/*
// Program:   hijax.js
// Version:   0.01
// Description:
//            JavaScript functions for Ajax manipulations of HTML pages.  
//            - produced for the Archives Hub v3.0
//
// Language:  JavaScript
// Author:    John Harrison <john.harrison@liv.ac.uk>
// Date:      28/07/2008
//
// Copyright: &copy; University of Liverpool 2005-2008
//
// Version History:
// 0.01 - 28/07/2008 - JH - functions scripted
// 0.02 - 28/01/2009 - JH - useability tweaks
*/

function createXMLHttpRequest() {
	var xmlHttp=null;
	try {
		// Firefox, Opera 8.0+, Safari
		xmlHttp=new XMLHttpRequest();
	}
	catch (e) {
		// Internet Explorer
		try {
			xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
			}
		catch (e) {
			try {
		    	xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
		    }
			catch (e) {
			    alert("Your browser does not support AJAX! Some functionality will be unavailable.");
			    return false;
		    }
		}
	}
	return xmlHttp;
}

function updateElementByUrl(id, url) {
	if( !document.getElementById) {
		window.alert("Your browser does not support functions essential for updating this page with AJAX!\n\nYou should still be able to use all functions of this site by disabling JavaScript in your browser settings.")
		return true;
	}
	var el = document.getElementById(id);
	// first obscure target to avoid repeat clicks
	displayLoading(el);
	var xmlHttp = createXMLHttpRequest();
	if (xmlHttp==null) {
		alert ("Your browser does not support AJAX!");
		return true;
	}
	xmlHttp.onreadystatechange=function() {
		if(xmlHttp.readyState==4) {
			if (xmlHttp.status == 200 || xmlHttp.status == 304) {
				el.innerHTML=xmlHttp.responseText;
				ajaxifyLinks(el);
				try {
					fadeToWhite(el, 196, 214, 248);
				} catch(err) {
				}
			}
		}
	}
	xmlHttp.open("GET",url,true);
  	xmlHttp.send(null);
  	return false;
}

function displayLoading(el) {
	el.innerHTML = '<div class="loading"><img src="/ead/img/ajax-loader.gif" alt=""/></div>';
}

function ajaxifyLinks(el){
	if( !el.getElementsByTagName) {
  		return;
  	}
  	var linkList = el.getElementsByTagName("a");
	for (var i = 0; i < linkList.length; i++) {
		var el = linkList[i]
		if (el.className.match('ajax')){
			el.onclick = function() {
				var hrefParts = this.getAttribute("href").split("#")
				var div = hrefParts.pop()
				hrefParts.push("&ajax=1")
				return updateElementByUrl(div, hrefParts.join(""));
				
			}
		}
	}
}

olf = function() { ajaxifyLinks(document);};
if (addLoadEvent) {
	addLoadEvent(olf);
} else {
	window.onload = olf;
}