BackboneJS with XML ajax

问题:

this is a two part question from a JS newbie.

So, I was trying to create a backbone application using requireJS by following Thomas Davis's tutorial.

1. How do I go create Backbone collections out of an ajax call to a server that provides data in XML? collections.fetch() seem to be expecting a JSON backend.

2. while trying some things, I ended up with the following code, in which the page doesn't refresh upon populating the collection "bookStore" from within Ajax success-callback.

   Here is how far I have gotten so far.

   var bookListView = Backbone.View.extend({
       el: $("#books"),
       initialize: function () {
           thisView = this;
           $.ajax({
               type: "GET",
               url: "books.xml",
               dataType: "xml",
               success: function (data) {
                   console.log(data);
                   $(data).find('book').each(function (index) {
                       var bookTitle = $(this).find('name').text();
                       bookStore.add({ title: bookTitle });
   
                       console.log(seid);
                   });
                   thisView.collection = bookStore;
                   thisView.collection.bind('add', thisView.tryBind);
   
               }
           }).done(function (msg) {
               alert("Data retrieved: " + msg);
           });
   
           this.collection = bookStore;
           this.collection.bind("add", this.exampleBind);
           this.collection.bind("refresh", function () { thisView.render(); });
           /*
           // This one works!
           bookStore.add({ name: "book1" });
           bookStore.add({ name: "book2" });
           bookStore.add({ name: "book3" });
           */
       },
       tryBind: function (model) {
           console.log(model);
       },
       render: function () {
           var data = {
               books: this.collection.models,
           };
           var compiledTemplate = _.template(bookListTemplate, data);
           $("#books").html(compiledTemplate);
       }
   });
   

Here, the success call-back in the "initialize" function seems to be processing the data properly and adding to the collection. However, the page doesn't refreshed.

While I was stepping through the Firebug console, the page gets refreshed however. How do I solve this problem?

回答1:

1. You can override the default parse function to provide XML support. It should return the data transformed into JSON http://backbonejs.org/#Collection-parse

2. Bind the render to a reset event instead of refresh for Backbone<1.0 or to a sync event for Backbone>=1.0

It could look like this

var Book = Backbone.Model.extend();

var Books = Backbone.Collection.extend({
    model: Book,
    url: "books.xml",

    parse: function (data) {
        var $xml = $(data);

        return $xml.find('book').map(function () {
            var bookTitle = $(this).find('name').text();
            return {title: bookTitle};
        }).get();
    },

    fetch: function (options) {
        options = options || {};
        options.dataType = "xml";
        return Backbone.Collection.prototype.fetch.call(this, options);
    }
});

var bookListView = Backbone.View.extend({
    initialize: function () {
        this.listenTo(this.collection, "sync", this.render);
    },

    render: function () {
        console.log(this.collection.toJSON());
    }
});

var bks = new Books();
new bookListView({collection: bks});
bks.fetch();

And a demo http://jsfiddle.net/ULK7q/73/