Reconsider where to store configuration, data, and cache files

Agreed on all of these -- none of them were meant to be permanent resting places, they were just expedient places to put things until something better could be sorted out.

Issues and other notes:

1. Re Data: Implementing the interface is a tad fussy since you're navigating the server machine's filesystem from the client machine. But that's just fussy, not insurmountable.

2. Experiment Cache could also go in /tmp or ~/tmp, or anywhere else that is volatile (I assume that /Library/Caches gets trashed on log-outs?). It shouldn't functionally matter if users share a cache or not, this stuff gets rewritten on each and every load.

3. Re Configuration: No major objections on this, though this could end badly if multiple users are using the same account on the machine (which is pretty common in labs I've seen). Also potentially dangerous for users to be messing with their setup configuration in multiple places (e.g. if they forget that they changed it in one place and collect data that way). Life is full of such dangers, though, I guess, and people will just need to be careful.

Incidentally, there is also an "include" directive in the xml that could be used to achieve similar effects from the client-side.

Re Data: Implementing the interface is a tad fussy since you're navigating the server machine's filesystem from the client machine. But that's just fussy, not insurmountable.

For 0.4.4, I'd be happy just to switch from /Documents/MWorks/Data to ~/Documents/MWorks/Data. We can add the ability to choose an arbitrary save location in a later release.

Experiment Cache could also go in /tmp or ~/tmp, or anywhere else that is volatile (I assume that /Library/Caches gets trashed on log-outs?). It shouldn't functionally matter if users share a cache or not, this stuff gets rewritten on each and every load.

/Library/Caches is persistent and is never automatically emptied (however, it is not included in Time Machine backups). If the stuff in Experiment Cache is only meant to persist for a single session, then it probably should go in a more volatile location. It looks like the right way to do this is to use a combination of NSTemporaryDirectory and mkdtemp to create a temporary directory.

Re Configuration: No major objections on this, though this could end badly if multiple users are using the same account on the machine (which is pretty common in labs I've seen). Also potentially dangerous for users to be messing with their setup configuration in multiple places (e.g. if they forget that they changed it in one place and collect data that way). Life is full of such dangers, though, I guess, and people will just need to be careful.

Would it make more sense to look for the config only in ~/Library/...? That way, there'd be one and only one place to look for config files, but different user accounts on the same machine could have different configs, and you wouldn't have to worry about some other use changing the config without you knowing.

These changes are now in place. Data files are now stored in ~/Documents/MWorks/Data. When loading the config file, the core now looks first in ~/Library/Application Support/MWorks/Configuration. If it finds a config file there, it uses it. Otherwise, it looks in /Library/Application Support/MWorks/Configuration. Finally, experiment files are now cached in the directory returned by NSTemporaryDirectory, in the subdirectory MWorks/Experiment Cache. To get the path the current user's temp dir (e.g. for debugging), you can use the following command:

/usr/bin/python -c 'from Foundation import * ; print NSTemporaryDirectory()'