I am not quite sure how it works, and there are few details available, maybe someone who knows how it works can provide some insight?
The openlayer plugin is implemented as a plugin layer. It doesn't interact with other layers, but seems to do what you are talking about (gets queried on every pan/zoom/etc to retrieve the update data). Have a look at the code. API stuff: http://qgis.org/api/classQgsPluginLayer.html http://hub.qgis.org/issues/2392 On Wed, Aug 29, 2012 at 11:04 AM, G. Allegri <[email protected]> wrote: >> you might be able to achieve that using "plugin layers" which are map >> layers that can be created and updated by plugins > > > What do you mean Etienne? > How can I serve a layer, dynamically, through a python plugin? I don't want > to have a plugin that creates a memory layer, but that gets queried on every > pan/zoom/etc to retrieve the update data. > > giovanni > >> >> >> > The other is having the possibility to bridge, easily, any kind of data >> > source, using python as an adapter. >> > >> > giovanni >> > >> > >> > >> > >> > 2012/8/29 Barry Rowlingson <[email protected]> >> >> >> >> I have a vague memory that the python data provider idea was >> >> considered a while ago. I was thinking about how one could get direct >> >> access from Qgis to R spatial data sets stored in R's binary files. >> >> One method would have been to write a provider in python that used Rpy >> >> to bridge to R, but wasn't possible because you can't write data >> >> providers in Python. It could be done in C by linking to R's C >> >> library, but at that point I lost interest and used a looser coupling >> >> to get my R data into Qgis. >> >> >> >> The argument then went that if the provider was designed to access a >> >> file it would be a better idea to write a GDAL/OGR driver, then even >> >> people outside QGIS could use it. Obviously that would have to be >> >> C/C++ though. >> >> >> >> And then I think everyone got bored and went back to doing things. >> >> >> >> Do you have a specific use-case? >> >> >> >> On Wed, Aug 29, 2012 at 8:01 AM, G. Allegri <[email protected]> wrote: >> >> > Anybody interested in developing the concept and evaluating its >> >> > feasibility? >> >> > I'm considering the possibility to sponsor it. >> >> > >> >> > giovanni >> >> > >> >> > Sent from Nexus >> >> > >> >> > Il giorno 28/ago/2012 00:11, "G. Allegri" <[email protected]> ha >> >> > scritto: >> >> >> >> >> >> AFAIK it isn't possible to register a python script as a >> >> >> dataprovider. >> >> >> Maybe it sounds odd, but I think it would interesting if we could >> >> >> have >> >> >> it. >> >> >> Has it been ever considered? How hard would it be to implement it? >> >> >> >> >> >> Giovanni >> >> >> >> >> >> Sent from Nexus >> > >> > >> > >> > _______________________________________________ >> > Qgis-developer mailing list >> > [email protected] >> > http://lists.osgeo.org/mailman/listinfo/qgis-developer >> > > > _______________________________________________ Qgis-developer mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-developer
