sending an HTTP request with an unordinary method - ajax

I am trying to create a link on my web page that when accessed will cause an HTTP request with an unordinary method to be sent (for the sake of the example, the method is POSTS).
I know that regular HTML forms support only GET and POST and AJAX should support PUT and delete. Is there a way to issue requests with a method different than these standard HTTP methods?
Thanks in advance.
==============
After the tips I adjusted my page to have the following HTML:
<!DOCTYPE html>
<html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js">
</script>
<script>
$(document).ready(function(){
$("button").click(function(){
$.ajax({url:"http://www.example.php",type:"POSTS",dataType:"html"});
});
});
</script>
</head>
<body>
<button>Send Request</button>
</body>
</html>
Surprisingly, this did not work in Chrome and Firefox but did work in an updated version of IE:
When I tried to issue the request using Firefox and Chrome, the browser issued a request with an OPTIONS method and the following header:
Access-Control-Request-Method: POSTS
Only IE issued the request as per the requirement - using the POSTS HTTP method.
===
Turns out that the aforementioned HTML doesn't work.(The desired request with the custom header is not issued).
As I mentioned above, firefox and chrome issue an initial request with an Access-Control-Request-Method header , while IE doesn't issue a request at all.
I adjusted the browser security settings (enabled "Access data sources across domains),
but still, the browser did not issue the request.
I'm guessing there needs to be some further adjustments in the browser setting, does anyone have an idea how this can be solved?

Quick answer yes if you use javascript.
Methods are defined by the standard along with status codes however they are open to extension. Such as webdav which increases the method vocabulary.
Not all browsers support arbitrary http methods especially older versions of IE (surprise surprise!)
So you could simply have a link / button which calls a javascript function which makes your http request.
Simply using jQuery:
var request = $.ajax({
url: "script.php",
type: "POSTS",
data: { id : menuId },
dataType: "html"
});
request.done(function( msg ) {
$( "#log" ).html( msg );
});
request.fail(function( jqXHR, textStatus ) {
alert( "Request failed: " + textStatus );
});

Related

Is it true that I cannot request an API from a different domain using ajax, or am I just doing it wrong? [duplicate]

This question already has answers here:
Ways to circumvent the same-origin policy
(8 answers)
Closed 8 years ago.
I have a website on http://www.domain_a.com where I need to make a request to a JSON API hosted on http://domain_b.com. Now when I try the following:
<!DOCTYPE html>
<html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script>
$(document).ready(function() {
$.getJSON({
url: "http://domain_b.com/service_api/v1/find.json?name=abcd",
dataType: 'json',
beforeSend: setHeader,
success: function(data) {console.log (data)}
});
function setHeader (xhr) {
console.log (xhr);
xhr.setRequestHeader("Authorization", "sdkfhberg83hr87234bf87r432");
console.log (xhr);
}
});
</script>
</head>
<body>
</body>
</html>
I get this error in the firebug console:
Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at http://domain_b/service_api/v1/find.json?name=abcd. This can be fixed by moving the resource to the same domain or enabling CORS.
Am I doing something wrong, or is it simply not allowed (would surprise me)?
Cross-origin resource sharing is what you want. Basically, The Same Origin Policy allows only the scripts that are running on the same domain to access eachothers DOM, for security reasons, ofcourse. So unless the API that you're calling does not support - ie. have the following header for response - "Access-Control-Allow-Origin", "*" , this call is not allowed.
Not entirely sure about this - but try making use of PHP proxy
Also, this might be useful to you.

ajax from same site as JS reference file?

