Finalize first version

en/cookbook/advanced-field-value-conversion-using-custom-mapping-types.rst

@@ -13,11 +13,9 @@ class, converting the value on the database-level or a combination of both.
 This article describes the third way by implementing the MySQL specific column
 type `Point <http://dev.mysql.com/doc/refman/5.5/en/gis-class-point.html>`_.
 
-The `Point` type is part of the `Spatial extension <http://dev.mysql.com/doc/refman/5.5/en/spatial-extensions.html>`_
+The ``Point`` type is part of the `Spatial extension <http://dev.mysql.com/doc/refman/5.5/en/spatial-extensions.html>`_
 of MySQL and enables you to store a single location in a coordinate space by
-using x and y coordinates.
-
-As you might have already guessed, you can use the Point type to store a 
+using x and y coordinates. You can use the Point type to store a 
 longitude/latitude pair to represent a geographic location.
 
 The entity
@@ -42,27 +40,53 @@ The entity class:
         /**
          * @Column(type="point")
          *
-         * @var \Geo\Point
+         * @var \Geo\ValueObject\Point
          */
         private $point;
 
         /**
-         * @param \Geo\Point $point
+         * @Column(type="string")
+         *
+         * @var string
          */
-        public function setPoint(\Geo\Point $point)
+        private $address;
+
+        /**
+         * @param \Geo\ValueObject\Point $point
+         */
+        public function setPoint(\Geo\ValueObject\Point $point)
         {
             $this->point = $point;
         }
 
         /**
-         * @return \Geo\Point
+         * @return \Geo\ValueObject\Point
          */
         public function getPoint()
         {
             return $this->point;
         }
+
+        /**
+         * @param string $address
+         */
+        public function setAddress($address)
+        {
+            $this->address = $address;
         }
 
+        /**
+         * @return string
+         */
+        public function getAddress()
+        {
+            return $this->address;
+        }
+    }
+
+We use the custom type ``point`` in the ``@Column``  docblock annotation of the 
+``$point`` field. We will create this custom mapping type in the next chapter.
+
 The point class:
 
 .. code-block:: php
@@ -73,17 +97,28 @@ The point class:
 
     class Point
     {
+
+        /**
+         * @param float $latitude
+         * @param float $longitude
+         */
         public function __construct($latitude, $longitude)
         {
             $this->latitude  = $latitude;
             $this->longitude = $longitude;
         }
 
+        /**
+         * @return float
+         */
         public function getLatitude()
         {
             return $this->latitude;
         }
 
+        /**
+         * @return float
+         */
         public function getLongitude()
         {
             return $this->longitude;
@@ -93,10 +128,7 @@ The point class:
 The mapping type
 ----------------
 
-As you may have noticed, we used the custom type ``point`` in the ``@Column`` 
-docblock annotation of the ``$point`` field.
-
-Now we're going to create this type and implement all required methods.
+Now we're going to create the ``point`` type and implement all required methods.
 
 .. code-block:: php
 
@@ -144,12 +176,76 @@ Now we're going to create this type and implement all required methods.
             return sprintf('AsText(%s)', $sqlExpr);
         }
 
-        public function convertToDatabaseValue($sqlExpr, AbstractPlatform $platform)
+        public function convertToDatabaseValueSQL($sqlExpr, AbstractPlatform $platform)
         {
-            return sprintf('GeomFromText(%s)', $sqlExpr);
+            return sprintf('PointFromText(%s)', $sqlExpr);
         }
     }
 
-A few notes about the implementation:
+We do a 2-step conversion here. In the first step, we convert the ``Point``
+object into a string representation before saving to the database (in the
+``convertToDatabaseValue`` method) and back into an object after fetching the
+value from the database (in the ``convertToPHPValue`` method).
 
-  * 
+The format of the string representation format is called `Well-known text (WKT)
+<http://en.wikipedia.org/wiki/Well-known_text>`_. The advantage of this format
+is, that it is both human readable and parsable by MySQL.
+
+Internally, MySQL stores geometry values in a binary format that is not 
+identical to the WKT format. So, we need to let MySQL transform the WKT
+representation into its internal format.
+
+This is where the ``convertToPHPValueSQL`` and  ``convertToDatabaseValueSQL``
+methods come into play.
+
+This methods wrap a sql expression (the WKT representation of the Point) into
+MySQL functions `PointFromText <http://dev.mysql.com/doc/refman/5.5/en/creating-spatial-values.html#function_pointfromtext>`_
+and `AsText <http://dev.mysql.com/doc/refman/5.5/en/functions-to-convert-geometries-between-formats.html#function_astext>`_
+which convert WKT strings to and from the internal format of MySQL.
+
+.. note::
+
+    When using DQL queries, the ``convertToPHPValueSQL`` and  
+    ``convertToDatabaseValueSQL`` methods only apply to identification variables
+    and path expressions in SELECT clauses. Expressions in  WHERE clauses are 
+    **not** wrapped!
+
+    If you want to use Point values in WHERE clauses, you have to implement a
+    :doc:`user defined function <dql-user-defined-functions>` for 
+    ``PointFromText``.
+
+Example usage
+-------------
+
+.. code-block:: php
+
+    <?php
+
+    // Bootstrapping stuff...
+    // $em = \Doctrine\ORM\EntityManager::create($connectionOptions, $config);
+
+    // Setup custom mapping type
+    use Doctrine\DBAL\Types\Type;
+
+    Type::addType('point', 'Geo\Types\Point');
+    $em->getConnection()->getDatabasePlatform()->registerDoctrineTypeMapping('point', 'point');
+
+    // Store a Location object
+    use Geo\Entity\Location;
+    use Geo\ValueObject\Point;
+
+    $location = new Location();
+
+    $location->setAddress('1600 Amphitheatre Parkway, Mountain View, CA');
+    $location->setPoint(new Point(37.4220761, -122.0845187));
+
+    $em->persist($location);
+    $em->flush();
+    $em->clear();
+
+    // Fetch the Location object
+    $query = $em->createQuery("SELECT l FROM Geo\Entity\Location WHERE l.address = '1600 Amphitheatre Parkway, Mountain View, CA'");
+    $location = $query->getSingleResult();
+
+    /* @var Geo\ValueObject\Point */
+    $point = $location->getPoint();