Win 8 Apps : saving and retrieving data in roamingfolder - windows-8

Question

I'm trying to store few user data into a roamingFolder method/property of Windows Storage in an app using JavaScript. I'm following a sample code from the Dev Center, but no success. My code snippet is as follows : (OR SkyDrive link for the full project : https://skydrive.live.com/redir?resid=F4CAEFCD620982EB!105&authkey=!AE-ziM-BLJuYj7A )
filesReadCounter: function() {
roamingFolder.getFileAsync(filename)
.then(function (filename) {
return Windows.Storage.FileIO.readTextAsync(filename);
}).done(function (data) {
var dataToRead = JSON.parse(data);
var dataNumber = dataToRead.count;
var message = "Your Saved Conversions";
//for (var i = 0; i < dataNumber; i++) {
message += dataToRead.result;
document.getElementById("savedOutput1").innerText = message;
//}
//counter = parseInt(text);
//document.getElementById("savedOutput2").innerText = dataToRead.counter;
}, function () {
// getFileAsync or readTextAsync failed.
//document.getElementById("savedOutput2").innerText = "Counter: <not found>";
});
},
filesDisplayOutput: function () {
this.filesReadCounter();
}
I'm calling filesDisplayOutput function inside ready method of navigator template's item.js file, to retrieve last session's data. But it always shows blank. I want to save upto 5 data a user may need to save.

Answer 1

I had some trouble running your code as is, but that's tangential to the question. Bottom line, you're not actually reading the file. Note this code, there's no then or done to execute when the promise is fulfilled.
return Windows.Storage.FileIO.readTextAsync(filename);
I hacked this in your example solution and it's working... typical caveats of this is not production code :)
filesReadCounter: function () {
roamingFolder.getFileAsync(filename).then(
function (filename) {
Windows.Storage.FileIO.readTextAsync(filename).done(
function (data) {
var dataToRead = JSON.parse(data);
var dataNumber = dataToRead.count;
var message = "Your Saved Conversions";
//for (var i = 0; i < dataNumber; i++) {
message += dataToRead.result;
document.getElementById("savedOutput1").innerText = message;
//}
//counter = parseInt(text);
//document.getElementById("savedOutput2").innerText = dataToRead.counter;
}, function () {
// readTextAsync failed.
//document.getElementById("savedOutput2").innerText = "Counter: <not found>";
});
},
function () {
// getFileAsync failed
})
},