/*
 * Copyright (c) 2004 World Wide Web Consortium,
 *
 * (Massachusetts Institute of Technology, European Research Consortium for
 * Informatics and Mathematics, Keio University). All Rights Reserved. This
 * work is distributed under the W3C(r) Software License [1] in the hope that
 * it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * [1] http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231
 */

package org.w3c.dom;

/**
 *  The <code>TypeInfo</code> interface represents a type referenced from 
 * <code>Element</code> or <code>Attr</code> nodes, specified in the schemas 
 * associated with the document. The type is a pair of a namespace URI and 
 * name properties, and depends on the document's schema. 
 * <p> If the document's schema is an XML DTD [<a href='http://www.w3.org/TR/2004/REC-xml-20040204'>XML 1.0</a>], the values 
 * are computed as follows: 
 * <ul>
 * <li> If this type is referenced from an 
 * <code>Attr</code> node, <code>typeNamespace</code> is 
 * <code>"http://www.w3.org/TR/REC-xml"</code> and <code>typeName</code> 
 * represents the <b>[attribute type]</b> property in the [<a href='http://www.w3.org/TR/2004/REC-xml-infoset-20040204/'>XML Information Set</a>]
 * . If there is no declaration for the attribute, <code>typeNamespace</code>
 *  and <code>typeName</code> are <code>null</code>. 
 * </li>
 * <li> If this type is 
 * referenced from an <code>Element</code> node, <code>typeNamespace</code> 
 * and <code>typeName</code> are <code>null</code>. 
 * </li>
 * </ul>
 * <p> If the document's schema is an XML Schema [<a href='http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/'>XML Schema Part 1</a>]
 * , the values are computed as follows using the post-schema-validation 
 * infoset contributions (also called PSVI contributions): 
 * <ul>
 * <li> If the <b>[validity]</b> property exists AND is <em>"invalid"</em> or <em>"notKnown"</em>: the {target namespace} and {name} properties of the declared type if 
 * available, otherwise <code>null</code>. 
 * <p ><b>Note:</b>  At the time of writing, the XML Schema specification does 
 * not require exposing the declared type. Thus, DOM implementations might 
 * choose not to provide type information if validity is not valid. 
 * </li>
 * <li> If the <b>[validity]</b> property exists and is <em>"valid"</em>: 
 * <ol>
 * <li> If <b>[member type definition]</b> exists: 
 * <ol>
 * <li>If {name} is not absent, then expose {name} and {target 
 * namespace} properties of the <b>[member type definition]</b> property;
 * </li>
 * <li>Otherwise, expose the namespace and local name of the 
 * corresponding anonymous type name.
 * </li>
 * </ol>
 * </li>
 * <li> If the <b>[type definition]</b> property exists: 
 * <ol>
 * <li>If {name} is not absent, then expose {name} and {target 
 * namespace} properties of the <b>[type definition]</b> property;
 * </li>
 * <li>Otherwise, expose the namespace and local name of the 
 * corresponding anonymous type name.
 * </li>
 * </ol> 
 * </li>
 * <li> If the <b>[member type definition anonymous]</b> exists: 
 * <ol>
 * <li>If it is false, then expose <b>[member type definition name]</b> and <b>[member type definition namespace]</b> properties;
 * </li>
 * <li>Otherwise, expose the namespace and local name of the 
 * corresponding anonymous type name.
 * </li>
 * </ol> 
 * </li>
 * <li> If the <b>[type definition anonymous]</b> exists: 
 * <ol>
 * <li>If it is false, then expose <b>[type definition name]</b> and <b>[type definition namespace]</b> properties;
 * </li>
 * <li>Otherwise, expose the namespace and local name of the 
 * corresponding anonymous type name.
 * </li>
 * </ol> 
 * </li>
 * </ol>
 * </li>
 * </ul>
 * <p ><b>Note:</b>  Other schema languages are outside the scope of the W3C 
 * and therefore should define how to represent their type systems using 
 * <code>TypeInfo</code>. 
 * <p>See also the <a href='http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407'>Document Object Model (DOM) Level 3 Core Specification</a>.
 * @since DOM Level 3
 */
public interface TypeInfo {
    /**
     *  The name of a type declared for the associated element or attribute, 
     * or <code>null</code> if unknown. 
     */
    public String getTypeName();

