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/****************************************************************
*
* MODULE: v.example
*
* AUTHOR(S): GRASS Development Team, Radim Blazek, Maris Nartiss
*
* PURPOSE: copies vector data from source map to destination map
* prints out all point coordinates and attributes
*
* COPYRIGHT: (C) 2002-2009 by the GRASS Development Team
*
* This program is free software under the
* GNU General Public License (>=v2).
* Read the file COPYING that comes with GRASS
* for details.
*
****************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <grass/gis.h>
#include <grass/vector.h>
#include <grass/dbmi.h>
#include <grass/glocale.h>
int main(int argc, char *argv[])
{
struct Map_info In, Out;
static struct line_pnts *Points;
struct line_cats *Cats;
int i, type, cat, ncols, nrows, col, more, open3d;
char *mapset, sql[200];
struct GModule *module; /* GRASS module for parsing arguments */
struct Option *old, *new;
dbDriver *driver;
dbHandle handle;
dbCursor cursor;
dbTable *table;
dbColumn *column;
dbString table_name, dbsql, valstr;
struct field_info *Fi, *Fin;
/* initialize GIS environment */
/* reads grass env, stores program name to G_program_name() */
G_gisinit(argv[0]);
/* initialize module */
module = G_define_module();
G_add_keyword(_("vector"));
G_add_keyword(_("keyword2"));
G_add_keyword(_("keyword3"));
module->description = _("My first vector module");
/* Define the different options as defined in gis.h */
old = G_define_standard_option(G_OPT_V_INPUT);
new = G_define_standard_option(G_OPT_V_OUTPUT);
/* options and flags parser */
if (G_parser(argc, argv))
exit(EXIT_FAILURE);
/* Create and initialize struct's where to store
points/lines and categories
*/
Points = Vect_new_line_struct();
Cats = Vect_new_cats_struct();
/* Check 1) output is legal vector name; 2) if can find input map;
3) if input was found in current mapset, check if input != output.
lib/vector/Vlib/legal_vname.c
*/
Vect_check_input_output_name(old->answer, new->answer, G_FATAL_EXIT);
if ((mapset = (char *)G_find_vector2(old->answer, "")) == NULL)
G_fatal_error(_("Vector map <%s> not found"), old->answer);
/* Predetermine level at which a map will be opened for reading
lib/vector/Vlib/open.c
*/
if (Vect_set_open_level(2))
G_fatal_error(_("Unable to set predetermined vector open level"));
/* Open existing vector for reading
lib/vector/Vlib/open.c
*/
if (1 > Vect_open_old(&In, old->answer, mapset))
G_fatal_error(_("Unable to open vector map <%s>"), old->answer);
/* Check if old vector is 3D. We should preserve 3D data. */
if (Vect_is_3d(&In))
open3d = WITH_Z;
else
open3d = WITHOUT_Z;
/* Set error handler for input vector map */
Vect_set_error_handler_io(&In, NULL);
/* Open new vector for reading/writing */
if (0 > Vect_open_new(&Out, new->answer, open3d)) {
G_fatal_error(_("Unable to create vector map <%s>"), new->answer);
}
/* Set error handler for output vector map */
Vect_set_error_handler_io(NULL, &Out);
/* Let's get vector layers db connections information */
Fi = Vect_get_field(&In, 1);
if (!Fi) {
G_fatal_error(_("Database connection not defined for layer %d"), 1);
}
/* Output information useful for debugging
include/vect/dig_structs.h
*/
G_debug(1,
"Field number:%d; Name:<%s>; Driver:<%s>; Database:<%s>; "
"Table:<%s>; Key:<%s>;\n",
Fi->number, Fi->name, Fi->driver, Fi->database, Fi->table, Fi->key);
/* Prepeare strings for use in db_* calls */
