javascript - How to call methods inside of a Backbone Collection -

i'm new backbone.js, new javascript, not sure how put question in phrase, want function called , returns result attribute in same collection.

var enrollmentcollection = backbone.collection.extend({      url: "/some/prefix" + this.getpath() + "/some/suffix",      getpath: function() {         var result;          $.ajax({             type: 'get',             url: '/this/is/a/url',             async: false,             datatype: 'json',             success: function(data) {                 result = data[0].someattribute;             }         });          return result;     } }); 

as can see, getpath() method should returning value value of url, however, browser gives following error:

uncaught typeerror: cannot read property 'getpath' of undefined(anonymous function)

any appreciated.

with code using:

url: this.getpath(), 

you executing function this.getpath() , doesn't exist yet because defined below.

try doing

url: (function(){   var result;          $.ajax({             type: 'get',             url: '/this/is/a/url',             async: false,             datatype: 'json',             success: function(data) {                 result = data[0].someattribute;             }         });          return result; }())