jQuery.post()
jQuery.post( url [, data] [, success(data, textStatus, jqXHR)] [, dataType] ) Returns: jqXHR
Description: Load data from the server using a HTTP POST request.
-
version added: 1.0jQuery.post( url [, data] [, success(data, textStatus, jqXHR)] [, dataType] )
urlA string containing the URL to which the request is sent.
dataA map or string that is sent to the server with the request.
success(data, textStatus, jqXHR)A callback function that is executed if the request succeeds.
dataTypeThe type of data expected from the server. Default: Intelligent Guess (xml, json, script, text, html).
This is a shorthand Ajax function, which is equivalent to:
$.ajax({
type: 'POST',
url: url,
data: data,
success: success,
dataType: dataType
});
The success callback function is passed the returned data, which will be an XML root element or a text string depending on the MIME type of the response. It is also passed the text status of the response.
As of jQuery 1.5, the success callback function is also passed a "jqXHR" object (in jQuery 1.4, it was passed the XMLHttpRequest object).
Most implementations will specify a success handler:
$.post('ajax/test.html', function(data) {
$('.result').html(data);
});
This example fetches the requested HTML snippet and inserts it on the page.
Pages fetched with POST are never cached, so the cache and ifModified options in jQuery.ajaxSetup() have no effect on these requests.
The jqXHR Object
As of jQuery 1.5, all of jQuery's Ajax methods return a superset of the XMLHTTPRequest object. This jQuery XHR object, or "jqXHR," returned by $.post() implements the Promise interface, giving it all the properties, methods, and behavior of a Promise (see Deferred object for more information). For convenience and consistency with the callback names used by $.ajax(), it provides .error(), .success(), and .complete() methods. These methods take a function argument that is called when the request terminates, and the function receives the same arguments as the correspondingly-named $.ajax() callback.
The Promise interface in jQuery 1.5 also allows jQuery's Ajax methods, including $.post(), to chain multiple .success(), .complete(), and .error() callbacks on a single request, and even to assign these callbacks after the request may have completed. If the request is already complete, the callback is fired immediately.
// Assign handlers immediately after making the request,
// and remember the jqxhr object for this request
var jqxhr = $.post("example.php", function() {
alert("success");
})
.success(function() { alert("second success"); })
.error(function() { alert("error"); })
.complete(function() { alert("complete"); });
// perform other work here ...
// Set another completion function for the request above
jqxhr.complete(function(){ alert("second complete"); });
Additional 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, or protocol.
- If a request with jQuery.post() returns an error code, it will fail silently unless the script has also called the global .ajaxError() method. Alternatively, as of jQuery 1.5, the
.error()method of thejqXHRobject returned by jQuery.post() is also available for error handling.
Examples:
Example: Request the test.php page, but ignore the return results.
$.post("test.php");Example: Request the test.php page and send some additional data along (while still ignoring the return results).
$.post("test.php", { name: "John", time: "2pm" } );Example: pass arrays of data to the server (while still ignoring the return results).
$.post("test.php", { 'choices[]': ["Jon", "Susan"] });Example: send form data using ajax requests
$.post("test.php", $("#testform").serialize());Example: Alert out the results from requesting test.php (HTML or XML, depending on what was returned).
$.post("test.php", function(data) {
alert("Data Loaded: " + data);
});Example: Alert out the results from requesting test.php with an additional payload of data (HTML or XML, depending on what was returned).
$.post("test.php", { name: "John", time: "2pm" },
function(data) {
alert("Data Loaded: " + data);
});Example: Gets the test.php page content, store it in a XMLHttpResponse object and applies the process() JavaScript function.
$.post("test.php", { name: "John", time: "2pm" },
function(data) {
process(data);
},
"xml"
);Example: Posts to the test.php page and gets contents which has been returned in json format (<?php echo json_encode(array("name"=>"John","time"=>"2pm")); ?>).
$.post("test.php", { "func": "getNameAndTime" },
function(data){
console.log(data.name); // John
console.log(data.time); // 2pm
}, "json");Example: Post a form using ajax and put results in a div
<!DOCTYPE html>
<html>
<head>
<script src="http://code.jquery.com/jquery-latest.js"></script>
</head>
<body>
<form action="/" id="searchForm">
<input type="text" name="s" placeholder="Search..." />
<input type="submit" value="Search" />
</form>
<!-- the result of the search will be rendered inside this div -->
<div id="result"></div>
<script>
/* attach a submit handler to the form */
$("#searchForm").submit(function(event) {
/* stop form from submitting normally */
event.preventDefault();
/* get some values from elements on the page: */
var $form = $( this ),
term = $form.find( 'input[name="s"]' ).val(),
url = $form.attr( 'action' );
/* Send the data using post and put the results in a div */
$.post( url, { s: term },
function( data ) {
var content = $( data ).find( '#content' );
$( "#result" ).empty().append( content );
}
);
});
</script>
</body>
</html>