// =================================================================================================
// Copyright 2002-2008 Adobe Systems Incorporated
// All Rights Reserved.
//
// NOTICE:  Adobe permits you to use, modify, and distribute this file in accordance with the terms
// of the Adobe license agreement accompanying it.
// =================================================================================================

#include "XMP_Environment.h"	// ! This must be the first include!
#include "XMPCore_Impl.hpp"
#include "ExpatAdapter.hpp"

#include <cstring>

#if DEBUG
    #include <iostream>
#endif

using namespace std;

namespace DngXmpSdk {
#if XMP_WinBuild
    #pragma warning ( disable : 4189 )	// local variable is initialized but not referenced
    #pragma warning ( disable : 4505 )	// unreferenced local function has been removed
#endif

// =================================================================================================

// *** This might be faster and use less memory as a state machine. A big advantage of building an
// *** XML tree though is easy lookahead during the recursive descent processing.

// *** It would be nice to give a line number or byte offset in the exception messages.


// 7 RDF/XML Grammar (from http://www.w3.org/TR/rdf-syntax-grammar/#section-Infoset-Grammar)
//
// 7.1 Grammar summary
//
// 7.2.2 coreSyntaxTerms
//		rdf:RDF | rdf:ID | rdf:about | rdf:parseType | rdf:resource | rdf:nodeID | rdf:datatype
//
// 7.2.3 syntaxTerms
//		coreSyntaxTerms | rdf:Description | rdf:li
//
// 7.2.4 oldTerms
//		rdf:aboutEach | rdf:aboutEachPrefix | rdf:bagID
//
// 7.2.5 nodeElementURIs
//		anyURI - ( coreSyntaxTerms | rdf:li | oldTerms )
//
// 7.2.6 propertyElementURIs
//		anyURI - ( coreSyntaxTerms | rdf:Description | oldTerms )
//
// 7.2.7 propertyAttributeURIs
//		anyURI - ( coreSyntaxTerms | rdf:Description | rdf:li | oldTerms )
//
// 7.2.8 doc
//		root ( document-element == RDF, children == list ( RDF ) )
//
// 7.2.9 RDF
//		start-element ( URI == rdf:RDF, attributes == set() )
//		nodeElementList
//		end-element()
//
// 7.2.10 nodeElementList
//		ws* ( nodeElement ws* )*
//
// 7.2.11 nodeElement
//		start-element ( URI == nodeElementURIs,
//						attributes == set ( ( idAttr | nodeIdAttr | aboutAttr )?, propertyAttr* ) )
//		propertyEltList
//		end-element()
//
// 7.2.12 ws
//		A text event matching white space defined by [XML] definition White Space Rule [3] S in section Common Syntactic Constructs.
//
// 7.2.13 propertyEltList
//		ws* ( propertyElt ws* )*
//
// 7.2.14 propertyElt
//		resourcePropertyElt | literalPropertyElt | parseTypeLiteralPropertyElt |
//		parseTypeResourcePropertyElt | parseTypeCollectionPropertyElt | parseTypeOtherPropertyElt | emptyPropertyElt
//
// 7.2.15 resourcePropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr? ) )
//		ws* nodeElement ws*
//		end-element()
//
// 7.2.16 literalPropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr?, datatypeAttr?) )
//		text()
//		end-element()
//
// 7.2.17 parseTypeLiteralPropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr?, parseLiteral ) )
//		literal
//		end-element()
//
// 7.2.18 parseTypeResourcePropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr?, parseResource ) )
//		propertyEltList
//		end-element()
//
// 7.2.19 parseTypeCollectionPropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr?, parseCollection ) )
//		nodeElementList
//		end-element()
//
// 7.2.20 parseTypeOtherPropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr?, parseOther ) )
//		propertyEltList
//		end-element()
//
// 7.2.21 emptyPropertyElt
//		start-element ( URI == propertyElementURIs,
//						attributes == set ( idAttr?, ( resourceAttr | nodeIdAttr )?, propertyAttr* ) )
//		end-element()
//
// 7.2.22 idAttr
//		attribute ( URI == rdf:ID, string-value == rdf-id )
//
// 7.2.23 nodeIdAttr
//		attribute ( URI == rdf:nodeID, string-value == rdf-id )
//
// 7.2.24 aboutAttr
//		attribute ( URI == rdf:about, string-value == URI-reference )
//
// 7.2.25 propertyAttr
//		attribute ( URI == propertyAttributeURIs, string-value == anyString )
//
// 7.2.26 resourceAttr
//		attribute ( URI == rdf:resource, string-value == URI-reference )
//
// 7.2.27 datatypeAttr
//		attribute ( URI == rdf:datatype, string-value == URI-reference )
//
// 7.2.28 parseLiteral
//		attribute ( URI == rdf:parseType, string-value == "Literal")
//
// 7.2.29 parseResource
//		attribute ( URI == rdf:parseType, string-value == "Resource")
//
// 7.2.30 parseCollection
//		attribute ( URI == rdf:parseType, string-value == "Collection")
//
// 7.2.31 parseOther
//		attribute ( URI == rdf:parseType, string-value == anyString - ("Resource" | "Literal" | "Collection") )
//
// 7.2.32 URI-reference
//		An RDF URI Reference.
//
// 7.2.33 literal
//		Any XML element content that is allowed according to [XML] definition Content of Elements Rule [43] content
//		in section 3.1 Start-Tags, End-Tags, and Empty-Element Tags.
//
// 7.2.34 rdf-id
//		An attribute string-value matching any legal [XML-NS] token NCName.


