/// <summary>
/// Convert the first PostGis Geometry column or the column specified by geomOrdinal into the corresponding NetTopologyGeometry
/// Can throw the following Exceptions
/// - ArgumentNullException
/// - InvalidCastException in case of SRID not compatible for example.
/// - NotImplementedException if no converter is avaialble for this type.
/// </summary>
/// <param name="pgCursor">The cursor where to look for the Geometry column</param>
/// <param name="geomOrdinal">optionnal, geom. column index if known, otherwise will be search for.</param>
/// <returns>the NetTopology geometry equivalent.</returns>
public static Geometry ConvertFrom(IFieldValueGetter pgCursor, int?geomOrdinal = null)
{
Geometry retour = null;
if (pgCursor != null)
{
PostgisGeometry geometry = pgCursor.GetFieldValue <PostgisGeometry>(GetGeomtryColumnIndex(pgCursor, geomOrdinal));
if (geometry is PostgisPoint)
{
retour = ProcessPoint((PostgisPoint)geometry);
}
else if (geometry is PostgisMultiPoint)
{
retour = ProcessMultiPoint((PostgisMultiPoint)geometry);
}
else if (geometry is PostgisLineString)
{
retour = ProcessLineString((PostgisLineString)geometry);
}
else if (geometry is PostgisMultiLineString)
{
retour = ProcessMultiLineString((PostgisMultiLineString)geometry);
}
else if (geometry is PostgisPolygon)
{
retour = ProcessPolygon((PostgisPolygon)geometry);
}
else if (geometry is PostgisMultiPolygon)
{
retour = ProcessMultiPolygon((PostgisMultiPolygon)geometry);
}
else
{
throw new NotImplementedException();
}
SetSRID(retour, geometry);
}
else
{
throw new ArgumentNullException();
}
return(retour);
}
/// <summary>
/// 1- Check, if geomOrdinal is not null, it is corresponding to a Geom column type. Throw InvalidCastException if type is not geometry or IndexOutOfRangeException if not in column's range.
/// 2- Else, iterate from 0 to end the cursor columns and return as soon as a geometry column is found. If no column exists throw ArgumentOutOfRangeException
/// Throw ArgumentNullException if any of input marameter is null.
/// </summary>
/// <param name="pgCursor">a DB Cursor where to search a geometry column. Must be compatible with PostGIS.</param>
/// <param name="geomOrdinal">if not null, use to convert directly this field into NetTopologyGeometry, otherwise look for column indice one to the end.</param>
/// <returns>the index of geometry column in the cursor.</returns>
private static int GetGeomtryColumnIndex(IFieldValueGetter pgCursor, int?geomOrdinal)
{
if (pgCursor != null)
{
int cursorFieldCount = pgCursor.FieldCount;
//1-
if (geomOrdinal != null)
{
if (geomOrdinal >= 0 && geomOrdinal < cursorFieldCount)
{
if (IsGeomColumn(pgCursor.GetPostgresType(geomOrdinal.Value)))
{
return(geomOrdinal.Value);
}
else
{
throw new InvalidCastException();
}
}
else
{
throw new ArgumentOutOfRangeException();
}
}
//2-
else
{
for (int i = 0; i < cursorFieldCount; i++)
{
if (IsGeomColumn(pgCursor.GetPostgresType(i)))
{
return(i);
}
}
throw new ArgumentOutOfRangeException();
}
}
else
{
throw new ArgumentNullException();
}
}