jQuery Plugin: Conditional Custom Events

condevents.jquery.js

/**
 * Conditional Custom Events
 * jQuery Plugin
 * based on setInterval()
 */
;(function ($, window, undefined) {
	// Define conditional events
	function defineCondEvents(element, events) {
		var intervals = [];
		var delay = 10;
		
		$.each(events, function(index, eventObj) {
			if (eventObj['condition'] && eventObj['condition']) {
				intervals.push(
					setInterval(function() {
						if (eventObj['condition'].apply(element)) {
							if (!eventObj.occured) {
								eventObj.occured = true;
								$(element).trigger(eventObj['name']);
							}
						}
						else {
							if (eventObj.occured) {
								eventObj.occured = false;
							}
						}
					}, delay)
				);
			}
		});
		
		return intervals;
	}
	
	// Remove defined conditional events
	function removeCondEvents(element, events) {
		$.each(events, function(index, intervalId) {
			clearInterval(intervalId);
		});
		
		return null;
	}
	
	// jQuery plugin wrapper
	$.fn['condEvents'] = function (events) {
		return this.each(function () {
			var defined = $.data(this, 'condevents');
			
			if (!defined && events) {
				$.data(this, 'condevents', defineCondEvents(this, events));
			}
			else if (defined && !events) {
				$.data(this, 'condevents', removeCondEvents(this, defined));
			}
			else {
				return false;
			}
		});
	}
}(jQuery, window));

// Example of usage:
// defining 'scrollbar shows' and 'scrollbar hides' events for window
$(window).condEvents([
	{
		// event name
		name: 'hscrollshows',
		// condition for event triggering
		condition: function() {
			return ($('body')[0].scrollWidth > $(window).width());
		}
	},
	{
		name: 'hscrollhides',
		condition: function() {
			return ($('body')[0].scrollWidth <= $(window).width());
		}
	}
]);

// Adding events handlers
$(window).on('hscrollshows', function() { console.log('hscrollshows'); });
$(window).on('hscrollhides', function() { console.log('hscrollhides'); });

// Evoking method without params will remove all defined
// conditional custom events of element
//$(window).condEvents();