DepGraph

Simple dependency graph management in PHP.

What’s it for?

Say you have a set of resources that depend on each other in some way. These resources can be anything—files, chains of command, plot twists on Lost—whatever. All that matters is that each one has a unique string identifier, and a list of direct dependencies.

DepGraph makes it easy to compute “chains” of dependencies, with guaranteed logical ordering and no duplicates. That’s trivial in most cases, but if A depends on B and B depends on A, a naïve dependency graph would get trapped in an infinite loop. DepGraph throws an error if any such “cycles” are detected.

DepGraph is a PHP port from the excelent library [dep-graph] (http://github.com/TrevorBurnham/dep-graph), written in CoffeeScript for Node.JS by [Trevor Burnham] (https://github.com/TrevorBurnham). All credits for him.

API

require_once 'path/to/libs/diacronos/DepGraph/DepGraph.php';
use \diacronos\DepGraph\DepGraph;

$deps = new DepGraph();
$deps->add('A', 'B');  // => A requires B
$deps->add('B', 'C');  // => B requires C
$deps->getChain('A');  // => array('C', 'B', 'A')