A bookmarklet to investigate an XPath expression of a clicked element.

bookmarklet.txt

javascript:(function(){var dialog=document.createElement("div");var setUpDialog=function(){dialog.style.position="fixed";dialog.style.bottom="0";dialog.style.left="10%";dialog.style.width="80%";dialog.style.color="#333";dialog.style.background="#efe";dialog.style.border="thin solid #9a9";dialog.style.margin="0 0 0.5em";dialog.style.padding="0.5em 1em";dialog.style.fontFamily="monospace";document.getElementsByTagName("body")[0].appendChild(dialog)};var notify=function(message){dialog.textContent=message};var loadJavaScript=function(uri){var script=document.createElement("script");script.setAttribute("type","text/javascript");script.setAttribute("src",uri);document.getElementsByTagName("body")[0].appendChild(script)};var isJQueryLoaded=function(){return window.jQuery!==undefined};var waitLoadingJQuery=function(continuation){var tryCount=0;var step=function(){if(isJQueryLoaded())continuation();else{tryCount++;setTimeout(step,tryCount*100);notify("Loading"+(new Array(tryCount+1)).join("."))}};step()};var getXPath=function(target){var stack=[];var t=target;while(t.tagName){var $t=$(t);var $p=$t.parent();var i1=$p.children(t.tagName).index(t)+1;var id=$t.attr("id");var classes=$t.attr("class");if(classes){stack.push("]");stack.push('"');stack.push(classes);stack.push('"');stack.push("=");stack.push("@class");stack.push("[")}if(id){stack.push("]");stack.push('"');stack.push(id);stack.push('"');stack.push("=");stack.push("@id");stack.push("[")}if(1<i1){stack.push("]");stack.push(i1);stack.push("[")}stack.push(t.tagName.toLowerCase());stack.push("/");t=$p[0]}stack.reverse();return stack.join("")};var setUpCoreUI=function(){window.$=window.jQuery;$("*").click(function(e){notify(getXPath(this));return false});notify("Click an element to show an XPath expression to the element.")};setUpDialog();if(isJQueryLoaded())setUpCoreUI();else{loadJavaScript("http://code.jquery.com/jquery-1.7.2.min.js");waitLoadingJQuery(setUpCoreUI)}})();

investigate-xpath.js

(function () {
	var dialog = document.createElement('div');

	var setUpDialog = function () {
		dialog.style.position = 'fixed';
		dialog.style.bottom = '0';
		dialog.style.left = '10%';
		dialog.style.width = '80%';
		dialog.style.color = '#333';
		dialog.style.background = '#efe';
		dialog.style.border = 'thin solid #9a9';
		dialog.style.margin = '0 0 0.5em';
		dialog.style.padding = '0.5em 1em';
		dialog.style.fontFamily = 'monospace';
		document.getElementsByTagName('body')[0].appendChild(dialog);
	};

	var notify = function (message) {
		dialog.textContent = message;
	};

	var loadJavaScript = function (uri) {
		var script = document.createElement('script');
		script.setAttribute('type', 'text/javascript');
		script.setAttribute('src', uri);
		document.getElementsByTagName('body')[0].appendChild(script);
	};

	var isJQueryLoaded = function () {
		return window.jQuery !== undefined;
	};

	var waitLoadingJQuery = function (continuation) {
		var tryCount = 0;
		var step = function () {
			if (isJQueryLoaded()) {
				continuation();
			} else {
				tryCount++;
				setTimeout(step, tryCount * 100);
				notify('Loading' + new Array(tryCount + 1).join('.'));
			}
		};
		step();
	};

	var getXPath = function (target) {
		var stack = [];
		var t = target;

		while (t.tagName) {
			var $t = $(t);
			var $p = $t.parent();
			var i1 = $p.children(t.tagName).index(t) + 1;
			var id = $t.attr('id');
			var classes = $t.attr('class');

			if (classes) {
				stack.push(']');
				stack.push('"');
				stack.push(classes);
				stack.push('"');
				stack.push('=');
				stack.push('@class');
				stack.push('[');
			}
			if (id) {
				stack.push(']');
				stack.push('"');
				stack.push(id);
				stack.push('"');
				stack.push('=');
				stack.push('@id');
				stack.push('[');
			}
			if (1 < i1) {
				stack.push(']');
				stack.push(i1);
				stack.push('[');
			}
			stack.push(t.tagName.toLowerCase());
			stack.push('/');

			t = $p[0];
		}
		stack.reverse();

		return stack.join('');
	};

	var setUpCoreUI = function () {
		window.$ = window.jQuery;
		$('*').click(function (e) {
			notify(getXPath(this));
			return false;
		});
		notify('Click an element to show an XPath expression to the element.');
	};

	setUpDialog();
	if (isJQueryLoaded()) {
		setUpCoreUI();
	} else {
		loadJavaScript('http://code.jquery.com/jquery-1.7.2.min.js');
		waitLoadingJQuery(setUpCoreUI);
	}
})();