Add SDK\LanguageContext

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Changing post's language via bulk edit (#66).
 - Filter for posts without language or unknown languages in the back-office post list for translatable post types.
 - Filter `ubb_translatable_routes` for routes outside of post/term/archives that the user wants to be available in other languages when using the method `LangInterface::translate_current_url()`.
+- `SDK\LanguageContext` to provide a more human readable interface for language context switching.
 
 ### Changed
 

lib/LangInterface.php

@@ -6,6 +6,7 @@
 use TwentySixB\WP\Plugin\Unbabble\DB\PostTable;
 use TwentySixB\WP\Plugin\Unbabble\DB\TermTable;
 use TwentySixB\WP\Plugin\Unbabble\Options;
+use TwentySixB\WP\Plugin\Unbabble\SDK\LanguageContext;
 use WP_Post;
 use WP_Query;
 use WP_Term;
@@ -135,7 +136,7 @@ public static function get_current_language() : string {
 		 *
 		 * @param string $language Current language.
 		 */
-		return apply_filters( 'ubb_current_lang', \sanitize_text_field( $lang ) );
+		return \apply_filters( 'ubb_current_lang', \sanitize_text_field( $lang ) );
 	}
 
 	/**
@@ -939,21 +940,21 @@ public static function translate_current_url( string $lang ) : string {
 
 		// Try to translate posts archive url.
 		if ( $wp_the_query instanceof WP_Query && $wp_the_query->is_posts_page ) {
-			add_filter( 'ubb_current_lang', $fn = fn () => $lang );
-			$page_for_posts = get_option( 'page_for_posts' );
-			$home_url       = home_url();
-			remove_filter( 'ubb_current_lang', $fn );
+			LanguageContext::switch_to_language( $lang );
+			$page_for_posts = \get_option( 'page_for_posts' );
+			$home_url       = \home_url();
+			LanguageContext::restore_language();
 			if ( empty( $page_for_posts ) ) {
 				return $home_url;
 			}
-			return get_permalink( $page_for_posts );
+			return \get_permalink( $page_for_posts );
 		}
 
 		// Try to translate a post types archive url.
 		if ( $wp_the_query instanceof WP_Query && $wp_the_query->is_post_type_archive() ) {
-			add_filter( 'ubb_current_lang', $fn = fn () => $lang );
-			$archive_link = get_post_type_archive_link( $wp_the_query->query['post_type'] );
-			remove_filter( 'ubb_current_lang', $fn );
+			LanguageContext::switch_to_language( $lang );
+			$archive_link = \get_post_type_archive_link( $wp_the_query->query['post_type'] );
+			LanguageContext::restore_language();
 			return $archive_link;
 		}
 
@@ -964,17 +965,17 @@ public static function translate_current_url( string $lang ) : string {
 		) {
 			$term_id = $wp_the_query->queried_object->term_id ?? null;
 			if ( $term_id === null ) {
-				add_filter( 'ubb_current_lang', $fn = fn () => $lang );
+				LanguageContext::switch_to_language( $lang );
 				$home_url = home_url();
-				remove_filter( 'ubb_current_lang', $fn );
+				LanguageContext::restore_language();
 				return $home_url;
 			}
 
 			$translation = self::get_term_translation( $term_id, $lang );
 			if ( $translation ) {
-				add_filter( 'ubb_current_lang', $fn = fn () => $lang );
-				$translation_permalink = get_term_link( $translation );
-				remove_filter( 'ubb_current_lang', $fn );
+				LanguageContext::switch_to_language( $lang );
+				$translation_permalink = \get_term_link( $translation );
+				LanguageContext::restore_language();
 				return $translation_permalink;
 			}
 		}
@@ -983,17 +984,17 @@ public static function translate_current_url( string $lang ) : string {
 		if ( $wp_the_query instanceof WP_Query && $wp_the_query->is_singular() ) {
 			$post_id = $wp_the_query->queried_object->ID ?? null;
 			if ( $post_id === null ) {
-				add_filter( 'ubb_current_lang', $fn = fn () => $lang );
+				LanguageContext::switch_to_language( $lang );
 				$home_url = home_url();
-				remove_filter( 'ubb_current_lang', $fn );
+				LanguageContext::restore_language();
 				return $home_url;
 			}
 
 			$translation = self::get_post_translation( $post_id, $lang );
 			if ( $translation ) {
-				add_filter( 'ubb_current_lang', $fn = fn () => $lang );
+				LanguageContext::switch_to_language( $lang );
 				$translation_permalink = get_permalink( $translation );
-				remove_filter( 'ubb_current_lang', $fn );
+				LanguageContext::restore_language();
 				return $translation_permalink;
 			}
 		}
@@ -1042,9 +1043,9 @@ public static function translate_current_url( string $lang ) : string {
 		}
 
