Adding result sets to the query writer

Author: moufmouf

composer.json

@@ -16,7 +16,8 @@
     	"php": ">=5.3.0",
     	"mouf/database.dbconnection": "~2.0",
     	"mouf/utils.common.conditioninterface": "~2.0",
-    	"mouf/utils.value.value-interface": "~1.0"
+    	"mouf/utils.value.value-interface": "~1.0",
+    	"mouf/utils.common.paginable-interface": "~1.0"
     },
     "autoload": {
         "psr-0": {

src/Mouf/Database/QueryWriter/CountNbResult.php

@@ -0,0 +1,50 @@
+<?php
+namespace Mouf\Database\QueryWriter;
+
+use Mouf\Utils\Value\IntValueInterface;
+
+use Mouf\Database\DBConnection\ConnectionInterface;
+
+/**
+ * A utility class that can compute the number of results returned by a query.
+ * It does so by embedding the query into a SELECT count(*) query and computing the results.
+ * 
+ * @author David Negrier
+ */
+class CountNbResult implements IntValueInterface {
+
+	/**
+	 * The Select statement.
+	 *
+	 * @var Select
+	 */
+	private $select;
+
+	/**
+	 * The connection to the database.
+	 *
+	 * @var ConnectionInterface
+	 */
+	private $connection;
+
+	/**
+	 * 
+	 * @param Select $select
+	 * @param ConnectionInterface $connection
+	 */
+	public function __construct(Select $select, ConnectionInterface $connection) {
+		$this->select = $select;
+		$this->connection = $connection;
+	}
+
+	/**
+	 * (non-PHPdoc)
+	 * @see \Mouf\Utils\Value\ArrayValueInterface::val()
+	 */
+	public function val() {
+		$sql = "SELECT count(*) as cnt FROM (".$this->select->toSql().") tmp";
+		// FIXME: add support for params!
+		return $this->connection->getOne($sql);
+	}
+
+}

src/Mouf/Database/QueryWriter/QueryResult.php

@@ -0,0 +1,65 @@
+<?php
+namespace Mouf\Database\QueryWriter;
+
+use Mouf\Utils\Common\PaginableInterface;
+
+use Mouf\Utils\Value\ArrayValueInterface;
+
+use Mouf\Database\DBConnection\ConnectionInterface;
+
+/**
+ * A class that can execute a query and expose the results.
+ * 
+ * @author David Negrier
+ */
+class QueryResult implements ArrayValueInterface, PaginableInterface {
+
+	/**
+	 * The Select statement.
+	 *
+	 * @var Select
+	 */
+	private $select;
+
+	/**
+	 * The connection to the database.
+	 *
+	 * @var ConnectionInterface
+	 */
+	private $connection;
+	
+	private $limit;
+	private $offset;
+
+	/**
+	 * 
+	 * @param Select $select
+	 * @param ConnectionInterface $connection
+	 */
+	public function __construct(Select $select, ConnectionInterface $connection) {
+		$this->select = $select;
+		$this->connection = $connection;
+	}
+
+	/**
+	 * (non-PHPdoc)
+	 * @see \Mouf\Utils\Value\ArrayValueInterface::val()
+	 */
+	public function val() {
+		// FIXME: add support for params!
+		$pdoStatement = $this->connection->query($this->select->toSql(), $this->offset, $this->limit);
+		return new ResultSet($pdoStatement);
+	}
+	
+	/**
+	 * Paginates the result set.
+	 *
+	 * @param int $limit
+	 * @param int $offset
+	 */
+	public function paginate($limit, $offset = 0) {
+		$this->limit = $limit;
+		$this->offset = $offset;
+	}
+
+}

src/Mouf/Database/QueryWriter/ResultSet.php

@@ -0,0 +1,71 @@
+<?php
+namespace Mouf\Database\QueryWriter;
+
+use Mouf\Utils\Value\ArrayValueInterface;
+
+use Mouf\Database\DBConnection\ConnectionInterface;
+
+/**
+ * Wraps the results of a PDOStatement.
+ * 
+ * @author David Negrier
+ */
+class ResultSet implements \Iterator {
+
+	/**
+	 * 
+	 * @var \PDOStatement
+	 */
+	private $statement;
+	private $castToClass;
+	private $key = 0;
+	private $result;
+	private $fetched = false;
+	private $rewindCalls = 0;
+	
+	public function __construct(\PDOStatement $statement, $castToClass = "") {
+		$this->statement = $statement;
+		$this->castToClass = $castToClass;
+	}
+	
+
+	function rewind() {
+		$this->rewindCalls++;
+		if ($this->rewindCalls == 2) {
+			throw new \Exception("Error: rewind is not possible in a database rowset. You can call 'foreach' on the rowset only once. Use CachedResultSet to be able to call the result several times. TODO: develop CachedResultSet");
+		}
+	}
+	
+	function current() {
+		
+		if (!$this->fetched) {
+			$this->fetch();
+		}
+		
+		return $this->result;
+	}
+	
+	function key() {
+		return $this->key;
+	}
+	
+	function next() {
+		++$this->key;
+		$this->fetched = false;
+		$this->fetch();
+	}
+	
+	private function fetch() {
+		$this->result = $this->statement->fetch(\PDO::FETCH_ASSOC);
+		$this->fetched = true;
+	}
+	
+	function valid() {
+
+		if (!$this->fetched) {
+			$this->fetch();
+		}
+		
+		return $this->result !== false;
+	}
+}

src/Mouf/Database/QueryWriter/Select.php

@@ -123,4 +123,5 @@ public function toSql() {
 
 		return $sql;
 	}
+	
 }