<?php

/**

 *	PHPExcel

 *

 *	Copyright (c) 2006 - 2014 PHPExcel

 *

 *	This library is free software; you can redistribute it and/or

 *	modify it under the terms of the GNU Lesser General Public

 *	License as published by the Free Software Foundation; either

 *	version 2.1 of the License, or (at your option) any later version.

 *

 *	This library is distributed in the hope that it will be useful,

 *	but WITHOUT ANY WARRANTY; without even the implied warranty of

 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 *	Lesser General Public License for more details.

 *

 *	You should have received a copy of the GNU Lesser General Public

 *	License along with this library; if not, write to the Free Software

 *	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 *

 *	@category	PHPExcel

 *	@package	PHPExcel_Cell

 *	@copyright	Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)

 *	@license	http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt	LGPL

 *	@version	1.8.0, 2014-03-02

 */





/**

 *	PHPExcel_Cell

 *

 *	@category   PHPExcel

 *	@package	PHPExcel_Cell

 *	@copyright  Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)

 */

class PHPExcel_Cell

{



	/**

	 *  Default range variable constant

	 *

	 *  @var  string

	 */

	const DEFAULT_RANGE = 'A1:A1';



	/**

	 *	Value binder to use

	 *

	 *	@var	PHPExcel_Cell_IValueBinder

	 */

	private static $_valueBinder = NULL;



	/**

	 *	Value of the cell

	 *

	 *	@var	mixed

	 */

	private $_value;



	/**

	 *	Calculated value of the cell (used for caching)

	 *	This returns the value last calculated by MS Excel or whichever spreadsheet program was used to

	 *		create the original spreadsheet file.

	 *	Note that this value is not guaranteed to reflect the actual calculated value because it is

	 *		possible that auto-calculation was disabled in the original spreadsheet, and underlying data

	 *		values used by the formula have changed since it was last calculated.

	 *

	 *	@var mixed

	 */

	private $_calculatedValue = NULL;



	/**

	 *	Type of the cell data

	 *

	 *	@var	string

	 */

	private $_dataType;



	/**

	 *	Parent worksheet

	 *

	 *	@var	PHPExcel_CachedObjectStorage_CacheBase

	 */

	private $_parent;



	/**

	 *	Index to cellXf

	 *

	 *	@var	int

	 */

	private $_xfIndex;



	/**

	 *	Attributes of the formula

	 *

	 */

	private $_formulaAttributes;





	/**

	 *	Send notification to the cache controller

	 *

	 *	@return void

	 **/

	public function notifyCacheController() {

		$this->_parent->updateCacheData($this);



		return $this;

	}



	public function detach() {

		$this->_parent = NULL;

	}



	public function attach(PHPExcel_CachedObjectStorage_CacheBase $parent) {





		$this->_parent = $parent;

	}





	/**

	 *	Create a new Cell

	 *

	 *	@param	mixed				$pValue

	 *	@param	string				$pDataType

	 *	@param	PHPExcel_Worksheet	$pSheet

	 *	@throws	PHPExcel_Exception

	 */

	public function __construct($pValue = NULL, $pDataType = NULL, PHPExcel_Worksheet $pSheet = NULL)

	{

		// Initialise cell value

		$this->_value = $pValue;



		// Set worksheet cache

		$this->_parent = $pSheet->getCellCacheController();



		// Set datatype?

		if ($pDataType !== NULL) {

			if ($pDataType == PHPExcel_Cell_DataType::TYPE_STRING2)

				$pDataType = PHPExcel_Cell_DataType::TYPE_STRING;

			$this->_dataType = $pDataType;

		} else {

			if (!self::getValueBinder()->bindValue($this, $pValue)) {

				throw new PHPExcel_Exception("Value could not be bound to cell.");

			}

		}



		// set default index to cellXf

		$this->_xfIndex = 0;

	}



	/**

	 *	Get cell coordinate column

	 *

	 *	@return	string

	 */

	public function getColumn()

	{

		return $this->_parent->getCurrentColumn();

