Develop Reference

Failed posting data with axios [duplicate]

I'm trying to load a cross-domain HTML page using AJAX but unless the dataType is "jsonp" I can't get a response. However using jsonp the browser is expecting a script mime type but is receiving "text/html".
My code for the request is:
$.ajax({
type: "GET",
url: "http://saskatchewan.univ-ubs.fr:8080/SASStoredProcess/do?_username=DARTIES3-2012&_password=P#ssw0rd&_program=%2FUtilisateurs%2FDARTIES3-2012%2FMon+dossier%2Fanalyse_dc&annee=2012&ind=V&_action=execute",
dataType: "jsonp",
}).success( function( data ) {
$( 'div.ajax-field' ).html( data );
});
Is there any way of avoiding using jsonp for the request? I've already tried using the crossDomain parameter but it didn't work.
If not is there any way of receiving the html content in jsonp? Currently the console is saying "unexpected <" in the jsonp reply.

jQuery Ajax Notes
Due to browser security restrictions, most Ajax requests are subject to the same origin policy; the request can not successfully retrieve data from a different domain, subdomain, port, or protocol.
Script and JSONP requests are not subject to the same origin policy restrictions.
There are some ways to overcome the cross-domain barrier:
CORS Proxy Alternatives
Ways to circumvent the same-origin policy
Breaking The Cross Domain Barrier
There are some plugins that help with cross-domain requests:
Cross Domain AJAX Request with YQL and jQuery
Cross-domain requests with jQuery.ajax
Heads up!
The best way to overcome this problem, is by creating your own proxy in the back-end, so that your proxy will point to the services in other domains, because in the back-end not exists the same origin policy restriction. But if you can't do that in back-end, then pay attention to the following tips.
**Warning!**
Using third-party proxies is not a secure practice, because they can keep track of your data, so it can be used with public information, but never with private data.
The code examples shown below use jQuery.get() and jQuery.getJSON(), both are shorthand methods of jQuery.ajax()
CORS Anywhere
2021 Update
Public demo server (cors-anywhere.herokuapp.com) will be very limited by January 2021, 31st
The demo server of CORS Anywhere (cors-anywhere.herokuapp.com) is meant to be a demo of this project. But abuse has become so common that the platform where the demo is hosted (Heroku) has asked me to shut down the server, despite efforts to counter the abuse. Downtime becomes increasingly frequent due to abuse and its popularity.
To counter this, I will make the following changes:
The rate limit will decrease from 200 per hour to 50 per hour.
By January 31st, 2021, cors-anywhere.herokuapp.com will stop serving as an open proxy.
From February 1st. 2021, cors-anywhere.herokuapp.com will only serve requests after the visitor has completed a challenge: The user (developer) must visit a page at cors-anywhere.herokuapp.com to temporarily unlock the demo for their browser. This allows developers to try out the functionality, to help with deciding on self-hosting or looking for alternatives.
CORS Anywhere is a node.js proxy which adds CORS headers to the proxied request.
To use the API, just prefix the URL with the API URL. (Supports https: see github repository)
If you want to automatically enable cross-domain requests when needed, use the following snippet:
$.ajaxPrefilter( function (options) {
if (options.crossDomain && jQuery.support.cors) {
var http = (window.location.protocol === 'http:' ? 'http:' : 'https:');
options.url = http + '//cors-anywhere.herokuapp.com/' + options.url;
//options.url = "http://cors.corsproxy.io/url=" + options.url;
}
});
$.get(
'http://en.wikipedia.org/wiki/Cross-origin_resource_sharing',
function (response) {
console.log("> ", response);
$("#viewer").html(response);
});
Whatever Origin
Whatever Origin is a cross domain jsonp access. This is an open source alternative to anyorigin.com.
To fetch the data from google.com, you can use this snippet:
// It is good specify the charset you expect.
// You can use the charset you want instead of utf-8.
// See details for scriptCharset and contentType options:
// http://api.jquery.com/jQuery.ajax/#jQuery-ajax-settings
$.ajaxSetup({
scriptCharset: "utf-8", //or "ISO-8859-1"
contentType: "application/json; charset=utf-8"
});
$.getJSON('http://whateverorigin.org/get?url=' +
encodeURIComponent('http://google.com') + '&callback=?',
function (data) {
console.log("> ", data);
//If the expected response is text/plain
$("#viewer").html(data.contents);
//If the expected response is JSON
//var response = $.parseJSON(data.contents);
});
CORS Proxy
CORS Proxy is a simple node.js proxy to enable CORS request for any website.
It allows javascript code on your site to access resources on other domains that would normally be blocked due to the same-origin policy.
CORS-Proxy gr2m (archived)
CORS-Proxy rmadhuram
How does it work?
CORS Proxy takes advantage of Cross-Origin Resource Sharing, which is a feature that was added along with HTML 5. Servers can specify that they want browsers to allow other websites to request resources they host. CORS Proxy is simply an HTTP Proxy that adds a header to responses saying "anyone can request this".
This is another way to achieve the goal (see www.corsproxy.com). All you have to do is strip http:// and www. from the URL being proxied, and prepend the URL with www.corsproxy.com/
$.get(
'http://www.corsproxy.com/' +
'en.wikipedia.org/wiki/Cross-origin_resource_sharing',
function (response) {
console.log("> ", response);
$("#viewer").html(response);
});
The http://www.corsproxy.com/ domain now appears to be an unsafe/suspicious site. NOT RECOMMENDED TO USE.
CORS proxy browser
Recently I found this one, it involves various security oriented Cross Origin Remote Sharing utilities. But it is a black-box with Flash as backend.
You can see it in action here: CORS proxy browser
Get the source code on GitHub: koto/cors-proxy-browser

