/**
* Render state diagram
*/
public static function renderStateMachine(\Smalldb\StateMachine\AbstractBackend $smalldb, $machine, $format)
{
$dot = $smalldb->getMachine($machine)->exportDot();
if ($format == 'dot') {
header('Content-Type: text/plain; encoding=utf8');
echo $dot;
} else {
if ($format == 'png' || $format == 'pdf' || $format == 'svg') {
$image = FALSE;
// Check cache
$dot_hash = md5($dot) . '_' . $format;
if (function_exists('apcu_fetch')) {
$image = apcu_fetch($dot_hash);
}
if ($image === FALSE) {
// Render diagram using Graphviz
$p = proc_open('dot -T' . $format, [['pipe', 'r'], ['pipe', 'wb'], ['file', 'php://stdout', 'a']], $fp);
fwrite($fp[0], $dot);
fclose($fp[0]);
$image = stream_get_contents($fp[1]);
fclose($fp[1]);
$err = proc_close($p);
if ($err != 0) {
// Failed - drop corrupt image data
$image = FALSE;
} else {
if (function_exists('apcu_store')) {
// Store image in cache
apcu_store($dot_hash, $image, 3600);
}
}
}
if ($image) {
// Send image
switch ($format) {
case 'png':
header('Content-Type: image/png');
break;
case 'svg':
header('Content-Type: image/svg+xml');
break;
case 'pdf':
header('Content-Type: application/pdf');
break;
}
echo $image;
}
} else {
throw new \InvalidArgumentException('Unknown format');
}
}
}
