Merge pull request #16 from Yoast/stories/af/15-use-the-user-language

Use the user locale for the locale.

i18n-module.php

@@ -111,7 +111,7 @@ public function __construct( $args ) {
 			return;
 		}
 
-		$this->locale = get_locale();
+		$this->locale = $this->get_admin_locale();
 		if ( 'en_US' === $this->locale ) {
 			return;
 		}
@@ -123,6 +123,25 @@ public function __construct( $args ) {
 		}
 	}
 
+	/**
+	 * Returns the locale used in the admin.
+	 *
+	 * WordPress 4.7 introduced the ability for users to specify an Admin language
+	 * different from the language used on the front end. This checks if the feature
+	 * is available and returns the user's language, with a fallback to the site's language.
+	 * Can be removed when support for WordPress 4.6 will be dropped, in favor
+	 * of WordPress get_user_locale() that already fallbacks to the site’s locale.
+	 *
+	 * @returns string The locale.
+	 */
+	private function get_admin_locale() {
+		if ( function_exists( 'get_user_locale' ) ) {
+			return get_user_locale();
+		}
+
+		return get_locale();
+	}
+
 	/**
 	 * This is where you decide where to display the messages and where you set the plugin specific variables.
 	 *