## 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 320090 2004-10-04 22:00:42Z mrglavas $

# INTERNAL:

  Usage of this class is not supported. It may be altered or removed at any time.

Field Summary
`static short` `CHOICE` CHOICE
`static short` `SEQUENCE` SEQUENCE

Constructor Summary
`SimpleContentModel(short operator, org.apache.xerces.xni.QName firstChild, org.apache.xerces.xni.QName secondChild)` Constructs a simple content model.

Method Summary
`int` `validate(org.apache.xerces.xni.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
`clone, equals, finalize, 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,
                              org.apache.xerces.xni.QName firstChild,
                              org.apache.xerces.xni.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(org.apache.xerces.xni.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.

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