source: Dev/branches/cakephp/cake/libs/view/helpers/number.php @ 126

<?php
/**
 * Number Helper.
 *
 * Methods to make numbers more readable.
 *
 * PHP versions 4 and 5
 *
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright 2005-2011, Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright 2005-2011, Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @package       cake
 * @subpackage    cake.cake.libs.view.helpers
 * @since         CakePHP(tm) v 0.10.0.1076
 * @license       MIT License (http://www.opensource.org/licenses/mit-license.php)
 */

/**
 * Number helper library.
 *
 * Methods to make numbers more readable.
 *
 * @package       cake
 * @subpackage    cake.cake.libs.view.helpers
 * @link http://book.cakephp.org/view/1452/Number
 */
class NumberHelper extends AppHelper {

/**
 * Currencies supported by the helper.  You can add additional currency formats
 * with NumberHelper::addFormat
 *
 * @var array
 * @access protected
 */
        var $_currencies = array(
                'USD' => array(
                        'before' => '$', 'after' => 'c', 'zero' => 0, 'places' => 2, 'thousands' => ',',
                        'decimals' => '.', 'negative' => '()', 'escape' => true
                ),
                'GBP' => array(
                        'before'=>'&#163;', 'after' => 'p', 'zero' => 0, 'places' => 2, 'thousands' => ',',
                        'decimals' => '.', 'negative' => '()','escape' => false
                ),
                'EUR' => array(
                        'before'=>'&#8364;', 'after' => false, 'zero' => 0, 'places' => 2, 'thousands' => '.',
                        'decimals' => ',', 'negative' => '()', 'escape' => false
                )
        );

/**
 * Default options for currency formats
 *
 * @var array
 * @access protected
 */
        var $_currencyDefaults = array(
                'before'=>'', 'after' => '', 'zero' => '0', 'places' => 2, 'thousands' => ',',
                'decimals' => '.','negative' => '()', 'escape' => true
        );

/**
 * Formats a number with a level of precision.
 *
 * @param float $number A floating point number.
 * @param integer $precision The precision of the returned number.
 * @return float Formatted float.
 * @access public
 * @link http://book.cakephp.org/view/1454/precision
 */
        function precision($number, $precision = 3) {
                return sprintf("%01.{$precision}f", $number);
        }

/**
 * Returns a formatted-for-humans file size.
 *
 * @param integer $length Size in bytes
 * @return string Human readable size
 * @access public
 * @link http://book.cakephp.org/view/1456/toReadableSize
 */
        function toReadableSize($size) {
                switch (true) {
                        case $size < 1024:
                                return sprintf(__n('%d Byte', '%d Bytes', $size, true), $size);
                        case round($size / 1024) < 1024:
                                return sprintf(__('%d KB', true), $this->precision($size / 1024, 0));
                        case round($size / 1024 / 1024, 2) < 1024:
                                return sprintf(__('%.2f MB', true), $this->precision($size / 1024 / 1024, 2));
                        case round($size / 1024 / 1024 / 1024, 2) < 1024:
                                return sprintf(__('%.2f GB', true), $this->precision($size / 1024 / 1024 / 1024, 2));
                        default:
                                return sprintf(__('%.2f TB', true), $this->precision($size / 1024 / 1024 / 1024 / 1024, 2));
                }
        }

/**
 * Formats a number into a percentage string.
 *
 * @param float $number A floating point number
 * @param integer $precision The precision of the returned number
 * @return string Percentage string
 * @access public
 * @link http://book.cakephp.org/view/1455/toPercentage
 */
        function toPercentage($number, $precision = 2) {
                return $this->precision($number, $precision) . '%';
        }

/**
 * Formats a number into a currency format.
 *
 * @param float $number A floating point number
 * @param integer $options if int then places, if string then before, if (,.-) then use it
 *   or array with places and before keys
 * @return string formatted number
 * @access public
 * @link http://book.cakephp.org/view/1457/format
 */
        function format($number, $options = false) {
                $places = 0;
                if (is_int($options)) {
                        $places = $options;
                }

