I will post more details if required.
More details:
If I remove that save method, then I am getting correct attributes in the model.
If I don't remove that save method, that success and error callbacks are also appearing as attributes in the model.
Code:
addWeight : (e)->
arr=new Array()
arr['_id']=app._id
console.log "asdasd"
console.log arr
console.log arr['_id']
#user_model =new UserModel(arr)
#user_model.fetch({
success : (model,res,options) =>
console.log model
console.log res
arr=new Array()
arr['_id']=e.target.id
#arr['action']='weight' #means , update weight
##user_model.setArr(arr)
##user_model.set({weight : arr['_id']})
console.log "new : "+#user_model.isNew()
#user_model.save({weight : e.target.id})
##user_model.save({
# success : (model,res,options) =>
# console.log "model updated: "+JSON.stringify(model)
# console.log "Res : "+JSON.stringify(res)
# error : (model,res,options) =>
# console.log "Error : "+JSON.stringify(res)
#})
error : (model,res,options) =>
console.log "Error "
})
the above code is written in coffeescript, so even if you don't know coffeescript, don't worry, you can understand easily, and those # mean, it is a comment. here we follow indentation instead of braces.
one more doubt, a model's URL must be changed dynamically according to the requirement, right? what is the best way to achieve that? I am doing like this:
I am populating "array" containing the required fields that should be present in the URL. In model, s init func, I am using #arr=arr, then in URLs function, I check like this.
url : ->
if #arr['id']
"/user/#{#id}"
Is my approach right, or any better approach is there for dynamically setting URLs. Or can I directly set the URLs like this:
#user_model.setUrl "/someurl/someid" //this setUrl method is available in model's definition
#user_model.fetch() or save() or watever that needs url
Just a hunch, but you mentioned that you call model.fetch() to retrieve the _id field. Be sure to either return an id field instead _id (notice the underscore).
The call to model.isNew() returning true is an indicator that the id property was never set from the model.fetch() call.
I look forward to a possible further explanation with your code...
Looking at your code:
/* The model needs an 'id' attribute in order to marked as not new */
#user_model = new UserModel(id: arr['_id'])
Actually if you call
model.set({weight: "somevalue"});
It will update the value in the model, but it won't send a POST request
model.save(attribute);
Actually calls Backbone.sync as you probably know.
EDIT :
You might want ot set
m = Backbone.Model.extend({
idAttribute: '_id'
});
to every model, because the isNew method actually checks if the model has id attribute
Regarding to this you could see here that .set doesn't call backbone.sync here : http://jsfiddle.net/5M9HH/1/