issrg.pba.rbac.xmlpolicy.ifstatement
Class ArgNode

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

All Implemented Interfaces:

Term

public class ArgNode
extends NamedTermNode

This is the class that represents an Arg node and evaluates the arguments of an action at run-time.

If the policy contains the arguments of types for which there is no constructor provided by the AEF (not registered with the Types), or the AEF failed to provide the argument with the name stated in the policy, an EvaluationException will occur at run-time.

Note that if the evaluation does not reach the point where the argument is needed, no exception will be thrown.

Author:

A.Otenko

Field Summary

static java.lang.String

ARG_NODE This is the name of the node that represents the Arg - a reference to an argument of the action being authorised.

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

parameter_name, s_namedTerms, 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	ArgNode()
	ArgNode(XMLPolicyParser p, org.xml.sax.Attributes attr) This constructor builds an ArgNode, given a XMLPolicyParser and the set of attributes of this XML element.

Method Summary

java.lang.Object	evaluate(Environment env) This method returns the value of the action argument that this element refers to.
static void	register() This method should be called to register the node with the XML Parser

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

getAllNamedTerms, getName, getNamedTerms, getType, resetNamedTerms

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

construct, getInterpretersForNode, registerInterpreterForNode

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

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

Methods inherited from class java.lang.Object

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

Field Detail

ARG_NODE

public static final java.lang.String ARG_NODE

This is the name of the node that represents the Arg - a reference to an argument of the action being authorised.

See Also:

Constant Field Values

Constructor Detail

ArgNode

protected ArgNode()

ArgNode

public ArgNode(XMLPolicyParser p,
               org.xml.sax.Attributes attr)
        throws PolicyParsingException

This constructor builds an ArgNode, given a XMLPolicyParser and the set of attributes of this XML element. It expects that a issrg.pba.rbac.xmlpolicy.XMLTags.TYPE_ATTRIBUTE and issrg.pba.rbac.xmlpolicy.XMLTags.NAME_ATTRIBUTE ("Type" and "Name") are present in this XML element.

Parameters:

p - - the XMLPolicyParser that builds this ArgNode

attr - - the attributes of this XML element

Throws:

PolicyParsingException

Method Detail

register

public static void register()

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

evaluate

public java.lang.Object evaluate(Environment env)
                          throws EvaluationException

This method returns the value of the action argument that this element refers to. Types.construct() method is used to convert the String representation of the argument value in the Environment into a Java object.

Parameters:

env - - the Environment of the evaluation, including the arguments of the Action

Returns:

the Object, constructed from the String representation of the argument value

Throws:

EvaluationException - if the term cannot be evaluated