How to return a value from WinJS - javascript

I am developing an app which consumes a WebService like this
function callWS(filebytes, fpath, filename) { //consumes the webservice
var response;
var data = '<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ws="http://ws.myCompany.com">\n' +
' <soapenv:Header/>\n' +
' <soapenv:Body>\n' +
' <ws:uploadFileService>\n' +
' <ws:filebytes>' + filebytes + '</ws:filebytes>\n' +
' <ws:fpath>' + fpath + '</ws:fpath>\n' +
' <ws:filename>' + filename + '</ws:filename>\n' +
' </ws:uploadFileService>\n' +
' </soapenv:Body>\n' +
'</soapenv:Envelope>\n';
console.log("XML SOAP: " + data + "\r\n");
var options = {
url: "http://XXX.XXX.XX.XXX:XXXX/FILESERVERWS/services/FILESERVERWS?wsdl",
type: "post",
headers: {
"Content-Type": "text/xml; charset=utf-8",
"SOAPAction": "uploadFileService"
},
data: data
};
WinJS.Promise.timeout(8000, WinJS.xhr(options)).then(
function (request) {
var doc = request.responseXML.documentElement;
var output = doc.getElementsByTagName("uploadFileServiceReturn");
//Windows.UI.Popups.MessageDialog(output[0].textContent, "the XML message").showAsync();
console.log("the XML message: " + output[0].textContent + "\r\n");
result.style.backgroundColor = "#00A000";
response = true;
},
function (error) {
Windows.UI.Popups.MessageDialog(error.status + " : " + error.statusText, "Status").showAsync();
result.style.backgroundColor = "#FF0000";
response = false;
},
function (progress) {
result.innerText = "Ready state is " + progress.readyState;
result.style.backgroundColor = "#0000A0";
}
);
return response;
}
the purpose is to consume the webService and returns a value
on success response = true
on error response = false
because I want to take an action depending if the webService returned a value by doing this
if (callWS(document.getElementById("formfield" + i).value, UID_KEY[7], arrayCaptures[i - 1].name)) {
console.log("take action a");
}
else {
console.log("take action b");
}
but it always take action B even if the webService is consumed and I get answer from the webservice, what am I doing wrong???

You'll need to return a Promise object from your function, allowing the calling script to use a then() or done() call on it to get the result. You can read more about asynchronous programming in WinJS on the msdn site, but generally it looks like this:
function callWS(filebytes, fpath, filename) {
return new WinJS.Promise(function (complete, error) {
// put your functionality here...
WinJS.Promise.timeout(8000, WinJS.xhr(options)).then(
function (request) {
// more processing...
complete(true); // or false or a variable...
},
function (e) {
// error handling unique to this function
complete(false); // OR you could just call error(e);
},
...
);
});
}
And you would use it like this:
callWS( ... ).then(
function(response) {
// handle response...
// will be either true or false
},
function(err) {
// handle errors
}
);

Related

Array empty after pushes were made in get request in Node.js/Express

I am writing a function calling an API to fetch URLs. These are the steps that I wish to accomplish:
Parsing in an array of objects (restaurants) as arguments
For each object, call the Google Search API to get some imageURLs
Store those imageURLs in an array
Add imageURLs as an attribute called imageURLs to each object within the array in the argument
The code is able to log the imageURLs within the GET request, but outside of the request, imageURLs is just an empty array.
var googleSearch = function(restaurants, cb){
console.log("google starts");
const apiKey = google_apiKey;
const cseKey = cseID;
Array.from(restaurants).forEach(function(restaurant){
var keyWord = restaurant.name + " "+ restaurant.location.city
+ " "+ restaurant.location.state + " food";
var googleURL = "https://www.googleapis.com/customsearch/v1?key="+ apiKey +
"&q="+ keyWord +
"&searchType=image" +
"&cx=" + cseKey +
"&num=7" +
"&safe=medium"
;
//image URLs of each restaurants to be displayed in the front end
var imageURLs = [];
request
.get(googleURL,
{
json : true, headers: {
'User-Agent' : 'thaorell'
}
})
.then(function(response){
Array.from(response.items).forEach(function(item){
imageURLs.push(item.link)
});
})
.catch(e => {
console.log(e);
})
restaurant.imageURLs = imageURLs
})
cb(null, restaurants);
}
You're misunderstanding the Promise API:
var googleSearch = function (restaurants, cb) {
console.log("google starts");
const apiKey = google_apiKey;
const cseKey = cseID;
return Promise.all(Array.from(restaurants).map(function (restaurant) {
var keyWord = restaurant.name + " " + restaurant.location.city
+ " " + restaurant.location.state + " food";
var googleURL = "https://www.googleapis.com/customsearch/v1?key=" + apiKey +
"&q=" + keyWord +
"&searchType=image" +
"&cx=" + cseKey +
"&num=7" +
"&safe=medium"
;
return request
.get(googleURL,
{
json: true, headers: {
'User-Agent': 'thaorell'
}
}
)
.then(function (response) {
restaurant.imageURLs = Array.from(response.items).map(function (item) {
return item.link;
});
return restaurant;
})
})
)
.then(restaurants2 => cb(null, restaurants2))
.catch(cb)
}
As you can see you need to wait for all of the requests to finish before you pass the data back to the callback.

