PyAPI: add bpy.utils.manual_locale_code()

Move the function for getting the language code associated with the
user manual into a utility function (from the generated
rna_manual_reference.py).

This allows other parts of Blender to create a manual URL based on the
current locale preferences and environment.

Ref !104494

release/scripts/modules/bpy/utils/__init__.py

@@ -26,6 +26,7 @@ __all__ = (
     "register_tool",
     "make_rna_paths",
     "manual_map",
+    "manual_language_code",
     "previews",
     "resource_path",
     "script_path_user",
@@ -1035,6 +1036,53 @@ def manual_map():
         yield prefix, url_manual_mapping
 
 
+# Languages which are supported by the user manual (commented when there is no translation).
+_manual_language_codes = {
+    "ar_EG": "ar",  # Arabic
+    # "bg_BG": "bg",  # Bulgarian
+    # "ca_AD": "ca",  # Catalan
+    # "cs_CZ": "cz",  # Czech
+    "de_DE": "de",  # German
+    # "el_GR": "el",  # Greek
+    "es": "es",  # Spanish
+    "fi_FI": "fi",  # Finnish
+    "fr_FR": "fr",  # French
+    "id_ID": "id",  # Indonesian
+    "it_IT": "it",  # Italian
+    "ja_JP": "ja",  # Japanese
+    "ko_KR": "ko",  # Korean
+    # "nb": "nb",  # Norwegian
+    # "nl_NL": "nl",  # Dutch
+    # "pl_PL": "pl",  # Polish
+    "pt_PT": "pt",  # Portuguese
+    # Portuguese - Brazil, for until we have a pt_BR version.
+    "pt_BR": "pt",
+    "ru_RU": "ru",  # Russian
+    "sk_SK": "sk",  # Slovak
+    # "sl": "sl",  # Slovenian
+    "sr_RS": "sr",  # Serbian
+    # "sv_SE": "sv",  # Swedish
+    # "tr_TR": "th",  # Thai
+    "uk_UA": "uk",  # Ukrainian
+    "vi_VN": "vi",  # Vietnamese
+    "zh_CN": "zh-hans",  # Simplified Chinese
+    "zh_TW": "zh-hant",  # Traditional Chinese
+}
+
+
+def manual_language_code(default="en"):
+    """
+    :return:
+       The language code used for user manual URL component based on the current language user-preference,
+       falling back to the ``default`` when unavailable.
+    :rtype: str
+    """
+    language = _bpy.context.preferences.view.language
+    if language == 'DEFAULT':
+        language = _os.getenv("LANG", "").split(".")[0]
+    return _manual_language_codes.get(language, default)
+
+
 # Build an RNA path from struct/property/enum names.
 def make_rna_paths(struct_name, prop_name, enum_name):
     """

release/scripts/modules/rna_manual_reference.py

@@ -4,38 +4,10 @@
 # autopep8: off
 import bpy
 
-manual_version = '%d.%d' % bpy.app.version[:2]
-
-url_manual_prefix = "https://docs.blender.org/manual/en/" + manual_version + "/"
-
-language = bpy.context.preferences.view.language
-if language == 'DEFAULT':
-    import os
-    language = os.getenv('LANG', '').split('.')[0]
-
-LANG = {
-"ar_EG":        "ar",
-"de_DE":        "de",
-"es":           "es",
-"fi_FI":        "fi",
-"fr_FR":        "fr",
-"id_ID":        "id",
-"it_IT":        "it",
-"ja_JP":        "ja",
-"ko_KR":        "ko",
-"pt_PT":        "pt",
-"pt_BR":        "pt",
-"ru_RU":        "ru",
-"sk_SK":        "sk",
-"sr_RS":        "sr",
-"uk_UA":        "uk",
-"vi_VN":        "vi",
-"zh_CN":        "zh-hans",
-"zh_TW":        "zh-hant",
-}.get(language)
-
-if LANG is not None:
-    url_manual_prefix = url_manual_prefix.replace("manual/en", "manual/" + LANG)
+url_manual_prefix = "https://docs.blender.org/manual/%s/%d.%d/" % (
+    bpy.utils.manual_language_code(),
+    *bpy.app.version[:2],
+)
 
 url_manual_mapping = (
     ("bpy.types.movietrackingsettings.refine_intrinsics_tangential_distortion*", "movie_clip/tracking/clip/toolbar/solve.html#bpy-types-movietrackingsettings-refine-intrinsics-tangential-distortion"),