int OGRNASDataSource::Open( const char * pszNewName )
{
poReader = CreateNASReader();
if( poReader == NULL )
{
CPLError( CE_Failure, CPLE_AppDefined,
"File %s appears to be NAS but the NAS reader cannot\n"
"be instantiated, likely because Xerces support was not\n"
"configured in.",
pszNewName );
return FALSE;
}
poReader->SetSourceFile( pszNewName );
pszName = CPLStrdup( pszNewName );
/* -------------------------------------------------------------------- */
/* Can we find a NAS Feature Schema (.gfs) for the input file? */
/* -------------------------------------------------------------------- */
bool bHaveSchema = false;
const char *pszGFSFilename = CPLResetExtension( pszNewName, "gfs" );
VSIStatBuf sGFSStatBuf;
if( CPLStat( pszGFSFilename, &sGFSStatBuf ) == 0 )
{
VSIStatBuf sNASStatBuf;
if( CPLStat( pszNewName, &sNASStatBuf ) == 0 &&
sNASStatBuf.st_mtime > sGFSStatBuf.st_mtime )
{
CPLDebug( "NAS",
"Found %s but ignoring because it appears\n"
"be older than the associated NAS file.",
pszGFSFilename );
}
else
{
bHaveSchema = poReader->LoadClasses( pszGFSFilename );
}
}
/* -------------------------------------------------------------------- */
/* Force a first pass to establish the schema. Eventually we */
/* will have mechanisms for remembering the schema and related */
/* information. */
/* -------------------------------------------------------------------- */
CPLErrorReset();
if( !bHaveSchema
&& !poReader->PrescanForSchema( TRUE )
&& CPLGetLastErrorType() == CE_Failure )
{
// Assume an error has been reported.
return FALSE;
}
/* -------------------------------------------------------------------- */
/* Save the schema file if possible. Do not make a fuss if we */
/* cannot. It could be read-only directory or something. */
/* -------------------------------------------------------------------- */
if( !bHaveSchema && poReader->GetClassCount() > 0 )
{
FILE *fp = NULL;
pszGFSFilename = CPLResetExtension( pszNewName, "gfs" );
if( CPLStat( pszGFSFilename, &sGFSStatBuf ) != 0
&& (fp = VSIFOpen( pszGFSFilename, "wt" )) != NULL )
{
VSIFClose( fp );
poReader->SaveClasses( pszGFSFilename );
}
else
{
CPLDebug( "NAS",
"Not saving %s files already exists or can't be created.",
pszGFSFilename );
}
}
/* -------------------------------------------------------------------- */
/* Translate the NASFeatureClasses into layers. */
/* -------------------------------------------------------------------- */
papoLayers = (OGRLayer **)
CPLCalloc( sizeof(OGRNASLayer *), poReader->GetClassCount()+1 );
nLayers = 0;
while( nLayers < poReader->GetClassCount() )
{
papoLayers[nLayers] = TranslateNASSchema(poReader->GetClass(nLayers));
nLayers++;
}
poRelationLayer = new OGRNASRelationLayer( this );
// keep delete the last layer
if( nLayers>0 && EQUAL( papoLayers[nLayers-1]->GetName(), "Delete" ) )
{
papoLayers[nLayers] = papoLayers[nLayers-1];
papoLayers[nLayers-1] = poRelationLayer;
}
else
{
papoLayers[nLayers] = poRelationLayer;
}
nLayers++;
return TRUE;
}
int OGRNASDataSource::Open( const char * pszNewName, int bTestOpen )
{
FILE *fp;
char szHeader[8192];
/* -------------------------------------------------------------------- */
/* Open the source file. */
/* -------------------------------------------------------------------- */
fp = VSIFOpen( pszNewName, "r" );
if( fp == NULL )
{
if( !bTestOpen )
CPLError( CE_Failure, CPLE_OpenFailed,
"Failed to open NAS file `%s'.",
pszNewName );
return FALSE;
}
/* -------------------------------------------------------------------- */
/* If we aren't sure it is NAS, load a header chunk and check */
/* for signs it is NAS */
/* -------------------------------------------------------------------- */
if( bTestOpen )
{
size_t nRead = VSIFRead( szHeader, 1, sizeof(szHeader), fp );
if (nRead <= 0)
{
VSIFClose( fp );
return FALSE;
}