	}



	/**

	 *	Get cell coordinate row

	 *

	 *	@return	int

	 */

	public function getRow()

	{

		return $this->_parent->getCurrentRow();

	}



	/**

	 *	Get cell coordinate

	 *

	 *	@return	string

	 */

	public function getCoordinate()

	{

		return $this->_parent->getCurrentAddress();

	}



	/**

	 *	Get cell value

	 *

	 *	@return	mixed

	 */

	public function getValue()

	{

		return $this->_value;

	}



	/**

	 *	Get cell value with formatting

	 *

	 *	@return	string

	 */

	public function getFormattedValue()

	{

		return (string) PHPExcel_Style_NumberFormat::toFormattedString(

				$this->getCalculatedValue(),

				$this->getWorksheet()->getParent()->getCellXfByIndex($this->getXfIndex())

					->getNumberFormat()->getFormatCode()

			);

	}



	/**

	 *	Set cell value

	 *

	 *	Sets the value for a cell, automatically determining the datatype using the value binder

	 *

	 *	@param	mixed	$pValue					Value

	 *	@return	PHPExcel_Cell

	 *	@throws	PHPExcel_Exception

	 */

	public function setValue($pValue = NULL)

	{

		if (!self::getValueBinder()->bindValue($this, $pValue)) {

			throw new PHPExcel_Exception("Value could not be bound to cell.");

		}

		return $this;

	}



	/**

	 *	Set the value for a cell, with the explicit data type passed to the method (bypassing any use of the value binder)

	 *

	 *	@param	mixed	$pValue			Value

	 *	@param	string	$pDataType		Explicit data type

	 *	@return	PHPExcel_Cell

	 *	@throws	PHPExcel_Exception

	 */

	public function setValueExplicit($pValue = NULL, $pDataType = PHPExcel_Cell_DataType::TYPE_STRING)

	{

		// set the value according to data type

		switch ($pDataType) {

			case PHPExcel_Cell_DataType::TYPE_NULL:

				$this->_value = $pValue;

				break;

			case PHPExcel_Cell_DataType::TYPE_STRING2:

				$pDataType = PHPExcel_Cell_DataType::TYPE_STRING;

			case PHPExcel_Cell_DataType::TYPE_STRING:

			case PHPExcel_Cell_DataType::TYPE_INLINE:

				$this->_value = PHPExcel_Cell_DataType::checkString($pValue);

				break;

			case PHPExcel_Cell_DataType::TYPE_NUMERIC:

				$this->_value = (float)$pValue;

				break;

			case PHPExcel_Cell_DataType::TYPE_FORMULA:

				$this->_value = (string)$pValue;

				break;

			case PHPExcel_Cell_DataType::TYPE_BOOL:

				$this->_value = (bool)$pValue;

				break;

			case PHPExcel_Cell_DataType::TYPE_ERROR:

				$this->_value = PHPExcel_Cell_DataType::checkErrorCode($pValue);

				break;

			default:

				throw new PHPExcel_Exception('Invalid datatype: ' . $pDataType);

				break;

		}



		// set the datatype

		$this->_dataType = $pDataType;



		return $this->notifyCacheController();

	}



	/**

	 *	Get calculated cell value

	 *

	 *	@deprecated		Since version 1.7.8 for planned changes to cell for array formula handling

	 *

	 *	@param	boolean $resetLog  Whether the calculation engine logger should be reset or not

	 *	@return	mixed

	 *	@throws	PHPExcel_Exception

	 */

	public function getCalculatedValue($resetLog = TRUE)

	{

//echo 'Cell '.$this->getCoordinate().' value is a '.$this->_dataType.' with a value of '.$this->getValue().PHP_EOL;

		if ($this->_dataType == PHPExcel_Cell_DataType::TYPE_FORMULA) {

			try {

//echo 'Cell value for '.$this->getCoordinate().' is a formula: Calculating value'.PHP_EOL;

				$result = PHPExcel_Calculation::getInstance(

					$this->getWorksheet()->getParent()

				)->calculateCellValue($this,$resetLog);

