The document by John P. Bloch provides a guide on creating multilingual plugins and themes for WordPress, emphasizing the importance of internationalization (i18n) and localization (l10n). It covers definitions, functionality for translating texts, best practices for coding, and tools available for developers to facilitate translation processes. The document also highlights key aspects like text domains, functions for translation, and the significance of maintaining quality and consistency in translations.

1. How to Make Multilingual
Plugins and Themes
John P Bloch ● 2015-09-12 ● WordCamp DFW

2. About Me
John P Bloch
Lead Web Engineer at 10up
Yes 10up is hiring
Tell them I sent you
Seriously, we’re always hiring
Not a designer
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DFW Local (Irving)

3. Definitions

4. Definitions
Internationalization
The process of making your
code translatable at all.
Abbreviated as i18n
Localization
The process of using translated
text in internationalized code.
Abbreviated as l10n

5. Definitions
Internationalization
The process of making your
code translatable at all.
Abbreviated as i18n
Localization
The process of using translated
text in internationalized code.
Abbreviated as l10n

6. Why

9. Why
• Empathy
• Grow your potential user-base
• Potentially make more money
• Make more of an impact in the world

10. How

11. How translation works in WordPress
English text goes into a translation function
WP looks for translations of the text in the current language
If a translation is found, the function uses that
Otherwise it uses the English text

12. Text Domains
A text domain is a namespace for your code’s translations
If you use the wordpress.org repositories, you must use your
plugin or theme’s slug as the text domain
Even if you’re not on the official repos it’s still a good idea

13. Text Domains – Loading
Plugins
load_plugin_textdomain(
)
Run on plugins_loaded
action
Arguments
• The text domain
• false // deprecated
• Location of translations
• Relative to plugins directory
Themes
load_theme_textdomain()
Run on after_setup_theme
Arguments
• The text domain
• Location of translations
• Absolute path

14. Plugin and Theme Headers
Plugins and themes have two
special headers:
Text Domain
Domain Path

15. Basic Translation Functions
__()

16. Basic Translation Functions
__()
_e()

17. Basic Translation Functions
__()
_e()
_n()

18. Basic Translation Functions
__()
_e()
_n()
_x()
_ex()
_nx()

19. Basic Translation Functions
You can leave longer comments for the translators

20. Advanced Translation Functions
number_format_i18n()

21. Advanced Translation Functions
number_format_i18n()
date_i18n()

22. Advanced Translation Functions
number_format_i18n()
date_i18n()
wp_localize_script()
For adding translated strings to
javascript
Translates text in PHP and
outputs as a global javascript
variable

23. wp_localize_script()

24. wp_localize_script()

25. wp_localize_script()

26. Final Steps

27. Final Steps
• Generate .pot file
• Official repositories provide web tools
• Generate locally with PoEdit or makepot.php
• Publish .pot file
• Usually packaged with plugin or theme in the languages directory
• Add translation files to your plugin or theme

28. Gotchas
• Line breaks
• Empty strings
• Formatted strings vs. interpolation

29. _e( "You live in $state", 'my-plugin' );

30. _e( "You live in $state", 'my-plugin' );
printf( __( 'You live in %s', 'my-plugin' ),
$state );

31. printf(
__( 'Hi %s, you live in %s', 'my-plugin' ),
$user_name, $state
);

32. printf(
__( 'Hi %s, you live in %s', 'my-plugin' ),
$user_name, $state
);

33. printf(
__( 'Hi %s, you live in %s', 'my-plugin' ),
$user_name, $state
);
printf(
__( 'Hi %1$s, you live in %2$s', 'my-plugin'
),
$user_name, $state
);

34. Best Practices

35. Best Practices
• Use decent English style
• Avoid slang and abbreviations
• Keep text together
• Break at paragraphs
• Use formatted strings instead of
concatenation
• Translate phrases not words

36. Best Practices
Bad:
echo __( 'Click ', 'my-plugin' ) . '<a
href="/there">' .
__( 'here', 'my-plugin' ) . '</a>' .
__( ' for stuff.', 'my-plugin' );
Better:
_e( 'Click <a href="/there">here</a> for stuff.',
'my-plugin' );

37. Best Practices
Best:
echo '<a href="/there">' .
__( 'Click here for stuff.', 'my-plugin' )
.
'</a>';

38. Best Practices
Bad:
echo __( 'Thanks for using ', 'my-plugin' ) . 'My
Plugin!';
Better:
echo sprintf( __( 'Thanks for using %s', 'my-
plugin' ),
'My Plugin' ) . '!';
Best:
printf( __( 'Thanks for using %s!', 'my-plugin'
),
'My Plugin' );

39. Best Practices
• Use decent English style
• Avoid slang and abbreviations
• Keep text together
• Break at paragraphs
• Use formatted strings instead of
concatenation
• Translate phrases not words
• No unnecessary HTML
• Make no assumptions about
the translated text
• Length
• Word order
• Direction
• Punctuation
• Avoid translating URLs that
don’t have alternate
languages available

40. Tools
• Pig Latin (http://w.org/plugins/piglatin/)
• WP i18n Tools (develop.svn.wordpress.org/trunk/tools/i18n/)
• PoEdit (https://poedit.net/)
• GlotPress (http://blog.glotpress.org/)
• Language Packs

41. Questions?
Twitter: @johnpbloch
Website: https://johnpbloch.com
Email: john.bloch@10up.com