You can use Ajax-cross-origin a jQuery plugin.
With this plugin you use jQuery.ajax() cross domain. It uses Google services to achieve this:
The AJAX Cross Origin plugin use Google Apps Script as a proxy jSON
getter where jSONP is not implemented. When you set the crossOrigin
option to true, the plugin replace the original url with the Google
Apps Script address and send it as encoded url parameter. The Google
Apps Script use Google Servers resources to get the remote data, and
return it back to the client as JSONP.
It is very simple to use:
$.ajax({
crossOrigin: true,
url: url,
success: function(data) {
console.log(data);
}
});
You can read more here:
http://www.ajax-cross-origin.com/

If the external site doesn't support JSONP or CORS, your only option is to use a proxy.
Build a script on your server that requests that content, then use jQuery ajax to hit the script on your server.

Just put this in the header of your PHP Page and it ill work without API:
header('Access-Control-Allow-Origin: *'); //allow everybody
or
header('Access-Control-Allow-Origin: http://codesheet.org'); //allow just one domain
or
$http_origin = $_SERVER['HTTP_ORIGIN']; //allow multiple domains
$allowed_domains = array(
'http://codesheet.org',
'http://stackoverflow.com'
);
if (in_array($http_origin, $allowed_domains))
{
header("Access-Control-Allow-Origin: $http_origin");
}

I'm posting this in case someone faces the same problem I am facing right now. I've got a Zebra thermal printer, equipped with the ZebraNet print server, which offers a HTML-based user interface for editing multiple settings, seeing the printer's current status, etc. I need to get the status of the printer, which is displayed in one of those html pages, offered by the ZebraNet server and, for example, alert() a message to the user in the browser. This means that I have to get that html page in Javascript first. Although the printer is within the LAN of the user's PC, that Same Origin Policy is still staying firmly in my way. I tried JSONP, but the server returns html and I haven't found a way to modify its functionality (if I could, I would have already set the magic header Access-control-allow-origin: *). So I decided to write a small console app in C#. It has to be run as Admin to work properly, otherwise it trolls :D an exception. Here is some code:
// Create a listener.
HttpListener listener = new HttpListener();
// Add the prefixes.
//foreach (string s in prefixes)
//{
// listener.Prefixes.Add(s);
//}
listener.Prefixes.Add("http://*:1234/"); // accept connections from everywhere,
//because the printer is accessible only within the LAN (no portforwarding)
listener.Start();
Console.WriteLine("Listening...");
// Note: The GetContext method blocks while waiting for a request.
HttpListenerContext context;
string urlForRequest = "";
HttpWebRequest requestForPage = null;
HttpWebResponse responseForPage = null;
string responseForPageAsString = "";
while (true)
{
context = listener.GetContext();
HttpListenerRequest request = context.Request;
urlForRequest = request.RawUrl.Substring(1, request.RawUrl.Length - 1); // remove the slash, which separates the portNumber from the arg sent
Console.WriteLine(urlForRequest);
//Request for the html page:
requestForPage = (HttpWebRequest)WebRequest.Create(urlForRequest);
responseForPage = (HttpWebResponse)requestForPage.GetResponse();
responseForPageAsString = new StreamReader(responseForPage.GetResponseStream()).ReadToEnd();
// Obtain a response object.
HttpListenerResponse response = context.Response;
// Send back the response.
byte[] buffer = System.Text.Encoding.UTF8.GetBytes(responseForPageAsString);
// Get a response stream and write the response to it.
response.ContentLength64 = buffer.Length;
response.AddHeader("Access-Control-Allow-Origin", "*"); // the magic header in action ;-D
System.IO.Stream output = response.OutputStream;
output.Write(buffer, 0, buffer.Length);
// You must close the output stream.
output.Close();
//listener.Stop();
All the user needs to do is run that console app as Admin. I know it is way too ... frustrating and complicated, but it is sort of a workaround to the Domain Policy problem in case you cannot modify the server in any way.
edit: from js I make a simple ajax call:
$.ajax({
type: 'POST',
url: 'http://LAN_IP:1234/http://google.com',
success: function (data) {
console.log("Success: " + data);
},
error: function (e) {
alert("Error: " + e);
console.log("Error: " + e);
}
});
The html of the requested page is returned and stored in the data variable.

