jQuery/Ajax IE7 - Long requests fail - javascript

I have a problem with IE7 regarding an ajax call that is made by jQuery.load function.
Basically the request works in cases where the URL string is not too long, but as soon as the URL gets very large it fails. Doing some debugging on the Ajax call I found this error:
URL: <blanked out security reasons but it's very long>
Content Type:
Headers size (bytes): 0
Data size (bytes): 0
Total size (bytes): 0
Transferred data size (bytes): 0
Cached data: No
Error result: 0x800c0005
Error constant: INET_E_RESOURCE_NOT_FOUND
Error description: The server or proxy was not found
Extended error result: 0x7a
Extended error description: The data area passed to a system call is too small.
As you can see, it looks like nothing is being sent. Now this only happens on IE7 but not other browsers, with IE8 there is a small delay but still works. The same request works fine when the URL string is relatively small.
Now I need this working on IE7 for compatibility reasons, and I cannot find workarounds for this.
The actual AJAX call is like this:
$("ID").load("url?lotsofparams",callbac func(){});
"lotsofparams" can vary, sometimes being small or very large. It's when the string is very large that I get the above error for IE7 only.

since load uses HTTP Get method, there is limit to the size of the url, which is 4KB as far as I know. So instead of GET, use $.ajax with HTTP Post option. Post has no limit.
use the following code.
$.ajax({
url: url,
type: "POST",
async: true,
data: {name1: value1, name2: value2, ...}, // put your data.
success: function(data, textStatus) {
$("ID").html(data);
}
});

Don't put the query string parameters into the the url.
The second parameter of .load() is made just for that. Should be:
$("ID").load("url", {
foo: "bar",
morefoo: "morebar"
},callbac func(){});
or you can use $.post()
$.post("url", {
foo: "bar",
morefoo: "morebar"
}, function(data){
alert(data);
});
Since the .load() will internally use a "POST" request when parsing an object, you might consider to replace it with $.get() if you require a "GET" request.

I ran into this same problem. I had been sending everything via the URL (long querystring) and it was failing. I found out the key was to send the data in its own parameter (dataparms, in this example) which is just the querystring section of the URL.
$.ajax({type: "POST", url: URL, data: dataparams, dataType: "html", async:false});

Related

AJAX request posting data in body instead of URL concatenation

I see many websites pursuing their requests through data concatenation in their URL, for example: example.com/api?data=111.
On my website I handle the request in another way, through AJAX:
return $.ajax({ url: '../api.php',
data: {data: '111'},
type: 'post'
});
I was wondering if in my method there is any flaw or if it can be used like the standard method of URL concatenation.
Update for context
function createAJAXRequestToGetCategories() {
return $.ajax({
url: '../server.php',
data: {
method: 'requestCategories'
},
type: 'post'
});
}
ajaxRequest = createAJAXRequestToGetCategories();
ajaxRequest.done(functionToExecute);
functionToExecute(responseData) {}
Some differences that come to mind:
You cannot use the body in the same way during GET requests, obviously this is not what you are doing above but a lot of requests you are likely seeing are GET requests
Debugging, seeing someone hitting /api.php?action=create.user and receiving 500s in your logs is somewhat easier to debug than all of your endpoints under /api.php
URL character limits, just last week I managed to go over the limit for characters in an endpoint request, i.e. /api.php?id=1,2,3,4,5... (general limit is 2083 char), using the body circumvents this to an extent (your server will still limit data posted to an extent)
There may be more, compelling arguments either way. I typically use URL params for purpose/identification- and the body for actual data.

