backbone routes - ordering and filtering - backbone.js

Question

In my Backbone app, on my collection I have numerous sorting methods, when rendering the views based on the collection I am currently using a global var set via the route (I do it with a global as other actions add to the collection and I want the last ordering to be used). For example
routes : {
"" : "index",
'/ordering/:order' : 'ordering'
},
ordering : function(theorder) {
ordering = theorder;
listView.render();
},
then in my view
if (typeof ordering === 'undefined') {
d = this.collection.ordered();
}
else if(ordering == 'owners') {
d = this.collection.owners();
}
_.each(d, function(model){
model.set({request : self.model.toJSON()});
var view = new TB_BB.OfferItemView({model : model});
els.push(view.render().el);
});
Where ordered and owners are the 2 ordering methods.
So my first question is, based on routes could someone advice a better way of implementing above? This view gets rendered in multiple places hence me using a global rather than passing a ordered var to the method?
Second question is - I would like to also add some filtering, so lets say I want to sort by 'price' but also do some filtering (lets say by multiple categories id). How could I add a flexible 'route' to deal with filtering.
I guess I could do
routes : {
"" : "index",
'/ordering/:order/:filter1/:filter2' : 'ordering'
},
So the filter1 and filter2 would be the subsequent filtering, but if the filters could be 0 or 100 this will not work. Could anyone offer a solution?

Answer 1

Well, first you should be using Backbone's built-in ability to auto-sort collections. You can take advantage of this by defining a comparator function on your collection. This gives you all kinds of wins right out of the box — for example, the collection will re-sort itself every time you add or remove something from it, based on your comparator. If you want to define multiple sort functions, just define them all as functions and then update comparator when you need to. Then you can ditch that ugly global var.
For your second question, I'm not totally sure what you mean by "if the filters could be 0 or 100 this will not work." If you mean that you'll run into trouble if you don't specifiy all of the filters, then that's true. But you can use a wildcard to fix that. Here's what that might look like:
// your routes look like this:
routes : {
'/ordering/:order/filters/*filters' : 'ordering' // your routes will look like: /ordering/price/filters/filter_one/filter_two/filter_three
},
ordering: function (order, filters) {
filters = filters.split('/'); // creates an array of filters: ['filter_one', 'filter_two', 'filter_three']
listView.render(filters); // pass your filters to the view
}
// listView.render() looks like this:
render: function(filters) {
collection = this.collection;
_.each(filters, function (filter) {
collection = collection.filter(function () {
// your actual filtering code based on what the filter is
});
});
}