/*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 1999,2000 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
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* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation and was
* originally based on software copyright (c) 1999, International
* Business Machines, Inc., http://www.apache.org. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.xerces.impl.xs.models;
import org.apache.xerces.xni.QName;
import org.apache.xerces.impl.xs.SubstitutionGroupHandler;
import org.apache.xerces.impl.xs.XSParticleDecl;
import org.apache.xerces.impl.xs.XSElementDecl;
import org.apache.xerces.impl.xs.XMLSchemaException;
import org.apache.xerces.impl.xs.XSConstraints;
/**
* XSSimpleCM is a derivative of the abstract content model base
* class that handles a small set of simple content models that are just
* way overkill to give the DFA treatment.
* <p>
* This class handles the following scenarios:
* <ul>
* <li> a
* <li> a?
* <li> a
* <li> a+
* <li> a,b
* <li> a|b
* </ul>
* <p>
* These all involve a unary operation with one element type, or a binary
* operation with two elements. These are very simple and can be checked
* in a simple way without a DFA and without the overhead of setting up a
* DFA for such a simple check.
* This model validated on the way in.
*
* @author Elena Litani, IBM
* @version $Id: XSSimpleCM.java,v 1.2 2001/11/13 20:32:32 sandygao Exp $
*/
public class XSSimpleCM
implements XSCMValidator {
//
// Constants
//
// start the content model: did not see any children
private static final short STATE_START = 0;
// seen first child
private static final short STATE_FIRST = 1;
private static final short STATE_VALID = 2;
//
// Data
//
// element declaration in the XML Schema grammar.
private XSElementDecl fFirstElement = null;
private XSElementDecl fSecondElement = null;
/**
* The operation that this object represents. Since this class only
* does simple contents, there is only ever a single operation
* involved (i.e. the children of the operation are always one or
* two leafs.)
*/
private short fOperator;
//
// Constructors
//
/**
* Constructs a simple content model.
*
*
*/
public XSSimpleCM(short operator, XSElementDecl elem) {
fFirstElement = elem;
fOperator = operator;
}
/**
* Constructs a simple content model.
*
*
*/
public XSSimpleCM(short operator, XSElementDecl elem1, XSElementDecl elem2) {
fFirstElement = elem1;
fSecondElement = elem2;
fOperator = operator;
}
//
// XSCMValidator methods
//
/**
* This methods to be called on entering a first element whose type
* has this content model. It will return the initial state of the content model
*
* @return Start state of the content model
*/
public int[] startContentModel(){
return (new int[] {STATE_START});
}
/**
* The method corresponds to one transaction in the content model.
*
* @param elementName
* @param state Current state
* @return element index corresponding to the element from the Schema grammar
*/
public Object oneTransition (QName elementName, int[] currentState, SubstitutionGroupHandler subGroupHandler){
// error state
if (currentState[0] == XSCMValidator.FIRST_ERROR) {
currentState[0] = XSCMValidator.SUBSEQUENT_ERROR;
return null;
}
int state = currentState[0];
Object matchingDecl = null;
switch (fOperator) {
case XSParticleDecl.PARTICLE_ELEMENT :
case XSParticleDecl.PARTICLE_ZERO_OR_ONE :
if (state == STATE_START) {
matchingDecl = subGroupHandler.getMatchingElemDecl(elementName, fFirstElement);
if (matchingDecl != null) {
currentState[0] = STATE_VALID;
return matchingDecl;
}
//error
}
break;
case XSParticleDecl.PARTICLE_ZERO_OR_MORE :
case XSParticleDecl.PARTICLE_ONE_OR_MORE :
matchingDecl = subGroupHandler.getMatchingElemDecl(elementName, fFirstElement);
if (matchingDecl != null) {
currentState[0] = STATE_VALID;
return matchingDecl;
}
break;
case XSParticleDecl.PARTICLE_CHOICE :
if (state == STATE_START) {
matchingDecl = subGroupHandler.getMatchingElemDecl(elementName, fFirstElement);
if (matchingDecl != null) {
currentState[0] = STATE_VALID;
return matchingDecl;
}
matchingDecl = subGroupHandler.getMatchingElemDecl(elementName, fSecondElement);
if (matchingDecl != null) {
currentState[0] = STATE_VALID;
return matchingDecl;
}
//error
}
break;
case XSParticleDecl.PARTICLE_SEQUENCE :
//
// There must be two children and they must be the two values
// we stored, in the stored order.
//
if (state == STATE_START) {
matchingDecl = subGroupHandler.getMatchingElemDecl(elementName, fFirstElement);
if (matchingDecl != null) {
currentState[0] = STATE_FIRST;
return matchingDecl;
}
//error
}
else if (state == STATE_FIRST) {
matchingDecl = subGroupHandler.getMatchingElemDecl(elementName, fSecondElement);
if (matchingDecl != null) {
currentState[0] = STATE_VALID;
return matchingDecl;
}
//error
}
break;
default :
throw new RuntimeException("ImplementationMessages.VAL_CST");
}
//if we reach here there was an error
currentState[0] = XSCMValidator.FIRST_ERROR;
return null;
}
/**
* The method indicates the end of list of children
*
* @param state Current state of the content model
* @return true if the last state was a valid final state
*/
public boolean endContentModel (int[] currentState){
boolean isFinal = false;
int state = currentState[0];
// error
if (state < 0) {
return false;
}
switch (fOperator) {
case XSParticleDecl.PARTICLE_ELEMENT :
case XSParticleDecl.PARTICLE_ONE_OR_MORE :
case XSParticleDecl.PARTICLE_CHOICE :
case XSParticleDecl.PARTICLE_SEQUENCE :
isFinal = (state == STATE_VALID)? true: false;
break;
case XSParticleDecl.PARTICLE_ZERO_OR_ONE :
case XSParticleDecl.PARTICLE_ZERO_OR_MORE :
isFinal = (state == STATE_VALID || state == STATE_START)? true:false;
break;
default :
throw new RuntimeException("ImplementationMessages.VAL_CST");
}
return isFinal;
}
/**
* check whether this content violates UPA constraint.
*
* @param errors to hold the UPA errors
* @return true if this content model contains other or list wildcard
*/
public boolean checkUniqueParticleAttribution(SubstitutionGroupHandler subGroupHandler) throws XMLSchemaException{
if (fOperator == XSParticleDecl.PARTICLE_CHOICE) {
// only when it's a choice, and the two elements overlap,
// is it a UPA violation.
if (XSConstraints.overlapUPA(fFirstElement, fSecondElement, subGroupHandler)) {
throw new XMLSchemaException("cos-nonambig", new Object[]{fFirstElement.toString(),
fSecondElement.toString()});
}
}
return false;
}
} // class XSSimpleCM