ajax in object kapseln

Hallo,

ich habe eine Web-Seite mit zig Ajax Anwendungen.
Nun wollte ich eine Klasse schreiben um die Dinge uebersichtlich zu
machen.

AjaxProc,
mit 'callProc', diese setzt die Member und sendet den Request;
mit 'calledProc', die aufgerufen wird - aber hier ist 'this.req'
leider undefined.

--------------------------------------------------------------------
//ajax
function AjaxProc()
{
this.req = null;
this.calledProc = calledProc;
this.callProc = callProc;
this.userProc = null;
}

function calledProc(req)
{
if (this.req.readyState == 4)
{
if (this.req.status == 200)
{
var result = this.req.responseText;
this.userProc(result);
req = 0;
}
}
}
function callProc(url)
{
// branch for native XMLHttpRequest object
if (window.XMLHttpRequest)
{
this.req = new XMLHttpRequest();
alert(this.req);
this.req.onreadystatechange = this.calledProc;
this.req.open("GET", url, true);
this.req.send(null);
}
// branch for IE/Windows ActiveX version
else if (window.ActiveXObject)
{
this.req = new ActiveXObject("Microsoft.XMLHTTP");
alert(this.req);
if (this.req)
{
this.req.onreadystatechange = this.calledProc;
this.req.open("GET", url, true);
this.req.send();
}
}
}

var AjLoadTippe = null;
function loadTippe(spiel)
{
..
AjLoadTippe = new AjaxProc();
AjLoadTippe.userProc = processLoadTippe;
AjLoadTippe.callProc(url);
}
--------------------------------------------------------------------

Ich habe schon von aehnlichen Problemen gelesen - scheinbar laeuft die
automatisch aufgerufene Funktion
'calledProc' nicht im Kontext des Objects (wohl analog statischen
Funktionen in C++).
Nur wie stellt man dieses sicher.

Solong
Frank

Hier,
die Loesung mit closure.

------------------------------------------------------------
function AjaxProc()
{
var thisObj = this;
this.req = null;
this.calledProc = function() {
if (thisObj.req.readyState == 4)
{
if (thisObj.req.status == 200)
{
var result = thisObj.req.responseText;
//alert(result);
thisObj.userProc(result);
thisObj.req = 0;
}
}
}

this.callProc = function(url) {
// branch for native XMLHttpRequest object
if (window.XMLHttpRequest)
{
thisObj.req = new XMLHttpRequest();
thisObj.req.onreadystatechange = thisObj.calledProc;
thisObj.req.open("GET", url, true);
thisObj.req.send(null);
}
// branch for IE/Windows ActiveX version
else if (window.ActiveXObject)
{
thisObj.req = new ActiveXObject("Microsoft.XMLHTTP");
if (thisObj.req)
{
thisObj.req.onreadystatechange = thisObj.calledProc;
thisObj.req.open("GET", url, true);
thisObj.req.send();
}
}
}

this.userProc = null;
}


var AjLoadTippe = null;
function loadTippe(spiel)
{
...
AjLoadTippe = new AjaxProc();
AjLoadTippe.userProc = processLoadTippe;
AjLoadTippe.callProc(url);
}

function processLoadTippe(result)
{
document.getElementById("tippI").innerHTML = result;
}
------------------------------------------------------------

Hier die Loesung mit closures.

------------------------------------------------------------
//Ajax mit closure
function AjaxProc()
{
var thisObj = this;
this.req = null;
this.calledProc = function() {
if (thisObj.req.readyState == 4)
{
if (thisObj.req.status == 200)
{
var result = thisObj.req.responseText;
//alert(result);
thisObj.userProc(result);
thisObj.req = 0;
}
}
}

this.callProc = function(url) {
// branch for native XMLHttpRequest object
if (window.XMLHttpRequest)
{
thisObj.req = new XMLHttpRequest();
thisObj.req.onreadystatechange = thisObj.calledProc;
thisObj.req.open("GET", url, true);
thisObj.req.send(null);
}
// branch for IE/Windows ActiveX version
else if (window.ActiveXObject)
{
thisObj.req = new ActiveXObject("Microsoft.XMLHTTP");
if (thisObj.req)
{
thisObj.req.onreadystatechange = thisObj.calledProc;
thisObj.req.open("GET", url, true);
thisObj.req.send();
}
}
}

this.userProc = null;
}


var AjLoadTippe = null;
function loadTippe(spiel)
{
...
AjLoadTippe = new AjaxProc();
AjLoadTippe.userProc = processLoadTippe;
AjLoadTippe.callProc(url);
}
function processLoadTippe(result)
{
}
------------------------------------------------------------
Solong
Frank