// =================================================================================================
// Primary Parsing Functions
// =========================
//
// Each of these is responsible for recognizing an RDF syntax production and adding the appropriate
// structure to the XMP tree. They simply return for success, failures will throw an exception.

static void
RDF_RDF ( XMP_Node * xmpTree, const XML_Node & xmlNode );

static void
RDF_NodeElementList ( XMP_Node * xmpParent, const XML_Node & xmlParent, bool isTopLevel );

static void
RDF_NodeElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel );

static void
RDF_NodeElementAttrs ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel );

static void
RDF_PropertyElementList ( XMP_Node * xmpParent, const XML_Node & xmlParent, bool isTopLevel );
enum { kIsTopLevel = true, kNotTopLevel = false };

static void
RDF_PropertyElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel );

static void
RDF_ResourcePropertyElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel );

static void
RDF_LiteralPropertyElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel );

static void
RDF_ParseTypeLiteralPropertyElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel );

static void
RDF_ParseTypeResourcePropertyElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel );

static void
RDF_ParseTypeCollectionPropertyElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel );

static void
RDF_ParseTypeOtherPropertyElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel );

static void
RDF_EmptyPropertyElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel );


// =================================================================================================

typedef XMP_Uns8 RDFTermKind;

// *** Logic might be safer with just masks.

enum {
    kRDFTerm_Other				=  0,
    kRDFTerm_RDF				=  1,	// Start of coreSyntaxTerms.
    kRDFTerm_ID					=  2,
    kRDFTerm_about				=  3,
    kRDFTerm_parseType			=  4,
    kRDFTerm_resource			=  5,
    kRDFTerm_nodeID				=  6,
    kRDFTerm_datatype			=  7,	// End of coreSyntaxTerms.
    kRDFTerm_Description		=  8,	// Start of additions for syntaxTerms.
    kRDFTerm_li					=  9,	// End of additions for syntaxTerms.
    kRDFTerm_aboutEach			= 10,	// Start of oldTerms.
    kRDFTerm_aboutEachPrefix	= 11,
    kRDFTerm_bagID				= 12,	// End of oldTerms.

    kRDFTerm_FirstCore          = kRDFTerm_RDF,
    kRDFTerm_LastCore           = kRDFTerm_datatype,
    kRDFTerm_FirstSyntax        = kRDFTerm_FirstCore,	// ! Yes, the syntax terms include the core terms.
    kRDFTerm_LastSyntax         = kRDFTerm_li,
    kRDFTerm_FirstOld           = kRDFTerm_aboutEach,
    kRDFTerm_LastOld            = kRDFTerm_bagID
};

enum {
    kRDFMask_Other				= 1 << kRDFTerm_Other,
    kRDFMask_RDF				= 1 << kRDFTerm_RDF,
    kRDFMask_ID					= 1 << kRDFTerm_ID,
    kRDFMask_about				= 1 << kRDFTerm_about,
    kRDFMask_parseType			= 1 << kRDFTerm_parseType,
    kRDFMask_resource			= 1 << kRDFTerm_resource,
    kRDFMask_nodeID				= 1 << kRDFTerm_nodeID,
    kRDFMask_datatype			= 1 << kRDFTerm_datatype,
    kRDFMask_Description		= 1 << kRDFTerm_Description,
    kRDFMask_li					= 1 << kRDFTerm_li,
    kRDFMask_aboutEach			= 1 << kRDFTerm_aboutEach,
    kRDFMask_aboutEachPrefix	= 1 << kRDFTerm_aboutEachPrefix,
    kRDFMask_bagID				= 1 << kRDFTerm_bagID
};

enum {
    kRDF_HasValueElem = 0x10000000UL	// ! Contains rdf:value child. Must fit within kXMP_ImplReservedMask!
};

// -------------------------------------------------------------------------------------------------
// GetRDFTermKind
// --------------

static RDFTermKind
GetRDFTermKind ( const XMP_VarString & name )
{
    RDFTermKind term = kRDFTerm_Other;

    // Arranged to hopefully minimize the parse time for large XMP.

    if ( (name.size() > 4) && (strncmp ( name.c_str(), "rdf:", 4 ) == 0) ) {

        if ( name == "rdf:li" ) {
            term = kRDFTerm_li;
        } else if ( name == "rdf:parseType" ) {
            term = kRDFTerm_parseType;
        } else if ( name == "rdf:Description" ) {
            term = kRDFTerm_Description;
        } else if ( name == "rdf:about" ) {
            term = kRDFTerm_about;
        } else if ( name == "rdf:resource" ) {
            term = kRDFTerm_resource;
        } else if ( name == "rdf:RDF" ) {
            term = kRDFTerm_RDF;
        } else if ( name == "rdf:ID" ) {
            term = kRDFTerm_ID;
        } else if ( name == "rdf:nodeID" ) {
            term = kRDFTerm_nodeID;
        } else if ( name == "rdf:datatype" ) {
            term = kRDFTerm_datatype;
        } else if ( name == "rdf:aboutEach" ) {
            term = kRDFTerm_aboutEach;
        } else if ( name == "rdf:aboutEachPrefix" ) {
            term = kRDFTerm_aboutEachPrefix;
        } else if ( name == "rdf:bagID" ) {
            term = kRDFTerm_bagID;
        }

    }

    return term;

}	// GetRDFTermKind


// =================================================================================================


// -------------------------------------------------------------------------------------------------
// IsCoreSyntaxTerm
// ----------------
//
// 7.2.2 coreSyntaxTerms
//		rdf:RDF | rdf:ID | rdf:about | rdf:parseType | rdf:resource | rdf:nodeID | rdf:datatype

static bool
IsCoreSyntaxTerm ( RDFTermKind term )
{

    if 	( (kRDFTerm_FirstCore <= term) && (term <= kRDFTerm_LastCore) ) return true;
    return false;

}	// IsCoreSyntaxTerm

// -------------------------------------------------------------------------------------------------
// IsSyntaxTerm
// ------------
//
// 7.2.3 syntaxTerms
//		coreSyntaxTerms | rdf:Description | rdf:li

static bool
IsSyntaxTerm ( RDFTermKind term )
{

    if 	( (kRDFTerm_FirstSyntax <= term) && (term <= kRDFTerm_LastSyntax) ) return true;
    return false;

}	// IsSyntaxTerm

// -------------------------------------------------------------------------------------------------
// IsOldTerm
// ---------
//
// 7.2.4 oldTerms
//		rdf:aboutEach | rdf:aboutEachPrefix | rdf:bagID

static bool
IsOldTerm ( RDFTermKind term )
{

    if 	( (kRDFTerm_FirstOld <= term) && (term <= kRDFTerm_LastOld) ) return true;
    return false;

}	// IsOldTerm

// -------------------------------------------------------------------------------------------------
// IsNodeElementName
// -----------------
//
// 7.2.5 nodeElementURIs
//		anyURI - ( coreSyntaxTerms | rdf:li | oldTerms )

static bool
IsNodeElementName ( RDFTermKind term )
{

    if 	( (term == kRDFTerm_li) || IsOldTerm ( term ) ) return false;
    return (! IsCoreSyntaxTerm ( term ));