szHeader[MIN(nRead, sizeof(szHeader))-1] = '\0';
/* -------------------------------------------------------------------- */
/* Check for a UTF-8 BOM and skip if found */
/* */
/* TODO: BOM is variable-lenght parameter and depends on encoding. */
/* Add BOM detection for other encodings. */
/* -------------------------------------------------------------------- */
// Used to skip to actual beginning of XML data
char* szPtr = szHeader;
if( ( (unsigned char)szHeader[0] == 0xEF )
&& ( (unsigned char)szHeader[1] == 0xBB )
&& ( (unsigned char)szHeader[2] == 0xBF) )
{
szPtr += 3;
}
/* -------------------------------------------------------------------- */
/* Here, we expect the opening chevrons of NAS tree root element */
/* -------------------------------------------------------------------- */
if( szPtr[0] != '<'
|| strstr(szPtr,"opengis.net/gml") == NULL
|| strstr(szPtr,"NAS-Operationen.xsd") == NULL )
{
VSIFClose( fp );
return FALSE;
}
}
/* -------------------------------------------------------------------- */
/* We assume now that it is NAS. Close and instantiate a */
/* NASReader on it. */
/* -------------------------------------------------------------------- */
VSIFClose( fp );
poReader = CreateNASReader();
if( poReader == NULL )
{
CPLError( CE_Failure, CPLE_AppDefined,
"File %s appears to be NAS but the NAS reader can't\n"
"be instantiated, likely because Xerces support wasn't\n"
"configured in.",
pszNewName );
return FALSE;
}
poReader->SetSourceFile( pszNewName );
pszName = CPLStrdup( pszNewName );
/* -------------------------------------------------------------------- */
/* Can we find a NAS Feature Schema (.gfs) for the input file? */
/* -------------------------------------------------------------------- */
const char *pszGFSFilename;
VSIStatBuf sGFSStatBuf, sNASStatBuf;
int bHaveSchema = FALSE;
pszGFSFilename = CPLResetExtension( pszNewName, "gfs" );
if( CPLStat( pszGFSFilename, &sGFSStatBuf ) == 0 )
{
CPLStat( pszNewName, &sNASStatBuf );
if( sNASStatBuf.st_mtime > sGFSStatBuf.st_mtime )
{
CPLDebug( "NAS",
"Found %s but ignoring because it appears\n"
"be older than the associated NAS file.",
pszGFSFilename );
}
else
{
bHaveSchema = poReader->LoadClasses( pszGFSFilename );
}
}
/* -------------------------------------------------------------------- */
/* Force a first pass to establish the schema. Eventually we */
/* will have mechanisms for remembering the schema and related */
/* information. */
/* -------------------------------------------------------------------- */
if( !bHaveSchema && !poReader->PrescanForSchema( TRUE ) )
{
// we assume an errors have been reported.
return FALSE;
}
/* -------------------------------------------------------------------- */
/* Save the schema file if possible. Don't make a fuss if we */
/* can't ... could be read-only directory or something. */
/* -------------------------------------------------------------------- */
if( !bHaveSchema )
{
FILE *fp = NULL;
pszGFSFilename = CPLResetExtension( pszNewName, "gfs" );
if( CPLStat( pszGFSFilename, &sGFSStatBuf ) != 0
&& (fp = VSIFOpen( pszGFSFilename, "wt" )) != NULL )
{
VSIFClose( fp );
poReader->SaveClasses( pszGFSFilename );
}
else
{
CPLDebug("NAS",
"Not saving %s files already exists or can't be created.",
pszGFSFilename );
}
}
/* -------------------------------------------------------------------- */
/* Translate the NASFeatureClasses into layers. */
/* -------------------------------------------------------------------- */
papoLayers = (OGRLayer **)
CPLCalloc( sizeof(OGRNASLayer *), poReader->GetClassCount()+1 );
nLayers = 0;
while( nLayers < poReader->GetClassCount() )
{
papoLayers[nLayers] = TranslateNASSchema(poReader->GetClass(nLayers));
nLayers++;
}
poRelationLayer = new OGRNASRelationLayer( this );
papoLayers[nLayers++] = poRelationLayer;
return TRUE;
}