                $separators = array(',', '.', '-', ':');

                $before = $after = null;
                if (is_string($options) && !in_array($options, $separators)) {
                        $before = $options;
                }
                $thousands = ',';
                if (!is_array($options) && in_array($options, $separators)) {
                        $thousands = $options;
                }
                $decimals = '.';
                if (!is_array($options) && in_array($options, $separators)) {
                        $decimals = $options;
                }

                $escape = true;
                if (is_array($options)) {
                        $options = array_merge(array('before'=>'$', 'places' => 2, 'thousands' => ',', 'decimals' => '.'), $options);
                        extract($options);
                }

                $out = $before . number_format($number, $places, $decimals, $thousands) . $after;

                if ($escape) {
                        return h($out);
                }
                return $out;
        }

/**
 * Formats a number into a currency format.
 *
 * ### Options
 *
 * - `before` - The currency symbol to place before whole numbers ie. '$'
 * - `after` - The currency symbol to place after decimal numbers ie. 'c'. Set to boolean false to 
 *    use no decimal symbol.  eg. 0.35 => $0.35.
 * - `zero` - The text to use for zero values, can be a string or a number. ie. 0, 'Free!'
 * - `places` - Number of decimal places to use. ie. 2
 * - `thousands` - Thousands separator ie. ','
 * - `decimals` - Decimal separator symbol ie. '.'
 * - `negative` - Symbol for negative numbers. If equal to '()', the number will be wrapped with ( and )
 * - `escape` - Should the output be htmlentity escaped? Defaults to true
 *
 * @param float $number
 * @param string $currency Shortcut to default options. Valid values are 'USD', 'EUR', 'GBP', otherwise
 *   set at least 'before' and 'after' options.
 * @param array $options
 * @return string Number formatted as a currency.
 * @access public
 * @link http://book.cakephp.org/view/1453/currency
 */
        function currency($number, $currency = 'USD', $options = array()) {
                $default = $this->_currencyDefaults;

                if (isset($this->_currencies[$currency])) {
                        $default = $this->_currencies[$currency];
                } elseif (is_string($currency)) {
                        $options['before'] = $currency;
                }

                $options = array_merge($default, $options);

                $result = null;

                if ($number == 0 ) {
                        if ($options['zero'] !== 0 ) {
                                return $options['zero'];
                        }
                        $options['after'] = null;
                } elseif ($number < 1 && $number > -1 ) {
                        if ($options['after'] !== false) {
                                $multiply = intval('1' . str_pad('', $options['places'], '0'));
                                $number = $number * $multiply;
                                $options['before'] = null;
                                $options['places'] = null;
                        }
                } elseif (empty($options['before'])) {
                        $options['before'] = null;
                } else {
                        $options['after'] = null;
                }

                $abs = abs($number);
                $result = $this->format($abs, $options);

                if ($number < 0 ) {
                        if ($options['negative'] == '()') {
                                $result = '(' . $result .')';
                        } else {
                                $result = $options['negative'] . $result;
                        }
                }
                return $result;
        }

/**
 * Add a currency format to the Number helper.  Makes reusing
 * currency formats easier.
 *
 * {{{ $number->addFormat('NOK', array('before' => 'Kr. ')); }}}
 * 
 * You can now use `NOK` as a shortform when formatting currency amounts.
 *
 * {{{ $number->currency($value, 'NOK'); }}}
 *
 * Added formats are merged with the following defaults.
 *
 * {{{
 *      array(
 *              'before' => '$', 'after' => 'c', 'zero' => 0, 'places' => 2, 'thousands' => ',',
 *              'decimals' => '.', 'negative' => '()', 'escape' => true
 *      )
 * }}}
 *
 * @param string $formatName The format name to be used in the future.
 * @param array $options The array of options for this format.
 * @return void
 * @see NumberHelper::currency()
 * @access public
 */
        function addFormat($formatName, $options) {
                $this->_currencies[$formatName] = $options + $this->_currencyDefaults;
        }

}