To get the data form external site by passing using a local proxy as suggested by jherax you can create a php page that fetches the content for you from respective external url and than send a get request to that php page.
var req = new XMLHttpRequest();
req.open('GET', 'http://localhost/get_url_content.php',false);
if(req.status == 200) {
alert(req.responseText);
}
as a php proxy you can use https://github.com/cowboy/php-simple-proxy

Your URL doesn't work these days, but your code can be updated with this working solution:
var url = "http://saskatchewan.univ-ubs.fr:8080/SASStoredProcess/do?_username=DARTIES3-2012&_password=P#ssw0rd&_program=%2FUtilisateurs%2FDARTIES3-2012%2FMon+dossier%2Fanalyse_dc&annee=2012&ind=V&_action=execute";
url = 'https://google.com'; // TEST URL
$.get("https://images"+~~(Math.random()*33)+"-focus-opensocial.googleusercontent.com/gadgets/proxy?container=none&url=" + encodeURI(url), function(data) {
$('div.ajax-field').html(data);
});
<div class="ajax-field"></div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

You need CORS proxy which proxies your request from your browser to requested service with appropriate CORS headers. List of such services are in code snippet below. You can also run provided code snippet to see ping to such services from your location.
$('li').each(function() {
var self = this;
ping($(this).text()).then(function(delta) {
console.log($(self).text(), delta, ' ms');
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdn.rawgit.com/jdfreder/pingjs/c2190a3649759f2bd8569a72ae2b597b2546c871/ping.js"></script>
<ul>
<li>https://crossorigin.me/</li>
<li>https://cors-anywhere.herokuapp.com/</li>
<li>http://cors.io/</li>
<li>https://cors.5apps.com/?uri=</li>
<li>http://whateverorigin.org/get?url=</li>
<li>https://anyorigin.com/get?url=</li>
<li>http://corsproxy.nodester.com/?src=</li>
<li>https://jsonp.afeld.me/?url=</li>
<li>http://benalman.com/code/projects/php-simple-proxy/ba-simple-proxy.php?url=</li>
</ul>

Figured it out.
Used this instead.
$('.div_class').load('http://en.wikipedia.org/wiki/Cross-origin_resource_sharing #toctitle');

Problems getting an external file's info (status and size)

I was wondering if there is a way to check if an external file is online, or available with AngularJS (or JavaScript). And if I could determine the size in some way (would be a plus). I first thought of using the head function of $http. But it turns out this doesn't always work, and I can't seem to find the size in the header information...
var file = { src: '//code.jquery.com/jquery.min.js' };
$http.head(file.src)
.success(function(data, status, headers) {
file.size = headers(['content-length']); // always empty
file.status = 'online';
})
.error(function() {
file.status = 'offline';
});
Anyone any idea's?

The header you are looking for is HTTP content-length.
$http.head(file.src)
.then(function(data, status, headers, config) {
file.size = headers(['content-length']);
file.status = 'online';
});
Of course, since you are running on the browser you'll only be able to perform the request to your server or to any server that specify the CORS header Access-Control-Allow-Origin.
For everything else, you'll have to proxy the requests through your own server. Do notice, however, that not all servers respond to HEAD requests - in which case you'll have to perform a full GET and either cancel the request after a timeout (file is online and downloading) or an error is thrown (file is offline).

Ok. I have come to the conclusion that there is no (reliable) way to do this with JavaScript at this point in time. I tried implementing a solution by injecting a script tag into an hidden iframe, and then check the result with the onload or onerror events. However when there is an error in the external file you are loading your code stops as well. So even this method is not viable.
So from this point I will search for the solution on the server-side.

How can I quickly detect local service absent?