//echo $this->getCoordinate().' calculation result is '.$result.PHP_EOL;

				//	We don't yet handle array returns

				if (is_array($result)) {

					while (is_array($result)) {

						$result = array_pop($result);

					}

				}

			} catch ( PHPExcel_Exception $ex ) {

				if (($ex->getMessage() === 'Unable to access External Workbook') && ($this->_calculatedValue !== NULL)) {

//echo 'Returning fallback value of '.$this->_calculatedValue.' for cell '.$this->getCoordinate().PHP_EOL;

					return $this->_calculatedValue; // Fallback for calculations referencing external files.

				}

//echo 'Calculation Exception: '.$ex->getMessage().PHP_EOL;

				$result = '#N/A';

				throw new PHPExcel_Calculation_Exception(

					$this->getWorksheet()->getTitle().'!'.$this->getCoordinate().' -> '.$ex->getMessage()

				);

			}



			if ($result === '#Not Yet Implemented') {

//echo 'Returning fallback value of '.$this->_calculatedValue.' for cell '.$this->getCoordinate().PHP_EOL;

				return $this->_calculatedValue; // Fallback if calculation engine does not support the formula.

			}

//echo 'Returning calculated value of '.$result.' for cell '.$this->getCoordinate().PHP_EOL;

			return $result;

		} elseif($this->_value instanceof PHPExcel_RichText) {

//		echo 'Cell value for '.$this->getCoordinate().' is rich text: Returning data value of '.$this->_value.'<br />';

			return $this->_value->getPlainText();

		}

//		echo 'Cell value for '.$this->getCoordinate().' is not a formula: Returning data value of '.$this->_value.'<br />';

		return $this->_value;

	}



	/**

	 *	Set old calculated value (cached)

	 *

	 *	@param	mixed $pValue	Value

	 *	@return	PHPExcel_Cell

	 */

	public function setCalculatedValue($pValue = NULL)

	{

		if ($pValue !== NULL) {

			$this->_calculatedValue = (is_numeric($pValue)) ? (float) $pValue : $pValue;

		}



		return $this->notifyCacheController();

	}



	/**

	 *	Get old calculated value (cached)

	 *	This returns the value last calculated by MS Excel or whichever spreadsheet program was used to

	 *		create the original spreadsheet file.

	 *	Note that this value is not guaranteed to refelect the actual calculated value because it is

	 *		possible that auto-calculation was disabled in the original spreadsheet, and underlying data

	 *		values used by the formula have changed since it was last calculated.

	 *

	 *	@return	mixed

	 */

	public function getOldCalculatedValue()

	{

		return $this->_calculatedValue;

	}



	/**

	 *	Get cell data type

	 *

	 *	@return string

	 */

	public function getDataType()

	{

		return $this->_dataType;

	}



	/**

	 *	Set cell data type

	 *

	 *	@param	string $pDataType

	 *	@return	PHPExcel_Cell

	 */

	public function setDataType($pDataType = PHPExcel_Cell_DataType::TYPE_STRING)

	{

		if ($pDataType == PHPExcel_Cell_DataType::TYPE_STRING2)

			$pDataType = PHPExcel_Cell_DataType::TYPE_STRING;



		$this->_dataType = $pDataType;



		return $this->notifyCacheController();

	}



    /**

     *  Identify if the cell contains a formula

     *

     *  @return boolean

     */

    public function isFormula()

    {

        return $this->_dataType == PHPExcel_Cell_DataType::TYPE_FORMULA;

    }



	/**

	 *	Does this cell contain Data validation rules?