AJAX call data returned from mvc function is undefined

I know this has been asked 1000 times before but I have hit a brick wall with this.^have created a web application that inserts user data and feedback for the user and the code below is basically part of the PhoneGap application. The strange thing is that the code works perfectly in a web browser but not in Phonegap (output iPad via Xcode).
Therefore would someone know why I am getting an undefined error for the following AJAX call, just after the success callback and the alert(data.ResultId). , any help is appreciated.
Thank you!
// POST: /Result/Create
[HttpPost]
public ActionResult Create(Result result)
{
if (ModelState.IsValid)
{
result.ResultDate = DateTime.Now;
repository.InsertResult(result);
repository.Save();
if (Request.IsAjaxRequest())
{
int ResultId = result.ResultId;
try
{ //valid database entry..send back new ResultId
return Json(new { Success = true, ResultId, JsonRequestBehavior.AllowGet });
}
catch
{ // no database entry
return Json(new { Success = false, Message = "Error", JsonRequestBehavior.AllowGet });
}
}
return RedirectToAction("Index");
}
return View(result);
}
Insert QnA
function InsertQnA() {
//hardcoded for testing
Q1 = 10;
Q2 = 10;
Q3 = 10;
Q4 = 10;
Q5 = 10;
Q6 = 10;
Q7 = 10;
Q8 = 10;
Q9 = 10;
Q10 = 10;
localStorage.setItem("Total",100);
localStorage.setItem("CaseStudy", 1);
localStorage.setItem("UserId",1);
Attempts = "1";
////////////////
$.ajax({
url: Domain + '/Result/Create',
cache: false,
type: 'POST',
contentType: 'application/json; charset=utf-8',
data: '{"Q1":"' + Q1 + '","Q2":"' + Q2 + '","Q3":"' + Q3 + '","Q4":"' + Q4 + '","Q5":"' + Q5 + '","Q6":"' + Q6 + '","Q7":"' + Q7 + '","Q8":"' + Q8 + '","Q9":"' + Q9 + '","Q10":"' + Q10 + '","Total":"' + localStorage.getItem("Total") + '","CaseStudy":"' + localStorage.getItem("CaseStudy") + '","UserId":"' + localStorage.getItem("UserId") + '","Attempts":"' + QnANumAttempts + '"}',
// dataType : "json",
success: function (data) {
alert(data.ResultId);
if (data.Success==true) {
}
else if (data.Success==false) {
viewModel.UserId("Your entry has not been saved, please try again.");
}
},
}).fail(
function (xhr, textStatus, err) {
console.log(xhr.statusText);
console.log(textStatus);
console.log(err);
});
}
The problem was that I was tying to use the same ActionResult to serve an MVC view as well as an htlm5 cordova iOS app. I got round this by copying the ActionResult but changing the return type to a string, note the code looks a bit different in the action, however the original worked fine too. Many thanks to all who posted
[HttpPost]
public string CreateResult(Result result)
{
result.ResultDate = DateTime.Now;
repository.InsertResult(result);
repository.Save();
if (result == null)
{
// User entity does not exist in db, return 0
return JsonConvert.SerializeObject(0);
}
else
{
// Success return user
return JsonConvert.SerializeObject(result, Formatting.Indented, new JsonSerializerSettings { PreserveReferencesHandling = PreserveReferencesHandling.Objects });
}
}
AJAX
$.ajax({
url: Domain + '/Result/CreateResult',
cache: false,
type: 'POST',
dataType: 'json',
contentType: 'application/json; charset=utf-8',
data: '{"Q1":"' + Q1 + '","Q2":"' + Q2 + '","Q3":"' + Q3 + '","Q4":"' + Q4 + '","Q5":"' + Q5 + '","Q6":"' + Q6 + '","Q7":"' + Q7 + '","Q8":"' + Q8 + '","Q9":"' + Q9 + '","Q10":"' + Q10 + '","Total":"' + localStorage.getItem("Total") + '","CaseStudy":"' + localStorage.getItem("CaseStudy") + '","UserId":"' + localStorage.getItem("UserId") + '","Attempts":"' + QnANumAttempts + '"}',
success: function (data) {
try {
if (data != 0) {
//result id used for feedback insertion > update result entity
localStorage.setItem("ResultId", data.ResultId);
viewModel.UserId("You have successfully completed case study " + localStorage.getItem("CaseStudy") + ", please fill out the <a href=evaluation.html target=_self>evaluation.<a/>");
//reset locals
ResetLocalStorage();
//count number of entities for User
CountUserEntitiesInResults();
}
else
{
viewModel.UserId("Your entry has not been saved, please try again.");
}
}catch(error) {
alert("This is the error which might be: "+error.message);
}
},
}).fail(
function (xhr, textStatus, err) {
console.log(xhr.statusText);
console.log(textStatus);
console.log(err);
});​

