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Re: supporting additional file formats?

Eric Davies wrote:



Is there a mechanism for adding support for new file formats,
similar to the library registration of Convention classes?

Thank you.


Hi Eric:
Yes, and we'd love to include additional file readers in our releases if possible.
You just need to write a class implementing the ucar.nc2.IOServiceProvider interface, and register it with ucar.nc2.NetcdfFile.registerIOProvider(). For readonly files, you dont have to implement the create() and write() methods. If you arent using structures, you dont have to implement readNestedData(). All you really need to implement isValidFile(), open() and read(). Have a look at subclasses of ucar.nc2.iosp for examples. The gini and dmsp are good places to start.
Sorry not much docs yet, everything is very new. But Id be happy to work with you to get you going. Heres a little bit of documentation from latest version of the manual: 


     7.4 IOServiceProvider
The NetCDF API can be used to access other kinds of scientific data files. The general mechanism for this is to define a class that implements */IOServiceProvider/*, and register it with the /NetcdfFile/ class. When a file is opened through /NetcdfFile .open()/, it is first checked to see if it is a "native" (netcdf3, netcdf4, hdf5) file, then any registered /IOServiceProvider/s are checked by calling /isValidFile(). /If this returns true, then a new instance of the class is used for all I/O to the file. 

To register, call one of these static methods in *NetcdfFile*:

  static public void registerIOProvider( String iospClassName);

  static public void registerIOProvider( Class iospClass);
The /iospClass/ must have a no-argument constructor, and it must implement the /IOServiceProvider/ interface.
There are several standard IOServiceProvider implementations that ship with the complete library. If you are trying to minimize code size, you can leave any of the packages or supporting libraries out. The current standard implementations include: 

   * */ucar.nc2.iosp.dmsp/* : DMSP
   * */ucar.nc2.iosp.gini/* : GINI
   * */ucar.nc2.iosp.grib/* : WMO Grib (version 1 and version 2)