custom_tag_start

Description:

[ Version ( since = "2.12" ) ]
public abstract bool custom_tag_start (Builder builder, Object? child, string tagname, out MarkupParser parser, out void* data)

This is called for each unknown element under `<child>`.

Parameters:

this	a Buildable
builder	a Builder used to construct this object
child	child object or null for non-child tags
tagname	name of tag
parser	a MarkupParser to fill in
data	return location for user data that will be passed in to parser functions

Returns:

true if a object has a custom implementation, false if it doesn't.