Sprockets vs optional config files

[gravitystorm]

In app/assets/javascripts/osm.js.erb we need to tell sprockets to recompile the output whenever the settings change. To do this we mark that file as depending on config/settings.yml and config/settings.local.yml.

However, this throws up two problems:

• settings.local.yml is supposed to be optional, but Sprockets throws an error if the file can't be found.
• The config gem also supports a bunch of other files, which should also trigger a recompile if they exist and then get changed.

I've checked through the sprockets documentation, but I can't see any obvious guidance for approaches to this situation.

Potential solutions include:

• Remove the dependency on settings.local.yml. This will make the 'out-of-the-box' situation better for developers, but could lead to problems later on when changes to that file are not reflected in the compiled javascript (without manual asset recompilation).
• Ask the upstream sprockets developers what they think about depending on optional files, or if they have any suggestions.
• Create an initializer which outputs the computed settings to a file, and depend on that output file instead.

[gravitystorm]

For anyone who gets ActionView::Template::Error: couldn't find file 'settings.local.yml' or similar when first setting up your environment, then this issue is the root cause. You need to create an empty file in config/settings.local.yml, for example by running:

$ touch config/settings.local.yml

[mmd-osm]

How about:

• Create an empty settings.local.yml file in config.rb, in case no local settings have been created
• If that doesn't work, print out an error message and exit, asking the dev to create an empty file settings.local.yml file themselves.