Previous Next

Introduction

Zend_Locale is the Frameworks answer to the question, "How can the same application be used around the whole world?" Most people will say, "That's easy. Let's translate all our output to several languages." However, using simple translation tables to map phrases from one language to another is not sufficient. Different regions will have different conventions for first names, surnames, salutory titles, formatting of numbers, dates, times, currencies, etc.

We need » Localization and complementary » Internationalization . Both are often abbreviated to L10n and I18n. Internationalization refers more to support for use of systems, regardless of special needs unique to groups of users related by language, region, number format conventions, financial conventions, time and date conventions, etc. Localization involves adding explicit support to systems for special needs of these unique groups, such as language translation, and support for local customs or conventions for communicating plurals, dates, times, currencies, names, symbols, sorting and ordering, etc. L10n and I18n compliment each other. The Zend Framework provides support for these through a combination of components, including Zend_Locale, Zend_Date, Zend_Measure, Zend_Translate, Zend_Currency, and Zend_TimeSync.

Tip

Zend_Locale and setLocale()

» PHP's documentation states that setlocale() is not threadsave because it is maintained per process and not per thread. This means that, in multithreaded environments, you can have the problem that the locale changes while the script never has changed the locale itself. This can lead to unexpected behaviour when you use setlocale() in your scripts.

When you are using Zend_Locale you will not have this limitations, because Zend_Locale is not related to or coupled with PHP's setlocale().

What is Localization

Localization means that an application (or homepage) can be used from different users which speak different languages. But as you already have expected Localization means more than only translating strings. It includes

  • Zend_Locale - Backend support of locales available for localization support within other ZF components.

  • Zend_Translate - Translating of strings.

  • Zend_Date - Localization of dates, times.

  • Zend_Calendar - Localization of calendars (support for non-Gregorian calendar systems)

  • Zend_Currency - Localization of currencies.

  • Zend_Locale_Format - Parsing and generating localized numbers.

  • Zend_Locale_Data - Retrieve localized standard strings as country names, language names and » more from the CLDR .

  • TODO - Localization of collations

Each computer user makes use of Locales, even when they don't know it. Applications lacking localization support, normally have implicit support for one particular locale (the locale of the author). When a class or function makes use of localization, we say it is locale-aware. How does the code know which localization the user is expecting?

A locale string or object identifying a supported locale gives Zend_Locale and it's subclasses access to information about the language and region expected by the user. Correct formatting, normalization, and conversions are made based on this information.

How are Locales Represented?

Locale identifiers consist of information about the user's language and preferred/primary geographic region (e.g. state or province of home or workplace). The locale identifier strings used in the Zend Framework are internationally defined standard abbreviations of language and region, written as language_REGION. Both the language and region parts are abbreviated to alphabetic, ASCII characters.

Note:

Be aware that there exist not only locales with 2 characters as most people think. Also there are languages and regions which are not only abbreviated with 2 characters. Therefor you should NOT strip the region and language yourself, but use Zend_Locale when you want to strip language or region from a locale string. Otherwise you could have unexpected behaviour within your code when you do this yourself.

A user from USA would expect the language English and the region USA, yielding the locale identifier "en_US". A user in Germany would expect the language German and the region Germany, yielding the locale identifier "de_DE". See the » list of pre-defined locale and region combinations , if you need to select a specific locale within the Zend Framework.

Example #1 Choosing a specific locale



        

A German user in America might expect the language German and the region USA, but these non-standard mixes are not supported directly as recognized "locales". Instead, if an invalid combination is used, then it will automatically be truncated by dropping the region code. For example, "de_IS" would be truncated to "de", and "xh_RU" would be truncated to "xh", because neither of these combinations are valid. Additionally, if the base language code is not supported (e.g. "zz_US") or does not exist, then a default "root" locale will be used. The "root" locale has default definitions for internationally recognized representations of dates, times, numbers, currencies, etc. The truncation process depends on the requested information, since some combinations of language and region might be valid for one type of data (e.g. dates), but not for another (e.g. currency format).

Beware of historical changes, as ZF components do not know about or attempt to track the numerous timezone changes made over many years by many regions. For example, » we can see a historical list showing dozens of changes made by governments to when and if a particular region observes Daylight Savings Time, and even which timezone a particular geographic area belongs. Thus, when performing date math, the math performed by ZF components will not adjust for these changes, but instead will give the correct time for the timezone using current, modern rules for DST and timezone assignment for geographic regions.

