com.ibm.xml.policy.xacl
Class Parameter

java.lang.Object
  |
  +--com.ibm.xml.policy.xacl.Parameter

public class Parameter

extends java.lang.Object

A class correspoding to the <parameter> tag.

Author:

Satoshi Hada, IBM TRL

Method Summary

org.w3c.dom.Node[]	evaluate(AccessRequest accessReq, org.w3c.dom.Node query, DOMHandler targetDocHandler, org.w3c.dom.Element status) This method evaluates this parameter and returns an array of nodes as a result.
org.w3c.dom.Element	getElement() Get the original element from which this object is constructed.
java.lang.String	getName() Get the value of the name attribute.
java.lang.String	getValue() Get the value of the value attribute.

Methods inherited from class java.lang.Object

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

Method Detail

getName

public java.lang.String getName()

Get the value of the name attribute.

getValue

public java.lang.String getValue()

Get the value of the value attribute.

getElement

public org.w3c.dom.Element getElement()

Get the original element from which this object is constructed.

Returns:

the original element

evaluate

public org.w3c.dom.Node[] evaluate(AccessRequest accessReq,
                                   org.w3c.dom.Node query,
                                   DOMHandler targetDocHandler,
                                   org.w3c.dom.Element status)
                            throws XaclException

This method evaluates this parameter and returns an array of nodes as a result. If the parameter has a <function> element as a child then the evaluation result of the function will be returned. Otherwise, this method just returns the child nodes of the parameter. Recall that the <parameter> tags can have any child nodes.

• Case 1: A "value" attribute is specified
  Suppose that there is the following <parameter> element:
  

   <parameter value="Access Control"/>
   

  Then this method returns an array including a text node representing "Access Control".
• Case 2: No value attribute, but one or more child nodes are specified
  Suppose that there is the following <parameter> element:
  

   <parameter>
     <name>category</name>
     <value>Access Control</value>
   </parameter>
   

  Then this method returns an array including the two child elements, i.e., the <name> and <value> elements.



• Case 3: A <function> element is specified
  Suppose that there is the following <parameter> element that has a <function> child element:
  

   <parameter>
     <function name="getUid"/>
   </parameter>
   

  The "getUid" function will return a text node represeting the initiator's uid. Intuitively, after the "getUid" function is evaluated, the function element is replaced by the evaluation result as follows:

   <parameter>
     Alice
   </parameter>
   

  This corresonds to Case 2 above. Therefore, this method returns an array including the text node "Alice". The function is evaluated via the FunctionInterface interface.

The first parameter "query" represents a node for which the policy is currently evaluated. This may not always be the same as the requested target node specified in the access request because the evaluation is done for the subtree of the requested target node.

Parameters:

accessReq - an access request

query - a node for which the policy is currently evaluated

targetDocHandler - a handler of a target document

status - a <status> element associated with the target document.

Returns:

the result of the evaluation.

See Also:

FunctionInterface, PredicateInterface, ProvisionalActionInterface