MOBILE-4630 pluginfile: Add lang to file download request

src/core/services/filepool.ts

@@ -97,6 +97,7 @@ export class CoreFilepoolProvider {
         new RegExp('(\\?|&)forcedownload=[0-1]'),
         new RegExp('(\\?|&)preview=[A-Za-z0-9]+'),
         new RegExp('(\\?|&)offline=[0-1]', 'g'),
+        new RegExp(/(\\?|&)lang=[A-Za-z\-_]+/, 'g'),
     ];
 
     // To handle file downloads using the queue.

src/core/services/lang.ts

@@ -249,6 +249,19 @@ export class CoreLangProvider {
         return format ? this.formatLanguage(this.currentLanguage, format) : this.currentLanguage;
     }
 
+    /**
+     * Get current language sync.
+     *
+     * @returns Current language or undefined.
+     */
+    getCurrentLanguageSync(format?: CoreLangFormat): string | undefined {
+        if (this.currentLanguage === undefined) {
+            return;
+        }
+
+        return format ? this.formatLanguage(this.currentLanguage, format) : this.currentLanguage;
+    }
+
     /**
      * Update a language code to the given format.
      *

src/core/services/utils/url.ts

@@ -211,7 +211,8 @@ export class CoreUrlUtilsProvider {
             url = this.addParamsToUrl(url, { token });
         }
 
-        return this.addParamsToUrl(url, { offline: '1' }); // Always send offline=1 (it's for external repositories).
+        // Always send offline=1 (it's for external repositories).
+        return this.addParamsToUrl(url, { offline: '1', lang: CoreLang.getCurrentLanguageSync(CoreLangFormat.LMS) });
     }
 
     /**