[Wylug-help] Javascript and anonymous functions

[James Holden]

Hi Gary,

No idea, my JS is limited to a bit of jQuery. You might try asking in #leedsjs
on irc.freenode.net though.

This might help though:

http://stackoverflow.com/questions/2559318/how-to-check-for-undefined-or-null-variable-in-javascript

Regards,

James

On Wed, Jul 03, 2013 at 09:25:42PM +0100, Gary Stainburn wrote:
> I use AJAX on some of my web sites, and call it using the following code
> 
> var form=document.getElementById('testForm');
> AjaxRequest("/test8.php?formSubmit",function(xmlHttp) {
>        if(xmlHttp.readyState==4) {
>          generic_response(xmlHttp);
>        }
>      },form);
> 
> Which works fine. I have been trying to make the function argument accept 
> undefined or null as an argument. However, when I try to define the function 
> it is called immediately instead of the callback.
> 
> The core I've tried is below. Can anyone see what's wrong with it?
> 
> function AjaxRequest(Url,Fn,form,modal=false) {
>   var xmlHttp;
>   var requestComplete=0;
>   var requestResponse='';
>   var Func;
>   if (typeof(Fn) === "undefined" || Fn === null) {
>     Func=(function(xmlHttp) {
>          if(xmlHttp.readyState==4) 
>            generic_response();
>        });
>   } else {
>     Func=Fn;
>   }// Fn undefined
> 
> 
> 
> 
> 
> 
> -- 
> Gary Stainburn
> Group I.T. Manager
> Ringways Garages
> http://www.ringways.co.uk 
> 
> _______________________________________________
> Wylug-help mailing list
> Wylug-help at wylug.org.uk
> https://mailman.lug.org.uk/mailman/listinfo/wylug-help
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 198 bytes
Desc: Digital signature
URL: <http://mailman.lug.org.uk/pipermail/wylug-help/attachments/20130704/964d6f89/attachment.pgp>