I have a local application that contains a web server for exchanging JSON with a web application. The Web application itself is served from the web, meaning that browsers see them as cross-origin.
When the application is running, it provides correct cross-origin headers to allow the interchange. However, what I want is the option to quickly detect if the application is running or not.
The current method is to use AJAX to a "heartbeat" URL on the localhost service:
pg.init.getHeartbeat = function(port) {
var url = pg.utils.baseUrl('heartbeat', port); // returns a localhost URL
$.ajax({
url: url,
type: 'GET',
async: true,
success: function(data) {
// Hooray! Application is there. Do 'hooray' stuff
},
error: function(data) {
// Whoah the bus. Application not there. Do 'no application' stuff.
}
});
};
Works great in Webkit. Webkit tries to get a heartbeat, quickly fails, and does failure stuff very quickly.
Problem is in Firefox. Firefox tries to get a heartbeat, and takes between 4 and 10 seconds to fail. It might not seem like much, but 4 seconds before the UI moves the user to the next step is making the app feel very slow and unresponsive.
Any other ideas out there? As far as I can tell, changing an iFrame's src attribute and capturing a failure isn't working, either. It's not triggering the error event. And even when I can get an error to trigger from sample code, it's still taking 4 seconds, so there is no net improvement.
The web server side of things should not have any server-side scripting languages (PHP, etc.); I need the JavaScript to be able to take care of it independently.

You can do a timeout if the navigator is Firefox:
var timeoutcall = 0;
if(navigator.userAgent.toLowerCase().indexOf('firefox') > -1)
{
timeoutcall = 100;
}
$.ajax({
url: url,
type: 'GET',
timeout: timeoutcall ,
async: true,
success: function(data) {
// Hooray! Application is there. Do 'hooray' stuff
},
error: function(data) {
// Whoah the bus. Application not there. Do 'no application' stuff.
}
});
If the timeout is 0 then there is no timeout. So, if i am in firefox i set timeout to 100ms, and if im not in firefox set to unlimited.

Find out whether current request is a proxy request in firefox?

I need to automatically perform authorization with a proxy server using an addon.
I also checked out the source of other extensions that do that, and they do it like this:
var httpRequestObserver =
{
observe: function(subject, topic, data)
{
if (topic === "http-on-modify-request") {
var channel = subject.QueryInterface(Components.interfaces.nsIHttpChannel);
channel.setRequestHeader("Proxy-Authorization", "Basic myauthorizationtoken" , false);
}
}
};
A request observer adds the authorization header to every outgoing request. That works fine if a regular proxy is set, however in my case i have a proxy pac url where only specific requests are done using the proxy, and others not!
In that case the authorization header which basically includes credentials in the clear is transmitted to every website not accessed via proxy.
Obviously that cannot be, therefore I need to find out whether the current request is a proxy request, and only then set the header.
Or find another way alltogether...
In chrome I did it like this:
chrome.webRequest.onAuthRequired.addListener(handleAuthRequest,
{urls: ["<all_urls>"]}, ["asyncBlocking"]);
function handleAuthRequest(details, callback) {
if (details.isProxy === true){
callback({authCredentials: {username: localStorage['login'],
password: localStorage['pass']}});
}
callback();
}
Clearly this is optimal! However I cannot see a nice way in firefox to do it.

turns out that subject has an attribute proxyInfo which is null or set, also proxyInfo has further attributes to examine

Simple way to monitor result of request to detect session timeout?

I've got an Ajax app I would like to add sessions and logins to.
Currently the app uses jQuery get shorthand to send a request
that.ajaxRequest = $.get(query_string, function(data, textStatus, xhr) {
// do somthing with data
});
I have a system on the server that throws an error message if the session has expired.
On the client I know I can deal with this using the following:
that.ajaxRequest = $.get(query_string, function(data, textStatus, xhr) {
if (data == "E_TIMEOUT") {
// redirect to login
} else {
// do something
}
});
However I would prefer not to have to write the same timeout code for every $.get - there are a bunch of them throughout the app.
Is there a way to monitor the result of a request and take action if necessary, without rewriting all of my $.get statements?
Thanks,

You can use $.ajaxSetup() for this:
$.ajaxSetup({
complete: function (xhr) {
if (xhr.getResponseHeader('E_TIMEOUT') == "1") {
//redirect to login
}
}
});
This approach is slightly different, it uses response headers which you can get without parsing data an extra time every request (that is possible, though not documented and subject to break), which you would have to do otherwise, in a global situation.
On the server-side where you're sending E_TIMEOUT for the response, just change it to add a header as well, E_TIMEOUT=1 (or whatever header you want). I actually put this header on my login page only, the timeouts redirect via a 302 (which XmlHttpRequest transparently follows), so if the user timeouts and the AJAX request actually ended up at the login page, I do a location.reload() to reflect this on the page. That's just another option if you go that route, it looks like this:
$.ajaxSetup({
complete: function (xhr) {
if (xhr.getResponseHeader('LoginPage') == "1") {
location.reload();
}
}
});
Without knowing what server platform you're using I can't say how to set headers, but it's pretty easy on every common platform.

You should use firefox and download a program called 'FireBug'. This will show you all the requests being sent out, and the response that comes back from the AJAX call. It is action packed with goodness & web dev tools.