jQuery.post()


jQuery.post( url [, data ] [, success ] [, dataType ] )Returns: jqXHR

Description: Load data from the server using a HTTP POST request.

  • version added: 1.0jQuery.post( url [, data ] [, success ] [, dataType ] )

    • url
      Type: String
      A string containing the URL to which the request is sent.
    • data
      A plain object or string that is sent to the server with the request.
    • success
      Type: Function( Object data, String textStatus, jqXHR jqXHR )
      A callback function that is executed if the request succeeds. Required if dataType is provided, but can be null in that case.
    • dataType
      Type: String
      The 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:

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$.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:

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$.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 $.get() implements the Promise interface, giving it all the properties, methods, and behavior of a Promise (see Deferred object for more information). The jqXHR.done() (for success), jqXHR.fail() (for error), and jqXHR.always() (for completion, whether success or error) methods take a function argument that is called when the request terminates. For information about the arguments this function receives, see the jqXHR Object section of the $.ajax() documentation.

The Promise interface also allows jQuery's Ajax methods, including $.get(), to chain multiple .done(), .fail(), and .always() 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.

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// Assign handlers immediately after making the request,
// and remember the jqxhr object for this request
var jqxhr = $.post( "example.php", function() {
alert( "success" );
})
.done(function() {
alert( "second success" );
})
.fail(function() {
alert( "error" );
})
.always(function() {
alert( "finished" );
});
// Perform other work here ...
// Set another completion function for the request above
jqxhr.always(function() {
alert( "second finished" );
});

Deprecation Notice

The jqXHR.success(), jqXHR.error(), and jqXHR.complete() callback methods introduced in jQuery 1.5 are deprecated as of jQuery 1.8. To prepare your code for their eventual removal, use jqXHR.done(), jqXHR.fail(), and jqXHR.always() instead.

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, port, 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 the jqXHR object returned by jQuery.post() is also available for error handling.

Examples:

Example: Request the test.php page, but ignore the return results.

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$.post( "test.php" );

Example: Request the test.php page and send some additional data along (while still ignoring the return results).

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$.post( "test.php", { name: "John", time: "2pm" } );

Example: Pass arrays of data to the server (while still ignoring the return results).

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$.post( "test.php", { 'choices[]': [ "Jon", "Susan" ] } );

Example: Send form data using ajax requests

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$.post( "test.php", $( "#testform" ).serialize() );

Example: Alert the results from requesting test.php (HTML or XML, depending on what was returned).

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$.post( "test.php", function( data ) {
alert( "Data Loaded: " + data );
});

Example: Alert the results from requesting test.php with an additional payload of data (HTML or XML, depending on what was returned).

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$.post( "test.php", { name: "John", time: "2pm" })
.done(function( data ) {
alert( "Data Loaded: " + data );
});

Example: Post to the test.php page and get content which has been returned in json format (<?php echo json_encode(array("name"=>"John","time"=>"2pm")); ?>).

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$.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

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<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>jQuery.post demo</title>
<script src="//code.jquery.com/jquery-1.10.2.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
var posting = $.post( url, { s: term } );
// Put the results in a div
posting.done(function( data ) {
var content = $( data ).find( "#content" );
$( "#result" ).empty().append( content );
});
});
</script>
</body>
</html>

Demo: