Support extending Edge by registering to its vertices within ctor

Author: Christian Lück

lib/Fhaculty/Graph/Edge/Directed.php

@@ -25,7 +25,7 @@ class Directed extends Base
     private $to;
 
     /**
-     * creats a new Edge (MUST NOT BE CALLED MANUALLY!)
+     * create a new directed Edge from Vertex $from to Vertex $to
      *
      * @param Vertex $from start/source Vertex
      * @param Vertex $to   end/target Vertex
@@ -34,8 +34,16 @@ class Directed extends Base
      */
     public function __construct(Vertex $from, Vertex $to)
     {
+        if ($from->getGraph() !== $to->getGraph()) {
+            throw new InvalidArgumentException('Vertices have to be within the same graph');
+        }
+
         $this->from = $from;
         $this->to = $to;
+
+        $from->getGraph()->addEdge($this);
+        $from->addEdge($this);
+        $to->addEdge($this);
     }
 
     public function getVerticesTarget()

lib/Fhaculty/Graph/Edge/Undirected.php

@@ -23,16 +23,24 @@ class Undirected extends Base
     private $b;
 
     /**
-     * create new undirected edge between given vertices (MUST NOT BE CALLED MANUALLY!)
+     * create a new undirected edge between given vertices
      *
      * @param Vertex $a
      * @param Vertex $b
      * @see Vertex::createEdge() instead
      */
     public function __construct(Vertex $a, Vertex $b)
     {
+        if ($a->getGraph() !== $b->getGraph()) {
+            throw new InvalidArgumentException('Vertices have to be within the same graph');
+        }
+
         $this->a = $a;
         $this->b = $b;
+
+        $a->getGraph()->addEdge($this);
+        $a->addEdge($this);
+        $b->addEdge($this);
     }
 
     public function getVerticesTarget()

lib/Fhaculty/Graph/Vertex.php

@@ -133,16 +133,7 @@ public function getId()
      */
     public function createEdgeTo(Vertex $vertex)
     {
-        if ($vertex->getGraph() !== $this->graph) {
-            throw new InvalidArgumentException('Target vertex has to be within the same graph');
-        }
-
-        $edge = new EdgeDirected($this, $vertex);
-        $this->edges []= $edge;
-        $vertex->edges []= $edge;
-        $this->graph->addEdge($edge);
-
-        return $edge;
+        return new EdgeDirected($this, $vertex);
     }
 
     /**
@@ -155,16 +146,20 @@ public function createEdgeTo(Vertex $vertex)
      */
     public function createEdge(Vertex $vertex)
     {
-        if ($vertex->getGraph() !== $this->graph) {
-            throw new InvalidArgumentException('Target vertex has to be within the same graph');
-        }
-
-        $edge = new EdgeUndirected($this, $vertex);
-        $this->edges []= $edge;
-        $vertex->edges []= $edge;
-        $this->graph->addEdge($edge);
+        return new EdgeUndirected($this, $vertex);
+    }
 
-        return $edge;
+    /**
+     * add the given edge to list of connected edges (MUST NOT be called manually)
+     *
+     * @param  Edge                     $edge
+     * @return void
+     * @private
+     * @see self::createEdge() instead!
+     */
+    public function addEdge(Edge $edge)
+    {
+        $this->edges[] = $edge;
     }
 
     /**