jquery + codeigniter + knockout + sammy, cannot retrieve post data -

i'm using codeigniter 3.0rc2, jquery 1.11.3, knockout.js 3.3.0 , sammy.js. i'm trying post call , retrieve json data put in viewmodel.

my view is:

<!-- mails grid --> <table class="mails" data-bind="with: chosenfolderdata">     <thead><tr><th>from</th><th>to</th><th>subject</th><th>date</th></tr></thead>     <tbody data-bind="foreach: mails">         <tr data-bind="click: $root.gotomail">             <td data-bind="text: from"></td>             <td data-bind="text: to"></td>             <td data-bind="text: subject"></td>             <td data-bind="text: date"></td>         </tr>          </tbody> </table> 

my viewmodel is:

function webmailviewmodel() {     // data     var self = this;     self.folders = ['inbox', 'archive', 'sent', 'spam'];     self.chosenfolderid = ko.observable();     self.chosenfolderdata = ko.observable();     self.chosenmaildata = ko.observable();      // behaviours     self.gotofolder = function (folder) {         location.hash = folder     };     self.gotomail = function (mail) {         location.hash = mail.folder + '/' + mail.id     };      // client-side routes         sammy(function () {         this.get('#:folder', function () {             self.chosenfolderid(this.params.folder);             self.chosenmaildata(null);             $.post("<?php echo base_url().'index.php/app/getmail'; ?>", {                 folder: this.params.folder             }, self.chosenfolderdata)         });          this.get('#:folder/:mailid', function () {             self.chosenfolderid(this.params.folder);             self.chosenfolderdata(null);             $.post("<?php echo base_url().'index.php/app/getmail'; ?>", {                 mailid: this.params.mailid             }, self.chosenmaildata);         });          this.get('', function () {             this.app.runroute('get', '#inbox')         });     }).run(); }; 

at line of viewmodel:

        $.post("<?php echo base_url().'index.php/app/getmail'; ?>", { folder : this.params.folder }, self.chosenfolderdata) 

i know app/getmail send me correct data. tested with:

        $.post("<?php echo base_url().'index.php/app/getmail'; ?>", { folder : this.params.folder }, function(data) { console.log(data) } ) 

and can see data retrieved @ console. if replace $.post data directly self.chosenfolderdata, that:

self.chosenfolderdata( { "id" : "inbox", "mails" : [{"id" : 1, "folder" : "inbox" ... }] ); 

it worked well. code is, return:

uncaught referenceerror: unable process binding "foreach: function (){return mails }" message: mails not defined 

i realize data not assigned self.chosenfolderdata. tried that:

        $.post("<?php echo base_url().'index.php/app/getmail'; ?>", { folder : this.params.folder }, function(data) { console.log(data); self.chosenfolderdata(data); } ) 

but not works. can see data @ console, have same error.

by way, based on knockoutjs.com tutorial here: webmail

can me?

i found answer. need put 'json' @ end of $.post call, this:

    $.post("<?php echo base_url().'index.php/app/getmail'; ?>", { folder : this.params.folder }, self.chosenfolderdata, 'json');