Currency.php 28.7 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894
<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category  Zend
 * @package   Zend_Currency
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license   http://framework.zend.com/license/new-bsd     New BSD License
 * @version   $Id: Currency.php 23775 2011-03-01 17:25:24Z ralph $
 */

/**
 * include needed classes
 */
require_once 'Zend/Locale.php';
require_once 'Zend/Locale/Data.php';
require_once 'Zend/Locale/Format.php';

/**
 * Class for handling currency notations
 *
 * @category  Zend
 * @package   Zend_Currency
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license   http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Currency
{
    // Constants for defining what currency symbol should be displayed
    const NO_SYMBOL     = 1;
    const USE_SYMBOL    = 2;
    const USE_SHORTNAME = 3;
    const USE_NAME      = 4;

    // Constants for defining the position of the currencysign
    const STANDARD = 8;
    const RIGHT    = 16;
    const LEFT     = 32;

    /**
     * Options array
     *
     * The following options are available
     * 'position'  => Position for the currency sign
     * 'script'    => Script for the output
     * 'format'    => Locale for numeric output
     * 'display'   => Currency detail to show
     * 'precision' => Precision for the currency
     * 'name'      => Name for this currency
     * 'currency'  => 3 lettered international abbreviation
     * 'symbol'    => Currency symbol
     * 'locale'    => Locale for this currency
     * 'value'     => Money value
     * 'service'   => Exchange service to use
     *
     * @var array
     * @see Zend_Locale
     */
    protected $_options = array(
        'position'  => self::STANDARD,
        'script'    => null,
        'format'    => null,
        'display'   => self::NO_SYMBOL,
        'precision' => 2,
        'name'      => null,
        'currency'  => null,
        'symbol'    => null,
        'locale'    => null,
        'value'     => 0,
        'service'   => null,
        'tag'       => 'Zend_Locale'
    );

    /**
     * Creates a currency instance. Every supressed parameter is used from the actual or the given locale.
     *
     * @param  string|array       $options OPTIONAL Options array or currency short name
     *                                              when string is given
     * @param  string|Zend_Locale $locale  OPTIONAL locale name
     * @throws Zend_Currency_Exception When currency is invalid
     */
    public function __construct($options = null, $locale = null)
    {
        if (is_array($options)) {
            $this->setLocale($locale);
            $this->setFormat($options);
        } else if (Zend_Locale::isLocale($options, false, false)) {
            $this->setLocale($options);
            $options = $locale;
        } else {
            $this->setLocale($locale);
        }

        // Get currency details
        if (!isset($this->_options['currency']) || !is_array($options)) {
            $this->_options['currency'] = self::getShortName($options, $this->_options['locale']);
        }

        if (!isset($this->_options['name']) || !is_array($options)) {
            $this->_options['name']     = self::getName($options, $this->_options['locale']);
        }

        if (!isset($this->_options['symbol']) || !is_array($options)) {
            $this->_options['symbol']   = self::getSymbol($options, $this->_options['locale']);
        }

        if (($this->_options['currency'] === null) and ($this->_options['name'] === null)) {
            require_once 'Zend/Currency/Exception.php';
            throw new Zend_Currency_Exception("Currency '$options' not found");
        }

        // Get the format
        if (!empty($this->_options['symbol'])) {
            $this->_options['display'] = self::USE_SYMBOL;
        } else if (!empty($this->_options['currency'])) {
            $this->_options['display'] = self::USE_SHORTNAME;
        }
    }

    /**
     * Returns a localized currency string
     *
     * @param  integer|float $value   OPTIONAL Currency value
     * @param  array         $options OPTIONAL options to set temporary
     * @throws Zend_Currency_Exception When the value is not a number
     * @return string
     */
    public function toCurrency($value = null, array $options = array())
    {
        if ($value === null) {
            if (is_array($options) && isset($options['value'])) {
                $value = $options['value'];
            } else {
                $value = $this->_options['value'];
            }
        }

        if (is_array($value)) {
            $options += $value;
            if (isset($options['value'])) {
                $value = $options['value'];
            }
        }

