backbone javascript setTimeOut method - javascript

im have a problem with method setTimeOut that call the function self and set a delay, the function should be called again and again after every request is done but it only runs once. It works without using backbone.js tho, don't know it doesnt work after integration with backbone.js. Any help is appreciated!
So this is a function in client that runs a GET request gets data from server, the request runs in a time interval(decided in the server), as soon as a data comes in, client gets it and the request runs again after.
getRequest:function() {
var XHR = $.ajax({
url: '/nextdocument',
type: 'GET',
async: true,
cache: false,
timeout: 11000,
success:function(data) {
var name = data.description;
var price = data.price;
console.log("read--> " + name + price);
setTimeout("this.getRequest", 1000);
if (data.ok == "true") {
data["ok"] = data.ok;
$.ajax(
{
url: "/customerdone",
data: JSON.stringify(data),
processData: false,
type: 'POST',
contentType: 'application/json'
}
)
}else{
//no document if no read in
console.log("error--> " + data.errorMessage)
}
}
})
return XHR;
}

The problem is that you're using "this" in your setTimeout call. You can't do this because "this" will be the global object when the timer executes the function you're trying to reference.
like others have suggested, you need to pass an actual function to your timer, not a string. then you can reference whatever function from whatever object you want.

probably, the function getRequest isn't being called. This is, as far as I think, because you are sending a string -- "this.getRequest" to the setTimeout function. As a rule of thumb, never pass string to this, pass functions. Although, it might be perfectly ok in some situations (i'd never recommend it anyway), here 'this' might be causing trouble. Use something like this:
getRequest:function() {
var fn = arguments.callee;
var XHR = $.ajax({
url: '/nextdocument',
type: 'GET',
async: true,
cache: false,
timeout: 11000,
success:function(data) {
var name = data.description;
var price = data.price;
console.log("read--> " + name + price);
setTimeout(fn, 1000);
if (data.ok == "true") {
data["ok"] = data.ok;
$.ajax(
{
url: "/customerdone",
data: JSON.stringify(data),
processData: false,
type: 'POST',
contentType: 'application/json'
}
)
}else{
//no document if no read in
console.log("error--> " + data.errorMessage)
}
}
})
return XHR;
}

Related

Scope and Order AJAX Callbacks

This code needs to 1) check if users are online 2) get their information from a slightly different URL and 3) output both to HTML. It works, but inconsistently. In some cases when running the function for outputting the HTML it says that the data from the first request (online or not) is undefined. Right now streamData and userData are globals. But I wish I could get it to work without that. Having issues getting both data sources to consistently be available in the same place at the same time.
var getOnline = function(){
for (var i = 0; i < twitchFaves.length; i++) {
userName = twitchFaves[i];
streamAjaxOnline(userName);
}
}
var streamAjaxOnline = function(userName){
$.ajax({
type : 'GET',
url : "https://wind-bow.gomix.me/twitch-api/streams/" + userName,
dataType : 'jsonp',
success : function(twitchData) {
streamData = twitchData;
if (streamData.stream){
userAjaxOnline(userName);
}
}
});
}
var userAjaxOnline = function(userName){
$.ajax({
type : 'GET',
url : "https://wind-bow.gomix.me/twitch-api/users/" + userName,
dataType : 'jsonp',
success : function(twitchData) {
userData = twitchData;
displayTwitchOnline(streamData, userData);
}
});
}
Right now streamData and userData are globals
That's really bad. It means that multiple calls to the functions will share the same variables and overwrite the results of each other.
But I wish I could get it to work without that.
That's relatively easy: Pass the data to the functions instead. A very simple solution would be:
var streamAjaxOnline = function(userName) {
$.ajax({
type: 'GET',
url: "https://wind-bow.gomix.me/twitch-api/streams/" + userName,
dataType: 'jsonp',
success: function(twitchData) {
if (streamData.stream) {
userAjaxOnline(userName, streamData); // pass streamData here
}
}
});
}
var userAjaxOnline = function(userName, streamData) { // accept streamData here
$.ajax({
type: 'GET',
url: "https://wind-bow.gomix.me/twitch-api/users/" + userName,
dataType: 'jsonp',
success: function(twitchData) {
// no need to store userData if you only use it here
displayTwitchOnline(streamData, twitchData);
}
});
}

What is the right way to use "context:..." in an AJAX call?