Ajax request to current path requests `text/html` instead of `application/json`

I have two almost identical JQuery requests that I issue after the page loads, the first one requests json for the current path and the second for a different url. I was surprised to see, though, that the first request type is text/html and the second is application/json. I would have expected both to be application/json. The requests look something like this:
$.ajax({
url: window.location.pathname,
type: 'GET',
dataType: 'json',
success: doSomething
});
$.ajax({
url: '/tags',
type: 'GET',
dataType: 'json',
success: doSomethingElse
});
Yet in the network tab I'm seeing:
What am I missing?
dataType: 'json' has two main effects:
It causes jQuery to ignore the content-type of the document it gets back from the server and to treat it as JSON regardless
It sets an Accept header (for HTTP content negotiation) requesting JSON
The server may use HTTP content negotiation to decide what to put in the response if it has different representations of the content in different formats. Most servers do not.
It looks like yours does not. It will always return HTML for the first URL and always return JSON for the second URL.
If you want your server to pay attention to the Accept header, then you have to configure it to do so (as well as providing a JSON version of the document as well as the HTML version).
The content type shown is the type of the response the server is sending you, not the type of request you are sending to the server.

jQuery $.ajax done callback not firing

I have the following code :
$("#loginSubmitButton").on("click",function(){
var loginUserDetails = {
email: $("#email").val(),
password: $("#password").val()
};
//Send the AJAX request to authenticate the user
$.ajax({
type: "POST",
url: "/somewebservice/v1/users/authenticate",
data: JSON.stringify(loginUserDetails),
contentType: "application/json;charset=UTF-8",
dataType: "json",
}).done(function() {
$("#loginResult").text("Login successful");
})
.fail(function() {
$("#loginResult").text("Login failed");
});
});
As per the jquery documentation (unless I am understanding something incorrectly) I expect the done to be fired if I receive a 200 OK from my web server. However, in chrome console I can see a 200 OK response but jquery seems to fire the fail handler.
Does anyone have any idea what I might be doing wrong here?
You need to remove:
dataType: "json"
There are lots of suggestions to remove
dataType: "json"
While I grant that this works it's probably ignoring the underlying issue. It's most likely caused by a parser error (the browser parsing the json response). Firstly examine the XHR parameter in either .always() or .fail().
Assuming it is a parser fail then why? Perhaps the return string isn't JSON. Or it could be errant whitespace at the start of the response. Consider having a look at it in fiddler. Mine looked like this:
Connection: Keep-Alive
Content-Type: application/json; charset=utf-8
{"type":"scan","data":{"image":".\/output\/ou...
In my case this was a problem with PHP spewing out unwanted characters (in this case UTF file BOMs). Once I removed these it fixed the problem while also keeping
dataType: json
If your server returns empty string for a json response (even if with a 200 OK), jQuery treats it as failed. Since v1.9, an empty string is considered invalid json.
Whatever is the cause, a good place to look at is the 'data' parameter passed to the callbacks:
$.ajax( .. ).always(function(data) {
console.log(JSON.stringify(data));
});
Its contents will give you an understanding of what's wrong.
Need to remove , from dataType: "json",
dataType: "json"
The ajax URL must be the same domain. You can't use AJAX to access cross-domain scripts. This is because of the Same Origin Policy.
add "dataType:JSONP" to achieve cross domain communication
use below code
$.ajax({
URL: cross domain
dataType: 'jsonp'
// must use dataType:JSONP to achieve cross domain communication, otherwise done function would not called.
// jquery ajax will return "statustext error" at }).always(function(data){}
}).always(function(data){
alert(JSON.stringify(data));
}
A few things that should clear up your issue and a couple hints in general.
Don't listen for a click on a submit button. You should wait for the submit event on the form.
The data option for $.ajax isn't expecting a JSON string. It wants a serialized string or an array with name and value objects. You can create either of those easily with .serialize() or .serializeArray().
Here is what I was thinking for your script.
$('#form-with-loginSubmitButton').on('submit', function(e){
e.preventDefault():
var $form = $(this),
data = $form.serializeArray();
$.ajax({
type: "POST",
url: "/somewebservice/v1/users/authenticate",
data: data
}).done(function(result){
console.log(result);
});
});

