GetFeatureInfo requests never get answers

classic Classic list List threaded Threaded
8 messages Options
Reply | Threaded
Open this post in threaded view
|

GetFeatureInfo requests never get answers

Marc Desharnais
Hi all,

I'm new to this mailing list. I work for the government of Canada on a
project to develop visualization tools.
I tried to adapt the example from

http://www.openlayers.org/dev/examples/getfeatureinfo.html


To get the getfeatureInfo working. I get the loading message in the div
section 'nodeList'. The problem is that it never seems to get an answer.
I get the checkpoint popup when I click the map so I guess that this
part is executed well. But it stays forever with the loading message.
So probably "wmsLayer1.getFullRequestString" is not correct or my
database is not quite right... I just have a layer with points.
And I want to query information about thoise points in the database to
display it beside the map.

I'm using a local Geoserver with PostGIS. I would like to know too how
the getFeatureInfo query works.
Like if I have anything I have to do specially into the database. I
figure that it's querying the database for info, but what info?
Do I have to define what I want to be queried?  Maybe this is off-topic
here sorry.

I searched for informations on the UTIL package for openlayers but
didn't find real documentation about that.

Please let me know if you would like more info.


Any help will be greatly appreciated.
Thanks in advance





/******* CODE START HERE - !!! Note that this code is not complete. I
posted only the parts I found relevant. !!!
  function init(){

          var map = new OpenLayers.Map($('map'), {controls:[]} );
          OpenLayers.IMAGE_RELOAD_ATTEMPTS = 5;
         
         
          var yahooLayer = new OpenLayers.Layer.Yahoo( "Globe (Yahoo)",
{reproject: "true"} );
         
          map.addLayer(yahooLayer);
         

          var wmsLayer1 = new OpenLayers.Layer.WMS(
                "POSTGIS villes",
"http://ulysse.cmc.ec.gc.ca:8081/geoserver/wms",
          {
             layers: 'topp:villes',
             format: 'image/png' , transparent: "true", reproject: "true"}
          );
                   

          map.addLayer(wmsLayer1);
         

          map.addControl(new OpenLayers.Control.LayerSwitcher());

          map.addControl(new OpenLayers.Control.NavToolbar());
          map.addControl(new OpenLayers.Control.PanZoomBar($('map')));
   
          map.addControl(new OpenLayers.Control.MouseDefaults());
          map.addControl(new OpenLayers.Control.Scale($('scale')));
          map.addControl(new OpenLayers.Control.MousePosition({element:
$('position')}));

          map.events.register('click', map, function (e) {
                OpenLayers.Util.getElement('nodeList').innerHTML =
"<b>Téléchargement d'information...<br> Veuillez Attendre SVP...</b>";
                var url =  wmsLayer1.getFullRequestString({
                   REQUEST: "GetFeatureInfo",
                   EXCEPTIONS: "application/vnd.ogc.se_xml",
                   BBOX: wmsLayer1.map.getExtent().toBBOX(),
                   X: e.xy.x,
                   Y: e.xy.y,
                   INFO_FORMAT: 'text/html',
                   QUERY_LAYERS: wmsLayer1.params.LAYERS,
                   WIDTH: wmsLayer1.map.size.w,
                   HEIGHT: wmsLayer1.map.size.h});
                   OpenLayers.loadURL(url, '', this, setHTML);

                   alert("Checkpoint");

                   Event.stop(e);
             });


       }
             
       function setHTML(response) {
          alert("before answer");
          OpenLayers.Util.getElement('nodeList').innerHTML =
response.responseText;
          alert("after answer");
       }

/********* CODE STOPS HERE
_______________________________________________
Users mailing list
[hidden email]
http://openlayers.org/mailman/listinfo/users
Reply | Threaded
Open this post in threaded view
|

Re: GetFeatureInfo requests never get answers

Marc Desharnais
Hi all,

I wish to update my problem in hope to get more precise help.
I checked what is returned by the server and every time and do a manual attempt by entering the request URL myself I get "no features were found".
Is it because of the server or from OpenLayers?
I tried to change the name of the layer in the reuqest to something random, and I received a message telling that the feature type was not found.

