Make sure the language selector works on the lessons page.

user/themes/textbook/templates/partials/language-selector.html.twig

@@ -13,19 +13,25 @@
 {% for language in language_selector.languages %}
 
     {% set show_language = true %}
-    {% if language == language_selector.current %}
-        {% set lang_url = page.url %}
-    {% else %}
+
+    {% if uri.paths(0) == "lesson" %}
         {% set base_lang_url = base_url_simple ~ grav.language.getLanguageURLPrefix(language) %}
-        {% set lang_url = base_lang_url ~ language_selector.page_route ~ page.urlExtension %}
-        {% set untranslated_pages_behavior = grav.config.plugins.language_selector.untranslated_pages_behavior %}
-        {% if untranslated_pages_behavior != 'none' %}
-            {% set translated_page = language_selector.translated_pages[language] %}
-            {% if (not translated_page) or (not translated_page.published) %}
-                {% if untranslated_pages_behavior == 'redirect' %}
-                    {% set lang_url = base_lang_url ~ '/' %}
-                {% elseif untranslated_pages_behavior == 'hide' %}
-                    {% set show_language = false %}
+        {% set lang_url = base_lang_url ~ uri.path %}
+    {% else %}
+        {% if language == language_selector.current %}
+            {% set lang_url = page.url %}
+        {% else %}
+            {% set base_lang_url = base_url_simple ~ grav.language.getLanguageURLPrefix(language) %}
+            {% set lang_url = base_lang_url ~ language_selector.page_route ~ page.urlExtension %}
+            {% set untranslated_pages_behavior = grav.config.plugins.language_selector.untranslated_pages_behavior %}
+            {% if untranslated_pages_behavior != 'none' %}
+                {% set translated_page = language_selector.translated_pages[language] %}
+                {% if (not translated_page) or (not translated_page.published) %}
+                    {% if untranslated_pages_behavior == 'redirect' %}
+                        {% set lang_url = base_lang_url ~ '/' %}
+                    {% elseif untranslated_pages_behavior == 'hide' %}
+                        {% set show_language = false %}
+                    {% endif %}
                 {% endif %}
             {% endif %}
         {% endif %}