MarkupParser

Any of the fields in MarkupParser can be null, in which case they will be ignored.

Except for the error function, any of these callbacks can set an error; in particular the g_markup_error_unknown_element, g_markup_error_unknown_attribute, and g_markup_error_invalid_content errors are intended to be set from these callbacks. If you set an error from a callback, parse will report that error back to its caller.