pulsar/docs/advanced/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 via the atom.config global. You can read the current value of a namespaced config key with atom.config.get:

# read a value with `config.get`
@showInvisibles() if atom.config.get "editor.showInvisibles"

Or you can use the ::subscribe with atom.config.observe to track changes from any view object.

class MyView extends View
  initialize: ->
    @subscribe atom.config.observe 'editor.fontSize', (newValue, {previous}) =>
      @adjustFontSize()

The atom.config.observe 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 ::subscribe are automatically canceled when the view is removed. You can cancel config subscriptions manually via the off method on the subscription object that atom.config.observe returns.

fontSizeSubscription = atom.config.observe 'editor.fontSize', (newValue, {previous}) =>
  @adjustFontSize()

# ... later on

fontSizeSubscription.off() # Stop observing

Writing Config Settings

The atom.config database is populated on startup from ~/.atom/config.cson, but you can programmatically write to it with atom.config.set:

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

You should never mutate the value of a config key, because that would circumvent the notification of observers. You can however use methods like pushAtKeyPath, unshiftAtKeyPath, and removeAtKeyPath to manipulate mutable config values.

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

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.

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