Paul, Look at the DataStore architecture in JUMP 1.2 - it does exactly what you're asking for, I think.
Paul Austin wrote: > All, > > I've been looking at the existing database and file plugins and the > com.vividsolutions.jump.io.datasource.DataSource class and from what I > can tell there is a one to one relationship between a layer and a data > source. > > What I would like to do for some of the file and database based data > sources is to have the concept of a DataSource that can contain many > different layers. Within a project you would be able to select which > layers you wanted to view from that data source. > > In the database world this concept would relate to having a connection > to the data base using a java.sql.Connection. When adding the database > connection to a project there would be a UI that would list the > available layers (database tables) and the user could select which > layers they wish to view. This compares to the current PostGIS plug-in > where you have to manually enter the connection and table details for > each layer. > > When the project is closed then the "connection" must also be closed. > > In the Jump project file the "connection" parameters would be stored > once, then the data sources used for each layer would reference the > "connection" and have a different query for each table. > > Now if we look at a file based example, I have a file format which is > basically a zip file that contains one file for each layer along with > some metadata files. I would like to be able to open the zip file and > create a layer for each of the layers in the zip file. To do this I > would extract the file to the temp directory and as required load the > data from the individual files in the temp directory. Then when you > close the project the "connection" is closed by deleting the temporary > files. > > Another file based example would be to open a directory of files, > loading each layer file in that directory, this is basically the same as > the zip file idea but without the temporary files. > > In both the file cases once the file is loaded the first time the user > can select which of the layers to view. > > So the question is, does any of the existing functionality in JUMP allow > for multi-layer data sources? If not I'm going to do some prototyping > for the file format I have and then share this with the group for > comment to see if it would be useful elsewhere. > > After that I have an interest in Oracle connections so would need to do > the same kind of thing there. > > One other question, where would I find the code for writing out the > project .jmp XML files as I'd need to add the "connection" definitions > to this. > > Cheers, > Paul > > ------------------------------------------------------------------------- > This SF.net email is sponsored by DB2 Express > Download DB2 Express C - the FREE version of DB2 express and take > control of your XML. No limits. Just data. Click to get it now. > http://sourceforge.net/powerbar/db2/ > _______________________________________________ > Jump-pilot-devel mailing list > Jump-pilot-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > > -- Martin Davis Senior Technical Architect Refractions Research, Inc. (250) 383-3022 ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
