Internationalization Getting Started

• Unicode supports a wider range of characters.
• More space is needed to store Unicode characters.
• The maximum size of nchar and nvarchar columns is 4,000 characters, not 8,000 characters like char and varchar.
• Unicode constants are specified with a leading N: N'A Unicode string'. The following example shows how to insert Unicode values (Russian) into an nvarchar column.

Once you have defined a Unicode compatible column in database, inserting and retrieving multilingual data is same as working with regular (ASCII) data. While migrating databases, care should be taken while mapping source and target data columns. If the data type of source is nchar, and the data type of target is char, on migration, data loss can happen.

Globalization: Writing culture-aware code

In a single code base approach, the code has to be constructed to handle multiple cultures. Representation and interpretation of formatted data such as date, time and currency values vary from one culture to another. The simplest example is that of date. In United States the default standard is mm/dd/yyyy. But in countries like India and United Kingdom, the standard date format in use is dd/mm/yyyy.

Following general guidelines are useful in writing globalization ready code

1. Currency formatting
   Culture aware currency formatting has to take into account the following elements
   
   • Currency symbol: The symbol can be placed either before the currency value or after the value. Moreover, it can be a predefined symbol like '$' or a series of letters like 'Rs'.
   • Negative-amount display: The placement of negative symbol can be before the currency symbol or before the digits but after the symbol or after the digits.
     
     

     int digits = 100;
     System.Threading.Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");
     string formattedCurrency = digits.ToString("C");
     Console.WriteLine(formattedCurrency);
     
     The above example initializes the thread's culture to US region and English language. Hence, when formatting a number in currency format, the output will be '$100.00'. If the culture is set to "en-GB" instead of "en-US", the output would be '£100.00'.
     

2. String operations
   Culture aware String manipulations have to take into account the following operations
   
   • String casing
     In English, the first character in the names of days of week is capitalized. But in Russian, the days are week start with a small case. In fact, capitalizing the word for 'Wednesday' changes the meaning to 'environment'. Moreover, some of the languages like Tamil and Hindi (Indic) do not have casing.
   • String comparison and sorting
     The alphabetical order can vary among languages. Thus the sequencing in dictionaries and phone books varies accordingly. In Swedish, for example, some vowels with an accent sort after "Z", whereas in other European countries the same accented vowel comes right after the non-diacritic vowel. Languages outside the Latin scripts like some Asian languages have several sort orders depending on phonetics, radical order, etc. While performing comparison, it is important to know when to perform a locale aware comparison. For example, while comparing a value retrieved from registry against another value, we need to perform a culture independent comparison. The same would apply for application specific settings that are usually stored in configuration files. .NET framework provides an Invariant Culture for these types of comparisons. The invariant culture is neither associated with a language nor a culture or region.
     
     

3. Number formatting
   Numbers are represented in different formats in different regions. While handling and formatting numbers, the following aspects should be taken care of

   • The character used as a thousands separator
     In United States, this character is a comma (example 10,000,000). In Germany, it is a period (example 10.000.000.
   • The character used as the decimal separator
     The India, this character is a period (.). In Germany, it is a comma (,).
     
     Consider the following example to illustrate the above two concepts. An integer value is first parsed from a numeric string containing numeric data as per US culture. Later, the same integer value is printed out as a string representation in German culture. The output is 1.000.000,00. Notice the change in decimal operator symbol and thousands separator.
     
     

     string str = "1,000,000.00";
     int digits = int.Parse(str,NumberStyles.Number, new CultureInfo("en-US"));
     Console.WriteLine(digits.ToString("N",new CultureInfo("de-DE")));
     
     

   • The way negative numbers are displayed.
     Negative numbers can be represented with the negative sign appearing before the digits or with a trailing negative sign.
   • The placement of percentage sign (%)
     Similarly, the percentage sign can be placed before (%100) or after the digits (100%).
   • Digits grouping
     Digits grouping refers to the ways the in which the digits in a numbers are separated. For example, in India, the digits are separated at 2 digits except for the 3-digit grouping for denoting the hundreds.
     
     The user can define preferred number-formatting parameters by making selections from the Numbers tab of the Customize Regional Options property sheet, within the Regional And Language Options property sheet.
     
     In .NET framework, to retrieve the number format settings, the NumberFormat property of the Current thread's Current culture can be used.
     
     For example, assume that the user has selected the negative number format as (1.1). This means that the user represents negative numbers by having a left and right parenthesis.
     
     The following example parses a negative number input by the user in a Culture aware manner. After parsing, it prints the number as per German format. The output being -100,00.
     
     

     string str = "(100)";
     int digits = int.Parse(str,NumberStyles.Any,
     System.Threading.Thread.CurrentThread.CurrentCulture.NumberFormat);
     Console.WriteLine(digits.ToString("N",new CultureInfo("de-DE")));
     
     

4. Date and Time formatting
   Date formatting varies throughout the world. Although each culture will have a long format and a short date format, the way they are represented differs. The name of months, the character used to separate the days, months and years, the placement of day and month relative to each other, etc vary from one culture to another. Even the number of digits used to represent the year can vary.
   