}	// IsNodeElementName

// -------------------------------------------------------------------------------------------------
// IsPropertyElementName
// ---------------------
//
// 7.2.6 propertyElementURIs
//		anyURI - ( coreSyntaxTerms | rdf:Description | oldTerms )

static bool
IsPropertyElementName ( RDFTermKind term )
{

    if 	( (term == kRDFTerm_Description) || IsOldTerm ( term ) ) return false;
    return (! IsCoreSyntaxTerm ( term ));

}	// IsPropertyElementName

// -------------------------------------------------------------------------------------------------
// IsPropertyAttributeName
// -----------------------
//
// 7.2.7 propertyAttributeURIs
//		anyURI - ( coreSyntaxTerms | rdf:Description | rdf:li | oldTerms )

static bool
IsPropertyAttributeName ( RDFTermKind term )
{

    if 	( (term == kRDFTerm_Description) || (term == kRDFTerm_li) || IsOldTerm ( term ) ) return false;
    return (! IsCoreSyntaxTerm ( term ));

}	// IsPropertyAttributeName


// =================================================================================================
// AddChildNode
// ============

static XMP_Node *
AddChildNode ( XMP_Node * xmpParent, const XML_Node & xmlNode, const XMP_StringPtr value, bool isTopLevel )
{
    #if 0
        cout << "AddChildNode, parent = " << xmpParent->name << ", child = " << xmlNode.name;
        cout << ", value = \"" << value << '"';
        if ( isTopLevel ) cout << ", top level";
        cout << endl;
    #endif

    if ( xmlNode.ns.empty() ) {
        XMP_Throw ( "XML namespace required for all elements and attributes", kXMPErr_BadRDF );
    }

    XMP_StringPtr  childName    = xmlNode.name.c_str();
    const bool     isArrayItem  = (xmlNode.name == "rdf:li");
    const bool     isValueNode  = (xmlNode.name == "rdf:value");
    XMP_OptionBits childOptions = 0;

    if ( isTopLevel ) {

        // Lookup the schema node, adjust the XMP parent pointer.
        XMP_Assert ( xmpParent->parent == 0 );	// Incoming parent must be the tree root.
        XMP_Node * schemaNode = FindSchemaNode ( xmpParent, xmlNode.ns.c_str(), kXMP_CreateNodes );
        if ( schemaNode->options & kXMP_NewImplicitNode ) schemaNode->options ^= kXMP_NewImplicitNode;	// Clear the implicit node bit.
            // *** Should use "opt &= ~flag" (no conditional), need runtime check for proper 32 bit code.
        xmpParent = schemaNode;

        // If this is an alias set the isAlias flag in the node and the hasAliases flag in the tree.
        if ( sRegisteredAliasMap->find ( xmlNode.name ) != sRegisteredAliasMap->end() ) {
            childOptions |= kXMP_PropIsAlias;
            schemaNode->parent->options |= kXMP_PropHasAliases;
        }

    }

    // Make sure that this is not a duplicate of a named node.
    if ( ! (isArrayItem | isValueNode) ) {
        if ( FindChildNode ( xmpParent, childName, kXMP_ExistingOnly ) != 0 ) {
            XMP_Throw ( "Duplicate property or field node", kXMPErr_BadXMP );
        }

    }

    // Add the new child to the XMP parent node.
    XMP_Node * newChild = new XMP_Node ( xmpParent, childName, value, childOptions );
    if ( (! isValueNode) || xmpParent->children.empty() ) {
         xmpParent->children.push_back ( newChild );
    } else {
         xmpParent->children.insert ( xmpParent->children.begin(), newChild );
    }
    if ( isValueNode ) {
        if ( isTopLevel || (! (xmpParent->options & kXMP_PropValueIsStruct)) ) XMP_Throw ( "Misplaced rdf:value element", kXMPErr_BadRDF );
        xmpParent->options |= kRDF_HasValueElem;
    }

    if ( isArrayItem ) {
        if ( ! (xmpParent->options & kXMP_PropValueIsArray) ) XMP_Throw ( "Misplaced rdf:li element", kXMPErr_BadRDF );
        newChild->name = kXMP_ArrayItemName;
        #if 0	// *** XMP_DebugBuild
            newChild->_namePtr = newChild->name.c_str();
        #endif
    }

    return newChild;

}	// AddChildNode


// =================================================================================================
// AddQualifierNode
// ================

static XMP_Node *
AddQualifierNode ( XMP_Node * xmpParent, const XMP_VarString & name, const XMP_VarString & value )
{

    #if 0
        cout << "AddQualifierNode, parent = " << xmpParent->name << ", name = " << name;
        cout << ", value = \"" << value << '"' << endl;
    #endif

    const bool isLang = (name == "xml:lang");
    const bool isType = (name == "rdf:type");

    XMP_Node * newQual = 0;

        newQual = new XMP_Node ( xmpParent, name, value, kXMP_PropIsQualifier );

        if ( ! (isLang | isType) ) {
            xmpParent->qualifiers.push_back ( newQual );
        } else if ( isLang ) {
            if ( xmpParent->qualifiers.empty() ) {
                xmpParent->qualifiers.push_back ( newQual );
            } else {
                xmpParent->qualifiers.insert ( xmpParent->qualifiers.begin(), newQual );
            }
            xmpParent->options |= kXMP_PropHasLang;
        } else {
            XMP_Assert ( isType );
            if ( xmpParent->qualifiers.empty() ) {
                xmpParent->qualifiers.push_back ( newQual );
            } else {
                size_t offset = 0;
                if ( XMP_PropHasLang ( xmpParent->options ) ) offset = 1;
                xmpParent->qualifiers.insert ( xmpParent->qualifiers.begin()+offset, newQual );
            }
            xmpParent->options |= kXMP_PropHasType;
        }

        xmpParent->options |= kXMP_PropHasQualifiers;

    return newQual;

}	// AddQualifierNode


// =================================================================================================
// AddQualifierNode
// ================

static XMP_Node *
AddQualifierNode ( XMP_Node * xmpParent, const XML_Node & attr )
{
    if ( attr.ns.empty() ) {
        XMP_Throw ( "XML namespace required for all elements and attributes", kXMPErr_BadRDF );
    }

    return AddQualifierNode ( xmpParent, attr.name, attr.value );