I have a JS file running on my site, it works fine.
Now I want to put on another site with the full url of the script back to my site.
<script src="http://www-js.mydomains.com/some/path/file.js"></script>
now is it really still cross domain to an xml request on my server?
so in the file.js I have something like
dojo.xhrGet({url: '/some/path/file.xml', sync: true, handleAs: 'xml', error: function(result,args){alert(result.responseText+'-'+args.responseText)}, load: function(result){ ....
this just dies on other sites (great dojo response of undefined)... is there away around it
I think you should use "script" dojo/request/script instead of xhr.
require(["dojo/request/script", "dojo/dom", "dojo/dom-construct", "dojo/json", "dojo/on", "dojo/domReady!"],
function(script, dom, domConst, JSON, on){
on(dom.byId("startButton"), "click", function(){
domConst.place("<p>Requesting...</p>", "output");
script.get("helloworld.jsonp.js", {
jsonp: "callback"
}).then(function(data){
domConst.place("<p>response data: <code>" + JSON.stringify(data) + "</code></p>", "output");
});
});
});
http://dojotoolkit.org/reference-guide/1.9/dojo/request/script.html
now is it really still cross domain to an xml request on my server?
Yes. The origin is based on the URI of the HTML document hosting the script, not the URI the script was sourced from.
You should send the HTTP headers defined in the CORS specification to allow other sites to use your script (or their own scripts) to access content on your server.
Additionally, URIs accessed by JS are also relative to the document and not the script, so you will need to use an absolute or scheme relative URI instead of the server root relative URI you are presently using.

AJAX call appears cached for about 2 minutes on Mac

I have an Ajax widget that monitors the status of a connection on a web page, and alerts the user when the server can no longer be reached. It works on Windows 7, but fails on Mac OSX 10.5.8 (both Safari and Firefox).
The crucial code is here:
(function(e){
e.fn.checknet=function(config){
function checkConnection(config){
e.ajax({
url:config.checkURL,
cache:false,
success:function(){
window.checknet.conIsActive=true
},
error:function(){
window.checknet.conIsActive=false
},
complete:function(){
if(window.checknet.conIsActive){
connectionExtablished()
}
else{
connectionLost()
}
}
})
setTimeout(
function(){checkConnection(config)},
config.checkInterval
)
}
}
})(jQuery);
I'm calling it every five seconds. When I shut down the server, Windows browsers do indeed notice within five seconds. However, the browsers on my Mac need about two and a half minutes.
From other questions, I gather that caching can be an issue. However, I've tried inserting parameters:"defeatcache=" + new Date().getTime() to the Ajax call and $.ajaxSetup({ cache: false }); before the Ajax call; neither works.
Does anybody have any suggestions for how I can get my Mac browsers to notice the downed connection sooner?
As mentioned in the comment and here How to disable Ajax caching in Safari browser?, you need to append the paramater to the URL, I'm not sure what this bit is doing parameters:"defeatcache=" but the way I have always used it is on the url:
url = url + '&nocache=' + new Date().getTime();
To modify your example where checkURL is the plain url unedited it should be
url:config.checkURL + '&nocache=' + new Date().getTime(),
If the above still does not work you want to add no-cache headers to the URL you are trying to access - for example if the url you were accessing was called "status.php" then you could try adding no-cached headers to the status.php page itself:
header('Cache-Control: no-cache, no-store, must-revalidate'); // HTTP 1.1.
header('Pragma: no-cache'); // HTTP 1.0.
Obviously this code above (for PHP) would be different depending on your sever side language (taken from & more examples for other server side languages here: einternals)
when you make your .ajax() call use the option cache: false
.ajax(
{url: 'http://...',
cache: false });
or
before your ajax call use ajaxSetup
$.ajaxSetup({ cache: false });
I used to disable caching in the response's header. So in the service that provides the response, look into setting various fields to disable caching from that end of the call. Sorry I don't have any ready examples!! Hope this helps.

