ScalaCSS

Global Registry

mutable.GlobalRegistry is an optional convenience for working with inline stylesheets.

Ideally inline stylesheet modules should either be merged into a single app-wide object, or passed around like normal dependencies.

If that is unpalatable to your circumstances or preferences, you can instead register style modules with the global registry, and have client-code retrieve modules from the global registry by type.

There are three operations:

1. register

This stores stylesheets in the registry.

class BoxStyles extends StyleSheet.Inline {
  import dsl._
  val mainBox = style(
    margin(2 px, 1 ex),
    padding(1 ex),
    border(1 px, solid, black))
}

import scalacss.internal.mutable.GlobalRegistry

def onStartup(): Unit = {
  // Register styles
  GlobalRegistry.register(new BoxStyles)
}

2. onRegistration & onRegistrationN

onRegistration allows you to specify code to be executed once per stylesheet added to the registry. onRegistrationN does the same but in bulk (i.e. takes a Vector of stylesheets).

Specified functions will be applied retroactively to all styles already registered, and applied to new styles when they're added.

onRegistration can be called called multiple times to have multiple actions applied.

GlobalRegistry.onRegistration { s =>
  val styleCount = s.styles.size
  println(s"Registered $styleCount styles.")
}

GlobalRegistry.onRegistrationN { ss =>
  val sheetCount = ss.size
  val styleCount = ss.map(_.styles.size).sum
  println(s"Registered $sheetCount sheets with a total of $styleCount styles.")
}

3. apply

This is used to retrieve a stylesheet from the registry. If it hasn't been registered, the result will be None.

// Calling Option.get will throw an exception if BoxStyles hasn't been registered
val boxStyles = GlobalRegistry[BoxStyles].get

<.div(boxStyles.mainBox, "Yay")