How to Work with Currencies
To use Zend_Currency within your application, create an instance of it without any
parameters. This will create an instance of Zend_Currency with your locale set and defines
the currency which should be used for this locale.
Creating an Instance of Zend_Currency from the Locale
Assume you have 'en_US' set as the set locale by the user or your environment. By passing no
parameters while creating the instance you tell Zend_Currency to use the currency
from the locale 'en_US'. This leads to an instance with US Dollar set as the currency with
formatting rules from 'en_US'.
Zend_Currency also supports the usage of an application-wide locale. You can set a Zend_Locale instance in the registry as shown
below. With this notation you can avoid setting the locale manually for each instance when
you want to use the same locale throughout the application.
If your system has no default locale, or if the locale of your system can not be
detected automatically, Zend_Currency will throw an exception. If see this exception, you should consider setting the locale manually.
Depending on your needs, several parameters can be speicified at instantiation. Each of these parameters
is optional and can be omitted. Even the order of the parameters can be switched. The meaning of each
parameter is described in this list:
currency:
A locale can include several currencies. Therefore the first parameter
'currency' can define which currency should be used by giving
the short name or full name of that currency. If that currency in not recognized in any locale an
exception will be thrown. Currency short names are always made up of 3 letters, written in uppercase.
Well known currency shortnames include USD or EUR.
locale:
The 'locale' parameter defines which locale should be
used for formatting the currency. The specified locale will also be used to get the script and symbol for this currency if these parameters are not given.
Note that Zend_Currency only accepts locales which include a region. This means that all
locales that only include a language will result in an exception. For example the locale
en will cause an exception to be thrown whereas the locale
en_US will return USD
as currency.
Other Ways to Create Instances of Zend_Currency
You can omit any of the parameters to Zend_Currency's constructor if you want to use the default values. This has no negative effect
on handling the currencies. It can be useful if, for example, you don't know the default currency for a region.
For many countries there are several known currencies. Typically, one currency will currently be in use, with one or more ancient currencies. If the 'currency' parameter
is suppressed the contemporary currency will be used. The region 'de' for
example knows the currencies 'EUR' and
'DEM'... 'EUR' is the contemporary currency
and will be used if the currency parameter is omitted.
Creating and Output String from a Currency
To get a numeric value converted to an output string formatted for the currency at hand, use the method
toCurrency(). It takes the value which should be converted.
The value itself can be any normalized number.
If you have a localized number you will have to convert it first to an normalized number with
Zend_Locale_Format::getNumber(). It may then
be used with toCurrency() to create a currency output string.
toCurrency(array $options) accepts an array with options which can be used to temporarily set another
format or currency representation. For details about which options can be used see
Changing the Format of a Currency.
Creating an Output String for a CurrencytoCurrency(1000);
// prints '$ 1.000,00'
echo $currency->toCurrency(1000, array('format' => 'de_AT'));
// prints '$ ١٬٠٠٠٫٠٠'
echo $currency->toCurrency(1000, array('script' => 'Arab'));
]]>Changing the Format of a Currency
The format which is used by creation of a Zend_Currency instance is, of course, the
standard format. But occasionally it is necessary to change this format.
The format of an currency output includes the following parts:
Currency symbol, shortname or name:
The symbol of the currency is normally displayed within the currency output string. It can be suppressed
when needed or even overwritten.
Currency position:
The position of the currency symbol is normally automatically defined by the locale. It can be
changed if necessary.
Script:
The script which shall be used to display digits. Detailed information about scripts and their
usage can be found in the documentation of Zend_Locale in the chapter
.
Number formatting:
The amount of currency (formally known as value of money) is formatted by the usage of
formatting rules within the locale. For example is in English the ',' sign used as separator for
thousands, and in German the '.' sign.
So if you need to change the format, you should the
setFormat() method. It takes an array which should include every
option you want to change. The options array supports the following
settings:
position: Defines the position at which the currency
description should be displayed. The supported positions can be found in
this table.
script: Defined which script should be used for
displaying digits. The default script for most locales is
'Latn', which includes the digits 0 to 9. Other
scripts such as 'Arab' (Arabian) can be used.
format: Defines the format which should be used for displaying
numbers. This number-format includes for example the thousand separator. You can eighter use
a default format by giving a locale identifier, or define the number-format manually.