AJAX post not working with HTTPS

I am having a rather frustrating problem with the jquery post function that probably stems from not understanding how it works correctly.
I have a function that should post some form information to a php script that I wrote and that script then runs curl requests against an API to get around the cross-domain policy of javascript. It seems to work fine as long as it submits to "http" but when I send it to "https" the form never gets submitted.
I ran wireshark on my computer and it showed no traffic towards the destination ip until I made the url use http. I have basic auth on the server so I am passing the user and password through the url, but tested without that there and got the same results.
Here is the not working code:
$j.post("https://<api user>:<password>#<ip>:444/ProxyScript.php",
$j("#spoke_ticket").serialize(),
function(msg) {
log_status(msg);
fade_status();
$j(':input','#createtheticket')
.not(':button, :submit, :reset, :hidden')
.val('')
.removeAttr('checked')
.removeAttr('selected');
});
Here is the working function:
$j.post("http://<other ip>/ProxyScript.php",
$j("#spoke_ticket").serialize(),
function(msg) {
log_status(msg);
fade_status();
$j(':input','#createtheticket')
.not(':button, :submit, :reset, :hidden')
.val('')
.removeAttr('checked')
.removeAttr('selected');
});
Any ideas as to why the traffic is not being sent?
Let me know if I left out some key information or anything.
Thanks for the help
If you are doing the AJAX post from a http page to a https URL then the Cross-Domain policy kicks in because the protocol is also part of the origin specification, as it is described here. The browser will refuse to make the AJAX call, so that's why you're not seeing any traffic.
A solution is discussed here:
Ajax using https on an http page
So your best bet is the Access-Control-Allow-Origin header which should be supported on most modern browsers now.
So make your server add the following header to the responses:
Access-Control-Allow-Origin: https://www.mysite.com
If for some reason you cannot enforce this, then the only choice left would be JSONP.
Why not use a proxy to get over the cross-domain issue? It sounds more easy. An simple example is when i want to retrieve the danish administration national geo-data for counties,road names and so on (lucky for me, their data is in json or XML optional)
simplified proxy.php
<?
header('Content-type: application/json');
$url=$_GET['url'];
$html=file_get_contents($url);
echo $html;
?>
in ajax, get the lat/longs for a county borderline
var url= "proxy.php?url=https://geo.oiorest.dk/"+type+"/"+nr+"/graense.json";
$.ajax({
url: url,
dataType: 'json',
success: function (data) {
...
});
notice the https - the url could be, real example, https://geo.oiorest.dk/kommuner/0810/graense.json

Cross Domain issue(Working in IE not in other browser)

