Owlkettle

BeforeBuild Hook

The beforeBuild hook runs once before the build-hook and thus also before any values are assigned to the WidgetState. They are mainly used in renderables to instantiate the GTK-Widget and assign it to internalWidget on WidgetState.

It should be noted that unlike build hooks, beforeBuild hooks are not inherited by any child-widget. For more information, see the build hooks section.

Here a simple code-example for writing a beforeBuild hook:

import owlkettle
import owlkettle/bindings/gtk
import std/json

renderable MyRenderable:
  text: string

  hooks:
    beforeBuild:
      echo state.repr
      state.internalWidget = gtk_label_new("ExampleText")

viewable App:
  discard

method view(app: AppState): Widget =
  result = gui:
    Window:
      MyRenderable()

when not defined(owlkettleNimiDocs):
  brew(gui(App()))

We set the label-text to render directly via the gtk_label_new proc. But what if we want to have a parent widget decide the text to render once and then never update it again?

That leads us to what afterBuild hooks are...