Selecting the Right Locale

For most situations, new Zend_Locale() will automatically select the correct locale, with preference given to information provided by the user's web browser. However, if new Zend_Locale(Zend_Locale::ENVIRONMENT) is used, then preference will be given to using the host server's environment configuration, as described below.

Example #2 Automatically selecting a locale



        

The seach algorithm used by Zend_Locale for automatic selection of a locale uses three sources of information:

  1. const Zend_Locale::BROWSER - The user's Web browser provides information with each request, which is published by PHP in the global variable HTTP_ACCEPT_LANGUAGE. If no matching locale can be found, then preference is given to ENVIRONMENT and lastly FRAMEWORK.

  2. const Zend_Locale::ENVIRONMENT - PHP publishes the host server's locale via the PHP internal function setlocale(). If no matching locale can be found, then preference is given to FRAMEWORK and lastly BROWSER.

  3. const Zend_Locale::FRAMEWORK - When the Zend Framework has a standardized way of specifying component defaults (planned, but not yet available), then using this constant during instantiation will give preference to choosing a locale based on these defaults. If no matching locale can be found, then preference is given to ENVIRONMENT and lastly BROWSER.

Usage of automatic Locales

Zend_Locale provides three additionally locales. These locales do not belong to any language or region. They are "automatic" locales which means that they have the same effect as the method getDefault() but without the negative effects like creating an instance. These "automatic" locales can be used anywhere, where also a standard locale and also the definition of a locale, it's string representation, can be used. This offers simplicity for situations like working with locales which are provided by a browser.

There are three locales which have a slightly different behaviour:

  1. 'browser' - Zend_Locale should work with the information which is provided by the user's Web browser. It is published by PHP in the global variable HTTP_ACCEPT_LANGUAGE.

    If a user provides more than one locale within his browser, Zend_Locale will use the first found locale. If the user does not provide a locale or the script is being called from the commandline the automatic locale 'environment' will automatically be used and returned.

  2. 'environment' - Zend_Locale should work with the information which is provided by the host server. It is published by PHP via the internal function setlocale().

    If a environment provides more than one locale, Zend_Locale will use the first found locale. If the host does not provide a locale the automatic locale 'browser' will automatically be used and returned.

  3. 'auto' - Zend_Locale should automatically detect any locale which can be worked with. It will first search for a users locale and then, if not successfull, search for the host locale.

    If no locale can be detected, it will throw an exception and tell you that the automatical detection has been failed.

Example #3 Using automatic locales



        

Using a default Locale

In some environments it is not possible to detect a locale automatically. You can expect this behaviour when you get an request from commandline or the requesting browser has no language tag set and additionally your server has the default locale 'C' set or another properitary locale.

In such cases Zend_Locale will normally throw an exception with a message that the automatic detection of any locale was not successfull. You have two options to handle such a situation. Either through setting a new locale per hand, or defining a default locale.

Example #4 Handling locale exceptions



        

But this has one big negative effect. You will have to set your locale object within every class using Zend_Locale. This could become very unhandy if you are using multiple classes.

Since Zend Framework Release 1.5 there is a much better way to handle this. You can set a default locale which the static setDefault() method. Of course, every unknown or not full qualified locale will also throw an exception. setDefault() should be the first call before you initiate any class using Zend_Locale. See the following example for details:

Example #5 Setting a default locale



        

In the case that no locale can be detected, automatically the locale de will be used. Otherwise, the detected locale will be used.

ZF Locale-Aware Classes

In the ZF, locale-aware classes rely on Zend_Locale to automatically select a locale, as explained above. For example, in a ZF web application, constructing a date using Zend_Date without specifying a locale results in an object with a locale based on information provided by the current user's web browser.

Example #6 Dates default to correct locale of web users



        

To override this default behavior, and force locale-aware ZF components to use specific locales, regardless of the origin of your website visitors, explicitly specify a locale as the third argument to the constructor.

Example #7 Overriding default locale selection



        

If you know many objects should all use the same default locale, explicitly specify the default locale to avoid the overhead of each object determining the default locale.

Example #8 Performance optimization when using a default locale



        

Zend_Locale_Format::setOptions(array $options)

The 'precision' option of a value is used to truncate or stretch extra digits. A value of '-1' disables modification of the number of digits in the fractional part of the value. The 'locale' option helps when parsing numbers and dates using separators and month names. The date format 'format_type' option selects between CLDR/ISO date format specifier tokens and PHP's date() tokens. The 'fix_date' option enables or disables heuristics that attempt to correct invalid dates. The 'number_format' option specifies a default number format for use with toNumber() (see Number localization ).