	 *

	 *	@return	boolean

	 *	@throws	PHPExcel_Exception

	 */

	public function hasDataValidation()

	{

		if (!isset($this->_parent)) {

			throw new PHPExcel_Exception('Cannot check for data validation when cell is not bound to a worksheet');

		}



		return $this->getWorksheet()->dataValidationExists($this->getCoordinate());

	}



	/**

	 *	Get Data validation rules

	 *

	 *	@return	PHPExcel_Cell_DataValidation

	 *	@throws	PHPExcel_Exception

	 */

	public function getDataValidation()

	{

		if (!isset($this->_parent)) {

			throw new PHPExcel_Exception('Cannot get data validation for cell that is not bound to a worksheet');

		}



		return $this->getWorksheet()->getDataValidation($this->getCoordinate());

	}



	/**

	 *	Set Data validation rules

	 *

	 *	@param	PHPExcel_Cell_DataValidation	$pDataValidation

	 *	@return	PHPExcel_Cell

	 *	@throws	PHPExcel_Exception

	 */

	public function setDataValidation(PHPExcel_Cell_DataValidation $pDataValidation = NULL)

	{

		if (!isset($this->_parent)) {

			throw new PHPExcel_Exception('Cannot set data validation for cell that is not bound to a worksheet');

		}



		$this->getWorksheet()->setDataValidation($this->getCoordinate(), $pDataValidation);



		return $this->notifyCacheController();

	}



	/**

	 *	Does this cell contain a Hyperlink?

	 *

	 *	@return boolean

	 *	@throws	PHPExcel_Exception

	 */

	public function hasHyperlink()

	{

		if (!isset($this->_parent)) {

			throw new PHPExcel_Exception('Cannot check for hyperlink when cell is not bound to a worksheet');

		}



		return $this->getWorksheet()->hyperlinkExists($this->getCoordinate());

	}



	/**

	 *	Get Hyperlink

	 *

	 *	@return	PHPExcel_Cell_Hyperlink

	 *	@throws	PHPExcel_Exception

	 */

	public function getHyperlink()

	{

		if (!isset($this->_parent)) {

			throw new PHPExcel_Exception('Cannot get hyperlink for cell that is not bound to a worksheet');

		}



		return $this->getWorksheet()->getHyperlink($this->getCoordinate());

	}



	/**

	 *	Set Hyperlink

	 *

	 *	@param	PHPExcel_Cell_Hyperlink	$pHyperlink

	 *	@return	PHPExcel_Cell

	 *	@throws	PHPExcel_Exception

	 */

	public function setHyperlink(PHPExcel_Cell_Hyperlink $pHyperlink = NULL)

	{

		if (!isset($this->_parent)) {

			throw new PHPExcel_Exception('Cannot set hyperlink for cell that is not bound to a worksheet');

		}



		$this->getWorksheet()->setHyperlink($this->getCoordinate(), $pHyperlink);



		return $this->notifyCacheController();

	}



	/**

	 *	Get parent worksheet

	 *

	 *	@return PHPExcel_CachedObjectStorage_CacheBase

	 */

	public function getParent() {

		return $this->_parent;

	}



	/**

	 *	Get parent worksheet

	 *

	 *	@return PHPExcel_Worksheet

	 */

	public function getWorksheet() {

		return $this->_parent->getParent();

	}



	/**

	 *	Get cell style

	 *

	 *	@return	PHPExcel_Style

	 */

	public function getStyle()

	{

		return $this->getWorksheet()->getParent()->getCellXfByIndex($this->getXfIndex());

	}



	/**

	 *	Re-bind parent

	 *

	 *	@param	PHPExcel_Worksheet $parent

	 *	@return	PHPExcel_Cell

	 */

	public function rebindParent(PHPExcel_Worksheet $parent) {

		$this->_parent = $parent->getCellCacheController();



		return $this->notifyCacheController();

	}



	/**

	 *	Is cell in a specific range?

