issrg.pba.rbac.xmlpolicy.ifstatement
Class OperatorNode

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

All Implemented Interfaces:

Term

public class OperatorNode
extends OperationNode

This is the class for Operator node of the IF-statement. Its functionality is very much determined by OperationNode, which is configured to deliver the following semantics:

This operation expects no or any number of Terms of any type, and returns a value of type determined by the matching Interpreter. There must be an interpreter for the required set of Terms, and it implements the semantics of the evaluation.

It is possible to register the interpreters for specific combinations of Terms. Use registerOperatorInterpreter method to do that. There is no default Interpreter.

Author:

A.Otenko

See Also:

registerOperatorInterpreter(java.lang.String, issrg.pba.rbac.xmlpolicy.ifstatement.Interpreter)

Field Summary

static java.lang.String

OPERATOR_NODE

Fields inherited from class issrg.pba.rbac.xmlpolicy.ifstatement.OperationNode

interpreter, type

Fields inherited from class issrg.pba.rbac.xmlpolicy.ifstatement.TermNode

maxOperand, minOperand, terms

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

attributes, children, name, nodeStr

Constructor Summary

protected	OperatorNode()
	OperatorNode(XMLPolicyParser p, org.xml.sax.Attributes attrs) This constructor builds a OperatorNode given the XMLPolicyParser and the set of attributes of this XML element.

Method Summary

static void	register() This method should be called to register the node with the XML Parser
static void	registerOperatorInterpreter(java.lang.String name, Interpreter i) This method maintains a register of interpreters for specific combinations of Terms for the specified operator.

Methods inherited from class issrg.pba.rbac.xmlpolicy.ifstatement.OperationNode

construct, evaluate, getType

Methods inherited from class issrg.pba.rbac.xmlpolicy.ifstatement.TermNode

getInterpretersForNode, registerInterpreterForNode

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

Field Detail

OPERATOR_NODE

public static final java.lang.String OPERATOR_NODE

See Also:

Constant Field Values

Constructor Detail

OperatorNode

protected OperatorNode()

OperatorNode

public OperatorNode(XMLPolicyParser p,
                    org.xml.sax.Attributes attrs)
             throws PolicyParsingException

This constructor builds a OperatorNode given the XMLPolicyParser and the set of attributes of this XML element. It expects that there are no or many child nodes. It expects there is a issrg.pba.rbac.xmlpolicy.XMLTags.NAME_ATTRIBUTE ("Name") attribute in this XML element.

Parameters:

p - - the XMLPolicyParser that builds this LtNode

attrs - - the attributes of this XML element

Throws:

PolicyParsingException - if there is no issrg.pba.rbac.xmlpolicy.XMLTags.NAME_ATTRIBUTE in this XML element

Method Detail

register

public static void register()

This method should be called to register the node with the XML Parser

registerOperatorInterpreter

public static void registerOperatorInterpreter(java.lang.String name,
                                               Interpreter i)

This method maintains a register of interpreters for specific combinations of Terms for the specified operator. If no special interpreters are registered, the evaluation error occurs. The semantics of the interpreters ensure the semantics of evaluation of the operator.

Parameters:

name - - the operator name

i - - the Interpreter instance that can evaluate the expression for some combination of Terms

See Also:

Interpreter.evaluate(issrg.pba.rbac.xmlpolicy.ifstatement.Environment, issrg.pba.rbac.xmlpolicy.ifstatement.Term[])