Django custom app settings loader

[atarkowska]

In addition to #8022 there is a potential need for having additional app specific settings in the additional applications. This could be resolved by the adding to the INSTALL_APP validator code ​like, where we basically check if any additional apps have own settings and then load them automaticly. This require extra documentation to make sure developer does not override core settings. Suggestion was to request prefix on each custom settings like:

emdb/settings.py

EMDB_VAR1 = True
EMDB_VAR2 = False

[wmoore]

Chris - you wanna have a look at this? Not for 4.4 though.

[wmoore]

A similar use case: I want to be able to add an app, and have it's RIGHT_PLUGINS and CENTER_PLUGINS Added to the existing webclient ones.

In the example above, would

emdb.settings.EMDB_VAR1 = True 

result in

omeroweb.settings.VAR1 = True

?

Maybe easier to do

emdb/settings.py

CUSTOM_SETTINGS_MAPPINGS = {
    'RIGHT_PLUGINS': ['[a, b, c]', add],
    'CENTER_PLUGINS': ['[a, b, c]', overwrite],
}

[wmoore]

This reads in settings from additional apps. In the case of the setting being a list (E.g. plugins) it appends the app's settings to the default settings. Needs more discussion. See

​https://github.com/will-moore/openmicroscopy/commit/6a3e9330ecc662e6a1f4275b7ecd4f44f5959688

[cxallan]

Moved from sprint 2012-07-31 (1)

[wmoore]

​https://github.com/will-moore/openmicroscopy/commits/web_app_settings_8164

[wmoore]

After discussion with Chris yesterday, have simplified parsing of additional apps settings. Simply import <APP>.settings. The <APP>.settings.py code can directly manipulate any settings.
​https://github.com/will-moore/openmicroscopy/commit/440d3ebb792c5b0be46e61a4aa61261587db3298

An example of <APP>.settings
​https://github.com/will-moore/weblabs/blob/master/settings.py

[Will Moore <will@…>]

(In [f7c92f03bf7258462aca8b84c2bc8eb3f92d702e/ome.git] on branch develop) Load custom settings from ADDITIONAL_APPS. See #8164

Need to discuss if we want these to override the defaults in omeroweb.settings.py and/or the
defaults set by bin/omero config set