[Chameleon] Problem with ZoomAllLayers and sid (session id)

Jimmy Lam j.lam at i-real.nl
Wed Apr 12 08:29:16 EDT 2006

Hi all,

While working on my first Chameleon app, I experienced a problem with 
the ZoomAllLayers widget. It just wouldn't zoom to full extent when I 
clicked on the button. I'm using chameleon.map from the examples where 
it functioned normally, so the cause weren't the original_extents and 
original_projection from the WEB/META settings. Then I started to slowly 
strip sample_enhanced.html from all the widgets and settings till it 
resembled my own html file. Finally, after comparing the generated phtml 
files, I found the cause. Widgets like KeepSessionAlive or ZoomFactor, 
which are direct descendants from CWCWidget, were responsible for adding 
<INPUT TYPE=HIDDEN NAME=sid VALUE="<alphanumeric#>"> to the phtml. This 
is necessary for ZoomAllLayers to work. Widget descendants from NavTool, 
which inherits from CWCWidget, don't add this. I'm not sure if this is 
just with ZoomAllLayers or with other widgets too, as I haven't tested 
with others.
There are a few workarounds like adding the sid manually or just use a 
widget that adds it.

Best regards,


More information about the Chameleon mailing list