}	// AddQualifierNode


// =================================================================================================
// FixupQualifiedNode
// ==================
//
// The parent is an RDF pseudo-struct containing an rdf:value field. Fix the XMP data model. The
// rdf:value node must be the first child, the other children are qualifiers. The form, value, and
// children of the rdf:value node are the real ones. The rdf:value node's qualifiers must be added
// to the others.

static void
FixupQualifiedNode ( XMP_Node * xmpParent )
{
    size_t qualNum, qualLim;
    size_t childNum, childLim;

    XMP_Enforce ( (xmpParent->options & kXMP_PropValueIsStruct) && (! xmpParent->children.empty()) );

    XMP_Node * valueNode = xmpParent->children[0];
    XMP_Enforce ( valueNode->name == "rdf:value" );

    xmpParent->qualifiers.reserve ( xmpParent->qualifiers.size() + xmpParent->children.size() + valueNode->qualifiers.size() );

    // Move the qualifiers on the value node to the parent. Make sure an xml:lang qualifier stays at
    // the front. Check for duplicate names between the value node's qualifiers and the parent's
    // children. The parent's children are about to become qualifiers. Check here, between the
    // groups. Intra-group duplicates are caught by AddChildNode.

    qualNum = 0;
    qualLim = valueNode->qualifiers.size();

    if ( valueNode->options & kXMP_PropHasLang ) {

        if ( xmpParent->options & kXMP_PropHasLang ) XMP_Throw ( "Redundant xml:lang for rdf:value element", kXMPErr_BadXMP );

        XMP_Node * langQual = valueNode->qualifiers[0];

        XMP_Assert ( langQual->name == "xml:lang" );
        langQual->parent = xmpParent;
        xmpParent->options |= kXMP_PropHasLang;

        if ( xmpParent->qualifiers.empty() ) {
            xmpParent->qualifiers.push_back ( langQual );	// *** Should use utilities to add qual & set parent.
        } else {
            xmpParent->qualifiers.insert ( xmpParent->qualifiers.begin(), langQual );
        }
        valueNode->qualifiers[0] = 0;	// We just moved it to the parent.

        qualNum = 1;	// Start the remaining copy after the xml:lang qualifier.

    }

    for ( ; qualNum != qualLim; ++qualNum ) {

        XMP_Node * currQual = valueNode->qualifiers[qualNum];
        if ( FindChildNode ( xmpParent, currQual->name.c_str(), kXMP_ExistingOnly ) != 0 ) {
            XMP_Throw ( "Duplicate qualifier node", kXMPErr_BadXMP );
        }

        currQual->parent = xmpParent;
        xmpParent->qualifiers.push_back ( currQual );
        valueNode->qualifiers[qualNum] = 0;	// We just moved it to the parent.

    }

    valueNode->qualifiers.clear();	// ! There should be nothing but null pointers.

    // Change the parent's other children into qualifiers. This loop starts at 1, child 0 is the
    // rdf:value node. Put xml:lang at the front, append all others.

    for ( childNum = 1, childLim = xmpParent->children.size(); childNum != childLim; ++childNum ) {

        XMP_Node * currQual = xmpParent->children[childNum];

            bool isLang = (currQual->name == "xml:lang");

            currQual->options |= kXMP_PropIsQualifier;
            currQual->parent = xmpParent;

            if ( isLang ) {
                if ( xmpParent->options & kXMP_PropHasLang ) XMP_Throw ( "Duplicate xml:lang qualifier", kXMPErr_BadXMP );
                xmpParent->options |= kXMP_PropHasLang;
            } else if ( currQual->name == "rdf:type" ) {
                xmpParent->options |= kXMP_PropHasType;
            }

            if ( (! isLang) || xmpParent->qualifiers.empty() ) {
                xmpParent->qualifiers.push_back ( currQual );
            } else {
                xmpParent->qualifiers.insert ( xmpParent->qualifiers.begin(), currQual );
            }
            xmpParent->children[childNum] = 0;	// We just moved it to the qualifers.

    }

    if ( ! xmpParent->qualifiers.empty() ) xmpParent->options |= kXMP_PropHasQualifiers;

    // Move the options and value last, other checks need the parent's original options. Move the
    // value node's children to be the parent's children. Delete the now useless value node.

    XMP_Assert ( xmpParent->options & (kXMP_PropValueIsStruct | kRDF_HasValueElem) );
    xmpParent->options &= ~ (kXMP_PropValueIsStruct | kRDF_HasValueElem);
    xmpParent->options |= valueNode->options;

    xmpParent->value.swap ( valueNode->value );
    #if 0	// *** XMP_DebugBuild
        xmpParent->_valuePtr = xmpParent->value.c_str();
    #endif

    xmpParent->children[0] = 0;	// ! Remove the value node itself before the swap.
    xmpParent->children.swap ( valueNode->children );

    for ( size_t childNum = 0, childLim = xmpParent->children.size(); childNum != childLim; ++childNum ) {
        XMP_Node * currChild = xmpParent->children[childNum];
        currChild->parent = xmpParent;
    }

    delete valueNode;

}	// FixupQualifiedNode


// =================================================================================================
// ProcessRDF
// ==========
//
// Parse the XML tree of the RDF and build the corresponding XMP tree.

