I've also developed a DataMapper adapter for Google App Engine, although it requires using the next branch of DataMapper (0.10.0). It's available along with wrappers for several of the App Engine APIs at http://code.google.com/p/appengine-jruby

Thank you for telling me that!

Hi,

Thanks for your post but I have the followings errors... I'm a merb newbie :-(

org.jruby.rack.RackInitializationException: no such file to load -- file:/C:/_/work/guestbook/war/WEB-INF/lib/gems.jar!/gems/dm-core-0.9.11/lib/dm-core/adapters/datastore_adapter from file:/C:/_/work/guestbook/war/WEB-INF/lib/jruby-complete.jar!/META-INF/jruby.home/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in require from file:/C:/_/work/guestbook/war/WEB-INF/lib/gems.jar!/gems/dm-core-0.9.11/lib/dm-core.rb:146:in setup from file:/C:/_/work/guestbook/war/WEB-INF/lib/gems.jar!/gems/merb_datamapper-1.0.11/lib/merb/orms/data_mapper/connection.rb:44:in setup_connections [...]

If you have time, could you tell me what's the problem ?

Thanks, Seb

Oh, are you using Windows?

I've never tried it. JRuby probably couldn't be looking up the file from the jar archive on Windows.

If it is possible, I recommend you to try it on POSIX OS.

Good luck :-)

Thanks for your quick reply !

Yes, I'm using windows :-( I finally got it working by putting your files directly inside the dm-core-0.9.11 gem (putting the file of your directory 'dm-datastore-adapter' inside 'dm-core-0.9.11/lib/dm-core/adapters' and the others files (dm-datastore-adapter.rb and appengine-api-1.0-sdk-1.2.0.jar) inside 'dm-core-0.9.11/lib' directory. Thanks again, Seb.

That's good to hear. Thank you for reporting :-)

Me again ;-) So, I tried on Ubuntu but this is the same (=failing)... And on Google App Engine, I have the same error: "no such file to load -- file:/base/data/home/apps/brocoli79/1.332952556716181332/WEB-INF/lib/gems.jar!/gems/dm-core-0.9.11/lib/dm-core/adapters/datastore_adapter"

Do you use a special version of datamapper ???

I do not want to bother you but if you could help or write a little article about how getting started with your adapter (what to install, how, ...).

Thanks, Seb.

I am using the released version of the datastore adapter.

My environment is as follows:

• JRuby-1.3.0 (edge version)
• JRuby rack-0.9.4 (edge version)
• All gems are unpacked into MERB_ROOT/gems (or lib/merb.jar)

Now I have no time, but I would post a how-to entry on this weekend.

I have the same versions but still the same error... So, I'm going to wait for your post. Thanks a lot !

Hi, I wrote the article here

• How to Make A Merb App on Google App Engine

Please check it out :-)

Hi,

Thanks for your work. I jump onto the next post to let my comments ;-)