Strange $.post() AJAX error when parsing JSON

I am facing this strange error in using $.post.
works
$("#add-video").click(function(){
var url = $("#new-video-url").val();
$('#loader').show();
$.post( base_url + "forms/coach/get_url.php", { url:url, base_url:base_url }, function(data){
alert(data);
$('#loader').hide();
});
});
The above piece of code, shows me the json array I am receiving using a php file, and also shows the title field here, and hides the loader image.
But when I alert(data.title), it shows me undefined. More over, when I add datatype 'json' to $.post,
doesn't work
$("#add-video").click(function(){
var url = $("#new-video-url").val();
$('#loader').show();
$.post( base_url + "forms/coach/get_url.php", { url:url, base_url:base_url }, function(data){
alert(data);
$('#loader').hide();
}, "json"); //Added datatype here.
});
This neither alerts anything nor does it hide the loader image. I also tried,
$("#add-video").click(function(){
var url = $("#new-video-url").val();
$('#loader').show();
$.post( base_url + "forms/coach/get_url.php", { url:url, base_url:base_url }, function(data){
jQuery.parseJSON(data);
alert(data.title);
$('#loader').hide();
});
});
The above one too neither alerts anything nor does it hide the loader. And then I tried this one too that did nothing.
$("#add-video").click(function(){
var url = $("#new-video-url").val();
$('#loader').show();
$.post( base_url + "forms/coach/get_url.php", { url:url, base_url:base_url }, function(data){
jQuery.parseJSON(data); //tried without this too.
alert(data['title']);
$('#loader').hide();
});
});
The strangest thing is that I have previously used json as I have shown in the 2nd script(out of 4), and that works normally. My JS console too doesn't show any errors or warning. What am I doing wrong here? How do I access the title field of data?
If this helps, here is how I send the json array,
$json = array("title" => $title, "embed" => $embed, "desc" => $desc, "duration" => $duration, "date" => $date);
print_r(json_encode($json));
I would really appreciate if someone can point out the error and tell me why my scripts are failing, similar functions worked in other js file.
here is my data, that is returned by server,
{"title":"Sunn Raha Hai Na Tu Aashiqui 2 Full Song With Lyrics |
Aditya Roy Kapur, Shraddha Kapoor","embed":"\r\t\t\t\t\t\r\t\t\t\t\t</param></param>\r\t\t\t\t\t</param>\r\t\t\t\t\t\r\t\t\t\t\t</embed></object>","desc":"Presenting
full song \"Sun Raha Hai Na Tu\" with lyrics from movie \"Aashiqui 2\"
produced by T-Series Films & Vishesh Films, starring Aditya Roy Kapur,
Shraddha Kapoor in voice of Ankit Tiwari. \n\nSong: SUNN RAHA
HAI\nSinger: ANKIT TIWARI\nMusic Director: ANKIT TIWARI\nAssistant Mix
Engineer - MICHAEL EDWIN PILLAI\nMixed and Mastered by ERIC PILLAI
(FUTURE SOUND OF BOMBAY)\nLyrics:SANDEEP NATH\nMovie: AASHIQUI
2\nProducer: BHUSHAN KUMAR KRISHAN KUAMR Producer: MUKESH BHATT
\nDirector: MOHIT SURI\nMusic Label: T-SERIES\n\nBuy from iTunes -
https://itunes.apple.com/in/album/aashiqui-2-original-motion/id630590910?ls=1\n\nEnjoy
& stay connected with us!! \n\nSUBSCRIBE T-Series channel for
unlimited entertainment\nhttp://www.youtube.com/tseries\n\nCircle
us on G+ \nhttp://www.google.com/+tseriesmusic\n\nLike us on
Facebook\nhttp://www.facebook.com/tseriesmusic\n\nFollow
us\nhttp://www.twitter.com/_Tseries","duration":"391","date":"2013-04-03"}
Edit
This worked suddenly.. :o
$("#add-video").click(function(){
var url = $("#new-video-url").val();
$('#loader').show();
$.post( base_url + "forms/coach/get_url.php", { url:url, base_url:base_url }, function(data){
alert(data.desc);
console.log(data.desc);
$("#loader").hide();
}, "json");
});
In comments, you mention that this AJAX corresponds to a YouTube API.
YouTube's blog announced in 2012 that they would support CORS, which uses server-side header flags that compatible browsers interpret as permitting requests that would otherwise be prohibited by browser security Same-Origin-Policy.
Assuming, as you say, the first example worked, the first issue was "Why did (a subsequent) alert(data.title) fail? (my edit) ". If you type alert(data.title) in the console, it will fail because the scope of data is the callback function where it is defined as a parameter, and in the global scope data is undefined. If you try to pass data back to the global scope somehow, it can still be undefined because $.post returns immediately, before the data has been fetched, and merely queues a request and sets the callback function you supply to handle the reply.
The second example, which explicitly sets the $.post dataType parameter to 'json', may fail with CORS based API because the mime types for json are not allowed to be sent up to the server as Content-Type: for a simple CORS request, and $.post will as far as I know only do simple requests without preflight. $.ajax can possibly do the more complex requests if correctly applied.
The work around to keep using $.post is not to use json as the expected data type, send requests up as form data, the server may send you back json anyway if that is what the API says will happen, which can be verified while testing the code.
From https://developer.mozilla.org/en-US/docs/HTTP/Access_control_CORS
Simple requests
A simple cross-site request is one that:
Only uses GET, HEAD or POST.
If POST is used to send data to the
server, the Content-Type of the data sent to the server with the HTTP
POST request is one of application/x-www-form-urlencoded,
multipart/form-data, or text/plain.
Notice that application/json did not make the list of what Content-Type is permissible in a simple CORS request.
See also A CORS POST request works from plain javascript, but why not with jQuery?
Use ajax as
$.ajax({
url:url,
type:'post',
dataType:'json',
success:callback
})
With this type you can set lots of parameter in low level.
With datatype attribute jQuery parses JSON and send data as callback function.
I think you have to replace all single \ with double '\' to feed it to JSON.parse.