So I guess that it is querying the server with something that exists. But it can't get any feature from the database. Again, if anyone has any experience of OpenLayers getting layers from geoserver with PostGIS, please tell me if there is anything to do in the database to make ot work.


Thank you :)

Marc


Tim Schaub wrote:
Hey Marc-

Marc Desharnais wrote:
To get the getfeatureInfo working. I get the loading message in the div section 'nodeList'. The problem is that it never seems to get an answer.
I get the checkpoint popup when I click the map so I guess that this part is executed well. But it stays forever with the loading message.
So probably "wmsLayer1.getFullRequestString" is not correct or my database is not quite right... I just have a layer with points.
And I want to query information about thoise points in the database to display it beside the map.

Since you are making an asynchronous request for the GetFeatureInfo results, you are subject to the same origin policies that browsers enforce.

This means that your GetFeatureInfo request won't go anywhere unless it is requested with the same protocol, from the same port, and on the same host as the request that initiated your application (see [1]).

If this sounds like your issue (i.e. you are making the request to GeoServer on a different port than the request for the rest of your application), see the FAQ on setting up a proxy host [2].  Note that if you are using the proxy.cgi that comes in the OL examples directory, you will need to add your host (and port) to the accepted list (in proxy.cgi).


I'm using a local Geoserver with PostGIS. I would like to know too how the getFeatureInfo query works.
Like if I have anything I have to do specially into the database. I figure that it's querying the database for info, but what info?
Do I have to define what I want to be queried?  Maybe this is off-topic here sorry.

Also, use Firebug to watch the requests go out.  Copy the request and paste in to a new tab to make sure you are getting what you expect.  If you don't get what you expect, then you'll have to troubleshoot your GeoServer configuration.

Hope that helps some,
Tim

[1] http://www.mozilla.org/projects/security/components/same-origin.html
[2] http://trac.openlayers.org/wiki/FrequentlyAskedQuestions#ProxyHost



I searched for informations on the UTIL package for openlayers but didn't find real documentation about that.

Please let me know if you would like more info.


Any help will be greatly appreciated.
Thanks in advance





/******* CODE START HERE - !!! Note that this code is not complete. I posted only the parts I found relevant. !!!
  function init(){

          var map = new OpenLayers.Map($('map'), {controls:[]} );
          OpenLayers.IMAGE_RELOAD_ATTEMPTS = 5;
                             var yahooLayer = new OpenLayers.Layer.Yahoo( "Globe (Yahoo)", {reproject: "true"} );
                    map.addLayer(yahooLayer);
                   var wmsLayer1 = new OpenLayers.Layer.WMS(
                "POSTGIS villes", "http://ulysse.cmc.ec.gc.ca:8081/geoserver/wms",
          {
             layers: 'topp:villes',
             format: 'image/png' , transparent: "true", reproject: "true"}
          );
                            map.addLayer(wmsLayer1);
                   map.addControl(new OpenLayers.Control.LayerSwitcher());

          map.addControl(new OpenLayers.Control.NavToolbar());
          map.addControl(new OpenLayers.Control.PanZoomBar($('map')));
              map.addControl(new OpenLayers.Control.MouseDefaults());
          map.addControl(new OpenLayers.Control.Scale($('scale')));
          map.addControl(new OpenLayers.Control.MousePosition({element: $('position')}));

          map.events.register('click', map, function (e) {
                OpenLayers.Util.getElement('nodeList').innerHTML = "<b>Téléchargement d'information...<br> Veuillez Attendre SVP...</b>";
                var url =  wmsLayer1.getFullRequestString({
                   REQUEST: "GetFeatureInfo",
                   EXCEPTIONS: "application/vnd.ogc.se_xml",
                   BBOX: wmsLayer1.map.getExtent().toBBOX(),
                   X: e.xy.x,
                   Y: e.xy.y,
                   INFO_FORMAT: 'text/html',
                   QUERY_LAYERS: wmsLayer1.params.LAYERS,
                   WIDTH: wmsLayer1.map.size.w,
                   HEIGHT: wmsLayer1.map.size.h});
                   OpenLayers.loadURL(url, '', this, setHTML);

                   alert("Checkpoint");

