Graphp not working at all

[codemann8]

I've been trying for hours to install this library and get a simple example to load. I installed this using composer using the one-line require statement listed on your main GitHub page. I'm getting an error:

Fatal error: Uncaught exception 'Fhaculty\Graph\Exception\UnexpectedValueException' with message 'Unable to invoke "dot" to create image file (code 127)' in /home/somedirectory/vendor/graphp/graphviz/src/GraphViz.php:207 Stack trace: #0 /home/somedirectory/vendor/graphp/graphviz/src/GraphViz.php(142): Graphp\GraphViz\GraphViz->createImageFile(Object(Fhaculty\Graph\Graph)) #1 /home/somedirectory/graph2.php(18): Graphp\GraphViz\GraphViz->createImageData(Object(Fhaculty\Graph\Graph)) #2 {main} thrown in /home/somedirectory/vendor/graphp/graphviz/src/GraphViz.php on line 207

using this code:

<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);

include 'vendor/autoload.php';

$graph = new Fhaculty\Graph\Graph();

$blue = $graph->createVertex( 'blue' );
$blue->setAttribute( 'graphviz.color', 'blue' );

$red = $graph->createVertex( 'red' );
$red->setAttribute( 'graphviz.color', 'red' );

$edge = $blue->createEdgeTo( $red );
$edge->setAttribute( 'graphviz.color', 'grey' );

$graphviz = new Graphp\GraphViz\GraphViz();
$data = $graphviz->createImageData( $graph );
$image = imagecreatefromstring( $data );
header( 'Content-Type: image/png' );
imagepng( $image );
imagedestroy( $image );
?>

Any ideas what I'm doing wrong?

[clue]

Fatal error: Uncaught exception 'Fhaculty\Graph\Exception\UnexpectedValueException' with message 'Unable to invoke "dot" to create image file (code 127)'

@codemann8 Thank you for reporting and welcome to GraPHP! 🎉

This error means that you do not have GraphViz installed (the dot executable is part of the GraphViz package). See also the install instructions. On Debian/Ubuntu-based system you may simply install it like this:

$ sudo apt install graphviz