Backbone order collection alphabetically

Question

I am working on a backbone application at the moment, and I wanting to order my collection based on various attributes, I have sorting working based on cost, duration, start and finish date (timestamps) but I am struggling to sort the collection based on the name attribute, here is my collection code,

var ProjectCollection = Backbone.Collection.extend({

   url: '/projects',
   model: app.Project,
   sort_key: "finish_date",
   sort_order: 1,
   parent_filter: false,

   initialize: function() {
       var pm = this.get('projectmanager');
       this.set("project_manager", new app.User(pm));

       var sp = this.get('salesperson');
       this.set("sales_person", new app.User(sp));
   },

   comparator: function (item1, item2) {
       return (item1.get(this.sort_key) - item2.get(this.sort_key)) * this.sort_order;
   },

   sortByField: function(fieldName, orderType) {
       this.sort_key = fieldName;
       this.sort_order = orderType == "desc" ? -1 : 1;
       console.log(this.sort_order);
       this.sort();
  },

});

Is there are way to sort alphabetically on a string?

I have added the new comparator function, and this is output I get when ordering via name in an ascending fashion,

Android Application
Hello World I am a new instance of a project
Java Application
Simon's Project
Some new project
Symfony App, Windows Application iPhone Application

As you can see iPhone application should not be last in the list.

this just put my page into an endless load. – Udders Nov 05 '14 at 12:19 — Udders, Nov 05 '14 at 12:19

mfarouk · Answer 1 · 2014-11-06T07:04:38.823

i changed your comprator function to support strings along with numerics the problem in your comprator function is that it subtracting strings which yields NaN i changed it to be like

comparator: function (item1, item2) {
    var sortValue = (item1.get(this.sort_key) > item2.get(this.sort_key)) ? 1 : -1;
    return sortValue * this.sort_order;
},

this will just compare, get a value 1 for a > b and then change it for desc sort like you did

check this jsFiddle

EDIT: to support case insensitive ordering, comparator function should be modified to handle strings separately

comparator: function (item1, item2) {
        var val1 = item1.get(this.sort_key);
        var val2 = item2.get(this.sort_key);
    if (typeof (val1) === "string") {
        val1 = val1.toLowerCase();
        val2 = val2.toString().toLowerCase();
    }

    var sortValue = val1 > val2 ? 1 : -1;
    return sortValue * this.sort_order;
}

jsFiddle updated

this happened because of the iPhone starts in lower case, i think we should modify the comparator function to handle strings separately, i will check and be back — mfarouk, Nov 06 '14 at 06:55

Backbone order collection alphabetically

1 Answers1