                   Event.stop(e);
             });


       }
                     function setHTML(response) {
          alert("before answer");
          OpenLayers.Util.getElement('nodeList').innerHTML = response.responseText;
          alert("after answer");
       }

/********* CODE STOPS HERE
_______________________________________________
Users mailing list
[hidden email]
http://openlayers.org/mailman/listinfo/users




_______________________________________________
Users mailing list
[hidden email]
http://openlayers.org/mailman/listinfo/users
Reply | Threaded
Open this post in threaded view
|

Re: GetFeatureInfo requests never get answers

Brent Pedersen
hi,
in mapserver, you'd have to add something to make getfeatureinfo work
('ows_include_items') is that the case in geoserver?
have you checked if the &X , &Y url parameters look like the correct
pixel values.
then what does postgres log for the query from geoserver?
-b


On 7/18/07, Marc Desharnais <[hidden email]> wrote:

>
>
> Hi all,
>
>  I wish to update my problem in hope to get more precise help.
>  I checked what is returned by the server and every time and do a manual
> attempt by entering the request URL myself I get "no features were found".
>  Is it because of the server or from OpenLayers?
>  I tried to change the name of the layer in the reuqest to something random,
> and I received a message telling that the feature type was not found.
>
>  So I guess that it is querying the server with something that exists. But
> it can't get any feature from the database. Again, if anyone has any
> experience of OpenLayers getting layers from geoserver with PostGIS, please
> tell me if there is anything to do in the database to make ot work.
>
>
>  Thank you :)
>
>  Marc
>
>
>  Tim Schaub wrote:
>
> Hey Marc-
>
>  Marc Desharnais wrote:
>
> To get the getfeatureInfo working. I get the loading message in the div
> section 'nodeList'. The problem is that it never seems to get an answer.
>  I get the checkpoint popup when I click the map so I guess that this part
> is executed well. But it stays forever with the loading message.
>  So probably "wmsLayer1.getFullRequestString" is not correct or my database
> is not quite right... I just have a layer with points.
>  And I want to query information about thoise points in the database to
> display it beside the map.
>
>  Since you are making an asynchronous request for the GetFeatureInfo
> results, you are subject to the same origin policies that browsers enforce.
>
>  This means that your GetFeatureInfo request won't go anywhere unless it is
> requested with the same protocol, from the same port, and on the same host
> as the request that initiated your application (see [1]).
>
>  If this sounds like your issue (i.e. you are making the request to
> GeoServer on a different port than the request for the rest of your
> application), see the FAQ on setting up a proxy host [2].  Note that if you
> are using the proxy.cgi that comes in the OL examples directory, you will
> need to add your host (and port) to the accepted list (in proxy.cgi).
>
>
>
>  I'm using a local Geoserver with PostGIS. I would like to know too how the
> getFeatureInfo query works.
>  Like if I have anything I have to do specially into the database. I figure
> that it's querying the database for info, but what info?
>  Do I have to define what I want to be queried?  Maybe this is off-topic
> here sorry.
>
>  Also, use Firebug to watch the requests go out.  Copy the request and paste
> in to a new tab to make sure you are getting what you expect.  If you don't
> get what you expect, then you'll have to troubleshoot your GeoServer
> configuration.
>
>  Hope that helps some,
>  Tim
>
>  [1]
> http://www.mozilla.org/projects/security/components/same-origin.html
>  [2]
> http://trac.openlayers.org/wiki/FrequentlyAskedQuestions#ProxyHost
>
>
>
>
>
>  I searched for informations on the UTIL package for openlayers but didn't
> find real documentation about that.
>
>  Please let me know if you would like more info.
>
>
>  Any help will be greatly appreciated.
>  Thanks in advance
>
>
>
>
>
>  /******* CODE START HERE - !!! Note that this code is not complete. I
> posted only the parts I found relevant. !!!
>    function init(){
>
>            var map = new OpenLayers.Map($('map'), {controls:[]} );
>            OpenLayers.IMAGE_RELOAD_ATTEMPTS = 5;
>                               var yahooLayer = new OpenLayers.Layer.Yahoo(
> "Globe (Yahoo)", {reproject: "true"} );
>                      map.addLayer(yahooLayer);
>                     var wmsLayer1 = new OpenLayers.Layer.WMS(
>                  "POSTGIS villes",
> "http://ulysse.cmc.ec.gc.ca:8081/geoserver/wms",
>            {
>               layers: 'topp:villes',
>               format: 'image/png' , transparent: "true", reproject: "true"}
>            );
>                              map.addLayer(wmsLayer1);
>                     map.addControl(new
> OpenLayers.Control.LayerSwitcher());
>
>            map.addControl(new OpenLayers.Control.NavToolbar());
>            map.addControl(new OpenLayers.Control.PanZoomBar($('map')));
>                map.addControl(new
> OpenLayers.Control.MouseDefaults());
>            map.addControl(new OpenLayers.Control.Scale($('scale')));
>            map.addControl(new
> OpenLayers.Control.MousePosition({element:
> $('position')}));
>
>            map.events.register('click', map, function (e) {
>                  OpenLayers.Util.getElement('nodeList').innerHTML =
> "<b>Téléchargement d'information...<br> Veuillez Attendre SVP...</b>";
>                  var url =  wmsLayer1.getFullRequestString({
>                     REQUEST: "GetFeatureInfo",
>                     EXCEPTIONS: "application/vnd.ogc.se_xml",
>                     BBOX: wmsLayer1.map.getExtent().toBBOX(),
>                     X: e.xy.x,
>                     Y: e.xy.y,
>                     INFO_FORMAT: 'text/html',
>                     QUERY_LAYERS: wmsLayer1.params.LAYERS,
>                     WIDTH: wmsLayer1.map.size.w,
>                     HEIGHT: wmsLayer1.map.size.h});
>                     OpenLayers.loadURL(url, '', this, setHTML);
>
>                     alert("Checkpoint");
>
>                     Event.stop(e);
>               });
>
>
>         }
>                       function setHTML(response) {
>            alert("before answer");
>            OpenLayers.Util.getElement('nodeList').innerHTML =
> response.responseText;
>            alert("after answer");
>         }
>
>  /********* CODE STOPS HERE
>  _______________________________________________
>  Users mailing list
>  [hidden email]
>  http://openlayers.org/mailman/listinfo/users
>
>
>
>
> _______________________________________________
> Users mailing list
> [hidden email]
> http://openlayers.org/mailman/listinfo/users
>
>
_______________________________________________
Users mailing list
[hidden email]
http://openlayers.org/mailman/listinfo/users
Reply | Threaded
Open this post in threaded view
|

