RsD0p9BK
5/2/2014 - 11:04 AM

https://gist.github.com/PizzaBrandon/5709010 or http://javascriptisawesome.blogspot.ru/2011/07/faster-than-jquerydocumentready-wait.html

;(function ($, window) {
 
var intervals = {};
var removeListener = function(selector) {
 
	if (intervals[selector]) {
		
		window.clearInterval(intervals[selector]);
		intervals[selector] = null;
	}
};
var found = 'waitUntilExists.found';
 
/**
 * @function
 * @property {object} jQuery plugin which runs handler function once specified
 *           element is inserted into the DOM
 * @param {function|string} handler 
 *            A function to execute at the time when the element is inserted or 
 *            string "remove" to remove the listener from the given selector
 * @param {bool} shouldRunHandlerOnce 
 *            Optional: if true, handler is unbound after its first invocation
 * @example jQuery(selector).waitUntilExists(function);
 */
 
$.fn.waitUntilExists = function(handler, shouldRunHandlerOnce, isChild) {
 
	var selector = this.selector;
	var $this = $(selector);
	var $elements = $this.not(function() { return $(this).data(found); });
	
	if (handler === 'remove') {
		
		// Hijack and remove interval immediately if the code requests
		removeListener(selector);
	}
	else {
 
		// Run the handler on all found elements and mark as found
		$elements.each(handler).data(found, true);
		
		if (shouldRunHandlerOnce && $this.length) {
			
			// Element was found, implying the handler already ran for all 
			// matched elements
			removeListener(selector);
		}
		else if (!isChild) {
			
			// If this is a recurring search or if the target has not yet been 
			// found, create an interval to continue searching for the target
			intervals[selector] = window.setInterval(function () {
				
				$this.waitUntilExists(handler, shouldRunHandlerOnce, true);
			}, 500);
		}
	}
	
	return $this;
};
 
}(jQuery, window));