src/org/apache/policy/model/Assertion.java

/*
 * Copyright 2001-2004 The Apache Software Foundation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.policy.model;

import org.apache.policy.util.PolicyRegistry;

/**
 * Assertion is an interface which all constructs of policy must implements. It
 * defines few policy operations that all policy constructs must support.
 */

public interface Assertion {
	/** Defines the short value for Primitive Assertions */
	public static final short PRIMITIVE_TYPE = 0x1;
	
	/** Defines the short value for ANDCompositeAssertion */                           
    public static final short COMPOSITE_AND_TYPE = 0x2;
    
    /** Defines the short value for XORCompositeAssertion*/
    public static final short COMPOSITE_XOR_TYPE = 0x3;
    
//    /**
//     * 
//     * @return
//     */
//    public Assertion normalize() throws UnsupportedOperationException;
//    
    /**
     * Returns an assertion which is the equivalent of intersect of 
     * self and argument. The rules to construct the equivalent assertion are
     * specified in WS Policy 1.0 specification.
     * 
     * @param assertion the assertion to intersect with
     * @return the equivalent of intersect of self and the argument
     */
    public Assertion intersect(Assertion assertion) 
    		throws UnsupportedOperationException;
    
    /**
     * Returns an assertion which is equivalent of intersect of self and 
     * argument. Here the external policy are resolved via a policy registry
     * that is supplied as an argument. 
     * 
     * @param assertion the assertion to intersect with
     * @param cache the policy registry which is used to resolve external 
     *              policy references
     * @return the equivalent of intersection of self and argument
     * @throws UnsupportedOperationException if the operation is not meaningful
     */
    public Assertion intersect(Assertion assertion, PolicyRegistry reg) 
    		throws UnsupportedOperationException;
            
    /**
     * Returns the equivalent of merge of self and argument. The rules to 
     * construct the equivalent of merge are defined in WS Policy specification
     * 1.0
     * 
     * @param assertion the argument to merge with  
     * @return the equivalent of the merge of self and argument
     */
    public Assertion merge(Assertion assertion) 
    		throws UnsupportedOperationException;
    
    /**
     * Returns the equivalent of merge of self and argument. The rules to 
     * construct argument are specified in WS Policy specification 1.0 Here the
     * external policy references are resolved via a policy registry that is
     * supplied as an argument
     * 
     * @param assertion the assertion to merge with
     * @param reg the policy registry that should be used to resolve external 
     *        policy references
     * @return the equivalent of merge of self and argument
     * @throws UnsupportedOperationException if the merge is not meaningful
     */
    public Assertion merge(Assertion assertion, PolicyRegistry reg) throws UnsupportedOperationException;
    
    /**
     * Returns ture if the assertion has a parent
     * 
     * @return true if a parent exists , false otherwise
     */
    public boolean hasParent();
    
    /**
     * Returns the parent of self or null if a parent non-exists 
     * 
     * @return the parent of self
     */
    public Assertion getParent();
    
    /**
     * Set the parent to argument
     * @param parent the parent that should be parent of self 
     */
    public void setParent(Assertion parent);
}