Adding Models to Backbone.js Collection Silently Fails

Question

I am implementing a Blog Engine as a learning exercise for a new job. I have a Backbone.js Collection class called BlogList that is composed of BlogModel objects (a BlogModel is a single post to a blog). I have a masterBlogList that keeps all blog posts in memory for the lifetime of the application (I realize this is not a realistic design, but it is part of the spec).

I have chosen to use masterBlogList to hold the canonical state of the application. All new posts, edits, etc. are persisted to the database (MongoDB) as well as masterBlogList. When I want to display a subset of the posts in masterBlogList, I copy them into a new BlogList instance and then narrow this new instance down based on search criteria. Again, I realize this might not be the best design (cloning BlogModels and BlogLists), but it is what I've got and I'd prefer not to rework it.

The problem is that copying one BlogList to another is not working. Even when the source list is non-empty, the destination list always ends up being empty. I have tried to debug this every which way with no luck. Here is the relevant portion of the BlogList source code:

// BlogList

$ (function () {
App.BlogList = Backbone.Collection.extend ({
    model : App.BlogModel,
    url : '/blog-entries',

    comparator : function (a) {
        return -(new Date (a.get ('date')));
    },

    populateFromMemory : function (sourceList) {
        // this.reset ();

        var self = this;
        sourceList.each (function (postModel) {
            self.add(postModel);
        });

        var foo = new App.BlogModel();
        this.add(foo);
    },

(continued...)

Even the last bit regarding foo is not working. I've also tried adding a clone() of postModel and also new App.BlogModel(postModel.toJSON()).

Any help would be extremely appreciated!

`self.add(postModel);` doesn't work? what `console.log(postModel)` inside `sourceList.each` says? — theotheo, Jun 06 '12 at 21:58

score 1 · Answer 1 · answered Jun 06 '12 at 22:43

Sorry to have bothered anyone :<, but I got it working. The code actually does work as written above. The problem is that my search criteria were filtering out all of the posts, so I wasn't seeing anything. End of a long day! Thanks to those who tried to help me...

Adding Models to Backbone.js Collection Silently Fails

1 Answers1