javascript - Getting each model from a Backbone Collection - Stack Overflow

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I'm convinced this is a very easy fix, but none of the posts I've found so far seem to have addressed this directly: how do I loop over a collection to get each model?

The first method I'm trying to use is underscore's each method. Here is my call and function:

collection_var.each(paintThings);

and here is my function:

function paintThings() {
        console.log(this);
        console.log(this.model);
            var thing_type = this.model.get("type"),
                thing_other = this.model.get("otherAttribute");

                console.log(this.model);
                console.log(thing_type);
                console.log(thing_other);
        }

Right now, this comes out as undefined, and this.model errors:

Uncaught TypeError: Cannot read property 'model' of undefined 

I know the answer is simple, but it's driving me crazy! I'm new to underscore. Can anyone here help? I'm also open to other non-underscore methods if they are faster/better.

I also tried this:

 for (var i = 0, l = collection_var.length; i < l; i++) {
            console.log(collection_var[i]);
 }

but that's not giving me what I want either.

I'm convinced this is a very easy fix, but none of the posts I've found so far seem to have addressed this directly: how do I loop over a collection to get each model?

The first method I'm trying to use is underscore's each method. Here is my call and function:

collection_var.each(paintThings);

and here is my function:

function paintThings() {
        console.log(this);
        console.log(this.model);
            var thing_type = this.model.get("type"),
                thing_other = this.model.get("otherAttribute");

                console.log(this.model);
                console.log(thing_type);
                console.log(thing_other);
        }

Right now, this comes out as undefined, and this.model errors:

Uncaught TypeError: Cannot read property 'model' of undefined 

I know the answer is simple, but it's driving me crazy! I'm new to underscore. Can anyone here help? I'm also open to other non-underscore methods if they are faster/better.

I also tried this:

 for (var i = 0, l = collection_var.length; i < l; i++) {
            console.log(collection_var[i]);
 }

but that's not giving me what I want either.

• javascript
• backbone.js
• underscore.js

Share Improve this question Follow asked Apr 15, 2013 at 12:12 streetlightstreetlight 5,9681313 gold badges6565 silver badges102102 bronze badges

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5 Answers 5

Sorted by: Reset to default 25

First method: use the models property of your collection:

var myModel
for(var i=0; i<myCollection.length; i++) {
  myModel = myCollection.models[i];
}

Second method is with the each method:

myCollection.each(function(model, index, [context]) {...});

Iterating over every model of a collection eg. as give by backbone.js is

books.each(function(book) {
  book.publish();
});

In your case it should be something like this

collection_var.each(function(paintThing){
    console.log(paintThing);
    var thing_type = this.model.get("type"),
        thing_other = this.model.get("otherAttribute");

    console.log(paintThing);
    console.log(thing_type);
    console.log(thing_other);
});

http://backbonejs.org/#Collection-Underscore-Methods

I think you should try collection_var.models.each(paintThings). That should give you direct access to the models of a collection.

Okay, stupid error! I just had to pass an extra parameter to the function so I can touch the model.

Like this:

function paintThings(thing) {
    //returns model
    console.log(thing);
        var thing_type = thing.get("type"),
            thing_other = thing.get("otherAttribute");

            //These all respond directly
            console.log(thing);
            console.log(thing_type);
            console.log(thing_other);
    }

I'm still going to review all answers and accept the most elegant solution!

I used underscores map.

docs = Backbone.Collection.extend();

this.subViews = _.map(docs.models, function(doc) {
    return new DocView({ model: doc });
}, this);

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