Load user overrides from PO file

mkdocs_static_i18n/config.py

@@ -80,6 +80,13 @@ def validate(self):
         return failed, warnings
 
 
+class I18nPoOverridesConfig(Config):
+    """configure the user overrides which should be read from a po file"""
+
+    po_dir = config_options.Type(str, default="")
+    override = config_options.Optional(config_options.ListOfItems(config_options.Type(str)))
+
+
 class I18nPluginConfig(Config):
     """ """
 
@@ -91,6 +98,7 @@ class I18nPluginConfig(Config):
     languages = config_options.ListOfItems(
         config_options.SubConfig(I18nPluginLanguage, validate=True)
     )
+    po_overrides = config_options.SubConfig(I18nPoOverridesConfig, validate=True)
 
     def validate(self):
         failed, warnings = super().validate()

mkdocs_static_i18n/reconfigure.py

@@ -1,9 +1,11 @@
+import os.path
 from collections import defaultdict
 from copy import deepcopy
 from pathlib import Path, PurePath
 from typing import Union
 from urllib.parse import urlsplit
 
+from babel.messages import pofile
 from mkdocs import localization
 from mkdocs.config.base import LegacyConfig
 from mkdocs.config.defaults import MkDocsConfig
@@ -77,6 +79,32 @@
     log.warning("Unable to detect lunr languages from mkdocs distribution")
 MKDOCS_THEMES = ["mkdocs", "readthedocs"]
 
+# some config overrides are forbidden as they make no sense
+FORBIDDEN_CONFIG_OVERRIDES = [
+    "dev_addr",
+    "docs_dir",
+    "edit_uri_template",
+    "edit_uri",
+    "exclude_docs",
+    "extra_css",
+    "extra_javascript",
+    "extra_templates",
+    "hooks",
+    "markdown_extensions",
+    "mdx_configs",
+    "not_in_nav",
+    "plugins",
+    "remote_branch",
+    "remote_name",
+    "repo_name",
+    "repo_url",
+    "site_dir",
+    "strict",
+    "use_directory_urls",
+    "validation",
+    "watch",
+]
+
 
 class ExtendedPlugin(BasePlugin[I18nPluginConfig]):
     def __init__(self, *args, **kwargs):
@@ -197,37 +225,63 @@ def apply_user_overrides(self, config: MkDocsConfig):
         # altered by a previous build
         config = self.reset_to_original_config(config)
 
-        # some config overrides are forbidden as they make no sense
-        forbidden_config_overrides = [
-            "dev_addr",
-            "docs_dir",
-            "edit_uri_template",
-            "edit_uri",
-            "exclude_docs",
-            "extra_css",
-            "extra_javascript",
-            "extra_templates",
-            "hooks",
-            "markdown_extensions",
-            "mdx_configs",
-            "not_in_nav",
-            "plugins",
-            "remote_branch",
-            "remote_name",
-            "repo_name",
-            "repo_url",
-            "site_dir",
-            "strict",
-            "use_directory_urls",
-            "validation",
-            "watch",
-        ]
+        overrides = dict()
+        # read po file if configured and override array is not empty
+        if self.config.po_overrides is not None and self.config.po_overrides.override:
+            po_file = os.path.normpath(
+                os.path.join(
+                    os.path.dirname(config.config_file_path),
+                    self.config.po_overrides.po_dir,
+                    self.current_language + ".po",
+                )
+            )
+            if os.path.exists(po_file):
+                with open(po_file, "r", encoding="utf-8") as fs:
+                    catalog = pofile.read_po(fs)
+
+                for key in self.config.po_overrides.override:
+                    if key in FORBIDDEN_CONFIG_OVERRIDES:
+                        log.warning(
+                            f"Ignoring forbidden '{self.current_language}' po override '{key}'"
+                        )
+                        continue
+                    # get original value
+                    if config.__contains__(key) and config[key]:
+                        msgid = config[key]
+                        translation = catalog.get(msgid)
+                        if translation is not None:
+                            if translation.string:
+                                overrides[key] = translation.string
+                            else:
+                                log.warning(
+                                    f"MsgId '{msgid}' is not translated, discarding override"
+                                )
+                        else:
+                            log.warning(
+                                f"MsgId '{msgid}' for config '{key}' not found in catalog '{po_file}'"
+                            )
+                    else:
+                        log.warning(
+                            f"no original value set for config '{key}', cannot look up translation"
+                        )
+            else:
+                log.warning(f"translation catalog '{po_file}' not found")
+
+        # read explicitly configured overrides
         for lang_key, lang_override in self.current_language_config.items():
-            if lang_key in forbidden_config_overrides:
+            if lang_key in FORBIDDEN_CONFIG_OVERRIDES:
                 log.warning(
                     f"Ignoring forbidden '{self.current_language}' config override '{lang_key}'"
                 )
                 continue
+            if lang_override is not None:
+                if lang_key in overrides:
+                    log.warning(
+                        f"Overwriting override '{lang_key}' from PO file with explicitly configured string '{lang_override}'"
+                    )
+                overrides[lang_key] = lang_override
+
+        for lang_key, lang_override in overrides.items():
             if lang_key in config.data and lang_override is not None:
                 mkdocs_config_option_type = type(config.data[lang_key])
                 # support special Theme object overrides