callbacks in browser after socket.io emit

i am developing a way to get callbacks in the browser page, following a emit to the socketio server.
server code:
/** exec php file and retrieve the stdout */
socket.on('php', function(func, uid, data) {
console.log('php'.green + ' act:' + func + ' uid:' + uid);
runner.exec("php " + php_[func].exec,
function(err, stdout, stderr) {
if (err == null) {
socket.emit('php', {uid: uid, o: stdout});
console.log('emitted');
} else {
console.log('err '.red + stdout + ' ' + stderr);
}
});
});
this code executes a php page and retrieves the output to display or parse in the browser
it receives an id to echo back to the page, so I can know what function to execute
browser code to execute callbacks:
function log(text) {
$('.out').append(text + '<br />');
}
window.callbacks = [];
function setcb(c) {
var max = 0;
$.each(window.callbacks, function(index) {max = (index > max ? index : max);});
window.callbacks[max+1] = c;
return max+1;
};
function C(k){return(document.cookie.match('(^|; )'+k+'=([^;]*)')||0)[2]}
var s = io.connect("http://"+ window.location.host +":8088");
//s.emit('debug', 'here');
s.on('getid', function(){
console.log('getid cookieis: ' + C('igr') );
s.emit('setid', C('igr'));
});
s.emit('php', 'test',
setcb(
function () {
var data = JSON.parse(this);
log('callback passed' + this);
}
), null
);
s.on('php', function(data) {
//window.callbacks[j.uid].call(j.o);
log('rec' + JSON.stringify(data));
//var jsn = JSON.parse(data);
console.log(data);
console.log(window.callbacks[data.uid]);
window.callbacks[data.uid].call(data.o);
delete window.callbacks[data.uid];
window.callbacks.splice(data.uid, 1);
console.log(window.callbacks);
});
this is working, but when I try to make two requests at the same time, it doesn't run like expected, leaving one callback to execute and in the callbacks array.
test code:
s.emit('php', 'test',
setcb(
function (data) {log('callback passed' + this);}
), null
);
s.emit('php', 'test',
setcb(
function (data) {log('callback passed' + this);}
), null
);
I want to eliminate this error, and for each event received, execute the callback I define.
This is way more simple than I've imagined
You can pass by reference the callback.
server side code:
/** exec php file and retrieve the stdout */
socket.on('php', function(func, data, callback) {
console.log('php'.green + ' act:' + func);
runner.exec("php " + php_[func].exec,
function(err, stdout, stderr) {
if (err == null) {
callback(stdout);
//socket.emit('php', {uid: uid, o: stdout});
console.log('emitted');
} else {
console.log('err '.red + stdout + ' ' + stderr);
}
});
});
client side code:
function log(text) {
$('.out').append(text + '<br />');
}
function C(k){return(document.cookie.match('(^|; )'+k+'=([^;]*)')||0)[2]}
var s = io.connect("http://"+ window.location.host +":8088");
//s.emit('debug', 'here');
s.on('getid', function(){
console.log('getid cookieis: ' + C('igr') );
s.emit('setid', C('igr'));
});
s.emit('php', 'test', null,
function(data) { log('d: ' + JSON.stringify(data)); }
);

