CppReflect.cpp

#include "CppReflect.h"
#include "pugixml\pugixml.hpp"          //pugi::xml_node

using namespace pugi;

//
//  Serializes class instance to xml node.
//
void DataToNode( xml_node& _node, void* pclass, CppTypeInfo& type )
{
    USES_CONVERSION;
    xml_node& node = _node.append_child( CA2W( type.name ) );

    for each (FieldInfo fi in type.fields)
    {
        void* p = ((char*)pclass) + fi.offset;
        CppTypeInfo* arrayType = nullptr;

        if( !fi.fieldType->GetArrayElementType( arrayType ) )
        {
            // Simple type, append as attribute.
            CStringW s = fi.fieldType->ToString( p );
            if( s.GetLength() )     // Don't serialize empty values.
                node.append_attribute( CA2W( fi.name ) ) = s;
            continue;
        }

        if( !arrayType )
            continue;

        xml_node& fieldNode = node.append_child( CA2W( fi.name ) );

        size_t size = fi.fieldType->ArraySize( p );
        for( size_t i = 0; i < size; i++ )
        {
            void* pstr2 = fi.fieldType->ArrayElement( p, i );
            DataToNode( fieldNode, pstr2, *arrayType );
        }
    } //for each
} //DataToNode

//  Helper class.
struct xml_string_writer : xml_writer
{
    CStringA result;
    virtual void write( const void* data, size_t size )
    {
        result += CStringA( (const char*)data, (int)size );
    }
};

CStringA ToXML_UTF8( void* pclass, CppTypeInfo& type )
{
    xml_document doc;
    xml_node decl = doc.prepend_child( pugi::node_declaration );
    decl.append_attribute( _T( "version" ) ) = _T( "1.0" );
    decl.append_attribute( _T( "encoding" ) ) = _T( "utf-8" );
    DataToNode( doc, pclass, type );

    xml_string_writer writer;
    doc.save( writer );
    return writer.result;
}

CStringW ToXML( void* pclass, CppTypeInfo& type )
{
    xml_document doc;
    xml_node decl = doc.prepend_child( pugi::node_declaration );
    decl.append_attribute( _T( "version" ) ) = _T( "1.0" );
    decl.append_attribute( _T( "encoding" ) ) = _T( "utf-8" );
    DataToNode( doc, pclass, type );

    xml_string_writer writer;
    doc.save( writer );
    return CStringW(CA2T(writer.result, CP_UTF8));
}


//
//  Deserializes xml to class structure, returns true if succeeded, false if fails.
//  error holds error information if any.
//
bool NodeToData( xml_node& node, void* pclass, CppTypeInfo& type, CStringW& error )
{
    CStringA name = node.name();

    if( type.name != name )
    {
        error.AppendFormat( _T( "Expected xml tag '%S', but found '%S' instead" ), type.name.GetBuffer(), name.GetBuffer() );
        return false;
    }

    for each (FieldInfo fi in type.fields)
    {
        void* p = ((char*)pclass) + fi.offset;
        CppTypeInfo* arrayType = nullptr;

        if( !fi.fieldType->GetArrayElementType( arrayType ) )
        {
            // Simple type, query from attribute value.
            xml_attribute& attr = node.attribute( CA2W( fi.name ) );
            fi.fieldType->FromString( p, attr.value() );
            continue;
        }

        if( !arrayType )
            continue;

        xml_node& fieldNode = node.child( CA2W( fi.name ) );
        if( fieldNode.empty() )
            continue;

        int size = 0;
        for( auto it = fieldNode.children().begin(); it != fieldNode.children().end(); it++ )
            size++;

        fi.fieldType->SetArraySize( p, size );
        int i = 0;
        for( auto it = fieldNode.children().begin(); it != fieldNode.children().end(); it++ )
        {
            void* pstr2 = fi.fieldType->ArrayElement( p, i );
            if( !NodeToData( *it, pstr2, *arrayType, error ) )
                return false;
            i++;
        }
    } //for each

    return true;
} //NodeToData

bool FromXml( void* pclass, CppTypeInfo& type, const wchar_t* xml, CStringW& error )
{
    xml_document doc2;

    xml_parse_result res = doc2.load_string( xml );
    if( !res )
    {
        error = L"Failed to load xml: ";
        error += res.description();
        return false;
    }

    return NodeToData( doc2.first_child(), pclass, type, error );
}