db_init_string(&dbsql);
db_init_string(&valstr);
db_init_string(&table_name);
db_init_handle(&handle);
/* Prepare database for use */
driver = db_start_driver(Fi->driver);
if (driver == NULL) {
G_fatal_error(_("Unable to start driver <%s>"), Fi->driver);
}
/* Set error handler for DB driver */
db_set_error_handler_driver(driver);
db_set_handle(&handle, Fi->database, NULL);
if (db_open_database(driver, &handle) != DB_OK) {
G_fatal_error(_("Unable to open database <%s> by driver <%s>"),
Fi->database, Fi->driver);
}
db_set_string(&table_name, Fi->table);
if (db_describe_table(driver, &table_name, &table) != DB_OK) {
G_fatal_error(_("Unable to describe table <%s>"), Fi->table);
}
ncols = db_get_table_number_of_columns(table);
/* Copy header and history data from old to new map */
Vect_copy_head_data(&In, &Out);
Vect_hist_copy(&In, &Out);
Vect_hist_command(&Out);
i = 1;
/* Let's do something with every vector feature in input map... */
/* Read in single line and get it's type */
while ((type = Vect_read_next_line(&In, Points, Cats)) > 0) {
/* If Points contain line... */
if (type == GV_LINE || type == GV_POINT || type == GV_CENTROID) {
if (Vect_cat_get(Cats, 1, &cat) == 0) {
Vect_cat_set(Cats, 1, i);
i++;
}
}
if (type == GV_POINT) {
/* Print out point coordinates */
printf("No:%d\tX:%f\tY:%f\tZ:%f\tCAT:%d\n", i, *Points->x,
*Points->y, *Points->z, cat);
/* Prepeare SQL query to get point attribute data */
sprintf(sql, "select * from %s where %s=%d", Fi->table, Fi->key,
cat);
G_debug(1, "SQL: \"%s\"", sql);
db_set_string(&dbsql, sql);
/* Now execute query */
if (db_open_select_cursor(driver, &dbsql, &cursor, DB_SEQUENTIAL) !=
DB_OK)
G_warning(_("Unable to get attribute data for cat %d"), cat);
else {
/* Result count */
nrows = db_get_num_rows(&cursor);
G_debug(1, "Result count: %d", nrows);
table = db_get_cursor_table(&cursor);
/* Let's output every columns name and value */
while (1) {
if (db_fetch(&cursor, DB_NEXT, &more) != DB_OK) {
G_warning(_("Error while retrieving database record "
"for cat %d"),
cat);
break;
}
if (!more)
break;
for (col = 0; col < ncols; col++) {
column = db_get_table_column(table, col);
db_convert_column_value_to_string(column, &valstr);
printf("%s: %s\t", db_get_column_name(column),
db_get_string(&valstr));
}
printf("\n");
}
db_close_cursor(&cursor);
}
}
/* Only now we write data into new vector */
Vect_write_line(&Out, type, Points, Cats);
}
/* Create database for new vector map */
Fin = Vect_default_field_info(&Out, 1, NULL, GV_1TABLE);
driver = db_start_driver_open_database(Fin->driver, Fin->database);
G_debug(1,
"Field number:%d; Name:<%s>; Driver:<%s>; Database:<%s>; "
"Table:<%s>; Key:<%s>;\n",
Fin->number, Fin->name, Fin->driver, Fin->database, Fin->table,
Fin->key);
/* Let's copy attribute table data */
if (db_copy_table(Fi->driver, Fi->database, Fi->table, Fin->driver,
Vect_subst_var(Fin->database, &Out),
Fin->table) == DB_FAILED)
G_warning(_("Unable to copy attribute table to vector map <%s>"),
new->answer);
else
Vect_map_add_dblink(&Out, Fin->number, Fin->name, Fin->table, Fi->key,
Fin->database, Fin->driver);
/* Build topology for vector map and close them */
Vect_build(&Out);
Vect_close(&In);
Vect_close(&Out);
db_close_database_shutdown_driver(driver);
/* Don't forget to report to caller successful end of data processing :) */
exit(EXIT_SUCCESS);
}
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