Re: GetFeatureInfo requests never get answers

Marc Desharnais
Hi,

I confirm that my geoserver is working fine. I exchanged some emails on
the geoserver mailing list and they suggested me to try the preview maps
given by geoserver. They now integer the getfeatureinfo functionality in
the default previews.

So I tried there and everything worked fine.

but, now, if I copy the html code entirely without any modification into
my webpage, I won't work. The map displays fine and everything. But it
hangs on the loading message and never get response. I used Firebug to
track the bug and I remarked that the request is never noticed in
firebug when I click on a point. The loadURL function is called but not
the setHTML. It makes me think that maybe it's a permission problem.
Since it semms to work from geoserver itself but not from apache (which
my web page is on).

Anyone had any experience like this?

Thank a lot,

Marc



Brent Pedersen wrote:

> hi,
> in mapserver, you'd have to add something to make getfeatureinfo work
> ('ows_include_items') is that the case in geoserver?
> have you checked if the &X , &Y url parameters look like the correct
> pixel values.
> then what does postgres log for the query from geoserver?
> -b
>
>
> On 7/18/07, Marc Desharnais <[hidden email]> wrote:
>>
>>
>> Hi all,
>>
>>  I wish to update my problem in hope to get more precise help.
>>  I checked what is returned by the server and every time and do a manual
>> attempt by entering the request URL myself I get "no features were
>> found".
>>  Is it because of the server or from OpenLayers?
>>  I tried to change the name of the layer in the reuqest to something
>> random,
>> and I received a message telling that the feature type was not found.
>>
>>  So I guess that it is querying the server with something that
>> exists. But
>> it can't get any feature from the database. Again, if anyone has any
>> experience of OpenLayers getting layers from geoserver with PostGIS,
>> please
>> tell me if there is anything to do in the database to make ot work.
>>
>>
>>  Thank you :)
>>
>>  Marc
>>
>>
>>  Tim Schaub wrote:
>>
>> Hey Marc-
>>
>>  Marc Desharnais wrote:
>>
>> To get the getfeatureInfo working. I get the loading message in the div
>> section 'nodeList'. The problem is that it never seems to get an answer.
>>  I get the checkpoint popup when I click the map so I guess that this
>> part
>> is executed well. But it stays forever with the loading message.
>>  So probably "wmsLayer1.getFullRequestString" is not correct or my
>> database
>> is not quite right... I just have a layer with points.
>>  And I want to query information about thoise points in the database to
>> display it beside the map.
>>
>>  Since you are making an asynchronous request for the GetFeatureInfo
>> results, you are subject to the same origin policies that browsers
>> enforce.
>>
>>  This means that your GetFeatureInfo request won't go anywhere unless
>> it is
>> requested with the same protocol, from the same port, and on the same
>> host
>> as the request that initiated your application (see [1]).
>>
>>  If this sounds like your issue (i.e. you are making the request to
>> GeoServer on a different port than the request for the rest of your
>> application), see the FAQ on setting up a proxy host [2].  Note that
>> if you
>> are using the proxy.cgi that comes in the OL examples directory, you
>> will
>> need to add your host (and port) to the accepted list (in proxy.cgi).
>>
>>
>>
>>  I'm using a local Geoserver with PostGIS. I would like to know too
>> how the
>> getFeatureInfo query works.
>>  Like if I have anything I have to do specially into the database. I
>> figure
