Namespace: preempt

Methods

<static> jQuery.fn.preempt(options, callback) → {jQuery}

Takes legacy inline JS (i.e. onclick and href="javascript:...") and creates event handler(s) to be run around the inlined code.

This:

• jQuery

Parameters:

Name	Type	Argument	Description
options	Object		attr is the attribute you want to replace event is the new event to bind before is a function you wish to execute before the inline handler. The second parameter, callback, will be overridden by this function. If this function returns false or halts immediate propagation, the inline function will not be called, and further immediate propagation of the event will not occur. after is a function you wish to execute after the inline handler. If this function returns false or halts immediate propagation, further immediate propagation of the event will not occur. forcePropagation causes your after function to be executed regardless of whether the inline function stopped immediate propagation or returned false. In this case, if the inline function happened to return false, the default action for the event (whatever that may be; see http://api.jquery.com/event.preventDefault/) will be prevented and bubbling will not occur. If after is not present, this does nothing. data is an object with keys before, and after. The values will be passed, respectively, to the before and after functions as the second parameter (the first will be the Event itself). A third key, js, is automatically added to the objects, and its value is the original contents of the attr attribute. It will have the javascript: prefix stripped, if present. It's worth remembering that the context (the this) of an inline function is the DOM element itself.
callback	function	<optional>	Event handler callback function to be executed before the inline handler. Alias for options.before; if both are present then options.before will take precedence.

Source:

• jquery.preempt.js, line 194

To Do:

• Document more thoroughly.
• support for delegate-style usage

Returns:

A jQuery obj

Type

jQuery

Example

// given <button onclick="doSomething()">do something</button>
// or <a href="javascript:doSomethingElse()">do something else</a>

// Basic usage:
$('button').preempt({
  attr: 'onclick',
  event: 'click',
}, function doSomethingBeforeSomething() {
  // do something else
});

// Restoring the inline JS:
$('button').preempt({
  attr: 'onclick',
  event: 'click',
  restore: true
});

// Fancy usage:
$('button').preempt({
  attr: 'onclick',
  event: 'click',
  before: function executedBeforeInlineJS(event, data) {
    // stuff; return false to halt propagation to inline JS
  },
  after: function exectedAfterInlineJS(event, data) {
    // things; return false to prevent the default action and stop propagation
  },
  // will execute the after() function even if the inlined JS returned false.
  forcePropagation: true,
  data: {
    before: 'some data to be passed to the before() function',
    after: 'some data to be passed to the after() function',
  }
});