So I'm aware that there are a big amount of threads about AJAX and the use of the context but after hours of reading and trying I open a new Thread.
So I have this (shorten version) javascript function:
this.CallService = function () {
var Type = this.Type;
var Url = this.Url;
var Data = this.Data;
var ContentType = this.ContentType;
var DataType = this.DataType;
var ProcessData = this.ProcessData;
var ClipUrl = this.ClipUrl;
var CountMax = this.CountMax;
var Callback = this.Callback;
var SucceededServiceCallback = this.SucceededServiceCallback;
var FailedServiceCallback = this.FailedServiceCallback;
return $.ajax({
type: Type, //GET or POST or PUT or DELETE verb
url: Url, // Location of the service
data: Data, //Data sent to server
contentType: ContentType, // content type sent to server
dataType: DataType, //Expected data format from server
processdata: ProcessData, //True or False
context: this,
}).done(function (msg) {//On Successfull service call
SucceededServiceCallback(this, msg);
}).fail(function (msg) {
FailedServiceCallback(this, msg);
});
}
The Important part here are the context: this and the two callbacks done and fail. Im those two callbacks I give the this context to my callback functions:
this.SucceededServiceCallback = function (context, result) {
if (null != context) {
UpdateDebugInfo(context, "succeeded: " + context.DataType + " URL: " + context.Url + " Data: " + context.Data + " Result: " +result);
}
if (context != null && context.DataType == "json" && result != null && context.Callback != null) {
context.Callback(context, result);
}
}
Here the important part is that I use the context to see access the variables DataType, Callback, Url etc.
The Problem now is that the context is set to the last context used (it's an asynchron call so all the variable are the variable from the last call). So I'm pretty sure something is wrong with that context: this, part. I just don't know how to use this right. Thanks for your help.
tl;dr:
I use context: this in an Ajax call. Context is always set to the last "this" called. I want to use the "this" of the call.
You are "caching" all your variables before you fire each request, but in your SucceededServiceCallback function you are inspecting this.XXX - which is not the var Type it looks like you are expecting, but the actual this.Type itself.
What you could do is put these properties into an object and pass it as context, rather than your main object:
this.CallService = function () {
var context = {
Type : this.Type,
Url : this.Url,
Data : this.Data,
ContentType : this.ContentType,
DataType : this.DataType,
ProcessData : this.ProcessData,
ClipUrl : this.ClipUrl,
CountMax : this.CountMax,
Callback : this.Callback
};
var SucceededServiceCallback = this.SucceededServiceCallback;
var FailedServiceCallback = this.FailedServiceCallback;
return $.ajax({
type: Type, //GET or POST or PUT or DELETE verb
url: Url, // Location of the service
data: Data, //Data sent to server
contentType: ContentType, // content type sent to server
dataType: DataType, //Expected data format from server
processdata: ProcessData, //True or False
context: context,
}).done(function (msg) {//On Successfull service call
SucceededServiceCallback(this, msg);
}).fail(function (msg) {
FailedServiceCallback(this, msg);
});
}

Stacking multiple AJAX requests on success (jQuery)