>> that it's querying the database for info, but what info?
>>  Do I have to define what I want to be queried?  Maybe this is off-topic
>> here sorry.
>>
>>  Also, use Firebug to watch the requests go out.  Copy the request
>> and paste
>> in to a new tab to make sure you are getting what you expect.  If you
>> don't
>> get what you expect, then you'll have to troubleshoot your GeoServer
>> configuration.
>>
>>  Hope that helps some,
>>  Tim
>>
>>  [1]
>> http://www.mozilla.org/projects/security/components/same-origin.html
>>  [2]
>> http://trac.openlayers.org/wiki/FrequentlyAskedQuestions#ProxyHost
>>
>>
>>
>>
>>
>>  I searched for informations on the UTIL package for openlayers but
>> didn't
>> find real documentation about that.
>>
>>  Please let me know if you would like more info.
>>
>>
>>  Any help will be greatly appreciated.
>>  Thanks in advance
>>
>>
>>
>>
>>
>>  /******* CODE START HERE - !!! Note that this code is not complete. I
>> posted only the parts I found relevant. !!!
>>    function init(){
>>
>>            var map = new OpenLayers.Map($('map'), {controls:[]} );
>>            OpenLayers.IMAGE_RELOAD_ATTEMPTS = 5;
>>                               var yahooLayer = new
>> OpenLayers.Layer.Yahoo(
>> "Globe (Yahoo)", {reproject: "true"} );
>>                      map.addLayer(yahooLayer);
>>                     var wmsLayer1 = new OpenLayers.Layer.WMS(
>>                  "POSTGIS villes",
>> "http://ulysse.cmc.ec.gc.ca:8081/geoserver/wms",
>>            {
>>               layers: 'topp:villes',
>>               format: 'image/png' , transparent: "true", reproject:
>> "true"}
>>            );
>>                              map.addLayer(wmsLayer1);
>>                     map.addControl(new
>> OpenLayers.Control.LayerSwitcher());
>>
>>            map.addControl(new OpenLayers.Control.NavToolbar());
>>            map.addControl(new OpenLayers.Control.PanZoomBar($('map')));
>>                map.addControl(new
>> OpenLayers.Control.MouseDefaults());
>>            map.addControl(new OpenLayers.Control.Scale($('scale')));
>>            map.addControl(new
>> OpenLayers.Control.MousePosition({element:
>> $('position')}));
>>
>>            map.events.register('click', map, function (e) {
>>                  OpenLayers.Util.getElement('nodeList').innerHTML =
>> "<b>Téléchargement d'information...<br> Veuillez Attendre SVP...</b>";
>>                  var url =  wmsLayer1.getFullRequestString({
>>                     REQUEST: "GetFeatureInfo",
>>                     EXCEPTIONS: "application/vnd.ogc.se_xml",
>>                     BBOX: wmsLayer1.map.getExtent().toBBOX(),
>>                     X: e.xy.x,
>>                     Y: e.xy.y,
>>                     INFO_FORMAT: 'text/html',
>>                     QUERY_LAYERS: wmsLayer1.params.LAYERS,
>>                     WIDTH: wmsLayer1.map.size.w,
>>                     HEIGHT: wmsLayer1.map.size.h});
>>                     OpenLayers.loadURL(url, '', this, setHTML);
>>
>>                     alert("Checkpoint");
>>
>>                     Event.stop(e);
>>               });
>>
>>
>>         }
>>                       function setHTML(response) {
>>            alert("before answer");
>>            OpenLayers.Util.getElement('nodeList').innerHTML =
>> response.responseText;
>>            alert("after answer");
>>         }
>>
>>  /********* CODE STOPS HERE
>>  _______________________________________________
>>  Users mailing list
>>  [hidden email]
>>  http://openlayers.org/mailman/listinfo/users
>>
>>
>>
>>
>> _______________________________________________
>> Users mailing list
>> [hidden email]
>> http://openlayers.org/mailman/listinfo/users
>>
>>