jQuery .getJSON vs .post which one is faster?

Using
$.getJSON();
or
$.post();
I'm trying to send some parameters through a page that is just for AJAX request
and get some results in JSON or html snippet.
What I want to know is that which one is faster?
Assume the HTML file would be simply plain boolean text (true or false)
As others said there is no real difference between the two functions, because both of them will be sent by XMLHttpRequest.
If the server is handling both of the requests with the same code then the handling times should be the same.
Therefore the question can be translated to which one is faster the HTTP GET request or the POST request?
Because the POST request needs two additional HTTP headers (Content-Type and Content-Length) comparing to the GET request the latter should be faster (because less data will be transferred).
But that's just the speed, I think it's better to follow the REST guidelines here. Use POST if you're modifying something, use GET if you want to fetch something.
And one another important thing, GET responses could be cached, but I was having problems caching POST ones.
i dont think it will make a difference both make use of ajax, .post loads the data using http post request where as getJSON uses a http get request more over you dont have to explicitly tell getJSON the dataType
If it is a HTTP action that is retrieving data from the server without persisting (updating) anything, GET is the correct semantic to use.
Both post and get use HTTP so performance difference will be negligible, especially considering the variables of WAN communication.
They are both wrappers/shorthand methods for jQuery.ajax, so there wont be a performance difference.
This is old but ...
We all have to remember about: CSRF/XSRF.
If you do it this way:
$.ajax({
type: "POST",
dataType: "json",
url: url,
data: {
token : 'pass-some-security-token-here'
},
cache: false,
success: function(data) {
//do your stuff here
}
});
you can receive it then like this, nullifying most CSRF/XSRF
if (isset($_POST['token'])) { //you can also test token further
//do your stuff her and send back result
} else {
//error: sorry, invalid, or no security token
}
In many cases GET is an invitation for bad guys, as getJSON uses GET HTTP request.
$.getJSON(); is a shortcut to $.ajax(); which also calls $.post(); so you won't see much difference (but it will be easier to use $.getJSON() directly).
See the jquery doc
[EDIT] NimChimpsky was faster than me...
There are no difference, Because both are using XMLHttpRequest.
First, $.getJSON() is a shorthand Ajax function, which is equivalent to:
$.ajax({
dataType: "json",
url: url,
data: data,
success: success
});
https://api.jquery.com/jQuery.getJSON/
Second, $.post() is also a shorthand Ajax function, which is equivalent to:
$.ajax({
type: "POST",
url: url,
data: data,
success: success,
dataType: dataType
});
https://api.jquery.com/jquery.post/

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