multiple JSON Data log and PUT to server

I have a javascript function which generates JSON data at every certain second and then PUT it to a cloud server. Now I don't want to POST in realtime, rather I want to log this data in a buffer and say after n number of data log I will PUT to cloud. For example I want to log 50 data point in 10 second and then with timestamp I will PUT to a server
Now JSON data is passed through var fromDatan. JSON data format is
{"value":"-2.1282838391939194"}
Now the code is:
var acc;
var watchID = null;
function startWatch() {
//set frequency of accelerometer update.1000 = 1 second
var options = { frequency: 1000 };
watchID = navigator.accelerometer.watchAcceleration(onSuccess, onError, options);
}
function stopWatch() {
if (watchID) {
navigator.accelerometer.clearWatch(watchID);
watchID = null;
}
}
//DISPLAY ACCELERATION DATA
function onSuccess(acceleration) {
acc = acceleration;
var element = document.getElementById("accelerometer");
element.innerHTML = 'Acceleration X: ' + acceleration.x + '<br />' +
'Acceleration Y: ' + acceleration.y + '<br />' +
'Acceleration Z: ' + acceleration.z + '<br />' +
'Timestamp: ' + acceleration.timestamp + '<br />';
datalock();
}
function postdata () {
var accx = acc.x;
alert(accx);
var fromDatan = JSON.stringify(fromData);
alert(fromDatan);
//POST JSON SENSOR DATA
$.ajax({
url: "http://abcd.com",
headers: {
"X-API-KEY": "2b9asdedqedqxdqd7956e6f7a",
"Content-Type": "application/json"
},
type: "PUT",
data: fromDatan,
dataType: "JSON",
success: function(fromData, status, jqXHR) {
alert(JSON.stringify(fromData));
},
error: function(jqXHR, status) {
alert(JSON.stringify(jqXHR));
}
});
return false;
//var fromData = {};
}
var fromData;
var jsonCounter = 0;
function datalock(){
alert("Entering");
fromData.push({
value: accx.toString(),
});
jsonCounter++;
// post only after 10 entries
if (jsonCounter >= 10) {
postdata ();
jsonCounter = 0; // reset
};
//var fromData; // make it global as it is used in other function.
}
But the code is not working now. Please let me know where the problem is. although all other things are correct, the pushing I couldn't implement properly. Can anyone please help me out? It is just hitting on "Entering alert . that's it .Not going to function postdata()

populated jquery objects show as undefined when passed

In the following script, although the two weather objects are both populated with data in the ajax calls, the updateWeather call shows them both as undefined prior to that line executing. I moved the variable declarations so they would be global but they still both show undefined prior to the updateWeather call. What am I missing? Can I not set up a variable in the ajax success function and then pass it later?
Note: If you want to test this use a different url as this one won't work for you with out my credentials
function getWeatherForecastStationCode() {
var d = new Date();
var parts = d.toString().split(" ");
var dDate = parts[1] + " " + parts[2] + ", " + parts[3];
var ampm;
if (parts[4].split(":")[0] <= 12) {
ampm = "AM";
} else {
ampm = "PM";
}
var dtime = parts[4].split(":")[0] + ":" + parts[4].split(":")[1];
var datetime = dDate + " " + dtime + ampm;
alert(datetime);
var weatherStation = "KPBI"; // get from GetWeatherService.svc
var forecastFields = "&fields=periods.maxTempF%2cperiods.minTempF%2cperiods.vaildTime%2cperiods.weather%2cperiods.icon";
var currentFields = "&fields=ob.tempC%2cob.tempF%2cob.icon%2cplace.name%2cplace.state";
var forecastUrlWeatherStation = 'http://api.aerisapi.com/forecasts/' + weatherStation + '?limit=1&client_id=' + AerisClientId + '&client_secret=' + AerisWeatherApiSecret + forecastFields;
var currentUrlWeatherStation = 'http://api.aerisapi.com/observations/' + weatherStation + '?limit=1&client_id=' + AerisClientId + '&client_secret=' + AerisWeatherApiSecret + currentFields;
$.ajax({
type: "GET",
url: forecastUrlWeatherStation,
dataType: "json",
success: function (json) {
if (json.success === true) {
forecastedWeather = {
weather: json.response[0].periods[0].weather,
maxTemp: json.response[0].periods[0].maxTempF,
minTemp: json.response[0].periods[0].minTempF,
weatherIcon: json.response[0].periods[0].icon,
obsTime: datetime
};
}
else {
alert('An error occurred: ' + json.error.description);
}
}
});
var location;
$.ajax({
type: "GET",
url: currentUrlWeatherStation,
dataType: "json",
success: function (json) {
if (json.success === true) {
var place = json.response.place.name.split(" ");
if (place.length === 1) {
location = place[0].charAt(0).toUpperCase() + place[0].substr(1, place[0].length);
} else {
location = place[0].charAt(0).toUpperCase() + place[0].substr(1, place[0].length) + " " + place[1].charAt(0).toUpperCase() + place[1].substr(1, place[1].length) + ", " + json.response.place.state.toUpperCase();
}
currentWeather = {
location: location,
currentTemp: json.response.ob.tempF
};
} else {
alert('An error occurred: ' + json.error.description);
}
}
});
updateWeather(forecastedWeather,currentWeather);
}
The problem is that AJAX is Asynchronous (Thats the "A" in "AJAX"), so the call to updateWeather is executing before a response is received from your 2 ajax calls.
The way to do this then, is to wait for all ajax calls to complete before calling updateWeather.
Something like the following (untested):
$.when(getForecast(),getCurrent()).done(function(f,c){
updateWeather(forecastedWeather,currentWeather)
});
function getForecast(){
return $.ajax({
type: "GET",
url: forecastUrlWeatherStation,
dataType: "json"
....
});
};
function getCurrent(){
return $.ajax({
type: "GET",
url: currentUrlWeatherStation,
dataType: "json"
....
});
};

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