_______________________________________________
Users mailing list
[hidden email]
http://openlayers.org/mailman/listinfo/users
Reply | Threaded
Open this post in threaded view
|

Re: GetFeatureInfo requests never get answers

Christopher Schmidt-2
On Thu, Jul 19, 2007 at 01:04:34PM +0000, Marc Desharnais wrote:

> Hi,
>
> I confirm that my geoserver is working fine. I exchanged some emails on
> the geoserver mailing list and they suggested me to try the preview maps
> given by geoserver. They now integer the getfeatureinfo functionality in
> the default previews.
>
> So I tried there and everything worked fine.
>
> but, now, if I copy the html code entirely without any modification into
> my webpage, I won't work. The map displays fine and everything. But it
> hangs on the loading message and never get response. I used Firebug to
> track the bug and I remarked that the request is never noticed in
> firebug when I click on a point. The loadURL function is called but not
> the setHTML. It makes me think that maybe it's a permission problem.
> Since it semms to work from geoserver itself but not from apache (which
> my web page is on).

http://trac.openlayers.org/wiki/FrequentlyAskedQuestions#WhydoIneedaProxyHost

Regards,
--
Christopher Schmidt
MetaCarta
_______________________________________________
Users mailing list
[hidden email]
http://openlayers.org/mailman/listinfo/users
Reply | Threaded
Open this post in threaded view
|

Re: GetFeatureInfo requests never get answers

Marc Desharnais
Hi Christopher,

Like you said, it turned out that the problem was a security issue.
To those who don't know (like me), you can't access a host with your browser and make query on another. The point I was missing was that the same machine with 2 different ports are considered to be 2 different hosts. It's a simple explanation when you realize that.

I learned too why the security exception in Firefox while I attempted to make request (via Firebug) didn't show like I would have expect.
That's a thing that really bothered me at the first place because I would have expected an clear error from the browser.
I have read that this kind of exception are treated silently in the browser so it's normal I've seen nothing while I was debugging.

Now everything is working well!

Thank you for your supportt! :)

Marc


Christopher Schmidt wrote:
On Thu, Jul 19, 2007 at 01:04:34PM +0000, Marc Desharnais wrote:
  
Hi,

I confirm that my geoserver is working fine. I exchanged some emails on 
the geoserver mailing list and they suggested me to try the preview maps 
given by geoserver. They now integer the getfeatureinfo functionality in 
the default previews.