// *** Throw an exception if no XMP is found? By option?
// *** Do parsing exceptions cause the partial tree to be deleted?

void ProcessRDF ( XMP_Node * xmpTree, const XML_Node & rdfNode, XMP_OptionBits options )
{
    IgnoreParam(options);

    RDF_RDF ( xmpTree, rdfNode );

}	// ProcessRDF


// =================================================================================================
// RDF_RDF
// =======
//
// 7.2.9 RDF
//		start-element ( URI == rdf:RDF, attributes == set() )
//		nodeElementList
//		end-element()
//
// The top level rdf:RDF node. It can only have xmlns attributes, which have already been removed
// during construction of the XML tree.

static void
RDF_RDF ( XMP_Node * xmpTree, const XML_Node & xmlNode )
{

    if ( ! xmlNode.attrs.empty() ) XMP_Throw ( "Invalid attributes of rdf:RDF element", kXMPErr_BadRDF );
    RDF_NodeElementList ( xmpTree, xmlNode, kIsTopLevel );

}	// RDF_RDF


// =================================================================================================
// RDF_NodeElementList
// ===================
//
// 7.2.10 nodeElementList
//		ws* ( nodeElement ws* )*

static void
RDF_NodeElementList ( XMP_Node * xmpParent, const XML_Node & xmlParent, bool isTopLevel )
{
    XMP_Assert ( isTopLevel );

    XML_cNodePos currChild = xmlParent.content.begin();	// *** Change these loops to the indexed pattern.
    XML_cNodePos endChild  = xmlParent.content.end();

    for ( ; currChild != endChild; ++currChild ) {
        if ( (*currChild)->IsWhitespaceNode() ) continue;
        RDF_NodeElement ( xmpParent, **currChild, isTopLevel );
    }

}	// RDF_NodeElementList


// =================================================================================================
// RDF_NodeElement
// ===============
//
// 7.2.5 nodeElementURIs
//		anyURI - ( coreSyntaxTerms | rdf:li | oldTerms )
//
// 7.2.11 nodeElement
//		start-element ( URI == nodeElementURIs,
//						attributes == set ( ( idAttr | nodeIdAttr | aboutAttr )?, propertyAttr* ) )
//		propertyEltList
//		end-element()
//
// A node element URI is rdf:Description or anything else that is not an RDF term.

static void
RDF_NodeElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel )
{
    RDFTermKind nodeTerm = GetRDFTermKind ( xmlNode.name );
    if ( (nodeTerm != kRDFTerm_Description) && (nodeTerm != kRDFTerm_Other) ) {
        XMP_Throw ( "Node element must be rdf:Description or typedNode", kXMPErr_BadRDF );
    }

    if ( isTopLevel && (nodeTerm == kRDFTerm_Other) ) {
        XMP_Throw ( "Top level typedNode not allowed", kXMPErr_BadXMP );
    } else {
        RDF_NodeElementAttrs ( xmpParent, xmlNode, isTopLevel );
        RDF_PropertyElementList ( xmpParent, xmlNode, isTopLevel );
    }

}	// RDF_NodeElement


// =================================================================================================
// RDF_NodeElementAttrs
// ====================
//
// 7.2.7 propertyAttributeURIs
//		anyURI - ( coreSyntaxTerms | rdf:Description | rdf:li | oldTerms )
//
// 7.2.11 nodeElement
//		start-element ( URI == nodeElementURIs,
//						attributes == set ( ( idAttr | nodeIdAttr | aboutAttr )?, propertyAttr* ) )
//		propertyEltList
//		end-element()
//
// Process the attribute list for an RDF node element. A property attribute URI is anything other
// than an RDF term. The rdf:ID and rdf:nodeID attributes are simply ignored, as are rdf:about
// attributes on inner nodes.

static const XMP_OptionBits kExclusiveAttrMask = (kRDFMask_ID | kRDFMask_nodeID | kRDFMask_about);

static void
RDF_NodeElementAttrs ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel )
{
    XMP_OptionBits exclusiveAttrs = 0;	// Used to detect attributes that are mutually exclusive.

    XML_cNodePos currAttr = xmlNode.attrs.begin();
    XML_cNodePos endAttr  = xmlNode.attrs.end();

    for ( ; currAttr != endAttr; ++currAttr ) {

        RDFTermKind attrTerm = GetRDFTermKind ( (*currAttr)->name );

        switch ( attrTerm ) {

            case kRDFTerm_ID     :
            case kRDFTerm_nodeID :
            case kRDFTerm_about  :

                if ( exclusiveAttrs & kExclusiveAttrMask ) XMP_Throw ( "Mutally exclusive about, ID, nodeID attributes", kXMPErr_BadRDF );
                exclusiveAttrs |= (1 << attrTerm);

                if ( isTopLevel && (attrTerm == kRDFTerm_about) ) {
                    // This is the rdf:about attribute on a top level node. Set the XMP tree name if
                    // it doesn't have a name yet. Make sure this name matches the XMP tree name.
                    XMP_Assert ( xmpParent->parent == 0 );	// Must be the tree root node.
                    if ( xmpParent->name.empty() ) {
                        xmpParent->name = (*currAttr)->value;
                    } else if ( ! (*currAttr)->value.empty() ) {
                        if ( xmpParent->name != (*currAttr)->value ) XMP_Throw ( "Mismatched top level rdf:about values", kXMPErr_BadXMP );
                    }
                }

                break;

            case kRDFTerm_Other :
                AddChildNode ( xmpParent, **currAttr, (*currAttr)->value.c_str(), isTopLevel );
                break;

            default :
                XMP_Throw ( "Invalid nodeElement attribute", kXMPErr_BadRDF );
                break;

        }

    }

}	// RDF_NodeElementAttrs


// =================================================================================================
// RDF_PropertyElementList
// =======================
//
// 7.2.13 propertyEltList
//		ws* ( propertyElt ws* )*

static void
RDF_PropertyElementList ( XMP_Node * xmpParent, const XML_Node & xmlParent, bool isTopLevel )
{
    XML_cNodePos currChild = xmlParent.content.begin();
    XML_cNodePos endChild  = xmlParent.content.end();

    for ( ; currChild != endChild; ++currChild ) {
        if ( (*currChild)->IsWhitespaceNode() ) continue;
        if ( (*currChild)->kind != kElemNode ) {
            XMP_Throw ( "Expected property element node not found", kXMPErr_BadRDF );
        }
        RDF_PropertyElement ( xmpParent, **currChild, isTopLevel );
    }