        // Validate the passed number
        if (!(isset($value)) or (is_numeric($value) === false)) {
            require_once 'Zend/Currency/Exception.php';
            throw new Zend_Currency_Exception("Value '$value' has to be numeric");
        }

        if (isset($options['currency'])) {
            if (!isset($options['locale'])) {
                $options['locale'] = $this->_options['locale'];
            }

            $options['currency'] = self::getShortName($options['currency'], $options['locale']);
            $options['name']     = self::getName($options['currency'], $options['locale']);
            $options['symbol']   = self::getSymbol($options['currency'], $options['locale']);
        }

        $options = $this->_checkOptions($options) + $this->_options;

        // Format the number
        $format = $options['format'];
        $locale = $options['locale'];
        if (empty($format)) {
            $format = Zend_Locale_Data::getContent($locale, 'currencynumber');
        } else if (Zend_Locale::isLocale($format, true, false)) {
            $locale = $format;
            $format = Zend_Locale_Data::getContent($format, 'currencynumber');
        }

        $original = $value;
        $value    = Zend_Locale_Format::toNumber($value, array('locale'        => $locale,
                                                               'number_format' => $format,
                                                               'precision'     => $options['precision']));

        if ($options['position'] !== self::STANDARD) {
            $value = str_replace('¤', '', $value);
            $space = '';
            if (iconv_strpos($value, ' ') !== false) {
                $value = str_replace(' ', '', $value);
                $space = ' ';
            }

            if ($options['position'] == self::LEFT) {
                $value = '¤' . $space . $value;
            } else {
                $value = $value . $space . '¤';
            }
        }

        // Localize the number digits
        if (empty($options['script']) === false) {
            $value = Zend_Locale_Format::convertNumerals($value, 'Latn', $options['script']);
        }

        // Get the sign to be placed next to the number
        if (is_numeric($options['display']) === false) {
            $sign = $options['display'];
        } else {
            switch($options['display']) {
                case self::USE_SYMBOL:
                    $sign = $this->_extractPattern($options['symbol'], $original);
                    break;

                case self::USE_SHORTNAME:
                    $sign = $options['currency'];
                    break;

                case self::USE_NAME:
                    $sign = $options['name'];
                    break;

                default:
                    $sign = '';
                    $value = str_replace(' ', '', $value);
                    break;
            }
        }

        $value = str_replace('¤', $sign, $value);
        return $value;
    }

    /**
     * Internal method to extract the currency pattern
     * when a choice is given based on the given value
     *
     * @param  string $pattern
     * @param  float|integer $value
     * @return string
     */
    private function _extractPattern($pattern, $value)
    {
        if (strpos($pattern, '|') === false) {
            return $pattern;
        }

        $patterns = explode('|', $pattern);
        $token    = $pattern;
        $value    = trim(str_replace('¤', '', $value));
        krsort($patterns);
        foreach($patterns as $content) {
            if (strpos($content, '<') !== false) {
                $check = iconv_substr($content, 0, iconv_strpos($content, '<'));
                $token = iconv_substr($content, iconv_strpos($content, '<') + 1);
                if ($check < $value) {
                    return $token;
                }
            } else {
                $check = iconv_substr($content, 0, iconv_strpos($content, '≤'));
                $token = iconv_substr($content, iconv_strpos($content, '≤') + 1);
                if ($check <= $value) {
                    return $token;
                }
            }

        }

        return $token;
    }

    /**
     * Sets the formating options of the localized currency string
     * If no parameter is passed, the standard setting of the
     * actual set locale will be used
     *
     * @param  array $options (Optional) Options to set
     * @return Zend_Currency
     */
    public function setFormat(array $options = array())
    {
        $this->_options = $this->_checkOptions($options) + $this->_options;
        return $this;
    }

    /**
     * Internal function for checking static given locale parameter
     *
     * @param  string             $currency (Optional) Currency name
     * @param  string|Zend_Locale $locale   (Optional) Locale to display informations
     * @throws Zend_Currency_Exception When locale contains no region
     * @return string The extracted locale representation as string
     */
    private function _checkParams($currency = null, $locale = null)
    {
        // Manage the params
        if ((empty($locale)) and (!empty($currency)) and
            (Zend_Locale::isLocale($currency, true, false))) {
            $locale   = $currency;
            $currency = null;
        }

