pulsar/docs/internals/configuration.md

Configuration API

Reading Config Settings

If you are writing a package that you want to make configurable, you'll need to read config settings. You can read a value from config with config.get:

# read a value with `config.get`
@autosave() if config.get "core.autosave"

Or you can use observeConfig to track changes from a view object.

class MyView extends View
  initialize: ->
    @observeConfig 'editor.fontSize', () =>
      @adjustFontSize()

The observeConfig method will call the given callback immediately with the current value for the specified key path, and it will also call it in the future whenever the value of that key path changes.

Subscriptions made with observeConfig are automatically cancelled when the view is removed. You can cancel config subscriptions manually via the unobserveConfig method.

view1.unobserveConfig() # unobserve all properties

You can add the ability to observe config values to non-view classes by extending their prototype with the ConfigObserver mixin:

ConfigObserver = require 'config-observer'
_.extend MyClass.prototype, ConfigObserver

Writing Config Settings

As discussed above, the config database is automatically populated from config.cson when Atom is started, but you can programmatically write to it in the following way:

# basic key update
config.set("core.autosave", true)

config.pushAtKeyPath("core.disabledPackages", "wrap-guide")

You can also use setDefaults, which will assign default values for keys that are always overridden by values assigned with set. Defaults are not written out to the the config.json file to prevent it from becoming cluttered.

config.setDefaults("editor", fontSize: 18, showInvisibles: true)