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libraries/f0f/database/iterator.php

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+<?php
+/**
+ * @package     FrameworkOnFramework
+ * @subpackage  database
+ * @copyright   Copyright (C) 2010-2016 Nicholas K. Dionysopoulos / Akeeba Ltd. All rights reserved.
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ *
+ * This file is adapted from the Joomla! Platform. It is used to iterate a database cursor returning F0FTable objects
+ * instead of plain stdClass objects
+ */
+
+// Protect from unauthorized access
+defined('F0F_INCLUDED') or die;
+
+/**
+ * Database iterator
+ */
+abstract class F0FDatabaseIterator implements Iterator
+{
+	/**
+	 * The database cursor.
+	 *
+	 * @var    mixed
+	 */
+	protected $cursor;
+
+	/**
+	 * The class of object to create.
+	 *
+	 * @var    string
+	 */
+	protected $class;
+
+	/**
+	 * The name of the column to use for the key of the database record.
+	 *
+	 * @var    mixed
+	 */
+	private $_column;
+
+	/**
+	 * The current database record.
+	 *
+	 * @var    mixed
+	 */
+	private $_current;
+
+	/**
+	 * The current database record as a F0FTable object.
+	 *
+	 * @var    F0FTable
+	 */
+	private $_currentTable;
+
+	/**
+	 * A numeric or string key for the current database record.
+	 *
+	 * @var    scalar
+	 */
+	private $_key;
+
+	/**
+	 * The number of fetched records.
+	 *
+	 * @var    integer
+	 */
+	private $_fetched = 0;
+
+	/**
+	 * A F0FTable object created using the class type $class, used by getTable
+	 *
+	 * @var   F0FTable
+	 */
+	private $_tableObject = null;
+
+	/**
+	 * Returns an iterator object for a specific database type
+	 *
+	 * @param   string  $dbName  The database type, e.g. mysql, mysqli, sqlazure etc.
+	 * @param   mixed   $cursor  The database cursor
+	 * @param   string  $column  An option column to use as the iterator key
+	 * @param   string  $class   The table class of the returned objects
+	 * @param   array   $config  Configuration parameters to push to the table class
+	 *
+	 * @return  F0FDatabaseIterator
+	 *
+	 * @throws  InvalidArgumentException
+	 */
+	public static function &getIterator($dbName, $cursor, $column = null, $class, $config = array())
+	{
+		$className = 'F0FDatabaseIterator' . ucfirst($dbName);
+
+		$object = new $className($cursor, $column, $class, $config);
+
+		return $object;
+	}
+
+	/**
+	 * Database iterator constructor.
+	 *
+	 * @param   mixed   $cursor  The database cursor.
+	 * @param   string  $column  An option column to use as the iterator key.
+	 * @param   string  $class   The table class of the returned objects.
+	 * @param   array   $config  Configuration parameters to push to the table class
+	 *
+	 * @throws  InvalidArgumentException
+	 */
+	public function __construct($cursor, $column = null, $class, $config = array())
+	{
+		// Figure out the type and prefix of the class by the class name
+		$parts = F0FInflector::explode($class);
+
+        if(count($parts) != 3)
+        {
+            throw new InvalidArgumentException('Invalid table name, expected a pattern like ComponentTableFoobar got '.$class);
+        }
+
+		$this->_tableObject = F0FTable::getInstance($parts[2], ucfirst($parts[0]) . ucfirst($parts[1]))->getClone();
+
+		$this->cursor   = $cursor;
+		$this->class    = 'stdClass';
+		$this->_column  = $column;
+		$this->_fetched = 0;
+
+		$this->next();
+	}
+
+	/**
+	 * Database iterator destructor.
+	 */
+	public function __destruct()
+	{
+		if ($this->cursor)
+		{
+			$this->freeResult($this->cursor);
+		}
+	}
+
+	/**
+	 * The current element in the iterator.
+	 *
+	 * @return  object
+	 *
+	 * @see     Iterator::current()
+	 */
+	public function current()
+	{
+		return $this->_currentTable;
+	}
+
+	/**
+	 * The key of the current element in the iterator.
+	 *
+	 * @return  scalar
+	 *
+	 * @see     Iterator::key()
+	 */
+	public function key()
+	{
+		return $this->_key;
+	}
+
+	/**
+	 * Moves forward to the next result from the SQL query.
+	 *
+	 * @return  void
+	 *
+	 * @see     Iterator::next()
+	 */
+	public function next()
+	{
+		// Set the default key as being the number of fetched object
+		$this->_key = $this->_fetched;
+
+		// Try to get an object
+		$this->_current = $this->fetchObject();
+
+		// If an object has been found
+		if ($this->_current)
+		{
+			$this->_currentTable = $this->getTable();
+
+			// Set the key as being the indexed column (if it exists)
+			if (isset($this->_current->{$this->_column}))
+			{
+				$this->_key = $this->_current->{$this->_column};
+			}
+
+			// Update the number of fetched object
+			$this->_fetched++;
+		}
+	}
+
+	/**
+	 * Rewinds the iterator.
+	 *
+	 * This iterator cannot be rewound.
+	 *
+	 * @return  void
+	 *
+	 * @see     Iterator::rewind()
+	 */
+	public function rewind()
+	{
+	}
+
+	/**
+	 * Checks if the current position of the iterator is valid.
+	 *
+	 * @return  boolean
+	 *
+	 * @see     Iterator::valid()
+	 */
+	public function valid()
+	{
+		return (boolean) $this->_current;
+	}
+
+	/**
+	 * Method to fetch a row from the result set cursor as an object.
+	 *
+	 * @return  mixed  Either the next row from the result set or false if there are no more rows.
+	 */
+	abstract protected function fetchObject();
+
+	/**
+	 * Method to free up the memory used for the result set.
+	 *
+	 * @return  void
+	 */
+	abstract protected function freeResult();
+
+	/**
+	 * Returns the data in $this->_current as a F0FTable instance
+	 *
+	 * @return  F0FTable
+	 *
+	 * @throws  OutOfBoundsException
+	 */
+	protected function getTable()
+	{
+		if (!$this->valid())
+		{
+			throw new OutOfBoundsException('Cannot get item past iterator\'s bounds', 500);
+		}
+
+		$this->_tableObject->bind($this->_current);
+
+		return $this->_tableObject;
+	}
+}