        // Validate the locale and get the country short name
        $country = null;
        if ((Zend_Locale::isLocale($locale, true, false)) and (strlen($locale) > 4)) {
            $country = substr($locale, (strpos($locale, '_') + 1));
        } else {
            require_once 'Zend/Currency/Exception.php';
            throw new Zend_Currency_Exception("No region found within the locale '" . (string) $locale . "'");
        }

        // Get the available currencies for this country
        $data = Zend_Locale_Data::getContent($locale, 'currencytoregion', $country);
        if ((empty($currency) === false) and (empty($data) === false)) {
            $abbreviation = $currency;
        } else {
            $abbreviation = $data;
        }

        return array('locale' => $locale, 'currency' => $currency, 'name' => $abbreviation, 'country' => $country);
    }

    /**
     * Returns the actual or details of other currency symbols,
     * when no symbol is available it returns the currency shortname (f.e. FIM for Finnian Mark)
     *
     * @param  string             $currency (Optional) Currency name
     * @param  string|Zend_Locale $locale   (Optional) Locale to display informations
     * @return string
     */
    public function getSymbol($currency = null, $locale = null)
    {
        if (($currency === null) and ($locale === null)) {
            return $this->_options['symbol'];
        }

        $params = self::_checkParams($currency, $locale);

        // Get the symbol
        $symbol = Zend_Locale_Data::getContent($params['locale'], 'currencysymbol', $params['currency']);
        if (empty($symbol) === true) {
            $symbol = Zend_Locale_Data::getContent($params['locale'], 'currencysymbol', $params['name']);
        }

        if (empty($symbol) === true) {
            return null;
        }

        return $symbol;
    }

    /**
     * Returns the actual or details of other currency shortnames
     *
     * @param  string             $currency OPTIONAL Currency's name
     * @param  string|Zend_Locale $locale   OPTIONAL The locale
     * @return string
     */
    public function getShortName($currency = null, $locale = null)
    {
        if (($currency === null) and ($locale === null)) {
            return $this->_options['currency'];
        }

        $params = self::_checkParams($currency, $locale);

        // Get the shortname
        if (empty($params['currency']) === true) {
            return $params['name'];
        }

        $list = Zend_Locale_Data::getContent($params['locale'], 'currencytoname', $params['currency']);
        if (empty($list) === true) {
            $list = Zend_Locale_Data::getContent($params['locale'], 'nametocurrency', $params['currency']);
            if (empty($list) === false) {
                $list = $params['currency'];
            }
        }

        if (empty($list) === true) {
            return null;
        }

        return $list;
    }

    /**
     * Returns the actual or details of other currency names
     *
     * @param  string             $currency (Optional) Currency's short name
     * @param  string|Zend_Locale $locale   (Optional) The locale
     * @return string
     */
    public function getName($currency = null, $locale = null)
    {
        if (($currency === null) and ($locale === null)) {
            return $this->_options['name'];
        }

        $params = self::_checkParams($currency, $locale);

        // Get the name
        $name = Zend_Locale_Data::getContent($params['locale'], 'nametocurrency', $params['currency']);
        if (empty($name) === true) {
            $name = Zend_Locale_Data::getContent($params['locale'], 'nametocurrency', $params['name']);
        }

        if (empty($name) === true) {
            return null;
        }

        return $name;
    }

    /**
     * Returns a list of regions where this currency is or was known
     *
     * @param  string $currency OPTIONAL Currency's short name
     * @throws Zend_Currency_Exception When no currency was defined
     * @return array List of regions
     */
    public function getRegionList($currency = null)
    {
        if ($currency === null) {
            $currency = $this->_options['currency'];
        }

        if (empty($currency) === true) {
            require_once 'Zend/Currency/Exception.php';
            throw new Zend_Currency_Exception('No currency defined');
        }