}	// RDF_PropertyElementList


// =================================================================================================
// RDF_PropertyElement
// ===================
//
// 7.2.14 propertyElt
//		resourcePropertyElt | literalPropertyElt | parseTypeLiteralPropertyElt |
//		parseTypeResourcePropertyElt | parseTypeCollectionPropertyElt | parseTypeOtherPropertyElt | emptyPropertyElt
//
// 7.2.15 resourcePropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr? ) )
//		ws* nodeElement ws*
//		end-element()
//
// 7.2.16 literalPropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr?, datatypeAttr?) )
//		text()
//		end-element()
//
// 7.2.17 parseTypeLiteralPropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr?, parseLiteral ) )
//		literal
//		end-element()
//
// 7.2.18 parseTypeResourcePropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr?, parseResource ) )
//		propertyEltList
//		end-element()
//
// 7.2.19 parseTypeCollectionPropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr?, parseCollection ) )
//		nodeElementList
//		end-element()
//
// 7.2.20 parseTypeOtherPropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr?, parseOther ) )
//		propertyEltList
//		end-element()
//
// 7.2.21 emptyPropertyElt
//		start-element ( URI == propertyElementURIs,
//						attributes == set ( idAttr?, ( resourceAttr | nodeIdAttr )?, propertyAttr* ) )
//		end-element()
//
// The various property element forms are not distinguished by the XML element name, but by their
// attributes for the most part. The exceptions are resourcePropertyElt and literalPropertyElt. They
// are distinguished by their XML element content.
//
// NOTE: The RDF syntax does not explicitly include the xml:lang attribute although it can appear in
// many of these. We have to allow for it in the attibute counts below.

static void
RDF_PropertyElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel )
{
    RDFTermKind nodeTerm = GetRDFTermKind ( xmlNode.name );
    if ( ! IsPropertyElementName ( nodeTerm ) ) XMP_Throw ( "Invalid property element name", kXMPErr_BadRDF );

    if ( xmlNode.attrs.size() > 3 ) {

        // Only an emptyPropertyElt can have more than 3 attributes.
        RDF_EmptyPropertyElement ( xmpParent, xmlNode, isTopLevel );

    } else {

        // Look through the attributes for one that isn't rdf:ID or xml:lang, it will usually tell
        // what we should be dealing with. The called routines must verify their specific syntax!

        XML_cNodePos currAttr = xmlNode.attrs.begin();
        XML_cNodePos endAttr  = xmlNode.attrs.end();
        XMP_VarString * attrName = 0;

        for ( ; currAttr != endAttr; ++currAttr ) {
            attrName = &((*currAttr)->name);
            if ( (*attrName != "xml:lang") && (*attrName != "rdf:ID") ) break;
        }

        if ( currAttr != endAttr ) {

            XMP_Assert ( attrName != 0 );
            XMP_VarString& attrValue = (*currAttr)->value;

            if ( *attrName == "rdf:datatype" ) {
                RDF_LiteralPropertyElement ( xmpParent, xmlNode, isTopLevel );
            } else if ( *attrName != "rdf:parseType" ) {
                RDF_EmptyPropertyElement ( xmpParent, xmlNode, isTopLevel );
            } else if ( attrValue == "Literal" ) {
                RDF_ParseTypeLiteralPropertyElement ( xmpParent, xmlNode, isTopLevel );
            } else if ( attrValue == "Resource" ) {
                RDF_ParseTypeResourcePropertyElement ( xmpParent, xmlNode, isTopLevel );
            } else if ( attrValue == "Collection" ) {
                RDF_ParseTypeCollectionPropertyElement ( xmpParent, xmlNode, isTopLevel );
            } else {
                RDF_ParseTypeOtherPropertyElement ( xmpParent, xmlNode, isTopLevel );
            }

        } else {

            // Only rdf:ID and xml:lang, could be a resourcePropertyElt, a literalPropertyElt, or an.
            // emptyPropertyElt. Look at the child XML nodes to decide which.

            if ( xmlNode.content.empty() ) {

                RDF_EmptyPropertyElement ( xmpParent, xmlNode, isTopLevel );

            } else {

                XML_cNodePos currChild = xmlNode.content.begin();
                XML_cNodePos endChild  = xmlNode.content.end();

                for ( ; currChild != endChild; ++currChild ) {
                    if ( (*currChild)->kind != kCDataNode ) break;
                }

                if ( currChild == endChild ) {
                    RDF_LiteralPropertyElement ( xmpParent, xmlNode, isTopLevel );
                } else {
                    RDF_ResourcePropertyElement ( xmpParent, xmlNode, isTopLevel );
                }

            }

        }

    }

}	// RDF_PropertyElement


// =================================================================================================
// RDF_ResourcePropertyElement
// ===========================
//
// 7.2.15 resourcePropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr? ) )
//		ws* nodeElement ws*
//		end-element()
//
// This handles structs using an rdf:Description node, arrays using rdf:Bag/Seq/Alt, and typedNodes.
// It also catches and cleans up qualified properties written with rdf:Description and rdf:value.

static void
RDF_ResourcePropertyElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel )
{
    if ( isTopLevel && (xmlNode.name == "iX:changes") ) return;	// Strip old "punchcard" chaff.

    XMP_Node * newCompound = AddChildNode ( xmpParent, xmlNode, "", isTopLevel );

    XML_cNodePos currAttr = xmlNode.attrs.begin();
    XML_cNodePos endAttr  = xmlNode.attrs.end();

    for ( ; currAttr != endAttr; ++currAttr ) {
        XMP_VarString & attrName = (*currAttr)->name;
        if ( attrName == "xml:lang" ) {
            AddQualifierNode ( newCompound, **currAttr );
        } else if ( attrName == "rdf:ID" ) {
            continue;	// Ignore all rdf:ID attributes.
        } else {
            XMP_Throw ( "Invalid attribute for resource property element", kXMPErr_BadRDF );
        }
    }

    XML_cNodePos currChild = xmlNode.content.begin();
    XML_cNodePos endChild  = xmlNode.content.end();

    for ( ; currChild != endChild; ++currChild ) {
        if ( ! (*currChild)->IsWhitespaceNode() ) break;
    }
    if ( currChild == endChild ) XMP_Throw ( "Missing child of resource property element", kXMPErr_BadRDF );
    if ( (*currChild)->kind != kElemNode ) XMP_Throw ( "Children of resource property element must be XML elements", kXMPErr_BadRDF );

    if ( (*currChild)->name == "rdf:Bag" ) {
        newCompound->options |= kXMP_PropValueIsArray;
    } else if ( (*currChild)->name == "rdf:Seq" ) {
        newCompound->options |= kXMP_PropValueIsArray | kXMP_PropArrayIsOrdered;
    } else if ( (*currChild)->name == "rdf:Alt" ) {
        newCompound->options |= kXMP_PropValueIsArray | kXMP_PropArrayIsOrdered | kXMP_PropArrayIsAlternate;
    } else {
        newCompound->options |= kXMP_PropValueIsStruct;
        if ( (*currChild)->name != "rdf:Description" ) {
            XMP_VarString typeName ( (*currChild)->ns );
            size_t        colonPos = (*currChild)->name.find_first_of(':');
            if ( colonPos == XMP_VarString::npos ) XMP_Throw ( "All XML elements must be in a namespace", kXMPErr_BadXMP );
            typeName.append ( (*currChild)->name, colonPos, XMP_VarString::npos );
            AddQualifierNode ( newCompound, XMP_VarString("rdf:type"), typeName );
        }
    }

