How to best let (advanced) users customise user data and config locations?

[alessandrofelder]

IIUC there are currently several ways to customise where downloaded atlases are stored

• by passing brainglobe_dir as an argument to the BrainGlobeAtlas constructor
• by passing config_dir as an argument to the BrainGlobeAtlas constructor
• by setting the BRAINGLOBE_CONFIG_DIR environmental variable and storing a config file there.

This has some consequences that can

• if both brainglobe_dir and config_dir are passed, brainglobe_dir takes precendence (I think, but this is undocumented!)
• if brainglobe_dir is passed to BrainGlobeAtlas() (and therefore an atlas is downloaded), that atlas will not be part of the output of get_downloaded_versions().
• it's unclear how widgets should best deal with customisable user data and config folders.

Additionally, code interacting with the bg_atlasapi API will need to remember to pass the right arguments, making this susceptible to having to change things in many different places if bg_atlasapi changes.

• we should also think about, and document, backwards compatibility and/or migration if we do decide on a new way of doing this.

This is possibly a more-fleshed-out duplicate of https://github.com/brainglobe/bg-atlasapi/issues/150 and should replace it in that repo?

[adamltyson]

This is possibly a more-fleshed-out duplicate of https://github.com/brainglobe/bg-atlasapi/issues/150 and should replace it in that repo?

yeah as with a lot of things, I think this is a bg-atlasapi issue really