=head1 NAME

dbfp_query_loation - get a list of stations matching a string from the DB
timetable API

=head1 SYNOPSIS

    #include <dbfp.h>

    int dbfp_query_location(struct dbfp *dbfp, char *input, size_t *n,
                    struct dbfp_location **locations);

=head1 DESCRIPTION

B<dbfp_query_location> queries a list of locations matching the query string
I<input> from the DB timetable API using the connection metadata stored in
I<dbfp>.  The number of results is stored in I<n>.  The results are stored in
I<locations>.  The memory for the I<locations> is allocated by the function.
The stored array contains exactly I<n> elements, and is not NULL terminated.

I<dbfp>, I<input>, I<n> and I<locations> must not be NULL.  I<dbfp> must have
been initialized with I<dbfp_init>.  The elements in I<locations> should be
closed with I<dbfp_location_close>.  I<locations> should be freed by the
caller.

If the query fails, the values of I<n> and I<locations> are set to 0 and NULL
respectively.

The B<dbfp_location> structure is defined as:

    struct dbfp_location {
            char *name;
            char *id;
            float lon;
            float lat;
    };

I<name> is the name of the station.  I<id> is the DB id of the station.  It
seems to be an integer, but this is not guaranteed.  I<lon> and I<lat> are the
coordinates of the station.

=head1 RETURN VALUE

B<dbfp_query_location> returns zero if successful, or a non-zero error code.
Positive error codes are from I<errno.h>, negative error codes are specific
to dbfp.

=head1 ERRORS

=over

=item EINVAL

if I<dbfp>, I<input>, I<n> or I<locations> is NULL

=item ENOMEM

if there is not enough memory to store the results of the query

=item DBFP_ERROR_CURL

if an error occured during the preparation or execution of the network request

=item DBFP_ERROR_FORMAT

if an error occurs during the formatting of the URL

=item DBFP_ERROR_PARSE

if an error occurs during the parsing of the XML response

=item DBFP_ERROR_STRUCTURE

if the API response has not the expected structure

=back

=head1 EXAMPLE

    #include <dbfp.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>

    int main(int argc, char **argv)
    {
            int err = 0;
            struct dbfp dbfp;
            struct dbfp_location *locations = NULL;
            size_t n = 0;
            size_t i;

            err = dbfp_init(&dbfp, "API key");
            if (err)
                    goto cleanup;
            err = dbfp_query_location(&dbfp, "Freibu", &n, &locations);
            if (err)
                    goto cleanup;

            printf("Number of matches: %zu\n", n);
            for (i = 0; i < n; i++)
                    printf("%s: %s (%.2f, %.2f)", locations[i].id,
                                    locations[i].name, locations[i].lon,
                                    locations[i].lat);

    cleanup:
            if (err)
                    printf("An error occured: %s\n", strerror(err));
            for (i = 0; i < n; i++)
                    dbfp_location_close(&locations[i]);
            free(locations);
            dbfp_close(&dbfp);

            return err ? EXIT_FAILURE : EXIT_SUCCESS;
    }

=head1 SEE ALSO

L<dbfp_init(3)>, L<dbfp_location_close(3)>