   Consider the following code snippet which is trying to parse a date string in 'dd/mm/yyyy' format. The date string could have been read from a file or from database.
   
   

   System.Threading.Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");
   DateTime dt = System.DateTime.Parse(@"15\02\2006");
   Console.WriteLine(dt.ToLongDateString());
   
   The current culture is set to 'en-US'. Hence, when you parse a date string, the expected format is 'mm/dd/yyyy'. The above code will fail as it is encountering an invalid date which is 'in dd/mm/yyyy' format. While parsing date strings, it is important to know the source of data. For example, if we knew that the date string is from Russian or Indian culture, we can provide that information to the parsing function as outlined below
   
   

   System.Threading.Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");
   DateTime dt = System.DateTime.Parse(@"15\02\2006" , new CultureInfo("hi-IN"));
   Console.WriteLine(dt.ToLongDateString());
   
   Similarly, time formats vary based upon the use of 12 hr or 24 hr clock, the character used to separate hours, minutes and seconds, the usage of time zones, etc
   

5. Addresses and telephone numbers
   Address formats differ across various parts of the world. Some regions may have a 'State'. The number of digits used in postal code will vary. For example, in India, a pin code is represented by 6 digits whereas in France it is 5 digits. Even the name used to represent the code is different. In some places it is known as PIN code whereas in many other places, it is known as postal code.
   
   Similarly, the telephone numbers vary from one region to another. There is no standard format for a telephone number. The differences include the number of digits, the separating characters, the presence/absence of country/state codes, etc.
   
   
6. Units of measure
   Units of measure also differ among countries. Even within a single country, multiple units may be used. The units of measurement that vary, relate to the following items
   • Lengths
   • Weights
   • Area
   • Volume
   • Temperature
   • Paper sizes
   • Angle notation

Localization Considerations

An Internationalized application can either have multiple binaries each targeting a separate locale or a single, world ready binary which supports multiple locales. The preferred approach is to go for a single, world ready functional core whose features and code design are developed for the input, display and output of a defined set of Unicode-supported language scripts and data related to specific locales. Among the many advantages offered by a single binary are simpler software updates and a single source code and development team. Moreover, all language versions can be shipped simultaneously.

Having decided upon a single world ready binary, the preferred mechanism for localization of the application is to create satellite assemblies. A satellite assembly is the name given to the creation of separate DLL for each language and which contains the translated resources as per that language. Usage of satellite assemblies greatly simplifies the addition of support for a new language without impacting the existing languages.

White labeling
Another important aspect of designing for Internationalization is to allow the user interface to be customizable based upon the region where the product would be sold. Additionally, it is possible that the product may need to integrate with other products belonging to the company. In this case, it is essential that this international product also takes on the same look n feel as that of the parent product. The company logo, background color, background images for dialog boxes can vary based on the location the product is being sold. Similarly, the product logo and the overall look n feel can differ based on whether it is sold independently or along with another product. As an example, products like Winamp allow users to change skins. Each skin gives a unique look n feel to the product.

Testing

There are two basic testing requirements which ensure that the products works well in all regions for which it was developed

• Testing to check if the product is locale aware (Globalization)
• Testing the localized versions of the product

The following diagrams depicts the breakdown the product with respect to testing for internationalization

Testing for localized content
Localized content includes both text and graphic artifacts on the user interface. Textual content to be localized include the static text on controls such as menus, button, etc and user specific messages. Language experts are required for testing the localized content in each language that the product supports.

Testing for culture awareness
User locale settings define the number, date and currency formatting. Input locales should be handled and user be allowed to input in that language.

In many cases data would need to be converted from one encoding to another. Correct handling and understanding of encoding is required in such cases. If coded incorrectly, it can result in loss of data as well. For example, converting from multibyte character set to single or double-byte character set can result in data loss if not handled properly. User locales do not impact conversion of data from one encoding to another.

Feature based testing
The product may be marketed such that some features are either applicable or not applicable to specific cultures. While testing, it is important to ensure that these features are turned on/off as required while switching locales.

References

1. Dr. International, Developing International Software, Microsoft Press, 2003.
2. Unicode and Character sets,
   http://www.joelonsoftware.com/articles/Unicode.html
3. Globalization Best Practices
   http://msdn.microsoft.com/library/default.asp?url=/library/enus/cpguide/html/cpconbestpracticesforglobalapplicationdesign.asp
4. Testing for World-Readiness
   http://www.microsoft.com/globaldev/handson/dev/wrtesting.mspx
5. I18n in Software Design, Architecture and Implementation
   http://developers.sun.com/dev/gadc/technicalpublications/articles/archi18n.html