	 *

	 *	@param	string	$pRange		Cell range (e.g. A1:A1)

	 *	@return	boolean

	 */

	public function isInRange($pRange = 'A1:A1')

	{

		list($rangeStart,$rangeEnd) = self::rangeBoundaries($pRange);



		// Translate properties

		$myColumn	= self::columnIndexFromString($this->getColumn());

		$myRow		= $this->getRow();



		// Verify if cell is in range

		return (($rangeStart[0] <= $myColumn) && ($rangeEnd[0] >= $myColumn) &&

				($rangeStart[1] <= $myRow) && ($rangeEnd[1] >= $myRow)

			   );

	}



	/**

	 *	Coordinate from string

	 *

	 *	@param	string	$pCoordinateString

	 *	@return	array	Array containing column and row (indexes 0 and 1)

	 *	@throws	PHPExcel_Exception

	 */

	public static function coordinateFromString($pCoordinateString = 'A1')

	{

		if (preg_match("/^([$]?[A-Z]{1,3})([$]?\d{1,7})$/", $pCoordinateString, $matches)) {

			return array($matches[1],$matches[2]);

		} elseif ((strpos($pCoordinateString,':') !== FALSE) || (strpos($pCoordinateString,',') !== FALSE)) {

			throw new PHPExcel_Exception('Cell coordinate string can not be a range of cells');

		} elseif ($pCoordinateString == '') {

			throw new PHPExcel_Exception('Cell coordinate can not be zero-length string');

		}



		throw new PHPExcel_Exception('Invalid cell coordinate '.$pCoordinateString);

	}



	/**

	 *	Make string row, column or cell coordinate absolute

	 *

	 *	@param	string	$pCoordinateString		e.g. 'A' or '1' or 'A1'

	 *					Note that this value can be a row or column reference as well as a cell reference

	 *	@return	string	Absolute coordinate		e.g. '$A' or '$1' or '$A$1'

	 *	@throws	PHPExcel_Exception

	 */

	public static function absoluteReference($pCoordinateString = 'A1')

	{

		if (strpos($pCoordinateString,':') === FALSE && strpos($pCoordinateString,',') === FALSE) {

			// Split out any worksheet name from the reference

			$worksheet = '';

			$cellAddress = explode('!',$pCoordinateString);

			if (count($cellAddress) > 1) {

				list($worksheet,$pCoordinateString) = $cellAddress;

			}

			if ($worksheet > '')	$worksheet .= '!';



			// Create absolute coordinate

			if (ctype_digit($pCoordinateString)) {

				return $worksheet . '$' . $pCoordinateString;

			} elseif (ctype_alpha($pCoordinateString)) {

				return $worksheet . '$' . strtoupper($pCoordinateString);

			}

			return $worksheet . self::absoluteCoordinate($pCoordinateString);

		}



		throw new PHPExcel_Exception('Cell coordinate string can not be a range of cells');

	}



	/**

	 *	Make string coordinate absolute

	 *

	 *	@param	string	$pCoordinateString		e.g. 'A1'

	 *	@return	string	Absolute coordinate		e.g. '$A$1'

	 *	@throws	PHPExcel_Exception

	 */

	public static function absoluteCoordinate($pCoordinateString = 'A1')

	{

		if (strpos($pCoordinateString,':') === FALSE && strpos($pCoordinateString,',') === FALSE) {

			// Split out any worksheet name from the coordinate

			$worksheet = '';

			$cellAddress = explode('!',$pCoordinateString);

			if (count($cellAddress) > 1) {

				list($worksheet,$pCoordinateString) = $cellAddress;

			}

			if ($worksheet > '')	$worksheet .= '!';



			// Create absolute coordinate

			list($column, $row) = self::coordinateFromString($pCoordinateString);

			$column = ltrim($column,'$');

			$row = ltrim($row,'$');

			return $worksheet . '$' . $column . '$' . $row;

		}



		throw new PHPExcel_Exception('Cell coordinate string can not be a range of cells');

	}



	/**

	 *	Split range into coordinate strings

	 *

	 *	@param	string	$pRange		e.g. 'B4:D9' or 'B4:D9,H2:O11' or 'B4'

	 *	@return	array	Array containg one or more arrays containing one or two coordinate strings

	 *								e.g. array('B4','D9') or array(array('B4','D9'),array('H2','O11'))

	 *										or array('B4')

	 */

	public static function splitRange($pRange = 'A1:A1')

	{

		// Ensure $pRange is a valid range

		if(empty($pRange)) {

			$pRange = self::DEFAULT_RANGE;