        $data = Zend_Locale_Data::getContent($this->_options['locale'], 'regiontocurrency', $currency);

        $result = explode(' ', $data);
        return $result;
    }

    /**
     * Returns a list of currencies which are used in this region
     * a region name should be 2 charachters only (f.e. EG, DE, US)
     * If no region is given, the actual region is used
     *
     * @param  string $region OPTIONAL Region to return the currencies for
     * @return array List of currencies
     */
    public function getCurrencyList($region = null)
    {
        if (empty($region) === true) {
            if (strlen($this->_options['locale']) > 4) {
                $region = substr($this->_options['locale'], (strpos($this->_options['locale'], '_') + 1));
            }
        }

        $data = Zend_Locale_Data::getContent($this->_options['locale'], 'currencytoregion', $region);

        $result = explode(' ', $data);
        return $result;
    }

    /**
     * Returns the actual currency name
     *
     * @return string
     */
    public function toString()
    {
        return $this->toCurrency();
    }

    /**
     * Returns the currency name
     *
     * @return string
     */
    public function __toString()
    {
        return $this->toString();
    }

    /**
     * Returns the set cache
     *
     * @return Zend_Cache_Core The set cache
     */
    public static function getCache()
    {
        return Zend_Locale_Data::getCache();
    }

    /**
     * Sets a cache for Zend_Currency
     *
     * @param  Zend_Cache_Core $cache Cache to set
     * @return void
     */
    public static function setCache(Zend_Cache_Core $cache)
    {
        Zend_Locale_Data::setCache($cache);
    }

    /**
     * Returns true when a cache is set
     *
     * @return boolean
     */
    public static function hasCache()
    {
        return Zend_Locale_Data::hasCache();
    }

    /**
     * Removes any set cache
     *
     * @return void
     */
    public static function removeCache()
    {
        Zend_Locale_Data::removeCache();
    }

    /**
     * Clears all set cache data
     *
     * @param string $tag Tag to clear when the default tag name is not used
     * @return void
     */
    public static function clearCache($tag = null)
    {
        Zend_Locale_Data::clearCache($tag);
    }

    /**
     * Sets a new locale for data retreivement
     * Example: 'de_XX' will be set to 'de' because 'de_XX' does not exist
     * 'xx_YY' will be set to 'root' because 'xx' does not exist
     *
     * @param  string|Zend_Locale $locale (Optional) Locale for parsing input
     * @throws Zend_Currency_Exception When the given locale does not exist
     * @return Zend_Currency Provides fluent interface
     */
    public function setLocale($locale = null)
    {
        require_once 'Zend/Locale.php';
        try {
            $locale = Zend_Locale::findLocale($locale);
            if (strlen($locale) > 4) {
                $this->_options['locale'] = $locale;
            } else {
                require_once 'Zend/Currency/Exception.php';
                throw new Zend_Currency_Exception("No region found within the locale '" . (string) $locale . "'");
            }
        } catch (Zend_Locale_Exception $e) {
            require_once 'Zend/Currency/Exception.php';
            throw new Zend_Currency_Exception($e->getMessage());
        }

        // Get currency details
        $this->_options['currency'] = $this->getShortName(null, $this->_options['locale']);
        $this->_options['name']     = $this->getName(null, $this->_options['locale']);
        $this->_options['symbol']   = $this->getSymbol(null, $this->_options['locale']);

        return $this;
    }

    /**
     * Returns the actual set locale
     *
     * @return string
     */
    public function getLocale()
    {
        return $this->_options['locale'];
    }

    /**
     * Returns the value
     *
     * @return float
     */
    public function getValue()
    {
        return $this->_options['value'];
    }

    /**
     * Adds a currency
     *
     * @param float|integer|Zend_Currency $value    Add this value to currency
     * @param string|Zend_Currency        $currency The currency to add
     * @return Zend_Currency
     */
    public function setValue($value, $currency = null)
    {
        $this->_options['value'] = $this->_exchangeCurrency($value, $currency);
        return $this;
    }