I am fetching data from a URL using an AJAX call. It is giving a json object to me.
When I run the application, the page is working fine in IE with a conformation that
the page is accessing information that is not under its control.
This poses a security risk. Do you want to continue?
But that is not working in other browsers like Firefox, Chrome, Safari, etc.
i don't know what is the problem. Please explain to me why it is occurring and how to solve the issue?
My Code:
<!DOCTYPE html>
<html>
<head>
<title>Search Engine</title>
<script src="JS/jquery-1.4.2.min.js"></script>
<script>
$(document).ready(function () {
$.support.cors = true;
// create a script tag element
var script = document.createElement("script");
// set the attribute, using the URL to pass data via query parameters
script.setAttribute("src", "http://192.168.13.111:7090/?uname=bhagirathip&wt=json&fl=*,score");
script.setAttribute("type", "text/javascript");
// add the script tag to the document head, forcing an HTTP request
document.getElementsByTagName("head")[0].appendChild(script);
});
function Search() {
function callbackJsonHandler(data) {
alert(data); // This is the JSON data
}
}
</script>
</head>
<body>
<form id="form">
<div style="text-align: center">
<input type="search" id="searchInput" autofocus />
<input type="button" id="btnSearch" onclick="Search()" value="Search" />
</div>
</form>
</body>
</html>
You can't make cross-domain AJAX calls across domains. This is a security feature in web browsers to prevent malicious JavaScript code from scraping rendered data in a web page and then shipping it off to some rogue website on some other domain.
By restricting AJAX requests to same domain, browser vendors ensure that JavaScript imported from other sources cannot send data to any server other than the server the HTML page was served from.
In Internet Explorer, it's prompting you, but any smart user who encounters such a message is likely to say no. Presenting your users with such warning messages is not a good design practice and does not inspire confidence in the legitimacy of your application.
The only way that you can send data across domains is to use a browser hack technique called "script tag remoting", which essentially involves using HTML elements that aren't restricted by the same domain policy. For instance script tags can make HTTP GET requests to any server:
// create a script tag element
var script = document.createElement("script");
// set the attribute, using the URL to pass data via query parameters
script.setAttribute("src","http://192.168.9.11/userInput/?key="+userInput);
script.setAttribute("type","text/javascript");
// add the script tag to the document head, forcing an HTTP request
document.getElementsByTagName("head")[0].appendChild(script);
Using this method, you can send data to a remote server. Note that, to get JSON data back, you must wrap it, or pad it, in a JavaScript function and define a callback in the JavaScript code to handle the response:
function callbackJsonHandler(data) {
alert(data); // This is the JSON data
}
And your server-side code must return content text/javascript, calling the handler, and passing your JSON as an argument:
callbackJsonHandler({"key":"value","key1":"value2"});
When the browser downloads the JavaScript to the browser, the JavaScript runs immediately, giving you a hook to use to access the JSON in the response.
Since you're using jQuery, you can also check out jQuery JSONP, or JSON with Padding, which can be used to generate a JavaScript response so that you can handle callbacks from these requests to the remote server. Note that the server must be setup to handle JSONP requests for this to work properly, similar to the above setup.
Another solution to the issue of making cross-domain requests from a browser whose HTML document is served from exampleA.com to a server whose domain is exampleB.com is to use a proxy.
Let's assume that the HTML document you're working with is served from exampleA.com. You own exampleA.com, and you can access the server side and client side code. exampleB.com, on the other hand, is a remote server owned or controlled by someone else. exampleB.com has some data you want to use in exampleA.com.
We know that AJAX won't work, because of the same origin policy, which is in place to protect rogue apps from doing bad things with people's data. However, servers aren't restricted to same domain policy. This means that your app can do the following:
||exampleA.com/test.html|| ---> http req --> ||exampleA.com/getData|| --http req --> ||exampleB.com/getJSON||
Server-side: (As in your server, exampleA.com):
In other words, on your server that you're using to serve the HTML, you write some code that makes an HTTP request from your server to the third-party server:
// JSON URL which should be requested
$json_url = 'http://www.exampleB.com/getJSON';
// Initializing curl
$ch = curl_init( $json_url );
// Configuring curl options
$options = array(
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => array('Content-type: application/json')
);
// Setting curl options
curl_setopt_array( $ch, $options );
// Getting results
$result = curl_exec($ch); // Getting JSON result string
See Getting JSON Data with PHP Curl for more details. Each server-side platform has the ability to make HTTP connections to servers.
// now, send the data in the response
HttpResponse::status(200);
HttpResponse::setContentType('application/json');
HttpResponse::setData($result);
HttpResponse::send();
See PHP HTTPResponse. Again, whatever language you're working with should have the ability to return data from a string.
Put the above code in a file called "getJSON.php", assuming you're using PHP. Make sure there is no whitespace between the opening <?php and the beginning of the document; otherwise, you will not be able to set the headers. There is likely a better way to send this response, but since your platform isn't specified, I'll leave that as an exercise for the reader.
Client-side code:
var searchURL = "/getJSON.php"; //From this URL json formatted data is present.
$.ajax({
url: searchURL,
type: 'GET',
dataType: 'json',
contentType: 'application/json; charset=utf-8',
success: function (data) {
try {
alert(data);
}
catch (err) {
alert(err);
}
}
});
Now, in the above JavaScript code, you make a same-domain AJAX request to your server exampleA.com, and then your server makes a request on your behalf to exampleB.com to get the data, then exampleA.com returns the data in the response to the browser.

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