find broken image

brokenimage.js

(function($){
	if ($.fn.brokenimage) {
		return false;
	}

	var RETRY = 1,
		MILSEC_INTERVAL = 747;

	$.fn.brokenimage = function(opt){
		var options = {
			retry: RETRY,
			interval: MILSEC_INTERVAL,
			callback: undefined
		};
		var $my = this;

		var init = function () {
			$.extend(options, opt || {});
			$my.each(
				function(i, elm) {
					if (elm.tagName.toLowerCase() === 'img' && isBrokenImage(elm)) {
						var $elm = $(elm);
						if ($elm.data('nophoto')) {
							return false;
						}
						// console.log([elm.src, ' IS BROKEN!!! ', options.interval].join(''));
						$elm.data('retrycount', 0);
						invokeTimeout(elm);
					}
				}
			);
		};

		var retryImage = function (elm) {
			var $elm = $(elm);
			var retrycount = parseInt($elm.data('retrycount'), 10);
			if (retrycount >= options.retry) {
				if (typeof options.callback === 'function') {
					options.callback(elm);
				}
				return false;
			}
			elm.src = buildRetryUrl(elm.src);
			$elm.data('retrycount', ++retrycount);
			invokeTimeout(elm);
		};

		var invokeTimeout = function (elm) {
			var $elm = $(elm);
			setTimeout(
				function () {
					if (isBrokenImage(elm)) {
						retryImage(elm);
					}
				},
				options.interval
			);
		};

		init();
	};

	var buildRetryUrl = function (url) {
		var result;
		var epoch = ('' + (new Date()).valueOf()).slice(-6);
		if (url.indexOf('?') > -1) {
			result = [url, '&__retry=', epoch].join('');
		}
		else {
			result = [url, '?__retry=', epoch].join('');
		}
		return result;
	};

	var isBrokenImage = function (elm) {
		var result = false;
		if (!elm.complete || typeof elm.naturalWidth == "undefined" || elm.naturalWidth == 0) {
			result = true;
		}
		return result;
	};

})(jQuery);