How do you generally programm a language selection - user-interface

Question

I wanted to know from someone with field experience, what the best practice of implementing a programm, with UI or CMD in multiple languages (letting the user choose e.g. between English, French, German) is.
If there already exists a discussion about this topic I would be grateful, if somebody could send me a link to it, the first few Google searches I only found things like how to choose a programming language
The first options that came to my mind where switch(globalStringLanguage) and #ifdef GERMAN #define PROGRESS Fortschritt... .
Would really like to know, if there is a best practice out there(and which one that would be) and how you guys implement it in your firm.
Thanks in advance for the replies,
1973ProgrammingDude

Answer 1

There are 4 'best practices / topics' that you can research:-
i18n - internationalisation
This is more about the way you design software. You design buttons etc. to 'lookup' the text they should contain from a dictionary file rather than hard coding them into your source code.
It also applies to things like dates and currency and allow them to be formatted differently depending on the language / locale.
If you design your product correctly you should be able to change all the text on buttons, links etc. and change the date format, currency formatting etc. with one language variable being changed.
Think of this part as designing your system to account for translation, local formatting and even right to left layouts for languages such as Arabic that are read from the right to the left
l10n - localisation
This is the process that follows on from designing your system under i18n. You would define formatting options so dates etc. are correct.
You would also define wording of buttons etc. so they are correct.
Finally you would also have a system so that content could be translated for the given locale.
Think of this part as the actual translation process.
l12y - Localisability
pretty much covers the process and considerations of l10n - just mentioned so you can research it for more complex scenarios and implementation ideas.
g11n - Globalisation
Encompasses all of the above standards, yet again just mentioned for reference as it occasionally throws up some different articles on Google when searching on how to solve a particular problem.
Quick sanity checks
When designing a system that supports glln it easier to have a couple of points to help make you think about decisions you are making.
If you enter ANY plain text within HTML tags / controls / whatever is applicable to your chosen programming language then you will likely have made a mistake. Every item of plain text should be programmatically inserted into a page.
Design a dictionary system - for every piece of plain text you want to add to the site add it to a dictionary. The dictionary can be a simple key:value list if you need with the key being the English translation and the Value being the translation for your locale. Make sure that you start with English:English translations so you can make sure you don't miss any. I would recommend JSON arrays as most translation companies will now understand how to use these nowadays without you needing to design a user interface for them.
When designing a widget / component consider implications of longer text - just because a layout works in English (i.e. a button group fits on one line) doesn't mean it will work in another. Some languages may be 3 times longer for the translation of a word so you must consider this when designing a layout.
Everything should be designed so it can easily be reversed. Right To Left versions of everything should be easy to implement so design your system so only a couple of variables need changing to create the RTL version. (i.e. if web based have a main CSS definition of a widget and then make sure a global CSS class applied to the body can switch the layout).
It isn't just text -> imagery needs to be different as different cultures will interpret an image differently. Also iconography should be internationalised as well as a dollar bill icon doesn't work well to represent money in the UK, never mind in other countries.
CSS Example but the principle applies to all languages / platforms
.widget{
//define general styles
}
.left-to-right .widget{
//add some formatting to adjust layout for left-to-right languages such as English when the 'left-to-right' global variable is set.
margin-left: 20px;
}
.right-to-left .widget{
//add some formatting to adjust layout for right-to-left languages such as Arabic when the 'right-to-left' global variable is set.
margin-right: 0px;
}