I'm just testing a local application and wanted to make something like this:
Click button, that's easy.
Perform AJAX request and create a database table.
Once the table is created, perform another series of AJAX requests and populate the table according to some parameters gotten from a series of select boxes.
"Animate" the whole thing using a progress bar.
Surprisingly, everything is working fine (apart the last point), but I'm getting some troubles.
The table gets created and populated but, for some reasons, the very last AJAX requests doesn't fire correctly, since it's not passing a parameter correctly.
My ajax requests are ALL asyncronous, if I set them syncronous the whole thing will freeze, but all the requests are executed correctly, even the very last one.
For instance, let's say that I don't want to use asyncronous requests in order to DON'T freeze the page and be able to show a progress bar.
The questions are the following:
Is it possible to call the same script twice?
Is there an efficient way to avoid ajax requests executing before other ajax requests?
After reading a whole bunch of topics here in stackoverflow, I edited my code and tried to:
use jQuery.AJAX prototype instead of jQuery.POST
Set everything asyncronously, in order to don't freeze the page and be able to handle a progress bar
perform the very next AJAX request into the "success" callback of the parent AJAX request.
At this point, I still have another question:
By stacking AJAX requests, is it actually TRUE that everything executed into the "success" callback will be executed AFTER the ajax requests has completed?
This is what I'm performing:
$.ajax({
type: "POST",
url: '../libs/php libraries/agenda.php',
data: {'action':'create>agenda', 'sqlname': createInfo},
processData: true,
dataType: "json",
timeout: 60000,
async: true,
success: function(res) {
$('#popup_content').append(res.log);
var dateList = new Array();
var dateObj = new Date();
var m = dateObj.getMonth();
var Y = dateObj.getFullYear();
for (var i = 1; i <= 31; i++) {
dateList.push(i+"/"+m+"/"+Y);
}
for (var i = 0; i < dateList.length; i++) {
var rs = false;
$.ajax({
type: 'POST',
url: '../libs/php libraries/agenda.php',
data: {'action':'validate>date', 'date': dateList[i]},
processData: true,
timeout: 60000,
async: true,
dataType: "json",
success: function(x) {
$('#popup_content').append(x.log);
if (x.res == 'true') {
rs = dateList[i];
}
if (rs != false) {
$.ajax({
type: 'POST',
url: '../libs/php libraries/agenda.php',
data: {'action':'create>day', 'date': rs, 'sqltable': createInfo},
processData: true,
timeout: 60000,
async: true,
dataType: "json",
success: function(newResult) {
console.log(newResult.res);
$('#popup_content').append(newResult.log);
}
});
}
}
});
}
}
});
the first AJAX request executes correctly, the second one does too, but in the third one (the one with data: {'action':'create>day', 'date': rs, 'sqltable': createInfo}) is getting fired but is missing the parameter rs defined above.
Also, to be clearer, rs is a temporary variable I've defined when I was trying to make the requests outside the "success" callback and when using $.when and $.done, in this case the variable rs is useless, but It won't change anything.
Again, as said above, the whole thing works using a syncronous request, but doesn't by using an asyncronous one.
Moreover, I'm just going to use this script locally, so delays or every problematic related to delays caused by servers and client are not important.
Is there any reason for the last request to don't work with an asyncronous request? if so is there a valuable solution for this case? I've also checked the topics about the queue, but it didn't solve my problem either. For some reasons, asyncronously, the last AJAX requests get just partially fired, since the variable rs is not getting passed correctly.
One solution is to use queue() function. This way you can execute as many functions as you want
var ajaxQueue = $({});
$.ajaxQueue = function(date, ajaxOpts) {
// queue the method. a second call wont execute until this dequeues
ajaxQueue.queue(function(next) {
// for this example I serialize params, but you can save them in several variables
// and concat into ajaxOpts.data
var params = method_that_get_params_and_serialize_them();
ajaxOpts.data = params;
ajaxOpts.complete = function() {
next();
};
$.ajax(ajaxOpts);
});
};
Then your functions have no need of shared vars, with the concurrency conflicts that it causes.
It should be like this:
$.ajax({
type: "POST",
url: '../libs/php libraries/agenda.php',
data: {'action':'create>agenda', 'sqlname': createInfo},
processData: true,
dataType: "json",
timeout: 60000,
async: true,
success: function(res) {
$('#popup_content').append(res.log);
var dateList = new Array();
var dateObj = new Date();
var m = dateObj.getMonth();
var Y = dateObj.getFullYear();
for (var i = 1; i <= 31; i++) {
dateList.push(i+"/"+m+"/"+Y);
}
for (var i = 0; i < dateList.length; i++) {
processDate(dateList[i]);
}
}
});
function processDate(date){
$.ajaxQueue({
type: 'POST',
url: '../libs/php libraries/agenda.php',
data: {'action':'validate>date', 'date': date},
processData: true,
timeout: 60000,
async: true,
dataType: "json",
success: function(x) {
$('#popup_content').append(x.log);
if (x.res == 'true') {
$.ajax({
type: 'POST',
url: '../libs/php libraries/agenda.php',
data: {'action':'create>day', 'date': date, 'sqltable': createInfo},
processData: true,
timeout: 60000,
async: true,
dataType: "json",
success: function(newResult) {
console.log(newResult.res);
$('#popup_content').append(newResult.log);
}
});
}
}
});
};
}

