DB2.sml

# DB2.SML
# Sample script for tutorial "Writing Scripts with SML".
# Illustrates creating database table, fields,
# and attaching records.

# Script creates a new vector with implied georeference
# read from the input vector. A point database table called
# "SoilTypes" is created for the new vector with fields
# "SYMBOL" (string), "SOIL" (string), and "WHEAT_YLD"
# (integer).  In the main processing loop the script reads
# centroid location for each polygon in the input vector
# and creates a point at that location. The value for the
# SYMBOL field is read from the Class polygon table, the
# value for the SOIL field is read from the DESCRIPTN polygon
# table, and the value for the WHEAT_YLD field is read from 
# the YIELD polygon table.  These values are read into a new
# record for the SoilTypes table and the record is
# attached to the current vector point.

### Declarations
class VECTOR VectIn, VectOut;

clear();
PopupMessage("Select / CB_DATA / CB_SOILS.RVC / CBSOILS_Lite" );

### Get input vector object with polygons.
GetInputVector(VectIn);

### Get georeference parameters for input vector.
class GEOREF georefV;
georefV = GetLastUsedGeorefObject( VectIn );

### Get information about "DESCRIPTN" polygon table;
### This is needed later to check if attached records exist.
class DATABASE polydb;					# handle for polygon database.
polydb = OpenVectorPolyDatabase( VectIn );
class DBTABLEINFO descriptn;			# handle for DESCRIPT table.
descriptn = TableGetInfo( VectIn.poly.DESCRIPTN );

### Get new output vector object initialized for use with
### with the Vector Toolkit, and create implied 
### georeference using parameters from input vector.
GetOutputVector( VectOut, "VectorToolkit,Planar" );
CreateImpliedGeoref( VectOut, georefV.Projection );

# Create point database for VectOut.
class DATABASE pdb;							# handle for point database
pdb = OpenVectorPointDatabase( VectOut );

# Create blank table "SoilTypes" in point database.
class DBTABLEINFO soiltype;				# handle for table
soiltype = TableCreate(pdb,"SoilTypes","Table created by SML script");
soiltype.OneRecordPerElement = 1;  		# set attachment type for records

# Create string field "SYMBOL" in "SoilTypes".
class DBFIELDINFO symbol;					# handle for field
symbol = TableAddFieldString(soiltype,"SYMBOL",6,6);

# Create string field "SOIL" in "SoilTypes".
class DBFIELDINFO soil;						# handle for field
soil = TableAddFieldString(soiltype,"SOIL",80,80);

# Create integer field "WHEAT_YLD" in "SoilTypes".
class DBFIELDINFO wheat;					# handle for field
wheat = TableAddFieldInteger(soiltype,"WHEAT_YLD",10);

array numeric polyrecords[1]; 	# array to hold polygon record number
array numeric ptrecords[1];		# array to hold point record number for attachment.

numeric numpolys;					# number of polygons in input vector
numeric i;							# counter for processing loop
string soil$;						# value for soil field
numeric wheatnum;					# value for wheat field
string symbol$;					# value for symbol field
numeric x, y;						# object coordinates of polygon centroid
numeric mapX, mapY;				# map coordinates of polygon centroid
numeric pointnum;					# counter for number of points added to outut vector
numeric recordnum;				# record number created by TableNewRecord() function call

numpolys = NumVectorPolys(VectIn);

# Main processing loop
for i = 1 to numpolys {
	soil$ = "";
	wheatnum = 0;

	x = VectIn.poly[i].POLYSTATS.CentX;
	y = VectIn.poly[i].POLYSTATS.CentY;
	ObjectToMap( VectIn, x, y, georefV, mapX, mapY );

	VectorAddPoint( VectOut, mapX, mapY );
	pointnum = pointnum + 1;

	symbol$ = VectIn.poly[i].CLASS.Class$;

	# polygons in WATER class don't have records in the
	# DESCRIPTN and YIELD tables so check for attached
	# record before trying to read values.

	if (TableReadAttachment( descriptn, i, polyrecords) > 0 ) {
		soil$ = VectIn.poly[i].DESCRIPTN.NAME$;
		wheatnum = VectIn.poly[i].YIELD.WHEAT;
	}

	# Create new record in SoilType table with current field
	# values.
	recordnum = TableNewRecord( soiltype, symbol$, soil$, wheatnum );
	ptrecords[1] = recordnum;

	# Attach this new record to current point element.
	TableWriteAttachment( soiltype, pointnum, ptrecords, 1, "point");
}
VectorValidate (VectOut);
print(TableReadFieldStr(soiltype, "SOIL", 371)); # Internal Automated Tests Check
CloseVector( VectOut );
# End