download the transliteration packages of polyglot during boot

app/init.py

@@ -2,9 +2,12 @@ import os
 from pathlib import Path
 from argostranslate import settings, package, translate
 import os, glob, shutil, zipfile
+from app.language import languages
+import polyglot
 
 def boot():
-	check_and_install_models()
+    check_and_install_models()
+    check_and_install_transliteration()
 
 def check_and_install_models(force=False):
     if len(package.get_installed_packages()) < 2 or force:
@@ -23,4 +26,26 @@ def check_and_install_models(force=False):
             package.install_from_path(download_path)
 
         print("Loaded support for %s languages (%s models total)!" % (len(translate.load_installed_languages()), len(available_packages)))
-	
+
+
+def check_and_install_transliteration(force=False):
+    # 'en' is not a supported transliteration language
+    transliteration_languages = [l.code for l in languages if l.code != "en"]
+
+    # check installed
+    install_needed = []
+    if not force:
+        t_packages_path = Path(polyglot.polyglot_path) / "transliteration2"
+        for lang in transliteration_languages:
+            if not (t_packages_path / lang / f"transliteration.{lang}.tar.bz2").exists():
+                install_needed.append(lang)
+    else:
+        install_needed = transliteration_languages
+
+    # install the needed transliteration packages
+    if install_needed:
+        from polyglot.downloader import Downloader
+        downloader = Downloader()
+
+        for lang in install_needed:
+            downloader.download(f"transliteration2.{lang}")

install_models.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env python
 
-from app.init import check_and_install_models
+from app.init import check_and_install_models, check_and_install_transliteration
 
 if __name__ == "__main__":
 	check_and_install_models(force=True)
+	check_and_install_transliteration(force=True)