[Qgis-user] QGIS Web Client with Google Background Maps works only in EPSG 3857

[Bernhard Ströbl]

Hi Markus,

Am 25.06.2014 14:02, schrieb Markus Weidenbach:
> Thanks, Bernhard and Giovanni for the quick response.
>
> Bernhard, unfortunately the project is pretty complex and it is too much
> work to reproject all data sets into the EPSG 3857 just for publishing
> (the perfect integration of QGIS Mapserver and QGIS, allowing the direct
> publication of QGIS projects with no extra work was the main reason for
> me to choose QGIS Mapserver/QWC).

I _think_ that otf reprojection of all your layers increases the 
answering time of your server when requesting maps in EPSG:3857.

> So, either I had to use my own reprojected background map or do
> everything in EPSG3857 .....
> :-\
>
> Alternatively I could use one of the regional and public WMS which
> serves 40 cm Orthos also in EPSG31467 and which I could use as
> background information.
> Do you know if there is a way to attach such WMS to the QWC?

Yes you can. You can either load a WMS layer into your project (so 
called cascading WMS). Thus this layer is printable. Or you can 
configure it as background layer (a OpenLayers.layer.WMS object see the 
OpenLayers documentation on how to do that).
I do this in Customizations.js:

function customBeforeMapInit() {
     var myBackgroundLayer = new OpenLayers.Layer.WMS("myName",
         "myURL", {
             layers: "myLayer",
             format: format,
             dpi: screenDpi,
             VERSION: "1.3.0"
         },
         {
             buffer:0,
             singleTile:true,
             ratio:1,
             transitionEffect:"resize",
             isBaseLayer: true,
             projection:authid
         }
     );
     baseLayers.push(myBackgroundLayer);
}

Bernhard
>
> Regards,
> Markus
>
>
> --
> Dr. Markus Weidenbach
> *landConsult.de*
> Geographical Information Management
> and Environmental Planning
> D-77815 Bühl
> Germany
> e.mail see: http://landConsult.de
> Am 25.06.2014 13:16, schrieb Bernhard Ströbl:
>> Hi,
>>
>> GoogleMaps is only available in GoogleMercator projection (3857), so
>> if you want to use them you have to use this projection (in which case
>> I would recommend to also reproject your data for the server, so QWC,
>> the QGIS project and the data are in the same projection.)
>> BTW: The GoogleMap is also not included in the print.
>>
>> Bernhard
>>
>> Am 25.06.2014 13:05, schrieb Markus Weidenbach:
>>> Dear List,
>>>
>>> I am running QWC on a Remote Debian 7 (QWC checkout from GIT HUB on
>>> 25.06.2014) and on a local Win 7 (checkout in Marc 2014) computer.
>>>
>>> I would like to publish my QGIS projects in its original CRS, which is
>>> EPSG 31467 together with the Google Satellite/Street Background Maps.
>>> So, I changed the "var authid" in the GlobalOption.js from 3857 to 31467
>>> (and I also added the missing EPSG31467 record to the
>>> libs/proj4js/defs).
>>>
>>> After many attempts, I found that the Background Maps work only when you
>>> set  var authid="EPSG"+3857 in GlobalOptions.js.
>>>
>>> Consequently I can publish QGIS projects in EPSG31647 after switching
>>> the "var authid" to EPSG 31467 only if I switch off the Google
>>> Background Maps (in GlobalOptions.js with var enableBGMaps = false;) at
>>> the same time.
>>>
>>> Can anybody confirm this?
>>> Or is there a setting to tell the Background Maps to transform
>>> automatically into the EPSG given in the "authid" variable?
>>>
>>> Thanks for any comments.
>>>
>>> Markus
>>>
>>> N.B.
>>> I know, that I could save my QGIS projects in EPSG3857 to publish them
>>> in QWC together with the Background Maps, but then I am loosing the
>>> original coordinates and this also leads to some geometrical
>>> inaccuracies.
>>>
>>>
>>>
>>> --
>>> Dr. Markus Weidenbach
>>> *landConsult.de*
>>> Geographical Information Management
>>> and Environmental Planning
>>> D-77815 Bühl
>>> Germany
>>> e.mail see: http://landConsult.de
>>>
>>>


__________ Information from ESET Mail Security, version of virus signature database 9998 (20140625) __________

The message was checked by ESET Mail Security.
http://www.eset.com