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-- Perl Weekly Challenge 165
-- Task 1
CREATE SCHEMA IF NOT EXISTS pwc165;
CREATE TABLE IF NOT EXISTS points( x1 int, y1 int, x2 int, y2 int );
TRUNCATE points;
INSERT INTO points
VALUES
(53,10, NULL, NULL)
,(53,10,23,30)
,(23,30, NULL, NULL)
;
--
-- This function generates the SVG XML document
-- from the 'points' table.
--
CREATE OR REPLACE FUNCTION
pwc165.plperl_generate_svg_xml( text )
RETURNS TEXT[]
AS $CODE$
my ( $filename ) = @_;
my @lines;
my @points;
my $result_set = spi_exec_query( 'SELECT * FROM points;' );
for my $row_number ( 0 .. $result_set->{ processed } - 1 ) {
my $row = $result_set->{ rows }[ $row_number ];
# if it has a single couple, it is a point
my ( $x1, $y1, $x2, $y2 ) = map { $row->{ $_ } } qw<x1 y1 x2 y2>;
my $is_line = $x1 && $y1 && $x2 && $y2;
push @points, [ $x1, $y1 ] if ! $is_line && $x1 && $y1;
push @points, [ $x2, $y2 ] if ! $is_line && $x2 && $y2;
push @lines, [ $x1, $y1, $x2, $y2 ] if $is_line;
}
my $svg = q{<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
<svg height="400" width="400" xmlns="http://www.w3.org/2000/svg" xmlns:svg="http://www.w3.org/2000/svg"> };
for my $line ( @lines ) {
$svg .= sprintf( '<polyline points="%s" stroke="#ff0000" stroke-width="6" />', join( ' ', @$line ) );
}
for my $point ( @points ) {
$svg .= sprintf( '<circle r="4" cx="%d" cy="%d" stroke-width="0" fill="#000000" />', $point->[ 0 ], $point->[ 1 ] );
}
if ( $filename ) {
open my $fh, ">", $filename || die "Cannot open $filename !";
print { $fh } $svg;
close $fh;
}
return( [ $svg, $filename ] );
$CODE$
LANGUAGE plperlu;
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