/******************************************************************************
 * The way I want to do 'AJAX' (2005) rev. (Jun 08, 2007)
 * If you find an error, or improvement, let me know: dev at ajas dot us
 * This file is free for use
 *
 * I'm not doing "Asynchronous JavaScript and XML" because I don't use XML
 * I'm doing 'AJAS', the 'S' is for "Stuff"  I have my backend gen a JS object
 *  definition for the data I want to pass back to the client, like this:
 *	function arrayToJS($aRef) {
 *		$sTEXT = '{ ';
 *		if (is_array($aRef) && count($aRef))
 *		foreach ($aRef as $i => $val){
 *			if (is_array($val)) {
 *				if (count($val) > 0) {
 *					$sTEXT .= "'".$i."':".arrayToJS($val).',';
 *				} else {
 *					$sTEXT .= "'".$i."':[],";
 *				}
 *			} else {
 *				$sTEXT .= "'".$i."':'".str_replace(array("\\","'","\n","\r"),
 *					array("\\\\","\\'","\\n","\\r"),$val).'\',';
 *			}
 *		}
 *		return substr($sTEXT,0,-1).'}';
 *	}
 * App. PHP now has a function for this, check out JSON
 *****************************************************************************/

if(!ajas)var ajas={};
if(!ajas.http)ajas.http={};
//An array to hold pending XMLHttpRequest objects
if(!ajas.http.aRequests)ajas.http.aRequests=[];       
       
ajas.http.oBlankForm={'method':'post','action':'','enctype':'application/x-www-form-urlencoded','sData':''};

document.write('<!--[if IE]><script type="text/javascript">var bIE=true;</script><![endif]-->');
if (!bIE) var bIE=false;

//get XMLHttpRequest object according to browser type
ajas.http.newRequest=function() {
	return (window.ActiveXObject?new ActiveXObject("Microsoft.XMLHTTP"):new XMLHttpRequest());
}

//add XMLHttpRequest object and parameters to queue
//keeping them in a queue simplifies the use of concurrent requests
ajas.http.enqueue=function(oXML,aParams,sCallback){
	//name of callback function can be passed, or taken from the querystring.
	if(!sCallback)sCallback=aParams['callback']||'ajas.http.nullHandler';
	ajas.http.aRequests.push([oXML,new Function('oXML','aParams',sCallback+'(oXML,aParams);'),aParams]);
}

//check each XMLRequest and handle the ready ones with their preset callback function
ajas.http.queueHandler=function(){
	for(var key in ajas.http.aRequests){
		if (ajas.http.aRequests[key][0].readyState == 4){
			var oXML=ajas.http.aRequests[key][0];
			var oFunc=ajas.http.aRequests[key][1];
			var aParams=ajas.http.aRequests[key][2];
			delete ajas.http.aRequests[key];
			oFunc(oXML,aParams);
		}
	}
	return true;
}

//this is the default, do nothing, response handler
//if you enqueue, and aParams doesn't contain a 'callback' property, it uses this
ajas.http.nullHandler=function(oXML, aParams) {
	//if (oXML.responseText=='')return;
	//eval('var aData='+oXML.responseText);
	// do something with the data
	//alert('ajas.http.nullHandler called');
}

//take a form's data and send it in an XMLHttpRequest
ajas.http.submitForm=function(oForm,sCallback){
	var oXML=ajas.http.newRequest();
	var formData=oForm.sData||ajas.util.buildQueryString(ajas.form.getValues(oForm));
	oXML.open(oForm.method,oForm.action,true);//true=aSync
	oXML.onreadystatechange=ajas.http.queueHandler;
	oXML.setRequestHeader("Content-Type",oForm.enctype);
	oXML.setRequestHeader("Connection", "close");
	oXML.setRequestHeader("Content-length", formData.length);
	oXML.send(formData);

	var aParams;
	if(oForm.action.indexOf('?')==-1){
		aParams=[];
	} else {
		aParams=ajas.util.parseQueryString(oForm.action.substr(oForm.action.indexOf('?')+1));
	}

	//name of callback function can be passed, or taken from the querystring.
	ajas.http.enqueue(oXML,aParams,sCallback);
	return false; // so the form submit cancels
}
//send a typical get request
ajas.http.sendRequest=function(sUrl,sQueryString,sCallback){
	//if(arguments.length < 2) {
	if(!sQueryString) {
		var a=sUrl.split('?');
		sUrl=a[0];
		sQueryString=a[1];
	}
	var oXML=ajas.http.newRequest();
	oXML.open('GET',sUrl+'?'+sQueryString,true);//true=aSync
	oXML.onreadystatechange=ajas.http.queueHandler;
	oXML.setRequestHeader("Content-Type",'application/x-www-form-urlencoded');
	oXML.setRequestHeader("Connection", "close");
	oXML.send(null);

	var aParams=ajas.util.parseQueryString(sQueryString);
	//name of callback function can be passed, or taken from the querystring.
	ajas.http.enqueue(oXML,aParams,sCallback);
	return false; // so the form submit cancels
}

ajas.http.uploadLocalFile=function(sUrl,sFilename,sCallback,iMaxLen) {
	if(arguments.length < 4)var iMaxLen=false;
	if(arguments.length < 3)var sCallback='ajas.http.nullHandler';
	// FireFox/Mozilla settings: Open about:config and check that
	//  [signed.applets.codebase_principal_support] is set to "true"
	// request local file read permission
	netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");

