Merge pull request #82 from clue/add-extend

Support extending Graph, Vertex and Edge

Author: clue

CHANGELOG.md

@@ -6,6 +6,12 @@ you spot any mistakes.
 
 ## 0.8.0 (2013-xx-xx)
 
+*   Feature: The base `Graph`, `Vertex` and `EdgeBase` classes can now be
+    extended in order to implement a custom behavior. As such, one can now also
+    instantiate them using the normal `new` operator instead of having to use
+    `Graph::createVertex()` family of methods.
+    ([#82](https://github.com/clue/graph/issues/82))
+
 *   BC break: Rename `Algorithm\Directed::isDirected()` to remove its ambiguity
     in regards to mixed and/or empty graphs
     ([#80](https://github.com/clue/graph/issues/80))
@@ -14,7 +20,7 @@ you spot any mistakes.
     |---|---|
     | `Algorithm\Directed::isDirected()` | `Algorithm\Directed::hasDirected()` |
 
-*   Feature:: Add new `Algorithm\Directed::hasUndirected()` and
+*   Feature: Add new `Algorithm\Directed::hasUndirected()` and
     `Algorithm\Directed::isMixed()` in order to complement the renamed
     `Algorithm\Directed::hasDirected()`
     ([#80](https://github.com/clue/graph/issues/80))

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/Graph.php

@@ -77,19 +77,12 @@ public function createVertex($id = NULL, $returnDuplicate = false)
         // no ID given
         if ($id === NULL) {
             $id = $this->getNextId();
-        } elseif (!is_int($id) && !is_string($id)) {
-            throw new InvalidArgumentException('Vertex ID has to be of type integer or string');
         }
-        if ($this->vertices->hasVertexId($id)) {
-            if ($returnDuplicate) {
-                return $this->vertices->getVertexId($id);
-            }
-            throw new OverflowException('ID must be unique');
+        if ($returnDuplicate && $this->vertices->hasVertexId($id)) {
+            return $this->vertices->getVertexId($id);
         }
-        $vertex = new Vertex($id, $this);
-        $this->verticesStorage[$id] = $vertex;
 
-        return $vertex;
+        return new Vertex($this, $id);
     }
 
     /**
@@ -105,12 +98,11 @@ public function createVertexClone(Vertex $originalVertex)
         if ($this->vertices->hasVertexId($id)) {
             throw new RuntimeException('Id of cloned vertex already exists');
         }
-        $newVertex = new Vertex($id, $this);
+        $newVertex = new Vertex($this, $id);
         // TODO: properly set attributes of vertex
         $newVertex->setLayout($originalVertex->getLayout());
         $newVertex->setBalance($originalVertex->getBalance());
         $newVertex->setGroup($originalVertex->getGroup());
-        $this->verticesStorage[$id] = $newVertex;
 
         return $newVertex;
     }
@@ -264,7 +256,7 @@ public function createVertices($n)
         $vertices = array();
         if (is_int($n) && $n >= 0) {
             for ($id = $this->getNextId(), $n += $id; $id < $n; ++$id) {
-                $vertices[$id] = $this->verticesStorage[$id] = new Vertex($id, $this);
+                $vertices[$id] = new Vertex($this, $id);
             }
         } elseif (is_array($n)) {
             // array given => check to make sure all given IDs are available (atomic operation)
@@ -283,7 +275,7 @@ public function createVertices($n)
 
             // actually create all requested vertices
             foreach ($n as $id) {
-                $vertices[$id] = $this->verticesStorage[$id] = new Vertex($id, $this);
+                $vertices[$id] = new Vertex($this, $id);
             }
         } else {
             throw new InvalidArgumentException('Invalid number of vertices given. Must be non-negative integer or an array of Vertex IDs');
@@ -332,6 +324,22 @@ public function hasVertex($id)
         return $this->vertices->hasVertexId($id);
     }
 
+    /**
+     * adds a new Vertex to the Graph (MUST NOT be called manually!)
+     *
+     * @param  Vertex $vertex instance of the new Vertex
+     * @return void
+     * @private
+     * @see self::createVertex() instead!
+     */
+    public function addVertex(Vertex $vertex)
+    {
+        if (isset($this->verticesStorage[$vertex->getId()])) {
+            throw new OverflowException('ID must be unique');
+        }
+        $this->verticesStorage[$vertex->getId()] = $vertex;
+    }
+
     /**
      * adds a new Edge to the Graph (MUST NOT be called manually!)
      *

lib/Fhaculty/Graph/Vertex.php

@@ -43,16 +43,22 @@ class Vertex extends Layoutable implements EdgesAggregate
     private $group = 0;
 
     /**
-     * Creates a Vertex (MUST NOT BE CALLED MANUALLY!)
+     * Create a new Vertex
      *
-     * @param string|int $id    identifier used to uniquely identify this vertex in the graph
      * @param Graph      $graph graph to be added to
+     * @param string|int $id    identifier used to uniquely identify this vertex in the graph
      * @see Graph::createVertex() to create new vertices
      */
-    public function __construct($id, Graph $graph)
+    public function __construct(Graph $graph, $id)
     {
+        if (!is_int($id) && !is_string($id)) {
+            throw new InvalidArgumentException('Vertex ID has to be of type integer or string');
+        }
+
         $this->id = $id;
         $this->graph = $graph;
+
+        $graph->addVertex($this);
     }
 
     /**
@@ -127,16 +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);
     }
 
     /**
@@ -149,16 +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;
     }
 
     /**

tests/Fhaculty/Graph/VertexTest.php

@@ -1,6 +1,7 @@
 <?php
 
 use Fhaculty\Graph\Graph;
+use Fhaculty\Graph\Vertex;
 
 class VertexTest extends TestCase
 {
@@ -10,6 +11,32 @@ public function setUp()
         $this->vertex = $this->graph->createVertex(1);
     }
 
+    public function testPrecondition()
+    {
+        $this->assertCount(1, $this->graph->getVertices());
+        $this->assertTrue($this->graph->hasVertex(1));
+        $this->assertFalse($this->graph->hasVertex(2));
+        $this->assertSame($this->vertex, $this->graph->getVertex(1));
+    }
+
+    public function testConstructor()
+    {
+        $v2 = new Vertex($this->graph, 2);
+
+        $this->assertCount(2, $this->graph->getVertices());
+        $this->assertTrue($this->graph->hasVertex(2));
+
+        $this->assertSame($v2, $this->graph->getVertex(2));
+    }
+
+    /**
+     * @expectedException OverflowException
+     */
+    public function testCanNotConstructDuplicateVertex()
+    {
+        $v2 = new Vertex($this->graph, 1);
+    }
+
     public function testEdges()
     {
         // v1 -> v2, v1 -- v3, v1 <- v4