iterate through an array in a collection

Question

So, I'm still very new to Backbone. My question is this: I have a collection that is made like this:

...
isCollection: true,
parse: function(response) {
    if (response.status == 'ok') {
        this.page = response.result.page;
        this.count = response.result.count;
        this.total = response.result.total;
        this.sort = response.result.sort;
        this.ascending = response.result.ascending;
        this.myReports = response.result.results;
        return this;
    } else {

    }

Where this.myReports is an array of objects. My question is how do I iterate over the array (myReports)? Do I have to convert it to a collection? If I try to use .each, i get an error about .each not being supported.

Thanks for any help!

Answer 1

Did you try iterating through it like a simple js array?

something like:

for(var i in myArray){
   var item = myArray[i];
   //dosomething
}

Maybe it's worth trying underscorejs for advanced array features.

Answer 2

I would put the elements of response.result.results into the collection this way:

parse: function(response) {
    if (response.status == 'ok') {
        this.page = response.result.page;
        this.count = response.result.count;
        this.total = response.result.total;
        this.sort = response.result.sort;
        this.ascending = response.result.ascending;
        return response.result.results;
    } else {

    }
}

Now if fetch ing the collection succeeds, and response.status is 'ok' , then:

• your collection will have fields called page , count , total , sort and ascending ,
• these fields will contain the values you get as the fields of response.result ,
• the length of the collection will be the length of response.result.results , and
• the items of the collection will be the items of response.result.results , so you can iterate over them inside the success handler of fetch .

If the fetch fails, or response.status is not 'ok' , then the length of the collection will be zero. The fields page , count , total , sort and ascending will be undefined , unless you define them somewhere, for example in initialize or in the else branch inside the above parse function.

Here is a working example. The output is printed in the console, so eg in Chrome, press F12 and change to the Console tab. Anyway, since Backbone collections have a method called sort , I would change the name of the sort field to something else ( sorted , toBeSorted , etc. - I don't know the semantics of this field).

Answer 3

When you call myCollection.each on a Backbone collection, you are essentially calling Underscore's each method, but it is being presented to you a bit nicer as a Backbone.Collection method.

You could just use the method on the array:

_.each(this.myReports, function (report) {
  // do whatever with report
})

Whether you should convert it to a backbone collection is another question. If you want to store models in it, or use any of the Backbone.Collection functionality, then sure, convert it using the each method above.