[OpenLayers-Users] WMSGetFeatureInfo not firing

[Andreas Hocevar]

Hi,

the one advice I can give you is: ask on the list or on irc before you 
struggle for two days. This time, the answer would have been simple:

either do as you discovered, or set the vendorParams option of the WMS 
GetFeatureInfo control 
(http://dev.openlayers.org/releases/OpenLayers-2.8/doc/devdocs/files/OpenLayers/Control/WMSGetFeatureInfo-js.html#OpenLayers.Control.WMSGetFeatureInfo.vendorParams)

Regards,
Andreas.

P Kishor wrote:
> On Sat, Sep 19, 2009 at 7:47 PM, P Kishor <punk.kish at gmail.com> wrote:
>   
>> I have a bizarre problem that I can't debug. My code is
>>
>> var info = new OpenLayers.Control.WMSGetFeatureInfo({
>>            url: "http://localhost/cgi-bin/mapserv?map=/path/to/my.map&",
>>            maxFeatures: 12,
>>            title: 'Identify features by clicking',
>>            queryVisible: true,
>>            layers: [wms_cds_stands],
>>            infoFormat: "text/plain",
>>            eventListeners: {
>>                getfeatureinfo: function(event) {
>>                    map.addPopup(new OpenLayers.Popup.FramedCloud( ... ), true);
>>                }
>>            }
>>        });
>>        map.addControl(info);
>>        info.activate();
>>
>> If I change the url to "http://localhost/cgi-bin/mapserv" it fires
>> correctly on click, and a framed cloud pops up with the error message
>> that CGI variable map is not declared. However, if I add the map
>> variable to the query string as shown above, then the event doesn't
>> fire on click at all. There is no proxy nor remote host involved.
>> Everything is on localhost. Doesn't matter if the url starts with
>> "http://localhost/cgi-bin//mapserv" or just "/cgi-bin//mapserv", it is
>> the presence of the url query string that seems to cause the click
>> event to not fire at all.
>>
>> What could I do to correct this?
>>
>>     
>
> So, after two days of struggling with this, I figured it out. Turns
> out, my layer was defined like so...
>
> var wms_cds_stands = new OpenLayers.Layer.WMS(
>   "CDS Stands",
>   "http://localhost/cgi-bin/mapserv",
>   { map: "/path/to/my.map", layers : "cds_stands", map_imagetype:
> "agga", transparent: true },
>   { reproject: true, singleTile: true }
> );
>
> and my WMSGetFeatureInfo control had url set like so
>
> url: "http://localhost/cgi-bin/mapserv?map=/Users/punkish/Data/cnnf/cnnf.map&"
>
> Well, the urlMatches() function in WMSGetFeatureInfo class was causing
> my control to fail. The url for my layer definition did not have the
> map parameter attached as a query string. Instead, it was provided as
> a separate parameter in the params hash supplied to the object
> constructor. However, the control constructor does not provide a
> similar facility to supply the map value separately.
>
> I changed my mapserver url in the layer constructor to
>
> "http://localhost/cgi-bin/mapserv?map=/Users/punkish/Data/cnnf/cnnf.map&"
>
> and now since urlMatches() returns true for the two urls, the click
> event fires and I get a popup bubble.
>
> Once again, I ask, was there a more efficient and obvious way for me
> to discover this?
>
> OpenLayers is an absolutely fantastic piece of work which is severely
> hampered by its documentation, UNLESS, there is a strategy to
> discovering how it works that I am completely missing. I am determined
> to using OL and making it a showcase in my work, so I can also
> evangelize it to others as a replacement for Google or Yahoo maps.
> But, right now, either its documentation, or the way I am going about
> it, is tripping me up severely. Any advice from you more seasoned
> folks is very welcome.
>
>
>
>
>   


-- 
Andreas Hocevar
OpenGeo - http://opengeo.org/
Expert service straight from the developers.