org.apache.xerces.validators.common
Class DFAContentModel

java.lang.Object
  |
  +--org.apache.xerces.validators.common.DFAContentModel
All Implemented Interfaces:
XMLContentModel

public class DFAContentModel
extends java.lang.Object
implements XMLContentModel

DFAContentModel is the derivative of ContentModel that does all of the non-trivial element content validation. This class does the conversion from the regular expression to the DFA that it then uses in its validation algorithm.

Version:
$Id: DFAContentModel.java 317282 2001-06-20 20:54:40Z neilg $

Constructor Summary
DFAContentModel(CMNode syntaxTree, int leafCount)
          Constructs a DFA content model.
DFAContentModel(CMNode syntaxTree, int leafCount, boolean dtd, boolean mixed)
          Constructs a DFA content model.
 
Method Summary
 void checkUniqueParticleAttribution(SchemaGrammar gram)
           
 ContentLeafNameTypeVector getContentLeafNameTypeVector()
           
 boolean isFinalState(int state)
          check whether the given state is one of the final states
 int oneTransition(QName curElem, int[] stateStack, int curPos)
          one transition only
 void setSubstitutionGroupComparator(SubstitutionGroupComparator comparator)
          The setter method to pass in the SubstitutionGroupComparator.
 int validateContent(QName[] children, int offset, int length)
          Check that the specified content is valid according to this content model.
 int validateContentSpecial(QName[] children, int offset, int length)
          This method is different from "validateContent" in that it will try to use the SubstitutionGroupComparator to match children against the content model.
 int whatCanGoHere(boolean fullyValid, InsertableElementsInfo info)
          Returns information about which elements can be placed at a particular point in the passed element's content model.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

DFAContentModel

public DFAContentModel(CMNode syntaxTree,
                       int leafCount)
                throws CMException
Constructs a DFA content model.
Parameters:
stringPool - The string pool.
syntaxTree - The syntax tree of the content model.
leafCount - The number of leaves.
Throws:
CMException - Thrown if DMA can't be built.

DFAContentModel

public DFAContentModel(CMNode syntaxTree,
                       int leafCount,
                       boolean dtd,
                       boolean mixed)
                throws CMException
Constructs a DFA content model.
Parameters:
stringPool - The string pool.
syntaxTree - The syntax tree of the content model.
leafCount - The number of leaves.
Throws:
CMException - Thrown if DMA can't be built.
Method Detail

validateContent

public int validateContent(QName[] children,
                           int offset,
                           int length)
                    throws CMException
Check that the specified content is valid according to this content model. This method can also be called to do 'what if' testing of content models just to see if they would be valid.

A value of -1 in the children array indicates a PCDATA node. All other indexes will be positive and represent child elements. The count can be zero, since some elements have the EMPTY content model and that must be confirmed.

Specified by:
validateContent in interface XMLContentModel
Parameters:
children - The children of this element. Each integer is an index within the StringPool of the child element name. An index of -1 is used to indicate an occurrence of non-whitespace character data.
offset - Offset into the array where the children starts.
length - The number of entries in the children array.
Returns:
The value -1 if fully valid, else the 0 based index of the child that first failed. If the value returned is equal to the number of children, then the specified children are valid but additional content is required to reach a valid ending state.
Throws:
CMException - Thrown on error.

validateContentSpecial

public int validateContentSpecial(QName[] children,
                                  int offset,
                                  int length)
                           throws java.lang.Exception
Description copied from interface: XMLContentModel
This method is different from "validateContent" in that it will try to use the SubstitutionGroupComparator to match children against the content model.

A value of -1 in the children array indicates a PCDATA node. All other indexes will be positive and represent child elements. The count can be zero, since some elements have the EMPTY content model and that must be confirmed.

Specified by:
validateContentSpecial in interface XMLContentModel
Following copied from interface: org.apache.xerces.validators.common.XMLContentModel
Parameters:
children - The children of this element. Each integer is an index within the StringPool of the child element name. An index of -1 is used to indicate an occurrence of non-whitespace character data.
offset - Offset into the array where the children starts.
length - The number of entries in the children array.
Returns:
The value -1 if fully valid, else the 0 based index of the child that first failed. If the value returned is equal to the number of children, then the specified children are valid but additional content is required to reach a valid ending state.
Throws:
java.lang.Exception - Thrown on error.

isFinalState

public boolean isFinalState(int state)
check whether the given state is one of the final states
Parameters:
state - the state to check
Returns:
whether it's a final state

oneTransition

public int oneTransition(QName curElem,
                         int[] stateStack,
                         int curPos)
                  throws java.lang.Exception
one transition only
Parameters:
curElem - The current element's QName
stateStack - stack to store the previous state
curPos - the current position of the stack
Returns:
The value -1 if not valid, otherwise the index of the matching leaf
Throws:
CMException - Thrown on error.

setSubstitutionGroupComparator

public void setSubstitutionGroupComparator(SubstitutionGroupComparator comparator)
Description copied from interface: XMLContentModel
The setter method to pass in the SubstitutionGroupComparator.
Specified by:
setSubstitutionGroupComparator in interface XMLContentModel
Following copied from interface: org.apache.xerces.validators.common.XMLContentModel
Parameters:
comparator - a SubstitutionGroupComparator object.
Returns:
 
Throws:
-  

whatCanGoHere

public int whatCanGoHere(boolean fullyValid,
                         InsertableElementsInfo info)
                  throws CMException
Returns information about which elements can be placed at a particular point in the passed element's content model.

Note that the incoming content model to test must be valid at least up to the insertion point. If not, then -1 will be returned and the info object will not have been filled in.

If, on return, the info.isValidEOC flag is set, then the 'insert after' element is a valid end of content. In other words, nothing needs to be inserted after it to make the parent element's content model valid.

Specified by:
whatCanGoHere in interface XMLContentModel
Parameters:
fullyValid - Only return elements that can be inserted and still maintain the validity of subsequent elements past the insertion point (if any). If the insertion point is at the end, and this is true, then only elements that can be legal final states will be returned.
info - An object that contains the required input data for the method, and which will contain the output information if successful.
Returns:
The value -1 if fully valid, else the 0 based index of the child that first failed before the insertion point. If the value returned is equal to the number of children, then the specified children are valid but additional content is required to reach a valid ending state.
See Also:
InsertableElementsInfo

getContentLeafNameTypeVector

public ContentLeafNameTypeVector getContentLeafNameTypeVector()
Specified by:
getContentLeafNameTypeVector in interface XMLContentModel

checkUniqueParticleAttribution

public void checkUniqueParticleAttribution(SchemaGrammar gram)
                                    throws java.lang.Exception
Specified by:
checkUniqueParticleAttribution in interface XMLContentModel


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