javax.xml.validation

Class TypeInfoProvider

public abstract class TypeInfoProvider extends Object

This class provides access to the type information determined by {@link ValidatorHandler}.

Some schema languages, such as W3C XML Schema, encourages a validator to report the "type" it assigns to each attribute/element. Those applications who wish to access this type information can invoke methods defined on this "interface" to access such type information.

Implementation of this "interface" can be obtained through the {@link ValidatorHandler#getTypeInfoProvider()} method.

Since: 1.5

Version: $Revision: 226183 $, $Date: 2005-04-08 06:39:14 -0400 (Fri, 08 Apr 2005) $

Author: Kohsuke Kawaguchi

See Also: TypeInfo

Constructor Summary
protected TypeInfoProvider()
Constructor for the derived class.
Method Summary
abstract TypeInfogetAttributeTypeInfo(int index)
Returns the immutable {@link TypeInfo} object for the specified attribute of the current element.
abstract TypeInfogetElementTypeInfo()

Returns the immutable {@link TypeInfo} object for the current element.

The method may only be called by the startElement event of the {@link org.xml.sax.ContentHandler} that the application sets to the {@link ValidatorHandler}.

abstract booleanisIdAttribute(int index)
Returns true if the specified attribute is determined to be ID.
abstract booleanisSpecified(int index)
Returns false if the attribute was added by the validator.

Constructor Detail

TypeInfoProvider

protected TypeInfoProvider()
Constructor for the derived class.

The constructor does nothing.

Method Detail

getAttributeTypeInfo

public abstract TypeInfo getAttributeTypeInfo(int index)
Returns the immutable {@link TypeInfo} object for the specified attribute of the current element.

The method may only be called by the startElement event of the {@link org.xml.sax.ContentHandler} that the application sets to the {@link ValidatorHandler}.

Parameters: index The index of the attribute. The same index for the {@link org.xml.sax.Attributes} object passed to the startElement callback.

Returns: An immutable {@link TypeInfo} object that represents the type of the specified attribute. Note that the caller can keep references to the obtained {@link TypeInfo} longer than the callback scope. Otherwise, this method returns null if the validator is unable to determine the type.

Throws: IndexOutOfBoundsException If the index is invalid. IllegalStateException If this method is called from other {@link org.xml.sax.ContentHandler} methods.

getElementTypeInfo

public abstract TypeInfo getElementTypeInfo()

Returns the immutable {@link TypeInfo} object for the current element.

The method may only be called by the startElement event of the {@link org.xml.sax.ContentHandler} that the application sets to the {@link ValidatorHandler}.

Returns: An immutable {@link TypeInfo} object that represents the type of the current element. Note that the caller can keep references to the obtained {@link TypeInfo} longer than the callback scope. Otherwise, this method returns null if the validator is unable to determine the type of the current element for some reason (for example, if the validator is recovering from an earlier error.)

Throws: IllegalStateException If this method is called from other {@link org.xml.sax.ContentHandler} methods.

isIdAttribute

public abstract boolean isIdAttribute(int index)
Returns true if the specified attribute is determined to be ID.

Exacly how an attribute is "determined to be ID" is up to the schema language. In case of W3C XML Schema, this means that the actual type of the attribute is the built-in ID type or its derived type.

A {@link javax.xml.parsers.DocumentBuilder} uses this information to properly implement {@link org.w3c.dom.Attr#isId()}.

The method may only be called by the startElement event of the {@link org.xml.sax.ContentHandler} that the application sets to the {@link ValidatorHandler}.

Parameters: index The index of the attribute. The same index for the {@link org.xml.sax.Attributes} object passed to the startElement callback.

Returns: true if the type of the specified attribute is ID.

Throws: IndexOutOfBoundsException If the index is invalid. IllegalStateException If this method is called from other {@link org.xml.sax.ContentHandler} methods.

isSpecified

public abstract boolean isSpecified(int index)
Returns false if the attribute was added by the validator.

This method provides information necessary for a {@link javax.xml.parsers.DocumentBuilder} to determine what the DOM tree should return from the {@link org.w3c.dom.Attr#getSpecified()} method.

The method may only be called by the startElement event of the {@link org.xml.sax.ContentHandler} that the application sets to the {@link ValidatorHandler}.

A general guideline for validators is to return true if the attribute was originally present in the pipeline, and false if it was added by the validator.

Parameters: index The index of the attribute. The same index for the {@link org.xml.sax.Attributes} object passed to the startElement callback.

Returns: true if the attribute was present before the validator processes input. false if the attribute was added by the validator.

Throws: IndexOutOfBoundsException If the index is invalid. IllegalStateException If this method is called from other {@link org.xml.sax.ContentHandler} methods.