    /**
     * Adds a currency
     *
     * @param float|integer|Zend_Currency $value    Add this value to currency
     * @param string|Zend_Currency        $currency The currency to add
     * @return Zend_Currency
     */
    public function add($value, $currency = null)
    {
        $value = $this->_exchangeCurrency($value, $currency);
        $this->_options['value'] += (float) $value;
        return $this;
    }

    /**
     * Substracts a currency
     *
     * @param float|integer|Zend_Currency $value    Substracts this value from currency
     * @param string|Zend_Currency        $currency The currency to substract
     * @return Zend_Currency
     */
    public function sub($value, $currency = null)
    {
        $value = $this->_exchangeCurrency($value, $currency);
        $this->_options['value'] -= (float) $value;
        return $this;
    }

    /**
     * Divides a currency
     *
     * @param float|integer|Zend_Currency $value    Divides this value from currency
     * @param string|Zend_Currency        $currency The currency to divide
     * @return Zend_Currency
     */
    public function div($value, $currency = null)
    {
        $value = $this->_exchangeCurrency($value, $currency);
        $this->_options['value'] /= (float) $value;
        return $this;
    }

    /**
     * Multiplies a currency
     *
     * @param float|integer|Zend_Currency $value    Multiplies this value from currency
     * @param string|Zend_Currency        $currency The currency to multiply
     * @return Zend_Currency
     */
    public function mul($value, $currency = null)
    {
        $value = $this->_exchangeCurrency($value, $currency);
        $this->_options['value'] *= (float) $value;
        return $this;
    }

    /**
     * Calculates the modulo from a currency
     *
     * @param float|integer|Zend_Currency $value    Calculate modulo from this value
     * @param string|Zend_Currency        $currency The currency to calculate the modulo
     * @return Zend_Currency
     */
    public function mod($value, $currency = null)
    {
        $value = $this->_exchangeCurrency($value, $currency);
        $this->_options['value'] %= (float) $value;
        return $this;
    }

    /**
     * Compares two currencies
     *
     * @param float|integer|Zend_Currency $value    Compares the currency with this value
     * @param string|Zend_Currency        $currency The currency to compare this value from
     * @return Zend_Currency
     */
    public function compare($value, $currency = null)
    {
        $value = $this->_exchangeCurrency($value, $currency);
        $value = $this->_options['value'] - $value;
        if ($value < 0) {
            return -1;
        } else if ($value > 0) {
            return 1;
        }

        return 0;
    }

    /**
     * Returns true when the two currencies are equal
     *
     * @param float|integer|Zend_Currency $value    Compares the currency with this value
     * @param string|Zend_Currency        $currency The currency to compare this value from
     * @return boolean
     */
    public function equals($value, $currency = null)
    {
        $value = $this->_exchangeCurrency($value, $currency);
        if ($this->_options['value'] == $value) {
            return true;
        }

        return false;
    }

    /**
     * Returns true when the currency is more than the given value
     *
     * @param float|integer|Zend_Currency $value    Compares the currency with this value
     * @param string|Zend_Currency        $currency The currency to compare this value from
     * @return boolean
     */
    public function isMore($value, $currency = null)
    {
        $value = $this->_exchangeCurrency($value, $currency);
        if ($this->_options['value'] > $value) {
            return true;
        }

        return false;
    }

    /**
     * Returns true when the currency is less than the given value
     *
     * @param float|integer|Zend_Currency $value    Compares the currency with this value
     * @param string|Zend_Currency        $currency The currency to compare this value from
     * @return boolean
     */
    public function isLess($value, $currency = null)
    {
        $value = $this->_exchangeCurrency($value, $currency);
        if ($this->_options['value'] < $value) {
            return true;
        }

        return false;

    }

    /**
     * Internal method which calculates the exchanges currency
     *
     * @param float|integer|Zend_Currency $value    Compares the currency with this value
     * @param string|Zend_Currency        $currency The currency to compare this value from
     * @return unknown
     */
    protected function _exchangeCurrency($value, $currency)
    {
        if ($value instanceof Zend_Currency) {
            $currency = $value->getShortName();
            $value    = $value->getValue();
        } else {
            $currency = $this->getShortName($currency, $this->getLocale());
        }

