Returns true if the attribute is allowed.
Parameters: name - the name of the attribute Parameters: value - the value of the attribute true if the attribute is allowed
Returns true if the element is allowed somewhere in the item.
allowsElement is used for error messages to give more information
in cases of order dependency.
Parameters: name - the name of the element true if the element is allowed somewhere
Returns the next item when an element of the given name is returned
Parameters: name - the name of the element Parameters: contItem - the continuation item the program for handling the element