I'm a bit confused about the asynchous call to the DataBase.
I just want to have a javasctipt adapter class for the calls to the web sql. But I'm not quite sure how to do this. Propably somebody have a good hint for me.
The function OfflneAppDBAdapter.prototype.IsDeviceConfigured() should return true or false depending if there are any items in the Table DeviceConfig.
function OfflneAppDBAdapter() {
self = this;
this.deviceIsConfigured = false;
this.Init = function () {
$data.Entity.extend("$de.offlineapp.DeviceConfig", {
Id: { type: "int", key: true, computed: true },
Name: { type: "string", required: true },
Token: { type: "string" },
Type: { type: "string" }
});
$data.EntityContext.extend("$de.offlineapp.DataContext", {
DeviceConfig: { type: $data.EntitySet, elementType: $de.offlineapp.DeviceConfig }
});
}
self.Init();
$de.offlineapp.context = new $de.offlineapp.DataContext({
name: "webSql", databaseName: "OfflineApp"
});
$de.offlineapp.context.onReady(function () {
});
}
// ************************************************************************
// PUBLIC METHODS -- ANYONE MAY READ/WRITE
// ************************************************************************
OfflneAppDBAdapter.prototype.AddDeviceConfig = function (deviceName, deviceToken, deviceTyp) {
$de.offlineapp.context.onReady(function () {
var promise = $de.offlineapp.context.DeviceConfig.toArray(function (x) {
if (x.length == 0) {
var emp = new $de.offlineapp.DeviceConfig({ Name: deviceName, Token: deviceToken, Type: deviceTyp });
$de.offlineapp.context.DeviceConfig.add(emp);
$de.offlineapp.context.saveChanges();
}
}
)
});
}
OfflneAppDBAdapter.prototype.IsDeviceConfigured = function () {
$de.offlineapp.context.onReady(function () {
var promise = $de.offlineapp.context.DeviceConfig.toArray(function (x) {
if (x.length == 0) {
this.deviceIsConfigured = true;
}
}
)
});
return this.deviceIsConfigured;
}
var myOfflineAppDBAdapter = new OfflneAppDBAdapter();
myOfflineAppDBAdapter.AddDeviceConfig("DeviceName", "Token", "iPad");
console.log(myOfflineAppDBAdapter.IsDeviceConfigured());
As expected the console prints "false". I' aware that the jaydata call works with callbacks and the callbacks are not part of the main class. But there must be a possibility to do so?
I would really apprechiate any help.
Thank you in advance.... Chris
UPDATE: As you requested the startup code:
function OfflineApplication()
{
self = this;
}
OfflineApplication.prototype.StartApplication = function () {
//Check if online, then sync and
if (navigator && navigator.onLine === true) {
this.IsDeviceConfigured();
}
else {
}
}
///check if the device has a base configuration
OfflineApplication.prototype.IsDeviceConfigured = function () {
myOfflineAppDBAdapter.GetDeviceConfiguration(function (result) {
if (result.length > 0) {
myOfflineAppDBAdapter.deviceIsConfigured = true;
myOfflineApplication.HasDeviceAnApplication();
}
else {
///Get the device base conf from the server.
myOfflineAppSynchronisationAdapter.getDeviceConfigurationByToken(token, myOfflineApplication.HasDeviceAnApplication);
myOfflineAppDBAdapter.deviceIsConfigured = true;
}
});
}
///check if the device has an "application config" in general
OfflineApplication.prototype.HasDeviceAnApplication = function () {
myOfflineAppDBAdapter.GetDeviceAnApplication(function (result) {
if (result.length > 0) {
myOfflineApplication.IsDeviceApplicationVersionLatest(result);
}
else {
myOfflineApplication.GetApplication(false);
}
});
}
///the application config could differ from time to time, so we have to check if a different application should be synct with the device
OfflineApplication.prototype.IsDeviceApplicationVersionLatest = function (result) {
myOfflineAppDBAdapter.DeleteDeviceAnApplication(function () { });
console.log(result);
}
///get the application from the server
OfflineApplication.prototype.GetApplication = function (clearConfig) {
if (clearConfig === true)
{
}
myOfflineAppSynchronisationAdapter.getDeviceApplicationByToken(token, myOfflineApplication.LoadApplication);
}
OfflineApplication.prototype.LoadApplication = function () {
console.log('Now everything is finde and the application gets loaded..');
}
var myOfflineAppDBAdapter = new OfflneAppDBAdapter();
var myOfflineAppSynchronisationAdapter = new OfflineAppSynchronisationAdapter();
var myOfflineApplication = new OfflineApplication();
myOfflineApplication.StartApplication();
There is no sync way. You handling promises wrong. Make your code simple :) You'll need something like this:
$data.Entity.extend("$de.offlineapp.DeviceConfig", {
Id: { type: "int", key: true, computed: true },
Name: { type: "string", required: true },
Token: { type: "string" },
Type: { type: "string" }
});
$data.EntityContext.extend("$de.offlineapp.DataContext", {
DeviceConfig: { type: $data.EntitySet, elementType: $de.offlineapp.DeviceConfig }
});
var context = new $de.offlineapp.DataContext({
name: "webSql", databaseName: "OfflineApp"
});
function AddDeviceConfig(deviceName, deviceToken, deviceTyp) {
return context.DeviceConfig.toArray()
.then(function (x) {
if (x.length == 0) {
var emp = new $de.offlineapp.DeviceConfig({ Name: deviceName, Token: deviceToken, Type: deviceTyp });
context.DeviceConfig.add(emp);
return context.saveChanges();
}
})
}
function IsDeviceConfigured() {
return context.DeviceConfig.toArray()
.then(function (x) {
return x.length > 0;
})
}
context.onReady()
.then(IsDeviceConfigured)
.then(console.log)
.then(function() { return AddDeviceConfig("DeviceName", "Token", "iPad"); })
.then(IsDeviceConfigured)
.then(console.log);
here's a fiddle which does this: http://jsfiddle.net/JayData/cpT5q/1/
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