Jukka, You can add this as a feature request to the tracker on our SourceForge page. It probably won't get implemented until a programmer gets an itch to do something about it.
Landon On Mon, Nov 16, 2009 at 4:08 AM, Rahkonen Jukka <jukka.rahko...@mmmtike.fi> wrote: > Hi, > > It would be nice to be able to query WMS layers with GetFeatureInfo > requests. DeeJUMP has implemented this feature but I have understood > that it is utilising deegree libraries. As a non-programmer I am > thinking that adding this feature to the existing WMS part of OpenJUMP > should not be extra difficult. The OGC standard text is here: > http://cite.opengeospatial.org/OGCTestData/wms/1.1.1/spec/wms1.1.1.html# > wmsops.getfeatureinfo > > What needs to be done for making GetFeatureInfo requests, starting from > a situation of successfull WMS GetMap request and the returned image > being in OJ map Window is about the following. > > 1. Get the service GetCapabilities document handy, let's say it is found > here: > http://myserver.fi/cgi-bin/WMS?REQUEST=GetCapabilities&SERVICE=WMS&VERSI > ON=1.1.1 > That is the initial query for using WMS get map so it is mostly > implemented already but I will come back to this in section 3. > 2. Take the WMS GetMap request as basis. Let's say it is like this: > http://myserver.fi/cgi-bin/WMS?REQUEST=GetMap&SERVICE=WMS&VERSION=1.1.1&; > WIDTH=600&HEIGHT=400&LAYERS=parcels2008,parcels2009&TRANSPARENT=TRUE&FOR > MAT=image/png&BBOX=430000,6943000,430600,6943400&SRS=EPSG:3067&STYLES= > > 3. Read and parse the GetFeatureInfo part of the GetCapabilities > document that was queried in step 1: > <GetFeatureInfo> > <Format>text/plain</Format> > <Format>application/vnd.ogc.gml</Format> > <DCPType> > <HTTP> > <Get><OnlineResource > xmlns:xlink="http://www.w3.org/1999/xlink"; > xlink:href="http://myserver.fi/cgi-bin/WMS?"/></Get> > <Post><OnlineResource > xmlns:xlink="http://www.w3.org/1999/xlink"; > xlink:href="http://myserver.fi/cgi-bin/WMS?"/></Post> > </HTTP> > </DCPType> > </GetFeatureInfo> > > 4. Build the GetFeatureInfo query from the following components: > a) Base url from step 3 > http://myserver.fi/cgi-bin/WMS? > This online resource is usually the same that is used for > GetCapabilities but according to the standard it may be something else, > so the correct way would be to read and interpret the document. > > b) Version number of GetFeatureInfo request, I suppose it can always be > the same that has been used for GetCapabilities and GetMap > VERSION=1.1.1 > > c) Request name > &REQUEST=GetFeatureInfo > > d) copy of the main part of GetMap request from the step 2 > &SERVICE=WMS&WIDTH=600&HEIGHT=400&LAYERS=parcels2008,parcels2009&TRANSPA > RENT=TRUE&FORMAT=image/png&BBOX=430000,6943000,430600,6943400&SRS=EPSG:3 > 067&STYLES= > So it is the whole GetMap request exept base url, version and request. > > d) Add QUERY_LAYERS parameter. Standard says: This parameter shall > contain at least one layer name, but may contain fewer layers than the > original GetMap request. To make things a bit more simple I think it > could always contain all the layers from the original GetMap request. > > e) Add INFO_FORMAT parameter. It is optional, but without giving it > server returns its default format and standard does not say what it > should be so perhaps it would be better if WMS client ask for a certain > format. Possible values are listed in GetFeatureInfo report in step 3. > > f) Add FEATURE_COUNT parameter. It is optional but it is good to have, > because the default is 1 and that gives, for example, feature info of > just one of the overlapping polygons which are queried. > > g) Add X and Y which are the pixel coordinates of the point that is > clicken on a map. > > h) EXCEPTIONS parameter is optional and only supported value seems to be > "application/vnd.ogc.se_xml" so there is no need to include it. > > When everything is put together the request should look like this: > > http://myserver.fi/cgi-bin/WMS?VERSION=1.1.1&REQUEST=GetFeatureInfo&SERV > ICE=WMS&WIDTH=600&HEIGHT=400&LAYERS=parcels2008,parcels2009&TRANSPARENT= > TRUE&FORMAT=image/png&BBOX=430000,6943000,430600,6943400&SRS=EPSG:3067&S > TYLES=&QUERY_LAYERS=parcels2008,parcels2009&INFO_FORMAT=text/plain&FEATU > RE_COUNT=100&X=162&Y=225 > > This was the request part, another part would be to make OJ to parse > what is sent back from WMS server. Standard does not order which > formats must of should be supported, but most common are propably > text/plain, text/html and INFO_FORMAT=application/vnd.ogc.gml which is > returning gml. > > Well, after writing all this I believe it is not necessarily so simple > to implement. > > -Jukka Rahkonen- > > ------------------------------------------------------------------------------ > Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day > trial. Simplify your report design, integration and deployment - and focus on > what you do best, core application coding. Discover what's new with > Crystal Reports now. http://p.sf.net/sfu/bobj-july > _______________________________________________ > Jump-pilot-devel mailing list > Jump-pilot-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