		}



		$exploded = explode(',', $pRange);

		$counter = count($exploded);

		for ($i = 0; $i < $counter; ++$i) {

			$exploded[$i] = explode(':', $exploded[$i]);

		}

		return $exploded;

	}



	/**

	 *	Build range from coordinate strings

	 *

	 *	@param	array	$pRange	Array containg one or more arrays containing one or two coordinate strings

	 *	@return	string	String representation of $pRange

	 *	@throws	PHPExcel_Exception

	 */

	public static function buildRange($pRange)

	{

		// Verify range

		if (!is_array($pRange) || empty($pRange) || !is_array($pRange[0])) {

			throw new PHPExcel_Exception('Range does not contain any information');

		}



		// Build range

		$imploded = array();

		$counter = count($pRange);

		for ($i = 0; $i < $counter; ++$i) {

			$pRange[$i] = implode(':', $pRange[$i]);

		}

		$imploded = implode(',', $pRange);



		return $imploded;

	}



	/**

	 *	Calculate range boundaries

	 *

	 *	@param	string	$pRange		Cell range (e.g. A1:A1)

	 *	@return	array	Range coordinates array(Start Cell, End Cell)

	 *					where Start Cell and End Cell are arrays (Column Number, Row Number)

	 */

	public static function rangeBoundaries($pRange = 'A1:A1')

	{

		// Ensure $pRange is a valid range

		if(empty($pRange)) {

			$pRange = self::DEFAULT_RANGE;

		}



		// Uppercase coordinate

		$pRange = strtoupper($pRange);



		// Extract range

		if (strpos($pRange, ':') === FALSE) {

			$rangeA = $rangeB = $pRange;

		} else {

			list($rangeA, $rangeB) = explode(':', $pRange);

		}



		// Calculate range outer borders

		$rangeStart = self::coordinateFromString($rangeA);

		$rangeEnd	= self::coordinateFromString($rangeB);



		// Translate column into index

		$rangeStart[0]	= self::columnIndexFromString($rangeStart[0]);

		$rangeEnd[0]	= self::columnIndexFromString($rangeEnd[0]);



		return array($rangeStart, $rangeEnd);

	}



	/**

	 *	Calculate range dimension

	 *

	 *	@param	string	$pRange		Cell range (e.g. A1:A1)

	 *	@return	array	Range dimension (width, height)

	 */

	public static function rangeDimension($pRange = 'A1:A1')

	{

		// Calculate range outer borders

		list($rangeStart,$rangeEnd) = self::rangeBoundaries($pRange);



		return array( ($rangeEnd[0] - $rangeStart[0] + 1), ($rangeEnd[1] - $rangeStart[1] + 1) );

	}



	/**

	 *	Calculate range boundaries

	 *

	 *	@param	string	$pRange		Cell range (e.g. A1:A1)

	 *	@return	array	Range coordinates array(Start Cell, End Cell)

	 *					where Start Cell and End Cell are arrays (Column ID, Row Number)

	 */

	public static function getRangeBoundaries($pRange = 'A1:A1')

	{

		// Ensure $pRange is a valid range

		if(empty($pRange)) {

			$pRange = self::DEFAULT_RANGE;

		}



		// Uppercase coordinate

		$pRange = strtoupper($pRange);



		// Extract range

		if (strpos($pRange, ':') === FALSE) {

			$rangeA = $rangeB = $pRange;

		} else {

			list($rangeA, $rangeB) = explode(':', $pRange);

		}



		return array( self::coordinateFromString($rangeA), self::coordinateFromString($rangeB));

	}



	/**

	 *	Column index from string

	 *

	 *	@param	string $pString

	 *	@return	int Column index (base 1 !!!)

