Loading a file on the server - timing issues?

[joe]

I am loading a text file to a variable with XMLHttpRequest( )
There seems to be some sort of timing issue since loadXML (source code below)
returns the contents of the file on seconds try. In Firefox I get an empty
string. No errors are reported.

If I look at the code with Firefox debugger (Venkman) everything works fine. I
should probably put a loop somewhere to check when loading the file is finished.


var xmlhttp;
...
[a lot of Javascipt code here]
...
loadXMLDoc("htt p://wwww.mysite.com/test.bin");
mystr=xmlhttp.s tatusText;
...


function loadXMLDoc(url)
{
xmlhttp=null;
if (window.XMLHttp Request)
{// code for IE7, Firefox, Opera, etc.
xmlhttp=new XMLHttpRequest( );
}
else if (window.ActiveX Object)
{// code for IE6, IE5
xmlhttp=new ActiveXObject(" Microsoft.XMLHT TP");
}
if (xmlhttp!=null)
{
xmlhttp.onready statechange=sta te_Change;
xmlhttp.open("G ET",url,true) ;
xmlhttp.send(nu ll);
}
else
{
alert("Browser not supported.");
}
}

function state_Change()
{
if (xmlhttp.readyS tate==4)
{// 4 = "loaded"
if (xmlhttp.status !=200)
{
alert("Problem: " + xmlhttp.statusT ext);
}
}
}

[Martin Honnen]

Re: Loading a file on the server - timing issues?

joe wrote:

loadXMLDoc("htt p://wwww.mysite.com/test.bin");
mystr=xmlhttp.s tatusText;

As your loadXMLDoc does asynchronous loading (third argument to open
method is true) you can't access the statusText in your code following
the loadXMLDoc call as that code is executed before the response to the
HTTP request will have been received.
Continue to use asynchronous loading but put any code trying to read
status, statusText and responseXML or responseText into the
onreadystatecha nge handler.


--

Martin Honnen

http://JavaScript.FAQTs.com/

[joe]

Re: Loading a file on the server - timing issues?

Martin Honnen <mahotrash@yaho o.dewrote:

>joe wrote:
>

>loadXMLDoc("ht tp://wwww.mysite.com/test.bin");
>mystr=xmlhttp. statusText;

>
>As your loadXMLDoc does asynchronous loading (third argument to open
>method is true) you can't access the statusText in your code following
>the loadXMLDoc call as that code is executed before the response to the
>HTTP request will have been received.
>Continue to use asynchronous loading but put any code trying to read
>status, statusText and responseXML or responseText into the
>onreadystatech ange handler.

Thanks. It helped.