The 'date_format' option can be used to specify a default date format string, but beware of using getDate(), checkdateFormat() and getTime() after using setOptions() with a 'date_format'. To use these four methods with the default date format for a locale, use array('date_format' => null, 'locale' => $locale) for their options.

Example #9 Dates default to correct locale of web users

 'en_US', 'fix_date' => true, 'format_type' => 'php'));

For working with the standard definitions of a locale the option Zend_Locale_Format::STANDARD can be used. Setting the option Zend_Locale_Format::STANDARD for date_format uses the standard definitions from the actual set locale. Setting it for number_format uses the standard number format for this locale. And setting it for locale uses the standard locale for this environment or browser.

Example #10 Using STANDARD definitions for setOptions()

 'en_US', 'date_format' => 'dd.MMMM.YYYY'));
// overriding the global set date format
$date = Zend_Locale_Format::getDate('2007-04-20, array('date_format' => Zend_Locale_Format::STANDARD);

// global setting of the standard locale
Zend_Locale_Format::setOptions(array('locale' => Zend_Locale_Format::STANDARD, 'date_format' => 'dd.MMMM.YYYY'));

Speed up Zend_Locale and it's subclasses

Zend_Locale and it's subclasses can be speed up by the usage of Zend_Cache. Use the static method Zend_Locale::setCache($cache) if you are using Zend_Locale. Zend_Locale_Format can be speed up the using the option cache within Zend_Locale_Format::setOptions(array('cache' => $adapter));. If you are using both classes you should only set the cache for Zend_Locale, otherwise the last set cache will overwrite the previous set cache. For convenience there is also static method Zend_Locale::getCache().