 		// Default to home_url of the language.
-		add_filter( 'ubb_current_lang', $fn = fn () => $lang );
+		LanguageContext::switch_to_language( $lang );
 		$lang_link = home_url();
-		remove_filter( 'ubb_current_lang', $fn );
+		LanguageContext::restore_language();
 		return $lang_link;
 	}
 

lib/Router/Directory.php

@@ -4,6 +4,7 @@
 
 use TwentySixB\WP\Plugin\Unbabble\LangInterface;
 use TwentySixB\WP\Plugin\Unbabble\Options;
+use TwentySixB\WP\Plugin\Unbabble\SDK\LanguageContext;
 use WP_Post;
 use WP_Term;
 
@@ -440,7 +441,7 @@ public function network_home_url( string $url, string $path ) : string {
 				$curr_origin_lang !== LangInterface::get_default_language()
 				&& LangInterface::is_language_allowed( $curr_origin_lang )
 			) {
-				add_filter( 'ubb_current_lang', $fn = fn () => $curr_origin_lang );
+				LanguageContext::switch_to_language( $curr_origin_lang );
 				$router_type = Options::get_router();
 				if ( $router_type === 'query_var' ) {
 					add_filter( 'ubb_home_url', '__return_true' );
@@ -450,7 +451,7 @@ public function network_home_url( string $url, string $path ) : string {
 				} else {
 					$new_url = home_url( $path );
 				}
-				remove_filter( 'ubb_current_lang', $fn );
+				LanguageContext::restore_language();
 			}
 		}
 		restore_current_blog();

lib/Router/QueryVar.php

@@ -4,6 +4,7 @@
 
 use TwentySixB\WP\Plugin\Unbabble\LangInterface;
 use TwentySixB\WP\Plugin\Unbabble\Options;
+use TwentySixB\WP\Plugin\Unbabble\SDK\LanguageContext;
 use WP_Post;
 use WP_Term;
 
@@ -305,7 +306,7 @@ public function network_home_url( string $url, string $path ) : string {
 				$curr_origin_lang !== LangInterface::get_default_language()
 				&& LangInterface::is_language_allowed( $curr_origin_lang )
 			) {
-				add_filter( 'ubb_current_lang', $fn = fn () => $curr_origin_lang );
+				LanguageContext::switch_to_language( $curr_origin_lang );
 				$router_type = Options::get_router();
 				if ( $router_type === 'directory' ) {
 					add_filter( 'ubb_home_url', '__return_true' );
@@ -315,7 +316,7 @@ public function network_home_url( string $url, string $path ) : string {
 				} else {
 					$new_url = home_url( $path );
 				}
-				remove_filter( 'ubb_current_lang', $fn );
+				LanguageContext::restore_language();
 			}
 		}
 		restore_current_blog();

lib/SDK/LanguageContext.php

@@ -0,0 +1,75 @@
+<?php
+
+namespace TwentySixB\WP\Plugin\Unbabble\SDK;
+
+/**
+ * Provide an interface to switch language contexts.
+ *
+ * @since [unreleased]
+ */
+class LanguageContext {
+
+	/**
+	 * The language stack.
+	 *
+	 * @since [unreleased]
+	 *
+	 * @var array
+	 */
+	static $language_stack = [];
+
+	/**
+	 * Switch to the language at the top of the stack.
+	 *
+	 * @since [unreleased]
+	 *
+	 * @param string $lang The language to switch to.
+	 * @return string
+	 */
+	private static function switch() {
+		return static::$language_stack[ count( static::$language_stack ) - 1 ];
+	}
+
+	/**
+	 * Push a  to a specific language.
+	 *
+	 * @since [unreleased]
+	 *
+	 * @param string $lang The language to switch to.
+	 * @return void
+	 *
+	 * @throws \InvalidArgumentException If the language is empty.
+	 */
+	public static function switch_to_language( string $lang ) {
+
+		// Throw to prevent empty language issues.
+		if ( empty( $lang ) ) {
+			throw new \InvalidArgumentException( 'Language cannot be empty' );
+		}
+
+		// Add only one filter instance to the hook.
+		if ( empty( static::$language_stack ) ) {
+			\add_filter( 'ubb_current_lang', [ self::class, 'switch' ] );
+		}
+
+		static::$language_stack[] = $lang;
+	}
+
+	/**
+	 * Restore the previous language in the stack.
+	 *
+	 * @since [unreleased]
+	 *
+	 * @return void
+	 */
+	public static function restore_language() {
+
+		// Take the last language off the stack.
+		array_pop( static::$language_stack );
+
+		// Remove the filter if the stack is empty.
+		if ( empty( static::$language_stack ) ) {
+			\remove_filter( 'ubb_current_lang', [ self::class, 'switch' ] );
+		}
+	}
+}