Ajax asynchronous response not loading into div

Here is what bothering me. My code is running on document.ready. I need the request to be asynchronous, meaning async: true
for (var i = 0; i < totalGraphs; i++) {
var kpiId = kpiIds[i];
jQuery.ajax({
type: 'POST',
url: graphUrl,
data: "kpiId="+kpiId+"&divId="+(i+1),
async: true, //if false things are working fine
cache:false,
success: function(response){
document.getDocumentById("graph" + (i + 1)).innerHTML("hello");
},
error:function(XMLHttpRequest, textStatus, errorThrown) {
}
});
}
This request does not put hello in my graphX divs, but whenever i put async: false things are working fine. I really need the request to be asynchronous.
Thanks in advance for any help.
Try this...
for (var i = 0; i < totalGraphs; i++){
(function ajaxCall(index) {
var kpiId = kpiIds[index];
jQuery.ajax({
type: "POST",
url: graphUrl,
data: {
kpiId : kpiId,
divId : index + 1
},
async: true, //if false things are working fine
cache: false,
success: function(response) {
document.getDocumentById("graph" + (index + 1)).innerHTML("hello");
},
error: function(XMLHttpRequest,textStatus,errorThrown) {}
});
})(i);
}
I've wrapped the ajax call in an anonymous function so that the value of i will never change, relative to the ajax call.
I'm guessing the i count is getting mixed up in your loop when success is returned. success will return after the loop has run through and thus this will give an unexpected result.
Can you return the i value that went sent in data in your response then use this in your getDocumentById method? I'm guessing this would fix your issue.
New code to try:
for(var i=0;i<totalGraphs;i++){
jQuery.ajax({
type: 'POST',
url: graphUrl,
data: { kpiId: kpiIds[i], divId: (i+1) },
async: true, //if false things are working fine
cache:false,
success: function(response){
document.getDocumentById("graph" + response.count).innerHTML("hello");
},
error:function(XMLHttpRequest,textStatus,errorThrown){}
});
}
First of all, you are running an ajax call inside a loop. This will be okay if you've turned off the async. But since you've turned on the async, the loop doesn't wait for the ajax to finish its work.
The best thing to do would be to get the values to a global variable using the inner loop ajax and then use the variable to draw the graph later.