Previous Next
Introduction to Zend Framework
Overview
Installation
Zend_Acl
Introduction
Refining Access Controls
Advanced Use
Zend_Auth
Introduction
Database Table Authentication
Digest Authentication
HTTP Authentication Adapter
LDAP Authentication
Open ID Authentication
Zend_Cache
Introduction
The theory of caching
Zend_Cache frontends
Zend_Cache backends
Zend_Captcha
Introduction
Captcha Operation
Captcha Adapters
Zend_Config
Introduction
Theory of Operation
Zend_Config_Ini
Zend_Config_Xml
Zend_Console_Getopt
Introduction to Getopt
Declaring Getopt Rules
Fetching Options and Arguments
Configuring Zend_Console_Getopt
Zend_Controller
Zend_Controller Quick Start
Zend_Controller Basics
The Front Controller
The Request Object
The Standard Router: Zend_Controller_Router_Rewrite
The Dispatcher
Action Controllers
Action Helpers
The Response Object
Plugins
Using a Conventional Modular Directory Structure
MVC Exceptions
Migrating from Previous Versions
Zend_Currency
Introduction to Zend_Currency
How to work with currencies
Migrating from Previous Versions
Zend_Date
Introduction
Theory of Operation
Basic Methods
Zend_Date API Overview
Creation of dates
Constants for General Date Functions
Working examples
Zend_Db
Zend_Db_Adapter
Zend_Db_Statement
Zend_Db_Profiler
Zend_Db_Select
Zend_Db_Table
Zend_Db_Table_Row
Zend_Db_Table_Rowset
Zend_Db_Table Relationships
Zend_Debug
Dumping Variables
Zend_Dojo
Introduction
Zend_Dojo_Data: dojo.data Envelopes
Dojo View Helpers
Dojo Form Elements and Decorators
Zend_Dom
Introduction
Zend_Dom_Query
Zend_Exception
Using Exceptions
Zend_Feed
Introduction
Importing Feeds
Retrieving Feeds from Web Pages
Consuming an RSS Feed
Consuming an Atom Feed
Consuming a Single Atom Entry
Modifying Feed and Entry structures
Custom Feed and Entry Classes
Zend_File
Zend_File_Transfer
Validators for Zend_File_Transfer
Zend_Filter
Introduction
Standard Filter Classes
Filter Chains
Writing Filters
Zend_Filter_Input
Zend_Filter_Inflector
Zend_Form
Zend_Form
Zend_Form Quick Start
Creating Form Elements Using Zend_Form_Element
Creating Forms Using Zend_Form
Creating Custom Form Markup Using Zend_Form_Decorator
Standard Form Elements Shipped With Zend Framework
Standard Form Decorators Shipped With Zend Framework
Internationalization of Zend_Form
Advanced Zend_Form Usage
Zend_Gdata
Introduction to Gdata
Authenticating with AuthSub
Authenticating with ClientLogin
Using Google Calendar
Using Google Documents List Data API
Using Google Spreadsheets
Using Google Apps Provisioning
Using Google Base
Using the YouTube Data API
Using Picasa Web Albums
Catching Gdata Exceptions
Zend_Http
Zend_Http_Client - Introduction
Zend_Http_Client - Advanced Usage
Zend_Http_Client - Connection Adapters
Zend_Http_Cookie and Zend_Http_CookieJar
Zend_Http_Response
Zend_InfoCard
Introduction
Zend_Json
Introduction
Basic Usage
JSON Objects
XML to JSON conversion
Zend_Json_Server - JSON-RPC server
Zend_Layout
Introduction
Zend_Layout Quick Start
Zend_Layout Configuration Options
Zend_Layout Advanced Usage
Zend_Ldap
Introduction
Zend_Loader
Loading Files and Classes Dynamically
Loading Plugins
Zend_Locale
Introduction
Using Zend_Locale
Normalization and Localization
Working with Dates and Times
Supported Languages for Locales
Supported Regions for Locales
Zend_Log
Overview
Writers
Formatters
Filters
Zend_Mail
Introduction
Sending via SMTP
Sending Multiple Mails per SMTP Connection
Using Different Transports
HTML E-Mail
Attachments
Adding Recipients
Controlling the MIME Boundary
Additional Headers
Character Sets
Encoding
SMTP Authentication
Securing SMTP Transport
Reading Mail Messages
Zend_Measure
Introduction
Creation of Measurements
Outputting measurements
Manipulating Measurements
Types of measurements
Zend_Memory
Overview
Memory Manager
Memory Objects
Zend_Mime
Zend_Mime
Zend_Mime_Message
Zend_Mime_Part
Zend_OpenId
Introduction
Zend_OpenId_Consumer Basics
Zend_OpenId_Provider
Zend_Paginator
Introduction
Usage
Configuration
Advanced usage
Zend_Pdf
Introduction.
Creating and loading PDF documents.
Save changes to the PDF document.
Document pages.
Drawing.
Document Info and Metadata.
Zend_Pdf module usage example.
Zend_Registry
Using the Registry
Zend_Rest
Introduction
Zend_Rest_Client
Zend_Rest_Server
Zend_Search_Lucene
Overview
Building Indexes
Searching an Index
Query Language
Query Construction API
Character Set
Extensibility
Interoperating with Java Lucene
Advanced
Best Practices
Zend_Server
Introduction
Zend_Server_Reflection
Zend_Service
Introduction
Zend_Service_Akismet
Zend_Service_Amazon
Zend_Service_Audioscrobbler
Zend_Service_Delicious
Zend_Service_Flickr
Zend_Service_Nirvanix
Zend_Service_ReCaptcha
Zend_Service_Simpy
Introduction
Zend_Service_StrikeIron
Zend_Service_StrikeIron: Bundled Services
Zend_Service_StrikeIron: Advanced Uses
Zend_Service_Technorati
Zend_Service_Yahoo
Zend_Session
Introduction
Basic Usage
Advanced Usage
Global Session Management
Zend_Session_SaveHandler_DbTable
Zend_Soap
Zend_Soap_Server
Zend_Soap_Client
WSDL Accessor
AutoDiscovery. Introduction
Class autodiscovering.
Functions autodiscovering.
Autodiscovering. Datatypes.
Zend_Test
Introduction
Zend_Test_PHPUnit
Zend_Text
Zend_Text_Figlet
Zend_TimeSync
Introduction
Working with Zend_TimeSync
Zend_Translate
Introduction
Adapters for Zend_Translate
Using Translation Adapters
Zend_Uri
Zend_Uri
Zend_Validate
Introduction
Standard Validation Classes
Validator Chains
Writing Validators
Zend_Version
Reading the Zend Framework Version
Zend_View
Introduction
Controller Scripts
View Scripts
View Helpers
Zend_View_Abstract
Zend_Wildfire
Zend_Wildfire
Zend_XmlRpc
Introduction
Zend_XmlRpc_Client
Zend_XmlRpc_Server
Zend Framework Requirements
PHP Version
PHP Extensions
Zend Framework Components
Zend Framework Dependencies
Zend Framework Coding Standard for PHP
Overview
PHP File Formatting
Naming Conventions
Coding Style
Copyright Information