	// open the local file
	var file = Components.classes["@mozilla.org/file/local;1"].createInstance(Components.interfaces.nsILocalFile);
	file.initWithPath( sFilename );
	stream = Components.classes["@mozilla.org/network/file-input-stream;1"].createInstance(Components.interfaces.nsIFileInputStream);
	stream.init(file, 0x01, 00004, null);
	var bstream =  Components.classes["@mozilla.org/network/buffered-input-stream;1"].getService();
	bstream.QueryInterface(Components.interfaces.nsIBufferedInputStream);
	bstream.init(stream, 1000);
	bstream.QueryInterface(Components.interfaces.nsIInputStream);
	var binary = Components.classes["@mozilla.org/binaryinputstream;1"].createInstance(Components.interfaces.nsIBinaryInputStream);
	binary.setInputStream (stream);

	if (iMaxLen && binary.available() > iMaxLen) {
		throw new Error('File size exceeds expressed limit of '+iMaxLen+' Bytes.');
		return false;
	}
	sFilename=sFilename.substr(Math.max(sFilename.lastIndexOf('/'),sFilename.lastIndexOf('\\'))+1);
	ajas.http.uploadAsFile(sUrl,sFilename,binary.readBytes(binary.available()),sCallback,iMaxLen);
	binary.close();
	bstream.close();
	stream.close();
}
ajas.http.uploadAsFile=function(sUrl,sFilename,sData,sCallback,iMaxLen) {
	if(arguments.length < 5)var iMaxLen=false;
	if(arguments.length < 4)var sCallback='ajas.http.nullHandler';
	if(arguments.length < 3)return false;
	// prepare the MIME POST data
	var boundaryString = '\\\\boundary\\\\';
	var boundary = '--' + boundaryString;
	var requestbody = boundary + '\n'
	+ 'Content-Disposition: form-data; name="myfile"; filename="' + sFilename + '"\n'
	+ 'Content-Type: application/octet-stream\n\n'
	+ ajas.util.escapePlus(sData)
	+ '\n' + boundary;

	oForm={'method':'POST','action':sUrl+'?callback='+sCallback,'sData':requestbody,'enctype':'multipart/form-data; boundary="'+boundaryString+'"'};
	ajas.http.submitForm(oForm);
}


//This object is useful for 'fixing' the back/forward buttons
// in 'ajax' (navigation) based sites
ajas.http.HashHistory = function (fCallback,sIeEchoURL,iMillis) {
	var private={
		fCallback:fCallback,		//function to call on hash changes
		sCurrentHash:'',			//to maintain #hash of current state
		oPollTimer:null,			//timer to poll #hash state changes
		iPollTime:500,				//poll time interval in ms, default
		sEchoURL:sIeEchoURL,        //URL that echos the querystring like this:
	                                //<?='#'.$_SERVER['QUERY_STRING'];?>
		iKey:0
	};

	if (bIE) { //if IE, use an iframe to keep history
		private.oIframeDiv=document.createElement('div');
		private.oIframeDiv.style.display='none';
		private.oIframeDiv.innerHTML='<iframe style="display:none;" '
			+'src="about:blank" name="ajas_http_History'+private.iKey+'">'
			+'</iframe>';
		private.oIframeName='ajas_http_History'+private.iKey;
		document.body.appendChild(private.oIframeDiv);
	}
	var public={
		//called from links, set the hashes that are polled to match link clicked
		addHash:function(sHash) {
			window.clearTimeout(private.oPollTimer);	//clear timer to avoid trigger during this function
			private.sCurrentHash=(sHash[0]=='#'?'':'#')+sHash;
			if (bIE) { //if IE
				//have to clear contents to deal with network latency
				window(private.oIframeName).document.body.innerText='';
				window(private.oIframeName).location=private.sEchoURL+'?'+private.sCurrentHash.substr(1);
			}
			window.location.hash=private.sCurrentHash;
			private.oPollTimer=window.setTimeout('ajas.util.store.get('+private.iKey+').pollHash();', private.iPollTime);
		},
		pollHash:function() {
			//Internet explorer needs special treatment.
			//don't forget to setup your echo URL described above
			if (bIE) {
				try{
					if (window.frames(private.oIframeName).document.body.innerText != private.sCurrentHash
						&& window.frames(private.oIframeName).document.body.innerText != '') {
						private.sCurrentHash = window.frames(private.oIframeName).document.body.innerText;
						window.location.hash = private.sCurrentHash;
						private.fCallback(private.sCurrentHash);
					}
				} catch(e){	}
			}
			//this portion handles FF, and IE's initial check
			if (window.location.hash != private.sCurrentHash
				&& window.location.hash != '') {
				private.sCurrentHash = window.location.hash;
				if (bIE) {
					try{window[private.oIframeName].document.body.innerText='';}catch(e){}
					window(private.oIframeName).location=private.sEchoURL+'?'+private.sCurrentHash.substr(1);
				}
				try{
					private.fCallback(private.sCurrentHash);
				}catch(e){}
			}
			private.oPollTimer=window.setTimeout('ajas.util.store.get('+private.iKey+').pollHash();', private.iPollTime);
			return true;
		}
	};
	private.iKey=ajas.util.store.add(public);
	public.pollHash();
	return public;
}