    RDF_NodeElement ( newCompound, **currChild, kNotTopLevel );
    if ( newCompound->options & kRDF_HasValueElem ) {
        FixupQualifiedNode ( newCompound );
    } else if ( newCompound->options & kXMP_PropArrayIsAlternate ) {
        DetectAltText ( newCompound );
    }

    for ( ++currChild; currChild != endChild; ++currChild ) {
        if ( ! (*currChild)->IsWhitespaceNode() ) XMP_Throw ( "Invalid child of resource property element", kXMPErr_BadRDF );
    }

}	// RDF_ResourcePropertyElement


// =================================================================================================
// RDF_LiteralPropertyElement
// ==========================
//
// 7.2.16 literalPropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr?, datatypeAttr?) )
//		text()
//		end-element()
//
// Add a leaf node with the text value and qualifiers for the attributes.

static void
RDF_LiteralPropertyElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel )
{
    XMP_Node * newChild = AddChildNode ( xmpParent, xmlNode, "", isTopLevel );

    XML_cNodePos currAttr = xmlNode.attrs.begin();
    XML_cNodePos endAttr  = xmlNode.attrs.end();

    for ( ; currAttr != endAttr; ++currAttr ) {
        XMP_VarString & attrName = (*currAttr)->name;
        if ( attrName == "xml:lang" ) {
            AddQualifierNode ( newChild, **currAttr );
        } else if ( (attrName == "rdf:ID") || (attrName == "rdf:datatype") ) {
            continue;	// Ignore all rdf:ID and rdf:datatype attributes.
        } else {
            XMP_Throw ( "Invalid attribute for literal property element", kXMPErr_BadRDF );
        }
    }

    XML_cNodePos currChild = xmlNode.content.begin();
    XML_cNodePos endChild  = xmlNode.content.end();
    size_t      textSize  = 0;

    for ( ; currChild != endChild; ++currChild ) {
        if ( (*currChild)->kind != kCDataNode ) XMP_Throw ( "Invalid child of literal property element", kXMPErr_BadRDF );
        textSize += (*currChild)->value.size();
    }

    newChild->value.reserve ( textSize );

    for ( currChild = xmlNode.content.begin(); currChild != endChild; ++currChild ) {
        newChild->value += (*currChild)->value;
    }

    #if 0	// *** XMP_DebugBuild
        newChild->_valuePtr = newChild->value.c_str();
    #endif

}	// RDF_LiteralPropertyElement


// =================================================================================================
// RDF_ParseTypeLiteralPropertyElement
// ===================================
//
// 7.2.17 parseTypeLiteralPropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr?, parseLiteral ) )
//		literal
//		end-element()

static void
RDF_ParseTypeLiteralPropertyElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel )
{
    IgnoreParam(xmpParent); IgnoreParam(xmlNode); IgnoreParam(isTopLevel);

    XMP_Throw ( "ParseTypeLiteral property element not allowed", kXMPErr_BadXMP );

}	// RDF_ParseTypeLiteralPropertyElement


// =================================================================================================
// RDF_ParseTypeResourcePropertyElement
// ====================================
//
// 7.2.18 parseTypeResourcePropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr?, parseResource ) )
//		propertyEltList
//		end-element()
//
// Add a new struct node with a qualifier for the possible rdf:ID attribute. Then process the XML
// child nodes to get the struct fields.

static void
RDF_ParseTypeResourcePropertyElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel )
{

    XMP_Node * newStruct = AddChildNode ( xmpParent, xmlNode, "", isTopLevel );
    newStruct->options  |= kXMP_PropValueIsStruct;

    XML_cNodePos currAttr = xmlNode.attrs.begin();
    XML_cNodePos endAttr  = xmlNode.attrs.end();

    for ( ; currAttr != endAttr; ++currAttr ) {
        XMP_VarString & attrName = (*currAttr)->name;
        if ( attrName == "rdf:parseType" ) {
            continue;	// ! The caller ensured the value is "Resource".
        } else if ( attrName == "xml:lang" ) {
            AddQualifierNode ( newStruct, **currAttr );
        } else if ( attrName == "rdf:ID" ) {
            continue;	// Ignore all rdf:ID attributes.
        } else {
            XMP_Throw ( "Invalid attribute for ParseTypeResource property element", kXMPErr_BadRDF );
        }
    }

    RDF_PropertyElementList ( newStruct, xmlNode, kNotTopLevel );

    if ( newStruct->options & kRDF_HasValueElem ) FixupQualifiedNode ( newStruct );

    // *** Need to look for arrays using rdf:Description and rdf:type.

}	// RDF_ParseTypeResourcePropertyElement


// =================================================================================================
// RDF_ParseTypeCollectionPropertyElement
// ======================================
//
// 7.2.19 parseTypeCollectionPropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr?, parseCollection ) )
//		nodeElementList
//		end-element()

static void
RDF_ParseTypeCollectionPropertyElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel )
{
    IgnoreParam(xmpParent); IgnoreParam(xmlNode); IgnoreParam(isTopLevel);

    XMP_Throw ( "ParseTypeCollection property element not allowed", kXMPErr_BadXMP );

}	// RDF_ParseTypeCollectionPropertyElement


// =================================================================================================
// RDF_ParseTypeOtherPropertyElement
// =================================
//
// 7.2.20 parseTypeOtherPropertyElt
//		start-element ( URI == propertyElementURIs, attributes == set ( idAttr?, parseOther ) )
//		propertyEltList
//		end-element()

static void
RDF_ParseTypeOtherPropertyElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel )
{
    IgnoreParam(xmpParent); IgnoreParam(xmlNode); IgnoreParam(isTopLevel);

    XMP_Throw ( "ParseTypeOther property element not allowed", kXMPErr_BadXMP );

