[Chameleon] Start up layers

[Eric Bridger]

I could not get the approach discussed below to work.  Not sure why and
I don't have time to really investigate it further now.

In my InitLayers widget e.g. when passing on the command line:
index.phtml?initLayers=layer1+layer2 the widgets
$this->isVarSet('initLayers') returns false, while if
isset($_GET['initLayers']) returns true!? Not sure why.

So my alternative and successful approach was to create a small
invisible InitLayers widget extending CWCWidget with really just a
ParseURL function that does anything. I set the priority last to ensure
the my XMLThemeLegend widget gets processed fist.

 $this->mnPriority = PRIORITY_LAST;

In the ParseURL I have:

// Initial Layer selection from GET Query string.
if (isset($_GET['initLayers']))
{
   $aInitLayers = explode(" ", $_GET['initLayers']);
       
   foreach( $aInitLayers as $the_layer )
   {
       $oLayer = $this->moMapObject->oMap->getLayerByName($the_layer);
       $oLayer->set("status", MS_ON);
   }
}

This is working well for me.  The only caveat is that I need to
explicitly set my <form action="index.phtml" method="post"> in my
template which ensures that the $_GET is only set the first time thru.

When I get some more time I will post the whole widget and notes to the
wiki because I think it might be useful.

Eric


On Thu, 2005-01-20 at 15:39, Paul Spencer wrote:
> Eric,
> 
> it should be possible to fake the application into turning on certain 
> layers as the app starts by passing the correct URL.  This is because 
> the legend widgets (HTML and XML) use form variables to track layer 
> state between page loads.  I'm not exactly sure what the syntax would be 
> so my suggestion is that you change your form method to GET, load the 
> app, set the right layer status, update the page and capture the URL 
> that is generated, then eliminate all the pieces that don't have to do 
> with layer status and that should be what you need to add to turn layers 
> on/off
> 
> If you get this to work, I would appreciate a note back to the list so 
> we can add it to the tikiwiki for future users
> 
> Cheers,
> 
> Paul
> 
> Eric Bridger wrote:
> > I'd like to be able to start up my application with various layers
> > turned on without using the map file.  Ideally with a CGI command line
> > parameter e.g. layers=land+boundaries+etc. In other cases a different
> > set of layers would be sent. Is this possible?
> > 
> > What do you think would be the best approach to this.
> > 
> > After the initial startup I'm using the XMLThemeLegend widget to control
> > layers.
> > 
> > Eric