Internationalization, or i18n, is the process of developing your plugin or theme so it can easily be translated into other languages. And since WordPress is used all over the world, it’s important to ensure your code can be easily translated into whatever language is needed.<\/p>\n
This is the seventh post in our WordPress Development for Intermediate Users series. This series follows on from our popular WordPress Development for Beginners<\/a> tutorials, which introduced you to the fundamentals of developing websites with WordPress, how to get started coding with PHP, and building themes and plugins.<\/p>\n In this final post in our Intermediate\u00a0series you’ll learn how to get your code translation-ready for users, or how to internationalize<\/em> it.<\/p>\n You’ll need to have a theme and\/or plugins to work with if you want to work along \u2013 either continue with the code you’ve developed during the series or download it from the source files<\/a>. You’ll need the code from part six, WordPress Development for Intermediate Users: Custom Fields and Metadata<\/a>.<\/p>\n In this final tutorial of the series, you’ll do three\u00a0things:<\/p>\n Let’s start with an overview of translation and internationalization.<\/p>\n Missed a tutorial in our WordPress Development for Intermediate Users series? You can catch up on all seven posts here:<\/strong><\/p>\n Translating the text in front-end and admin screens\u00a0makes your theme or plugin accessible to a much wider audience. According to Wikipedia<\/a>, 54% of websites are in English, while 26% of Internet users are English speakers, with Chinese as a very close second with 21%. In contrast, only 3% of websites are in Chinese. A scan of past WordCamps<\/a>\u00a0shows that WordPress developers are all over the world \u2013 across Europe and in India, Nepal and Japan, for example.<\/p>\n While many non-English speaking developers and Internet users are accustomed to coding or reading in English, this is by no means ideal. If you make your code available for translation, you are opening up your plugins and themes, and your clients\u2019 websites, to a vast and fast growing international audience.<\/p>\n It\u2019s not even as if translation is difficult \u2013 it simply involves the use of a few functions that WordPress provides.<\/p>\n Note: Don’t translate your code \u2013 that will always be in American English, as that\u2019s what browsers read. What you\u2019ll be translating is the text that appears on public sites using your themes and plugins and on any admin screens you create or modify.<\/em><\/p>\n It\u2019s easy to get confused between the two terms used in translation \u2013 localisation and i18n\u00a0\u2013\u00a0and you\u2019ll find plenty of tutorials and articles online which use the terminology incorrectly. The two terms can be defined as follows:<\/p>\n Let’s work through\u00a0how you\u00a0internationalize your code. This is sometimes referred to as i18n<\/em>, because there are 18 letters between the “i” and the “n” in internationalization.<\/p>\n Preparing your code for translation involves three steps:<\/p>\n Let’s start with the functions.<\/p>\n WordPress uses four main functions to internationalize text:<\/p>\n In our theme and plugins we have some text that needs to be translated, and some that we’ve already made translation-ready. Let’s work through these and identify the i18n already added and any more we need to add.<\/p>\n In our theme, there are two\u00a0files with internationalized text already:<\/p>\n There are also eight files with text that needs to be internationalized:<\/p>\n Let’s take a look at each of these, focusing on different\u00a0i18n functions in turn.<\/p>\n The\u00a0 Let’s look at an example. In customizer.php<\/em>\u00a0we have this code:<\/p>\n\n
\n
An Overview of\u00a0Internationalization<\/h3>\n
\n
\n
Internationalization\u00a0Functions<\/h3>\n
\n
__( \u2018message\u2019 )<\/code> translates the content of the message but doesn’t echo it out.<\/li>\n_e( \u2018message\u2019 )<\/code> echoes the content of the message.<\/li>\nprintf( __( \u2018message\u2019 ) )<\/code> is used with placeholders (for example the number of comments for a post or the queried object in an archive page).<\/li>\n_n( \u2018message\u2019 )<\/code> is used for singular and plural text, so if you’re showing how many comments there are, you use this to define whether the word ‘comment’ should be singular or the plural ‘comments’.<\/li>\n<\/ul>\n\n
\n
Using the __() Function to Translate Text<\/h4>\n
__()<\/code>function translates text but doesn’t echo it out. Use it when defining a string of text for use elsewhere. In our theme we already have some files where we’ve done that, when defining admin screen text.<\/p>\n