add_from_string

Parses a string containing a UI definition and merges it with the current contents of this.

This function is useful if you need to call [method@Gtk.Builder.set_current_object] to add user data to callbacks before loading `GtkBuilder` UI. Otherwise, you probably want [ctor@Gtk.Builder.new_from_string] instead.

Upon errors false will be returned and throws will be assigned a `GError` from the gtk_builder_error, g_markup_error or g_variant_parse_error domain.

It’s not really reasonable to attempt to handle failures of this call. The only reasonable thing to do when an error is detected is to call error.

Parameters:

this	a `GtkBuilder`
buffer	the string to parse
length	the length of buffer (may be -1 if buffer is nul-terminated)

Returns:

true on success, false if an error occurred