Merge pull request #6 from phonetworks/to_lax

Edge ready to serialize

src/Pho/Framework/AbstractEdge.php

@@ -11,47 +11,50 @@
 
 namespace Pho\Framework;
 
+use Pho\Lib\Graph;
+
 /**
  * Framework Edge Foundation
- * 
+ *
  * This abstract class extends {@link \Pho\Lib\Graph\Edge}
- * and acts as a placeholder that defines that its subclasses 
- * must implement HEAD_LABELS, TAIL_LABEL,TAIL_LABELS 
+ * and acts as a placeholder that defines that its subclasses
+ * must implement HEAD_LABELS, TAIL_LABEL,TAIL_LABELS
  * and SETTABLES constants.
- * 
+ *
  * @author Emre Sokullu <[email protected]>
  */
-abstract class AbstractEdge extends \Pho\Lib\Graph\Edge {
+abstract class AbstractEdge extends \Pho\Lib\Graph\Edge
+{
 
     /**
      * Head Node Label in Singular Form
-     * 
+     *
      * This is what the head node will be called.
-     * For example; for {@link ActorOut/Subscribes} 
+     * For example; for {@link ActorOut/Subscribes}
      * edge, it will be "Subscription".
      */
     const HEAD_LABEL = "";
 
     /**
      * Head Node Label in Plural Form
-     * 
+     *
      * Same as above, except written in plural
      * form.
      */
     const HEAD_LABELS = "";
 
     /**
      * Tail Node Label in Singular Form
-     * 
+     *
      * This is what the tail node will be called.
-     * For example; for {@link ActorOut/Subscribes} 
+     * For example; for {@link ActorOut/Subscribes}
      * edge, it will be "Subscriber".
      */
     const TAIL_LABEL = "";
 
     /**
      * Tail Node Label in Plural Form
-     * 
+     *
      * Same as above, except written in plural
      * form.
      */
@@ -71,5 +74,45 @@ public function __invoke(): ParticleInterface
     {
         return $this->head()->node();
     }
-
-}
+
+
+    /**
+    * @internal
+    *
+    * Used for serialization. Nothing special here. Declared for
+    * subclasses.
+    *
+    * @return string in PHP serialized format.
+    */
+    public function serialize(): string
+    {
+        return serialize($this->toArray());
+    }
+
+
+    /**
+    * @internal
+    *
+    * Used for deserialization. Nothing special here. Declared for
+    * subclasses.
+    *
+    * @param string $data
+    *
+    * @return void
+    *
+    * @throws Exceptions\PredicateClassDoesNotExistException when the predicate class does not exist.
+    */
+    public function unserialize(/* mixed */ $data): void
+    {
+        $data = unserialize($data);
+        $this->id = Graph\ID::fromString($data["id"]);
+        $this->tail_id = $data["tail"];
+        $this->head_id = $data["head"];
+        if (class_exists($data["predicate"])) {
+            $this->predicate_label = new $data["predicate"];
+        } else {
+            throw new PredicateClassDoesNotExistException((string)$this->id(), $data["predicate"]);
+        }
+        $this->attributes = new Graph\AttributeBag($this, $data["attributes"]);
+    }
+}

src/Pho/Framework/Exceptions/PredicateClassDoesNotExistException.php

@@ -0,0 +1,42 @@
+<?php
+
+/*
+ * This file is part of the Pho package.
+ *
+ * (c) Emre Sokullu <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Pho\Framework\Exceptions;
+
+use Pho\Framework\ParticleInterface;
+
+/**
+ * Thrown when the given predicate class does not exist.
+ * 
+ * This is called during serialization of edges. If the predicate does not
+ * exist, this is thrown and it means some libraries are not installed.
+ * 
+ * @author Emre Sokullu <[email protected]>
+ */
+class PredicateClassDoesNotExistException extends \Exception {
+
+    /**
+     * Constructor.
+     *
+     * @param string $edge_id The ID of the edge in pure string format
+     * @param string $predicate_class_name Full class name of the predicate
+     */
+    public function __construct(string $edge_id, string $predicate_class_name)
+    {
+        parent::__construct();
+        $this->message = sprintf(
+            "The edge (%s) predicate \"%s\" cannot be found.",
+            $edge_id,
+            $predicate_class_name
+        );
+    }
+
+}