	 */

	public static function columnIndexFromString($pString = 'A')

	{

		//	Using a lookup cache adds a slight memory overhead, but boosts speed

		//	caching using a static within the method is faster than a class static,

		//		though it's additional memory overhead

		static $_indexCache = array();



		if (isset($_indexCache[$pString]))

			return $_indexCache[$pString];



		//	It's surprising how costly the strtoupper() and ord() calls actually are, so we use a lookup array rather than use ord()

		//		and make it case insensitive to get rid of the strtoupper() as well. Because it's a static, there's no significant

		//		memory overhead either

		static $_columnLookup = array(

			'A' => 1, 'B' => 2, 'C' => 3, 'D' => 4, 'E' => 5, 'F' => 6, 'G' => 7, 'H' => 8, 'I' => 9, 'J' => 10, 'K' => 11, 'L' => 12, 'M' => 13,

			'N' => 14, 'O' => 15, 'P' => 16, 'Q' => 17, 'R' => 18, 'S' => 19, 'T' => 20, 'U' => 21, 'V' => 22, 'W' => 23, 'X' => 24, 'Y' => 25, 'Z' => 26,

			'a' => 1, 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5, 'f' => 6, 'g' => 7, 'h' => 8, 'i' => 9, 'j' => 10, 'k' => 11, 'l' => 12, 'm' => 13,

			'n' => 14, 'o' => 15, 'p' => 16, 'q' => 17, 'r' => 18, 's' => 19, 't' => 20, 'u' => 21, 'v' => 22, 'w' => 23, 'x' => 24, 'y' => 25, 'z' => 26

		);



		//	We also use the language construct isset() rather than the more costly strlen() function to match the length of $pString

		//		for improved performance

		if (isset($pString{0})) {

			if (!isset($pString{1})) {

				$_indexCache[$pString] = $_columnLookup[$pString];

				return $_indexCache[$pString];

			} elseif(!isset($pString{2})) {

				$_indexCache[$pString] = $_columnLookup[$pString{0}] * 26 + $_columnLookup[$pString{1}];

				return $_indexCache[$pString];

			} elseif(!isset($pString{3})) {

				$_indexCache[$pString] = $_columnLookup[$pString{0}] * 676 + $_columnLookup[$pString{1}] * 26 + $_columnLookup[$pString{2}];

				return $_indexCache[$pString];

			}

		}

		throw new PHPExcel_Exception("Column string index can not be " . ((isset($pString{0})) ? "longer than 3 characters" : "empty"));

	}



	/**

	 *	String from columnindex

	 *

	 *	@param	int $pColumnIndex Column index (base 0 !!!)

	 *	@return	string

	 */

	public static function stringFromColumnIndex($pColumnIndex = 0)

	{

		//	Using a lookup cache adds a slight memory overhead, but boosts speed

		//	caching using a static within the method is faster than a class static,

		//		though it's additional memory overhead

		static $_indexCache = array();



		if (!isset($_indexCache[$pColumnIndex])) {

			// Determine column string

			if ($pColumnIndex < 26) {

				$_indexCache[$pColumnIndex] = chr(65 + $pColumnIndex);

			} elseif ($pColumnIndex < 702) {

				$_indexCache[$pColumnIndex] = chr(64 + ($pColumnIndex / 26)) .

											  chr(65 + $pColumnIndex % 26);

			} else {

				$_indexCache[$pColumnIndex] = chr(64 + (($pColumnIndex - 26) / 676)) .

											  chr(65 + ((($pColumnIndex - 26) % 676) / 26)) .

											  chr(65 + $pColumnIndex % 26);

			}

		}

		return $_indexCache[$pColumnIndex];

	}



	/**

	 *	Extract all cell references in range

	 *

	 *	@param	string	$pRange		Range (e.g. A1 or A1:C10 or A1:E10 A20:E25)

	 *	@return	array	Array containing single cell references

	 */

	public static function extractAllCellReferencesInRange($pRange = 'A1') {

		// Returnvalue

		$returnValue = array();



		// Explode spaces

		$cellBlocks = explode(' ', str_replace('$', '', strtoupper($pRange)));

		foreach ($cellBlocks as $cellBlock) {

			// Single cell?

			if (strpos($cellBlock,':') === FALSE && strpos($cellBlock,',') === FALSE) {

				$returnValue[] = $cellBlock;

				continue;

			}



			// Range...

