Settings bundles provides a unified key-value store for querying information from multiple sources (i.g. configuration files or dictionaries).

Simply run Pkg.clone(“https://github.com/dustinrb/SettingsBundles.jl.git”) in the Julia REPL

A SettingsBundle acts as a unified interface to access all settings sources as if they were in a single dictionary. The last settings source added to the SettingsBundle has the highest priority, so its values take precedence if there are duplicate keys in the bundle. A settings source is any Associative type that accepts strings as keys.

SettingsBundles are read only. They do note have a setindex! method defined.

bundle is a SettingsBundle. associative is any Associative object that accepts strings as keys. After executing this function, associative has the highest priority in the bundle.

flatten takes a settings bundle and copies it into a dictionary. This is useful for passing a SettingsBundle to a PyCall.

path points to a YAML file which is then read in as a SettingsYAMLFile type compatible with SettingsBundles. If watched is true, an asynchronous process is spawned which will update the values in the SettingsYAMLFile (and subsequently the SettingsBundle) when changes are detected to the file specified with path.

path points to a JSON file which is then read in as a SettingsJSONFile type compatible with SettingsBundles. If watched is true, an asynchronous process is spawned which will update the values in the SettingsJSONFile (and subsequently the SettingsBundle) when changes are detected to the file specified with path.

Additional sources can easily be defined by creating a subtype of Associative that accepts keys as strings. See src/sources/SettingsYAMLFile.jl for an example. Pull requests specifying additional settings sources are appreciated.

Say you have an application that has a default config file and a user specified config, plus a few settings that must be configure at runtime.

# defaults.yaml
plugins_dir: ~/.myapp/plugins
format: yaml
color: red

# user_settings.yaml
username: user
email: [email protected]
color: blue

# Create out settings bundles
using SettingsBundles

settings = SettingsBundle(
    SettingsYAMLFile("defaults.yaml"),
    SettingsYAMLFile("user_settings.yaml"),
    Dict("working_dir" => pwd()) # Runtime settings
)

# Now `settings` contains all values form the settings sources
settings["plugins_dir"] # Returns `~/.myapp/plugins`
settings["username"] # Returns `user`
settings["working_dir"] # Returns `/Users/user/`

# Now what about the `color` setting? It's listed in both
#    defaults.yaml and user_settings.yaml.
settings["color"] # Returns `blue`

# Settings bundles prioritize the last settings source added
#   to the SettingsBundle

# Need to add another source after constructing `settings`?
add!(settings, Dict("color" => "yellow")) # Just call the add function
settings["color"] # Returns `yellow`

# To create a snapshot of the settings bundle, use `flatten`
flatten(settings) # Returns:
# Dict(
#     "plugins_dir" => "~/.myapp/plugins",
#     "format" => "yaml",
#     "color" => "yellow",
#     "username" => "user",
#     "email" => "[email protected]",
#     "working_dir" => "~/.myapp/plugins"
# )