README

PHP DependencyGraph

This library provides a simple Dependency Graph resolver. It supports multiple root nodes which are detected automatically.

Installation

You can install this library with Composer by requiring digilist/dependency-graph

Example Usage:

There are two ways to define dependencies. One way is to define the dependencies directly on the node by calling the dependsOn method. By using this method you have to add the nodes manually to the graph (or at least the root nodes).

$nodeA = new DependencyNode('A');
$nodeB = new DependencyNode('B');
$nodeC = new DependencyNode('C');
$nodeD = new DependencyNode('D');
$nodeE = new DependencyNode('E');

$nodeA->dependsOn($nodeB);
$nodeA->dependsOn($nodeD);
$nodeB->dependsOn($nodeC);
$nodeB->dependsOn($nodeE);
$nodeC->dependsOn($nodeD);
$nodeC->dependsOn($nodeE);

$graph = new DependencyGraph();
$graph->addNode($nodeA);
$resolved = DependencyGraph->resolve(); // returns [D, E, C, B, A]

Alternatively, you can define the dependencies on the graph. By using this method, the root node will be automatically detected.

$graph = new DependencyGraph();

$nodeA = new DependencyNode('A');
$nodeB = new DependencyNode('B');
$nodeC = new DependencyNode('C');
$nodeD = new DependencyNode('D');
$nodeE = new DependencyNode('E');

$graph->addDependency($nodeA, $nodeB);
$graph->addDependency($nodeA, $nodeD);
$graph->addDependency($nodeB, $nodeC);
$graph->addDependency($nodeB, $nodeE);
$graph->addDependency($nodeC, $nodeD);
$graph->addDependency($nodeC, $nodeE);

$resolved = DependencyGraph->resolve(); // returns [D, E, C, B, A]

The passed payload to DependencyNode can be any arbitrary PHP element (primitive, array, object, resource...).