Yep, the schema mapper concept is what I had in mind for a "utility class". It might be useful to have this in the Feature model package, if it's general-purpose.
Paul Austin wrote: > Hi Martin, > > Just a note on point 4, a feature without a schema is a Map not a > List, I guess what I mean a feature without a schema, is a feature > where the schema can be dynamically defined using the semantics of a Map. > > Although recently I have come with the concept of a schema mapper, > which using rules (such as renaming attribute names or more complex > processing) that would convert a feature from one schema to another in > a "single" step as far as features. In this case the JUMP feature > model will work as it's only the start and end features which need to > have a static schema. > > Paul > > > Martin Davis wrote: >> Some comments: >> >> 1. The IDs in JUMP were really intended to be for internal system use >> only, in order to give Features a unique identity. This capability is >> currently barely used (which is a good thing!), but I think it should be >> preserved as is (since this is the more memory, design and processing >> efficient way of assigning IDs). >> >> If you need a different kind of ID, just add another attribute to your >> FeatureSchema. >> >> 2&3. This is already really supported (at least for POJOs). What isn't >> supported is describing the resulting object model in the FeatureSchema >> model. Some extension here might be good (at the risk of making things >> more complex). I think the deegree Feature model might do this. >> >> 4. I am *really* not in favour of this concept. Once you throw away the >> schema, you don't have much left in a Feature. Java already has a >> "typeless variable-length container" - it's called a List. >> >> If you are finding it painful to migrate data between FeatureSchemas, >> you can always write some helper methods. Or dump your data into a List >> and move it that way. >> >> Paul Austin wrote: >> >>> I agree if the open source GIS community can agree on a single in >>> memory Java representation for geographic features that would make all >>> the tools more interoperable. Right now I'm using my own schema and >>> feature model but would prefer not to maintain that in the future. >>> Here are the requirements I have. >>> >>> 1. Ids can be any type not just an int >>> 2. Properties can contain complex objects including other features >>> or POJO >>> 3. Properties can contain a collection (List or Set) value >>> 4. Features don't have to have a schema (useful when transforming a >>> feature from one schema to another) >>> >>> >>> >>> 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 >>> >>> >> >> > > ------------------------------------------------------------------------ > > ------------------------------------------------------------------------- > 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
