How To Internationalize Your WordPress Plugin

Internationalization is the process of preparing your wordpress plugins for use in many languages .although wordpress uses english as its default language,it is used all over the world and many of its users don’t read or write in english .also as a developer ,you may need to reach a large scale of users and provide a simple tool for users to add their languages.

WordPress platform provide a bunch of built in translation functions so all you need is to follow simple steps during development process.

Make Your Plugin Ready For Translation :

The first step in internationalizing your plugin is to make wordpress load translation files of your plugin related to user language if file exist.

load_plugin_textdomain($domain, $abs_rel_path, $plugin_rel_path);

• $domain is an unique string represent your plugin domain .
• $abs_rel_path is the abs path to translation files and you should set to false .
• $plugin_rel_path is the relative path to translation files .

For example :if your plugin folder name is (smart-seo-plugin) and contain (includes,languages and assets) as sub-folders you code will look like this

/*
  * this function loads my plugin translation files
  */
 function smart_seo_load_translation_files() {
  load_plugin_textdomain('smart-seo-plugin-text', false, 'smart-seo-plugin/languages');
 }
 
 //add action to load my plugin files
 add_action('plugins_loaded', 'smart_seo_load_translation_files');

WordPress Translation Functions :

As i said before WordPress platform provide a bunch of built in translation functions .so everytime you add text in your plugin ,you should wrap this text in one of these functions .most of these functions has two variables (the text you need to be translated and your plugin domain).let’s list these functions and when you shoud use each one.

The __() Function

It makes text ready for translation and return it to be used in your code .

$wp_footer = __('WordPress is a great blogging platform.', 'smart-seo-plugin-text');

The _e() Function

Same as __() but it output text to browser .

_e('WPMU is a greet website.', 'smart-seo-plugin-text');

The esc_attr__() Function

It escapes HTML attributes so text passed to it will not break plugin security .

echo '<a href="http://clivern.com/support/" title="' . esc_attr__('Need Support', 'smart-seo-plugin-text') . '">' . __('Support', 'smart-seo-plugin-text') . '</a>';

The esc_attr_e() Function

It escapes HTML attributes and output text to browser .it is perfect if you like to use inline php code within HTML code .

<a href="http://clivern.com/support" title="<?php esc_attr_e('Need Support', 'smart-seo-plugin-text'); ?>"><?php _e('Support', 'smart-seo-plugin-text'); ?></a>

The esc_html__() Function

It is used to escape HTML code .if you provide a form with textarea .you will to wrap default value of textarea with this function .

echo '<textarea name="smseo-text" id="smseo-text">' . esc_html__('Please input keywords', 'smart-seo-plugin-text') . '</textarea>';

The esc_html_e() Function

It behaves the same as esc_html__() except that it output the translated text to browser .

<textarea name="smseo-text" id="smseo-text"><?php esc_html_e('Please input keywords', 'smart-seo-plugin-text'); ?></textarea>

The _x() Function

It is used to provide a context for each occurance of specific text .for example : Post-may be used as noun or verb .so you should mark the difference between the two by a context .

//post used as noun
 $post_as_noun=_x('Post', 'noun', 'smart-seo-plugin-text');
 //post used as verb
  $post_as_verb=_x('Post', 'verb', 'smart-seo-plugin-text');

The _ex() Function

Same as _x() but it output translated text to browser .

//post used as noun
 _ex('Post', 'noun', 'smart-seo-plugin-text');
 //post used as verb
 _ex('Post', 'verb', 'smart-seo-plugin-text');

The esc_attr_x() Function

It provides a context for text ,escape it for use in html attributes and return translated text for use in you code .it doesn’t have another function to output text to browser .

echo '<a href="' . admin_url('dashboard.php') . '" title="' . esc_attr_x('Administration', 'admin link', 'smart-seo-plugin-text') . '">' . _x('Administration', 'admin link', 'smart-seo-plugin-text') . '</a>';

The esc_html_x() Function

It is used for translation ,escaping HTML and provide a context for translators .suppose you created a form contain textarea for user favorite food ,so you need to show none as default value.

echo '<textarea name="smseo-text" id="smseo-text">' . esc_html_x('None', 'favorite food', 'smart-seo-plugin-text') . '</textarea>';

The _n() Function

Sometimes you don’t know how many items will be returned from your code .so you will provide this function with both singular and plural form of text and it will figure out which form should be used.

printf(_n('you inserted %s keyword.','you inserted %s keywords.',$keywords_count,'smart-seo-plugin-text'),$keywords_count);

The _nx() Function

It is the same as _n() except that it provides a context for the text.

printf(_n('%s post', '%s posts', $post_count, 'post count', 'smart-seo-plugin-text'), $post_count);

Creating Translation Files :

Many translation tools spread over the web and are free to download .one of most common tools for wordpress developers is Poedit .it has simple interface and enable you to create a POT file for your plugin .