gtk:builder-application (builder)

builder -- a gtk:builder object
application -- a gtk:application instance

Gets or sets the application associated with the builder. The application is used for creating action proxies as requested from XML that the builder is loading. By default, the builder uses the default application: the one from the g:application-default function. Use this function, if you want to use another application for constructing proxies.

You only need this function if there is more than one g:application instance in your process. The application argument cannot be nil.