issrg.pba.rbac.xmlpolicy.ifstatement
Class TermNode

java.lang.Object
  issrg.pba.rbac.xmlpolicy.PolicyXMLNode
      issrg.pba.rbac.xmlpolicy.ifstatement.TermNode

All Implemented Interfaces:

Term

Direct Known Subclasses:

ConstantNode, NamedTermNode, OperationNode

public abstract class TermNode
extends PolicyXMLNode
implements Term

This abstract class represents XML elements that are Terms of IF-expressions. It maintains a registry of Interpreters for each type of operation, which is used indirectly by OperationNode and other subclasses.

Author:

A.Otenko

Field Summary

protected int	maxOperand
protected int	minOperand
protected Term[]	terms

Fields inherited from class issrg.pba.rbac.xmlpolicy.PolicyXMLNode

attributes, children, name, nodeStr

Constructor Summary

protected	TermNode()
	TermNode(java.lang.String name, org.xml.sax.Attributes attr, int maxOperandCount, int minOperandCount) This constructor builds a TermNode object that will check that the child nodes are Terms and that there are not more than maxOperandCount of them and not less than minOperandCount.

Method Summary

void	construct() This method ensures the children are Terms and that there are not more than maxOperandCount and not less than minOperandCount of them, as specified in the constructor.
protected static Interpreter[]	getInterpretersForNode(java.lang.String nodeName) This method retrieves an array of interpreters for a particular kind of operation.
protected static void	registerInterpreterForNode(java.lang.String nodeName, Interpreter i) This method registers an interpreter for a given type of operation.

Methods inherited from class issrg.pba.rbac.xmlpolicy.PolicyXMLNode

addChild, addString, getAttributes, getChildren, getName, getString, toString, toXML, toXML

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface issrg.pba.rbac.xmlpolicy.ifstatement.Term

evaluate, getType

Field Detail

maxOperand

protected int maxOperand

minOperand

protected int minOperand

terms

protected Term[] terms

Constructor Detail

TermNode

protected TermNode()

TermNode

public TermNode(java.lang.String name,
                org.xml.sax.Attributes attr,
                int maxOperandCount,
                int minOperandCount)

This constructor builds a TermNode object that will check that the child nodes are Terms and that there are not more than maxOperandCount of them and not less than minOperandCount. The negative values of these two parameters mean no restriction on the amount of children.

Parameters:

name - is the name of the XML element for this operator

attr - is the set of attributes it has got

maxOperandCount - is the maximum amount of children allowed; -1 means "don't care"

minOperandCouns - is the minimum amount of children allowed; -1 means "don't care"

Method Detail

registerInterpreterForNode

protected static void registerInterpreterForNode(java.lang.String nodeName,
                                                 Interpreter i)

This method registers an interpreter for a given type of operation.

Parameters:

nodeName - - the name of the XML element that represents the operation

i - - the Interpreter for that operation

getInterpretersForNode

protected static Interpreter[] getInterpretersForNode(java.lang.String nodeName)

This method retrieves an array of interpreters for a particular kind of operation.

Parameters:

nodeName - - the name of the XML element that represents the operation

Returns:

an array of Interpreters for this kind of operation; can be null or empty if no Interpreters were registered for that kind of operation

construct

public void construct()
               throws PolicyParsingException

This method ensures the children are Terms and that there are not more than maxOperandCount and not less than minOperandCount of them, as specified in the constructor. It also creates an array of Terms that can be used by the sub-classes in their evaluations.

Overrides:

construct in class PolicyXMLNode

Throws:

PolicyParsingException - if one of the above-stated conditions is violated