XSAllCM


1   /*
2    * Copyright 1999-2004 The Apache Software Foundation.
3    * 
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    * 
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    * 
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  package org.apache.xerces.impl.xs.models;
18  
19  import org.apache.xerces.xni.QName;
20  import org.apache.xerces.impl.xs.XSElementDecl;
21  import org.apache.xerces.impl.xs.SubstitutionGroupHandler;
22  import org.apache.xerces.impl.xs.XMLSchemaException;
23  import org.apache.xerces.impl.xs.XSConstraints;
24  
25  import java.util.Vector  ;
26  
27  /**
28   * XSAllCM implements XSCMValidator and handles <all>
29   *
30   * @xerces.internal 
31   *
32   * @author Pavani Mukthipudi, Sun Microsystems Inc.
33   * @version $Id: XSAllCM.java,v 1.12 2004/10/06 15:14:53 mrglavas Exp $
34   */
35  public class XSAllCM implements XSCMValidator {
36  
37      //
38      // Constants
39      //
40  
41      // start the content model: did not see any children
42      private static final short STATE_START = 0;
43      private static final short STATE_VALID = 1;
44      private static final short STATE_CHILD = 1;
45  
46  
47      //
48      // Data
49      //
50  
51      private XSElementDecl fAllElements[];
52      private boolean fIsOptionalElement[];
53      private boolean fHasOptionalContent = false;
54      private int fNumElements = 0;
55  
56      //
57      // Constructors
58      //
59  
60      public XSAllCM (boolean hasOptionalContent, int size) {
61          fHasOptionalContent = hasOptionalContent;
62          fAllElements = new XSElementDecl[size];
63          fIsOptionalElement = new boolean[size];
64      }
65  
66      public void addElement (XSElementDecl element, boolean isOptional) {
67          fAllElements[fNumElements] = element;
68          fIsOptionalElement[fNumElements] = isOptional;
69          fNumElements++;
70      }
71  
72  
73      //
74      // XSCMValidator methods
75      //
76  
77      /**
78       * This methods to be called on entering a first element whose type
79       * has this content model. It will return the initial state of the
80       * content model
81       *
82       * @return Start state of the content model
83       */
84      public int[] startContentModel() {
85  
86          int[] state = new int[fNumElements + 1];
87  
88          for (int i = 0; i <= fNumElements; i++) {
89              state[i] = STATE_START;
90          }
91          return state;
92      }
93  
94      // convinient method: when error occurs, to find a matching decl
95      // from the candidate elements.
96      Object   findMatchingDecl(QName elementName, SubstitutionGroupHandler subGroupHandler) {
97          Object   matchingDecl = null;
98          for (int i = 0; i < fNumElements; i++) {
99              matchingDecl = subGroupHandler.getMatchingElemDecl(elementName, fAllElements[i]);
100             if (matchingDecl != null)
101                 break;
102         }
103         return matchingDecl;
104     }
105 
106     /**
107      * The method corresponds to one transition in the content model.
108      *
109      * @param elementName
110      * @param currentState  Current state
111      * @return an element decl object
112      */
113     public Object   oneTransition (QName elementName, int[] currentState, SubstitutionGroupHandler subGroupHandler) {
114 
115         // error state
116         if (currentState[0] < 0) {
117             currentState[0] = XSCMValidator.SUBSEQUENT_ERROR;
118             return findMatchingDecl(elementName, subGroupHandler);
119         }
120 
121         // seen child
122         currentState[0] = STATE_CHILD;
123         
124         Object   matchingDecl = null;
125 
126         for (int i = 0; i < fNumElements; i++) {
127             // we only try to look for a matching decl if we have not seen
128             // this element yet.
129             if (currentState[i+1] != STATE_START)
130                 continue;
131             matchingDecl = subGroupHandler.getMatchingElemDecl(elementName, fAllElements[i]);
132             if (matchingDecl != null) {
133                 // found the decl, mark this element as "seen".
134                 currentState[i+1] = STATE_VALID;
135                 return matchingDecl;
136             }
137         }
138 
139         // couldn't find the decl, change to error state.
140         currentState[0] = XSCMValidator.FIRST_ERROR;
141         return findMatchingDecl(elementName, subGroupHandler);
142     }
143 
144 
145     /**
146      * The method indicates the end of list of children
147      *
148      * @param currentState  Current state of the content model
149      * @return true if the last state was a valid final state
150      */
151     public boolean endContentModel (int[] currentState) {
152 
153         int state = currentState[0];
154 
155         if (state == XSCMValidator.FIRST_ERROR || state == XSCMValidator.SUBSEQUENT_ERROR) {
156             return false;
157         }
158 
159         // If <all> has minOccurs of zero and there are
160         // no children to validate, it is trivially valid
161         if (fHasOptionalContent && state == STATE_START) {
162             return true;
163         }
164 
165         for (int i = 0; i < fNumElements; i++) {
166             // if one element is required, but not present, then error
167             if (!fIsOptionalElement[i] && currentState[i+1] == STATE_START)
168                 return false;
169         }
170 
171         return true;
172     }
173 
174     /**
175      * check whether this content violates UPA constraint.
176      *
177      * @param subGroupHandler the substitution group handler
178      * @return true if this content model contains other or list wildcard
179      */
180     public boolean checkUniqueParticleAttribution(SubstitutionGroupHandler subGroupHandler) throws XMLSchemaException {
181         // check whether there is conflict between any two leaves
182         for (int i = 0; i < fNumElements; i++) {
183             for (int j = i+1; j < fNumElements; j++) {
184                 if (XSConstraints.overlapUPA(fAllElements[i], fAllElements[j], subGroupHandler)) {
185                     // REVISIT: do we want to report all errors? or just one?
186                     throw new XMLSchemaException("cos-nonambig", new Object  []{fAllElements[i].toString(),
187                                                                               fAllElements[j].toString()});
188                 }
189             }
190         }
191 
192         return false;
193     }
194 
195     /**
196      * Check which elements are valid to appear at this point. This method also
197      * works if the state is in error, in which case it returns what should
198      * have been seen.
199      * 
200      * @param state  the current state
201      * @return       a Vector whose entries are instances of
202      *               either XSWildcardDecl or XSElementDecl.
203      */
204     public Vector   whatCanGoHere(int[] state) {
205         Vector   ret = new Vector  ();
206         for (int i = 0; i < fNumElements; i++) {
207             // we only try to look for a matching decl if we have not seen
208             // this element yet.
209             if (state[i+1] == STATE_START)
210                 ret.addElement(fAllElements[i]);
211         }
212         return ret;
213     }
214 
215 } // class XSAllCM
216 
217
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