jQuery Form Plugin

Overview

The jQuery Form Plugin allows you to easily and unobtrusively upgrade HTML forms to use AJAX. The main methods, ajaxForm and ajaxSubmit, gather information from the form element to determine how to manage the submit process. Both of these methods support numerous options which allows you to have full control over how the data is submitted.

No special markup is needed, just a normal form. Submitting a form with AJAX doesn't get any easier than this!

API

ajaxForm( options )

Prepares a form to be submitted via AJAX by adding all of the necessary event listeners. It does not submit the form. Use ajaxForm in your document's ready function to prepare existing forms for AJAX submission, or with the delegation option to handle forms not yet added to the DOM.
Use ajaxForm when you want the plugin to manage all the event binding for you.

// prepare all forms for ajax submission
$('form').ajaxForm({
    target: '#myResultsDiv'
});

ajaxSubmit( options )

Immediately submits the form via AJAX. In the most common use case this is invoked in response to the user clicking a submit button on the form. Use ajaxSubmit if you want to bind your own submit handler to the form.

// bind submit handler to form
$('form').on('submit', function(e) {
    e.preventDefault(); // prevent native submit
    $(this).ajaxSubmit({
        target: 'myResultsDiv'
    })
});

Options

Note: all standard $.ajax options can be used.

beforeSerialize

Callback function invoked prior to form serialization. Provides an opportunity to manipulate the form before its values are retrieved. Returning false from the callback will prevent the form from being submitted. The callback is invoked with two arguments: the jQuery wrapped form object and the options object.

beforeSerialize: function($form, options) { 
    // return false to cancel submit                  
}

beforeSubmit

Callback function invoked prior to form submission. This provides an opportunity to manipulate the form before it's values are retrieved. Returning false from the callback will prevent the form from being submitted. The callback is invoked with three arguments: the form data in array format, the jQuery wrapped form object, and the options Oobject.

beforeSubmit: function(arr, $form, options) { 
    // form data array is an array of objects with name and value properties
    // [ { name: 'username', value: 'jresig' }, { name: 'password', value: 'secret' } ] 
    // return false to cancel submit                  
}

clearForm

Boolean flag indicating whether the form should be cleared if the submit is successful

data

An object containing extra data that should be submitted along with the form.

data: { key1: 'value1', key2: 'value2' }

dataType

Expected data type of the response. One of: null, 'xml', 'script', or 'json'. The dataType option provides a means for specifying how the server response should be handled. This maps directly to jQuery's dataType method. The following values are supported:

  • 'xml': server response is treated as XML and the 'success' callback method, if specified, will be passed the responseXML value
  • 'json': server response will be evaluted and passed to the 'success' callback, if specified
  • 'script': server response is evaluated in the global context

delegation

true to enable support for event delegation requires jQuery v1.7+

// prepare all existing and future forms for ajax submission
$('form').ajaxForm({
    delegation: true
});

error

Callback function to be invoked upon error.

forceSync

Only applicable when explicity using the iframe option or when uploading files on browses that don't support XHR2. Set to true to remove the short delay before posting form when uploading files. The delay is used to allow the browser to render DOM updates prior to performing a native form submit. This improves usability when displaying notifications to the user, such as "Please Wait..."

iframe

Boolean flag indicating whether the form should always target the server response to an iframe instead of leveraging XHR when possible.

iframeSrc

String value that should be used for the iframe's src attribute when/if an iframe is used.

iframeTarget

Identifies the iframe element to be used as the response target for file uploads. By default, the plugin will create a temporary iframe element to capture the response when uploading files. This options allows you to use an existing iframe if you wish. When using this option the plugin will make no attempt at handling the response from the server.

replaceTarget

Optionally used along with the the target option. Set to true if the target should be replaced or false if only the target contents should be replaced.

resetForm

Boolean flag indicating whether the form should be reset if the submit is successful

semantic

Boolean flag indicating whether data must be submitted in strict semantic order (slower). Note that the normal form serialization is done in semantic order with the exception of input elements of type="image". You should only set the semantic option to true if your server has strict semantic requirements and your form contains an input element of type="image".

success

Callback function to be invoked after the form has been submitted. If a success callback function is provided it is invoked after the response has been returned from the server. It is passed the following arguments:

  1. responseText or responseXML value (depending on the value of the dataType option).
  2. statusText
  3. xhr (or the jQuery-wrapped form element if using jQuery < 1.4)
  4. jQuery-wrapped form element (or undefined if using jQuery < 1.4)

target

Identifies the element(s) in the page to be updated with the server response. This value may be specified as a jQuery selection string, a jQuery object, or a DOM element.

type

The method in which the form data should be submitted, 'GET' or 'POST'.

uploadProgress

Callback function to be invoked with upload progress information (if supported by the browser). The callback is passed the following arguments:

  1. event; the browser event
  2. position (integer)
  3. total (integer)
  4. percentComplete (integer)

url

URL to which the form data will be submitted.

Utility Methods

formSerialize

Serializes the form into a query string. This method will return a string in the format: name1=value1&name2=value2

var queryString = $('#myFormId').formSerialize();

fieldSerialize

Serializes field elements into a query string. This is handy when you need to serialize only part of a form. This method will return a string in the format: name1=value1&name2=value2

var queryString = $('#myFormId .specialFields').fieldSerialize();

fieldValue

Returns the value(s) of the element(s) in the matched set in an array. This method always returns an array. If no valid value can be determined the array will be empty, otherwise it will contain one or more values.

resetForm

Resets the form to its original state by invoking the form element's native DOM method.

clearForm

Clears the form elements. This method emptys all of the text inputs, password inputs and textarea elements, clears the selection in any select elements, and unchecks all radio and checkbox inputs. It does not clear hidden field values.

clearFields

Clears selected field elements. This is handy when you need to clear only a part of the form.

File Uploads

The Form Plugin supports use of XMLHttpRequest Level 2 and FormData objects on browsers that support these features. As of today (March 2012) that includes Chrome, Safari, and Firefox. On these browsers (and future Opera and IE10) files uploads will occur seamlessly through the XHR object and progress updates are available as the upload proceeds. For older browsers, a fallback technology is used which involves iframes. More Info

The jQuery Form plugin is dual licensed under the MIT and GPL licenses:

You may use either license. The MIT License is recommended for most projects because it is simple and easy to understand and it places almost no restrictions on what you can do with the plugin.

If the GPL suits your project better you are also free to use the plugin under that license.

You don't have to do anything special to choose one license or the other and you don't have to notify anyone which license you are using. You are free to use the jQuery Form Plugin in commercial projects as long as the copyright header is left intact.

Additional documentation and examples at: http://malsup.com/jquery/form/