}	// RDF_ParseTypeOtherPropertyElement


// =================================================================================================
// RDF_EmptyPropertyElement
// ========================
//
// 7.2.21 emptyPropertyElt
//		start-element ( URI == propertyElementURIs,
//						attributes == set ( idAttr?, ( resourceAttr | nodeIdAttr )?, propertyAttr* ) )
//		end-element()
//
//	<ns:Prop1/>  <!-- a simple property with an empty value -->
//	<ns:Prop2 rdf:resource="http://www.adobe.com/"/> <!-- a URI value -->
//	<ns:Prop3 rdf:value="..." ns:Qual="..."/> <!-- a simple qualified property -->
//	<ns:Prop4 ns:Field1="..." ns:Field2="..."/> <!-- a struct with simple fields -->
//
// An emptyPropertyElt is an element with no contained content, just a possibly empty set of
// attributes. An emptyPropertyElt can represent three special cases of simple XMP properties: a
// simple property with an empty value (ns:Prop1), a simple property whose value is a URI
// (ns:Prop2), or a simple property with simple qualifiers (ns:Prop3). An emptyPropertyElt can also
// represent an XMP struct whose fields are all simple and unqualified (ns:Prop4).
//
// It is an error to use both rdf:value and rdf:resource - that can lead to invalid  RDF in the
// verbose form written using a literalPropertyElt.
//
// The XMP mapping for an emptyPropertyElt is a bit different from generic RDF, partly for
// design reasons and partly for historical reasons. The XMP mapping rules are:
//	1. If there is an rdf:value attribute then this is a simple property with a text value.
//		All other attributes are qualifiers.
//	2. If there is an rdf:resource attribute then this is a simple property with a URI value.
//		All other attributes are qualifiers.
//	3. If there are no attributes other than xml:lang, rdf:ID, or rdf:nodeID then this is a simple
//		property with an empty value.
//	4. Otherwise this is a struct, the attributes other than xml:lang, rdf:ID, or rdf:nodeID are fields.

static void
RDF_EmptyPropertyElement ( XMP_Node * xmpParent, const XML_Node & xmlNode, bool isTopLevel )
{
    bool hasPropertyAttrs = false;
    bool hasResourceAttr  = false;
    bool hasNodeIDAttr    = false;
    bool hasValueAttr     = false;

    const XML_Node * valueNode = 0;	// ! Can come from rdf:value or rdf:resource.

    if ( ! xmlNode.content.empty() ) XMP_Throw ( "Nested content not allowed with rdf:resource or property attributes", kXMPErr_BadRDF );

    // First figure out what XMP this maps to and remember the XML node for a simple value.

    XML_cNodePos currAttr = xmlNode.attrs.begin();
    XML_cNodePos endAttr  = xmlNode.attrs.end();

    for ( ; currAttr != endAttr; ++currAttr ) {

        RDFTermKind attrTerm = GetRDFTermKind ( (*currAttr)->name );

        switch ( attrTerm ) {

            case kRDFTerm_ID :
                // Nothing to do.
                break;

            case kRDFTerm_resource :
                if ( hasNodeIDAttr ) XMP_Throw ( "Empty property element can't have both rdf:resource and rdf:nodeID", kXMPErr_BadRDF );
                if ( hasValueAttr ) XMP_Throw ( "Empty property element can't have both rdf:value and rdf:resource", kXMPErr_BadXMP );
                hasResourceAttr = true;
                if ( ! hasValueAttr ) valueNode = *currAttr;
                break;

            case kRDFTerm_nodeID :
                if ( hasResourceAttr ) XMP_Throw ( "Empty property element can't have both rdf:resource and rdf:nodeID", kXMPErr_BadRDF );
                hasNodeIDAttr = true;
                break;

            case kRDFTerm_Other :
                if ( (*currAttr)->name == "rdf:value" ) {
                    if ( hasResourceAttr ) XMP_Throw ( "Empty property element can't have both rdf:value and rdf:resource", kXMPErr_BadXMP );
                    hasValueAttr = true;
                    valueNode = *currAttr;
                } else if ( (*currAttr)->name != "xml:lang" ) {
                    hasPropertyAttrs = true;
                }
                break;

            default :
                XMP_Throw ( "Unrecognized attribute of empty property element", kXMPErr_BadRDF );
                break;

        }

    }

    // Create the right kind of child node and visit the attributes again to add the fields or qualifiers.
    // ! Because of implementation vagaries, the xmpParent is the tree root for top level properties.
    // ! The schema is found, created if necessary, by AddChildNode.

    XMP_Node * childNode = AddChildNode ( xmpParent, xmlNode, "", isTopLevel );
    bool childIsStruct = false;

    if ( hasValueAttr | hasResourceAttr ) {
        childNode->value = valueNode->value;
        if ( ! hasValueAttr ) childNode->options |= kXMP_PropValueIsURI;	// ! Might have both rdf:value and rdf:resource.
    } else if ( hasPropertyAttrs ) {
        childNode->options |= kXMP_PropValueIsStruct;
        childIsStruct = true;
    }

    currAttr = xmlNode.attrs.begin();
    endAttr  = xmlNode.attrs.end();

    for ( ; currAttr != endAttr; ++currAttr ) {

        if ( *currAttr == valueNode ) continue;	// Skip the rdf:value or rdf:resource attribute holding the value.
        RDFTermKind attrTerm = GetRDFTermKind ( (*currAttr)->name );

        switch ( attrTerm ) {

            case kRDFTerm_ID       :
            case kRDFTerm_nodeID   :
                break;	// Ignore all rdf:ID and rdf:nodeID attributes.w

            case kRDFTerm_resource :
                AddQualifierNode ( childNode, **currAttr );
                break;

            case kRDFTerm_Other :
                if ( (! childIsStruct) || (*currAttr)->name == "xml:lang" ) {
                    AddQualifierNode ( childNode, **currAttr );
                } else {
                    AddChildNode ( childNode, **currAttr, (*currAttr)->value.c_str(), false );
                }
                break;

            default :
                XMP_Throw ( "Unrecognized attribute of empty property element", kXMPErr_BadRDF );
                break;

        }

    }

}	// RDF_EmptyPropertyElement

} // namespace DngXmpSdk
// =================================================================================================