			$ranges = self::splitRange($cellBlock);

			foreach($ranges as $range) {

				// Single cell?

				if (!isset($range[1])) {

					$returnValue[] = $range[0];

					continue;

				}



				// Range...

				list($rangeStart, $rangeEnd)	= $range;

				sscanf($rangeStart,'%[A-Z]%d', $startCol, $startRow);

				sscanf($rangeEnd,'%[A-Z]%d', $endCol, $endRow);

				$endCol++;



				// Current data

				$currentCol	= $startCol;

				$currentRow	= $startRow;



				// Loop cells

				while ($currentCol != $endCol) {

					while ($currentRow <= $endRow) {

						$returnValue[] = $currentCol.$currentRow;

						++$currentRow;

					}

					++$currentCol;

					$currentRow = $startRow;

				}

			}

		}



		//	Sort the result by column and row

		$sortKeys = array();

		foreach (array_unique($returnValue) as $coord) {

			sscanf($coord,'%[A-Z]%d', $column, $row);

			$sortKeys[sprintf('%3s%09d',$column,$row)] = $coord;

		}

		ksort($sortKeys);



		// Return value

		return array_values($sortKeys);

	}



	/**

	 * Compare 2 cells

	 *

	 * @param	PHPExcel_Cell	$a	Cell a

	 * @param	PHPExcel_Cell	$b	Cell b

	 * @return	int		Result of comparison (always -1 or 1, never zero!)

	 */

	public static function compareCells(PHPExcel_Cell $a, PHPExcel_Cell $b)

	{

		if ($a->getRow() < $b->getRow()) {

			return -1;

		} elseif ($a->getRow() > $b->getRow()) {

			return 1;

		} elseif (self::columnIndexFromString($a->getColumn()) < self::columnIndexFromString($b->getColumn())) {

			return -1;

		} else {

			return 1;

		}

	}



	/**

	 * Get value binder to use

	 *

	 * @return PHPExcel_Cell_IValueBinder

	 */

	public static function getValueBinder() {

		if (self::$_valueBinder === NULL) {

			self::$_valueBinder = new PHPExcel_Cell_DefaultValueBinder();

		}



		return self::$_valueBinder;

	}



	/**

	 * Set value binder to use

	 *

	 * @param PHPExcel_Cell_IValueBinder $binder

	 * @throws PHPExcel_Exception

	 */

	public static function setValueBinder(PHPExcel_Cell_IValueBinder $binder = NULL) {

		if ($binder === NULL) {

			throw new PHPExcel_Exception("A PHPExcel_Cell_IValueBinder is required for PHPExcel to function correctly.");

		}



		self::$_valueBinder = $binder;

	}



	/**

	 * Implement PHP __clone to create a deep clone, not just a shallow copy.

	 */

	public function __clone() {

		$vars = get_object_vars($this);

		foreach ($vars as $key => $value) {

			if ((is_object($value)) && ($key != '_parent')) {

				$this->$key = clone $value;

			} else {

				$this->$key = $value;

			}

		}

	}



	/**

	 * Get index to cellXf

	 *

	 * @return int

	 */

	public function getXfIndex()

	{

		return $this->_xfIndex;

	}



	/**

	 * Set index to cellXf

	 *

	 * @param int $pValue

	 * @return PHPExcel_Cell

	 */

	public function setXfIndex($pValue = 0)

	{

		$this->_xfIndex = $pValue;



		return $this->notifyCacheController();

	}



	/**

	 *	@deprecated		Since version 1.7.8 for planned changes to cell for array formula handling

	 */

	public function setFormulaAttributes($pAttributes)

	{

		$this->_formulaAttributes = $pAttributes;

		return $this;

	}



	/**

	 *	@deprecated		Since version 1.7.8 for planned changes to cell for array formula handling

	 */

	public function getFormulaAttributes()

	{

		return $this->_formulaAttributes;

	}



    /**

     * Convert to string

     *

     * @return string

     */

	public function __toString()

	{

		return (string) $this->getValue();

	}



}



