org.apache.xerces.impl.dtd.models
Class SimpleContentModel

java.lang.Object
  org.apache.xerces.impl.dtd.models.SimpleContentModel

All Implemented Interfaces:

ContentModelValidator

public class SimpleContentModel
extends java.lang.Object
implements ContentModelValidator

SimpleContentModel 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.

This class handles the following scenarios:

• a
• a?
• a*
• a+
• a,b
• a|b

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.

Version:

$Id: SimpleContentModel.java 572057 2007-09-02 18:03:20Z mrglavas $

Field Summary

static short	CHOICE CHOICE
static short	SEQUENCE SEQUENCE

Constructor Summary

SimpleContentModel(short operator, QName firstChild, QName secondChild)
Constructs a simple content model.

Method Summary

int	validate(QName[] children, int offset, int length) Check that the specified content is valid according to this content model.

Methods inherited from class java.lang.Object

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

Field Detail

CHOICE

public static final short CHOICE

CHOICE

See Also:

Constant Field Values

SEQUENCE

public static final short SEQUENCE

SEQUENCE

See Also:

Constant Field Values

Constructor Detail

SimpleContentModel

public SimpleContentModel(short operator,
                          QName firstChild,
                          QName secondChild)

Constructs a simple content model.

Parameters:

operator - The content model operator.

firstChild - qualified name of the first child

secondChild - qualified name of the second child

Method Detail

validate

public int validate(QName[] children,
                    int offset,
                    int length)

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:

validate in interface ContentModelValidator

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.