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Emulate "submit" and "change" events bubbling in IE for Prototype 1.7
/** Emulate "submit" and "change" events bubbling
*
* This plugin enables handling bubbling submit/change events by browsers which
* natively don't support this. It only augments `Element.on()` method and doesn't
* fix when this events are observed with `observe()`.
*/
;(function() {
// Technique from Juriy Zaytsev
// http://thinkweb2.com/projects/prototype/detecting-event-support-without-browser-sniffing/
function isEventSupported(eventName) {
var el = document.createElement('div');
eventName = 'on' + eventName;
var isSupported = (eventName in el);
if (!isSupported) {
el.setAttribute(eventName, 'return;');
isSupported = typeof el[eventName] == 'function';
}
el = null;
return isSupported;
}
function isForm(element) {
return Object.isElement(element) && element.nodeName.toUpperCase() == 'FORM'
}
function isInput(element) {
if (Object.isElement(element)) {
var name = element.nodeName.toUpperCase()
return name == 'INPUT' || name == 'SELECT' || name == 'TEXTAREA'
}
else return false
}
var submitBubbles = isEventSupported('submit'),
changeBubbles = isEventSupported('change')
if (!submitBubbles || !changeBubbles) {
// augment the Event.Handler class to observe custom events when needed
Event.Handler.prototype.initialize = Event.Handler.prototype.initialize.wrap(
function(init, element, eventName, selector, callback) {
init(element, eventName, selector, callback)
// is the handler being attached to an element that doesn't support this event?
if ( (!submitBubbles && this.eventName == 'submit' && !isForm(this.element)) ||
(!changeBubbles && this.eventName == 'change' && !isInput(this.element)) ) {
// "submit" => "emulated:submit"
this.eventName = 'emulated:' + this.eventName
}
}
)
}
/** FIXME: these implementations still don't handle the case when the real event
* has been stopped directly on the origin element. Emulated event would still bubble. */
if (!submitBubbles) {
// discover forms on the page by observing focus events which always bubble
document.on('focusin', 'form', function(focusEvent) {
// special handler for the real "submit" event (one-time operation)
if (!this.retrieve('emulated:submit')) {
this.on('submit', function(submitEvent) {
var emulated = this.fire('emulated:submit', submitEvent, true)
// if custom event received preventDefault, cancel the real one too
if (emulated.returnValue === false) submitEvent.preventDefault()
})
this.store('emulated:submit', true)
}
})
}
if (!changeBubbles) {
// discover form inputs on the page
document.on('focusin', 'input, select, texarea', function(focusEvent) {
// special handler for real "change" events
if (!this.retrieve('emulated:change')) {
this.on('change', function(changeEvent) {
this.fire('emulated:change', changeEvent, true)
})
this.store('emulated:change', true)
}
})
}
})()
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