So I tried there and everything worked fine.

but, now, if I copy the html code entirely without any modification into 
my webpage, I won't work. The map displays fine and everything. But it 
hangs on the loading message and never get response. I used Firebug to 
track the bug and I remarked that the request is never noticed in 
firebug when I click on a point. The loadURL function is called but not 
the setHTML. It makes me think that maybe it's a permission problem. 
Since it semms to work from geoserver itself but not from apache (which 
my web page is on).
    

http://trac.openlayers.org/wiki/FrequentlyAskedQuestions#WhydoIneedaProxyHost

Regards,
  


_______________________________________________
Users mailing list
[hidden email]
http://openlayers.org/mailman/listinfo/users
Reply | Threaded
Open this post in threaded view
|

Re: GetFeatureInfo requests never get answers

Christopher Schmidt-2
On Thu, Jul 19, 2007 at 03:48:05PM +0000, Marc Desharnais wrote:
> I learned too why the security exception in Firefox while I attempted to
> make request (via Firebug) didn't show like I would have expect.
> That's a thing that really bothered me at the first place because I
> would have expected an clear error from the browser.
> I have read that this kind of exception are treated silently in the
> browser so it's normal I've seen nothing while I was debugging.

Actually, that's not entirely true. Instead, this is a failing of
OpenLayers.Ajax, which has since been corrected in trunk:

http://trac.openlayers.org/ticket/534

So, had you been using SVN, you would have seen "Unable to call
XMLHttpRequest.open".

Just for the record.

Regards,
--
Christopher Schmidt
MetaCarta
_______________________________________________
Users mailing list
[hidden email]
http://openlayers.org/mailman/listinfo/users
Reply | Threaded
Open this post in threaded view
|

Re: GetFeatureInfo requests never get answers

Tim Schaub-2
In reply to this post by Marc Desharnais
Hey Marc-

Glad you figured this out.  Guess I should have put the same, protocol,
*same port*, and same host part in bold.

Hope others searching stumble across this sooner.

 > Since you are making an asynchronous request for the GetFeatureInfo
 > results, you are subject to the same origin policies that browsers
enforce.
 >
 > This means that your GetFeatureInfo request won't go anywhere unless it
 > is requested with the same protocol, from the same port, and on the same
 > host as the request that initiated your application (see [1]).
 >

Marc Desharnais wrote:

> Hi Christopher,
>
> Like you said, it turned out that the problem was a security issue.
> To those who don't know (like me), you can't access a host with your
> browser and make query on another. The point I was missing was that the
> same machine with 2 different ports are considered to be 2 different
> hosts. It's a simple explanation when you realize that.
>
> I learned too why the security exception in Firefox while I attempted to
> make request (via Firebug) didn't show like I would have expect.
> That's a thing that really bothered me at the first place because I
> would have expected an clear error from the browser.
> I have read that this kind of exception are treated silently in the
> browser so it's normal I've seen nothing while I was debugging.
>
> Now everything is working well!
>
> Thank you for your supportt! :)
>
> Marc
>
>
> Christopher Schmidt wrote:
>> On Thu, Jul 19, 2007 at 01:04:34PM +0000, Marc Desharnais wrote:
>>  
>>> Hi,
>>>
>>> I confirm that my geoserver is working fine. I exchanged some emails on
>>> the geoserver mailing list and they suggested me to try the preview maps
>>> given by geoserver. They now integer the getfeatureinfo functionality in
>>> the default previews.
>>>
>>> So I tried there and everything worked fine.
>>>
>>> but, now, if I copy the html code entirely without any modification into
>>> my webpage, I won't work. The map displays fine and everything. But it
>>> hangs on the loading message and never get response. I used Firebug to
>>> track the bug and I remarked that the request is never noticed in
>>> firebug when I click on a point. The loadURL function is called but not
>>> the setHTML. It makes me think that maybe it's a permission problem.
>>> Since it semms to work from geoserver itself but not from apache (which
>>> my web page is on).
>>>    
>>
>> http://trac.openlayers.org/wiki/FrequentlyAskedQuestions#WhydoIneedaProxyHost
>>
>> Regards,
>>  
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Users mailing list
> [hidden email]
> http://openlayers.org/mailman/listinfo/users

_______________________________________________
Users mailing list
[hidden email]
http://openlayers.org/mailman/listinfo/users