If no format is set the locale from the Zend_Currency object will be used.
display: Defines which part of the currency should be
used for displaying the currency representation. There are 4 representations which can be
used and which are all described in
this table.
precision: Defines the precision which should be used for
the currency representation. The default value is 2.
name: Defines the full currency name which should be
displayed. This option overwrites any currency name which is set through
the creation of Zend_Currency.
currency: Defines the international abbreviation which
should be displayed. This option overwrites any abbreviation which is set through
the creation of Zend_Currency.
symbol: Defines the currency symbol which should be
displayed. This option overwrites any symbol which is set through
the creation of Zend_Currency.
Constants for the selecting the currency descriptionconstantdescriptionNO_SYMBOLDo not display any currency representationUSE_SYMBOLDisplay the currency symbolUSE_SHORTNAMEDisplay the 3 lettered international currency abbreviationUSE_NAMEDisplay the full currency name
Constants for the selecting the position of the currency descriptionconstantdescriptionSTANDARDSet the standard position as defined within the localeRIGHTDisplay the currency representation at the right side of the valueLEFTDisplay the currency representation at the left side of the value
Changing the displayed format of a currencytoCurrency(1000);
$currency->setFormat(array('display' => Zend_Currency::USE_NAME,
'position' => Zend_Currency::RIGHT));
// prints '1.000,00 US Dollar'
echo $currency->toCurrency(1000);
$currency->setFormat(array('name' => 'American Dollar'));
// prints '1.000,00 American Dollar'
echo $currency->toCurrency(1000);
$currency->setFormat(array('format' => '##0.00'));
// prints '1000,00 American Dollar'
echo $currency->toCurrency(1000);
]]>Reference Methods for Zend_Currency
Of course, Zend_Currency supports also methods to get information about any existing
and many ancient currencies from Zend_Locale. The supported
methods are:
getSymbol():
Returns the known symbol of the set currency or a given currency. For example
$ for the US Dollar within the locale
'en_US.
getShortName():
Returns the abbreviation of the set currency or a given currency. For example
USD for the US Dollar within the locale
'en_US.
getName():
Returns the full name of the set currency of a given currency. For example
US Dollar for the US Dollar within the locale
'en_US.
getRegionList():
Returns a list of regions where the set currency or a given one is known to be used.
It is possible that a currency is used within several regions, so the return value
is always an array.
getCurrencyList():
Returns a list of currencies which are used in the given region.
The function getSymbol(), getShortName() and getName() accept
two optional parameters. If no parameter is given the expected data will be returned from the
set currency. The first parameter takes the shortname of a currency. Short names are always three
lettered, for example EUR for euro or USD for US Dollar. The second parameter defines from which
locale the data should be read. If no locale is given, the set locale is used.
Getting Information about CurrenciesgetSymbol();
// prints 'EUR'
echo $currency->getShortName('EUR');
// prints 'Österreichische Schilling'
echo $currency->getName('ATS', 'de_AT');
// returns an array with all regions where USD is used
print_r($currency->getRegionList();
// returns an array with all currencies which were ever used in this
// region
print_r($currency->getCurrencyList('de_AT');
]]>Settings new default values
The method setLocale allows to set a new locale for
Zend_Currency. All default
values for the currency will be overwritten when this method is invoked. This includes currency name,
abbreviation and symbol.
Setting a New LocaletoCurrency(1000);
// get the currency for AT
$currency->setLocale('de_AT');
print $currency->toCurrency(1000);
]]>Zend_Currency Performance OptimizationZend_Currency's performance can be optimized using Zend_Cache.
The static method Zend_Currency::setCache($cache) accepts one option: a
Zend_Cache adapter. If the cache adapter is set, the localization data that
Zend_Currency uses are cached. There are some static methods for manipulating the cache:
getCache(), hasCache(), clearCache() and
removeCache().
Caching currencies 120,
'automatic_serialization' => true),
array('cache_dir'
=> dirname(__FILE__) . '/_files/'));
Zend_Currency::setCache($cache);
]]>