Ajax function doesnt complete before the second runs

I got an Ajax function that looks like this
function PersonAtlLawUpdate(personRef) {
var selectionPanel = $('div#SelectionPanel');
var fromdate = selectionPanel.find('input#FromDateTextBox')[0].defaultValue;
var timeSpan = selectionPanel.find('select#TimeSpanDropdownList').data('timespanvalue');
var url = "MonthOverview.aspx/OnePersonAtlLawUpdate";
$.ajax({
url: url,
data: JSON.stringify({ personRef: personRef, fromdate: fromdate, timespan: timeSpan }),
type: "POST",
contentType: "application/json",
dataType: "JSON",
context: document.body,
success: function (atlError) {
changePersonAtlStatusIcon(atlError, personRef);
},
error: function (xhr, status, errorThrown) {
//alert(errorThrown + '\n' + status + '\n' + xhr.statusText);
}
});
}
In one function I need to run this twice like this:
PersonAtlLawUpdate($(gMarkedCell).parent("tr").attr("personref"));
PersonAtlLawUpdate(pRef);
The problem that can be is that in some cases doesn't work 100%. The dom doesnt update in one of the functions. And I think it is because the other one "overwrites" it.
So how do I make sure that the second "PersonAtlLawUpdate" runs after the first one completes? Doesnt seems good to put a delay on it. And is it a good solution to set async to false in the ajax call?
EDIT,
tride like this and placed a console.log in my success. But "all complete" will run first of them:
$.when(PersonAtlLawUpdate($(gMarkedCell).parent("tr").attr("personref")), PersonAtlLawUpdate(pRef)).then(function (){console.log("all complete")});
You can just use a callback function so that it executes right after the first one has executed:
PersonAtlLawUpdate($(gMarkedCell).parent("tr").attr("personref"), function(){
PersonAtlLawUpdate(pRef);
});
Or maybe you can rethink the problem, and come up with a solution that doesn't require calling the same function twice. Maybe you don't really need to do this.
I think what #Kyokasuigetsu suggests is you need to alter the PersonAtlLawUpdate method so that is accepts an optional second parameter: a callback function that need to be called in the success callback.
function PersonAtlLawUpdate(personRef, cbFunc) {
var selectionPanel = $('div#SelectionPanel');
var fromdate = selectionPanel.find('input#FromDateTextBox')[0].defaultValue;
var timeSpan = selectionPanel.find('select#TimeSpanDropdownList').data('timespanvalue');
var url = "MonthOverview.aspx/OnePersonAtlLawUpdate";
$.ajax({
url: url,
data: JSON.stringify({ personRef: personRef, fromdate: fromdate, timespan: timeSpan }),
type: "POST",
contentType: "application/json",
dataType: "JSON",
context: document.body,
success: function (atlError) {
changePersonAtlStatusIcon(atlError, personRef);
if (cbFunc != null)
cbFunc();
},
error: function (xhr, status, errorThrown) {
//alert(errorThrown + '\n' + status + '\n' + xhr.statusText);
}
});
And than make the call as;
PersonAtlLawUpdate($(gMarkedCell).parent("tr").attr("personref"), function(){
PersonAtlLawUpdate(pRef);
});
Your example will work fine if you return your $.ajax calls from your PersonAtLawUpdate function.
$.when needs a reference to the ajax calls, so make sure you return the Deferred (the ajax call) from your functions
function PersonAtlLawUpdate(personRef) {
var selectionPanel = $('div#SelectionPanel');
var fromdate = selectionPanel.find('input#FromDateTextBox')[0].defaultValue;
var timeSpan = selectionPanel.find('select#TimeSpanDropdownList').data('timespanvalue');
var url = "MonthOverview.aspx/OnePersonAtlLawUpdate";
//SEE THE NEXT LINE
return $.ajax({
url: url,
data: JSON.stringify({ personRef: personRef, fromdate: fromdate, timespan: timeSpan }),
type: "POST",
contentType: "application/json",
dataType: "JSON",
context: document.body,
success: function (atlError) {
changePersonAtlStatusIcon(atlError, personRef);
},
error: function (xhr, status, errorThrown) {
//alert(errorThrown + '\n' + status + '\n' + xhr.statusText);
}
});
}
Use:
$.when(PersonAtLawUpdate(ref1), PersonAtLawUpdate(ref2)).done(function(xhrRef1, xhrRef2) {
//do stuff w/ results from both calls
//if you return something from the server,
//the results will be available in xhrRef1[0]
//and xhrRef2[0], respectively (order they
//appear in the when(), not in the order they execute
});

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