        $rate = 1;
        if ($currency !== $this->getShortName()) {
            $service = $this->getService();
            if (!($service instanceof Zend_Currency_CurrencyInterface)) {
                require_once 'Zend/Currency/Exception.php';
                throw new Zend_Currency_Exception('No exchange service applied');
            }

            $rate = $service->getRate($currency, $this->getShortName());
        }

        $value *= $rate;
        return $value;
    }

    /**
     * Returns the set service class
     *
     * @return Zend_Service
     */
    public function getService()
    {
        return $this->_options['service'];
    }

    /**
     * Sets a new exchange service
     *
     * @param string|Zend_Currency_CurrencyInterface $service Service class
     * @return Zend_Currency
     */
    public function setService($service)
    {
        if (is_string($service)) {
            require_once 'Zend/Loader.php';
            if (!class_exists($service)) {
                $file = str_replace('_', DIRECTORY_SEPARATOR, $service) . '.php';
                if (Zend_Loader::isReadable($file)) {
                    Zend_Loader::loadClass($service);
                }
            }

            $service = new $service;
        }

        if (!($service instanceof Zend_Currency_CurrencyInterface)) {
            require_once 'Zend/Currency/Exception.php';
            throw new Zend_Currency_Exception('A currency service must implement Zend_Currency_CurrencyInterface');
        }

        $this->_options['service'] = $service;
        return $this;
    }

    /**
     * Internal method for checking the options array
     *
     * @param  array $options Options to check
     * @throws Zend_Currency_Exception On unknown position
     * @throws Zend_Currency_Exception On unknown locale
     * @throws Zend_Currency_Exception On unknown display
     * @throws Zend_Currency_Exception On precision not between -1 and 30
     * @throws Zend_Currency_Exception On problem with script conversion
     * @throws Zend_Currency_Exception On unknown options
     * @return array
     */
    protected function _checkOptions(array $options = array())
    {
        if (count($options) === 0) {
            return $this->_options;
        }

        foreach ($options as $name => $value) {
            $name = strtolower($name);
            if ($name !== 'format') {
                if (gettype($value) === 'string') {
                    $value = strtolower($value);
                }
            }

            switch($name) {
                case 'position':
                    if (($value !== self::STANDARD) and ($value !== self::RIGHT) and ($value !== self::LEFT)) {
                        require_once 'Zend/Currency/Exception.php';
                        throw new Zend_Currency_Exception("Unknown position '" . $value . "'");
                    }

                    break;

                case 'format':
                    if ((empty($value) === false) and (Zend_Locale::isLocale($value, null, false) === false)) {
                        if (!is_string($value) || (strpos($value, '0') === false)) {
                            require_once 'Zend/Currency/Exception.php';
                            throw new Zend_Currency_Exception("'" .
                                ((gettype($value) === 'object') ? get_class($value) : $value)
                                . "' is no format token");
                        }
                    }
                    break;

                case 'display':
                    if (is_numeric($value) and ($value !== self::NO_SYMBOL) and ($value !== self::USE_SYMBOL) and
                        ($value !== self::USE_SHORTNAME) and ($value !== self::USE_NAME)) {
                        require_once 'Zend/Currency/Exception.php';
                        throw new Zend_Currency_Exception("Unknown display '$value'");
                    }
                    break;

                case 'precision':
                    if ($value === null) {
                        $value = -1;
                    }

                    if (($value < -1) or ($value > 30)) {
                        require_once 'Zend/Currency/Exception.php';
                        throw new Zend_Currency_Exception("'$value' precision has to be between -1 and 30.");
                    }
                    break;

                case 'script':
                    try {
                        Zend_Locale_Format::convertNumerals(0, $options['script']);
                    } catch (Zend_Locale_Exception $e) {
                        require_once 'Zend/Currency/Exception.php';
                        throw new Zend_Currency_Exception($e->getMessage());
                    }
                    break;

                default:
                    break;
            }
        }

        return $options;
    }
}