    /**
     *  The namespace of the type declared for the associated element or 
     * attribute or <code>null</code> if the element does not have 
     * declaration or if no namespace information is available. 
     */
    public String getTypeNamespace();

    // DerivationMethods
    /**
     *  If the document's schema is an XML Schema [<a href='http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/'>XML Schema Part 1</a>]
     * , this constant represents the derivation by <a href='http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/#key-typeRestriction'>
     * restriction</a> if complex types are involved, or a <a href='http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/#element-restriction'>
     * restriction</a> if simple types are involved. 
     * <br>  The reference type definition is derived by restriction from the 
     * other type definition if the other type definition is the same as the 
     * reference type definition, or if the other type definition can be 
     * reached recursively following the {base type definition} property 
     * from the reference type definition, and all the <em>derivation methods</em> involved are restriction. 
     */
    public static final int DERIVATION_RESTRICTION    = 0x00000001;
    /**
     *  If the document's schema is an XML Schema [<a href='http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/'>XML Schema Part 1</a>]
     * , this constant represents the derivation by <a href='http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/#key-typeExtension'>
     * extension</a>. 
     * <br>  The reference type definition is derived by extension from the 
     * other type definition if the other type definition can be reached 
     * recursively following the {base type definition} property from the 
     * reference type definition, and at least one of the <em>derivation methods</em> involved is an extension. 
     */
    public static final int DERIVATION_EXTENSION      = 0x00000002;
    /**
     *  If the document's schema is an XML Schema [<a href='http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/'>XML Schema Part 1</a>]
     * , this constant represents the <a href='http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/#element-union'>
     * union</a> if simple types are involved. 
     * <br> The reference type definition is derived by union from the other 
     * type definition if there exists two type definitions T1 and T2 such 
     * as the reference type definition is derived from T1 by 
     * <code>DERIVATION_RESTRICTION</code> or 
     * <code>DERIVATION_EXTENSION</code>, T2 is derived from the other type 
     * definition by <code>DERIVATION_RESTRICTION</code>, T1 has {variety} <em>union</em>, and one of the {member type definitions} is T2. Note that T1 could be 
     * the same as the reference type definition, and T2 could be the same 
     * as the other type definition. 
     */
    public static final int DERIVATION_UNION          = 0x00000004;
    /**
     *  If the document's schema is an XML Schema [<a href='http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/'>XML Schema Part 1</a>]
     * , this constant represents the <a href='http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/#element-list'>list</a>. 
     * <br> The reference type definition is derived by list from the other 
     * type definition if there exists two type definitions T1 and T2 such 
     * as the reference type definition is derived from T1 by 
     * <code>DERIVATION_RESTRICTION</code> or 
     * <code>DERIVATION_EXTENSION</code>, T2 is derived from the other type 
     * definition by <code>DERIVATION_RESTRICTION</code>, T1 has {variety} <em>list</em>, and T2 is the {item type definition}. Note that T1 could be the same as 
     * the reference type definition, and T2 could be the same as the other 
     * type definition. 
     */
    public static final int DERIVATION_LIST           = 0x00000008;

    /**
     *  This method returns if there is a derivation between the reference 
     * type definition, i.e. the <code>TypeInfo</code> on which the method 
     * is being called, and the other type definition, i.e. the one passed 
     * as parameters. 
     * @param typeNamespaceArg  the namespace of the other type definition. 
     * @param typeNameArg  the name of the other type definition. 
     * @param derivationMethod  the type of derivation and conditions applied 
     *   between two types, as described in the list of constants provided 
     *   in this interface. 
     * @return  If the document's schema is a DTD or no schema is associated 
     *   with the document, this method will always return <code>false</code>
     *   .  If the document's schema is an XML Schema, the method will 
     *   <code>true</code> if the reference type definition is derived from 
     *   the other type definition according to the derivation parameter. If 
     *   the value of the parameter is <code>0</code> (no bit is set to 
     *   <code>1</code> for the <code>derivationMethod</code> parameter), 
     *   the method will return <code>true</code> if the other type 
     *   definition can be reached by recursing any combination of {base 
     *   type definition}, {item type definition}, or {member type 
     *   definitions} from the reference type definition. 
     */
    public boolean isDerivedFrom(String typeNamespaceArg, 
                                 String typeNameArg, 
                                 int derivationMethod);

}