feat: add i18n support

app/config.py.example

@@ -12,6 +12,9 @@ MEDIA_DIRECTORY = 'media'
 PICTURE_EXTENSION = '.png'
 AVATAR_SIZE = (120, 120)
 
+# DEFAULT WEBSITE LANGUAGE
+WEBSITE_LANGUAGE = "en"
+
 email_conf = ConnectionConfig(
     MAIL_USERNAME=os.getenv("MAIL_USERNAME") or "user",
     MAIL_PASSWORD=os.getenv("MAIL_PASSWORD") or "password",

app/database/models.py

@@ -14,8 +14,8 @@ class User(Base):
     full_name = Column(String)
     description = Column(String, default="Happy new user!")
     avatar = Column(String, default="profile.png")
-
     is_active = Column(Boolean, default=True)
+    language_id = Column(Integer, ForeignKey("languages.id"))
 
     events = relationship(
         "Event", cascade="all, delete", back_populates="owner")
@@ -32,3 +32,10 @@ class Event(Base):
     owner_id = Column(Integer, ForeignKey("users.id"))
 
     owner = relationship("User", back_populates="events")
+
+
+class Language(Base):
+    __tablename__ = "languages"
+
+    id = Column(Integer, primary_key=True, index=True)
+    name = Column(String, unique=True, nullable=False)

app/internal/languages.py

@@ -0,0 +1,100 @@
+from functools import lru_cache
+import glob
+import json
+from pathlib import PureWindowsPath
+from typing import Dict, Union
+
+from app import config
+
+LANGUAGE_FILES_PATH = "app/languages/*.json"
+LANGUAGE_FILES_PATH_TEST = "../app/languages/*.json"
+
+
+@lru_cache()
+def get_translation_words(display_language: str = None) -> \
+        Dict[str, Union[str, Dict[str, str]]]:
+    """Gets and returns the translation words for a given language.
+    The returned object is a dictionary of the translated words in either
+    the user's language setting, or the default app setting.
+
+    Using the @lru_cache() decorator makes the function return the same
+    translation for a given language that was previously used, instead of
+    computing it again, executing the code of the function every time.
+
+    Args:
+        display_language (str): a valid code that follows RFC 1766.
+        See also the Language Code Identifier (LCID) Reference for a list of
+        valid codes.
+
+    Returns:
+        Dict[str, Union[str, Dict[str, str]]]: a dictionary of string keys and
+        their translation as their values. The value can either be a string,
+        or a nested dictionary for plural translations.
+
+    .. _RFC 1766:
+        https://tools.ietf.org/html/rfc1766.html
+
+    .. _Language Code Identifier (LCID) Reference:
+        https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-lcid/a9eac961-e77d-41a6-90a5-ce1a8b0cdb9c?redirectedfrom=MSDN # noqa: E501
+    """
+
+    if display_language:
+        return _populate_with_language(display_language)
+    else:
+        # TODO: Waiting for user registration. Restore when done.
+        # display_language = _get_display_language(user_id)
+        # return populate_with_language(display_language)
+        return _populate_with_language(config.WEBSITE_LANGUAGE)
+
+
+# TODO: Waiting for user registration. Add doc.
+# def _get_display_language(user_id: int) -> str:
+#     # TODO: handle user language setting:
+#     #  If user is logged in, get language setting.
+#     #  If user is not logged in, get default site setting.
+#
+#     if db_user:
+#         return db_user.language
+#     return config.WEBSITE_LANGUAGE
+
+
+def _populate_with_language(display_language: str) -> \
+        Dict[str, Union[str, Dict[str, str]]]:
+    """Updates the translation_words to the requested language.
+    If the language code is not supported by the applications, the dictionary
+    defaults to the config.WEBSITE_LANGUAGE setting.
+
+    Args:
+        display_language (str): a valid code that follows RFC 1766.
+        See also the Language Code Identifier (LCID) Reference for a list of
+        valid codes.
+
+    Returns:
+        Dict[str, Union[str, Dict[str, str]]]: a dictionary of string keys and
+        their translation as their values. The value can either be a string,
+        or a nested dictionary for plural translations.
+    """
+    translation_words_all_languages = _get_translation_words_all_languages()
+    if display_language in translation_words_all_languages:
+        return translation_words_all_languages[display_language]
+    return translation_words_all_languages[config.WEBSITE_LANGUAGE]
+
+
+def _get_translation_words_all_languages() -> \
+        Dict[str, Dict[str, Union[str, Dict[str, str]]]]:
+    """Gets and returns a dictionary of nested language dictionaries from
+     the language translation files.
+
+    Returns:
+        Dict[str, Dict[str, Union[str, Dict[str, str]]]]: a dictionary of
+        language codes as string keys, and nested dictionaries of translations
+        as their values.
+    """
+    language_translations = {}
+    language_files = (glob.glob(LANGUAGE_FILES_PATH)
+                      or glob.glob(LANGUAGE_FILES_PATH_TEST))
+    for language_file in language_files:
+        language_code = PureWindowsPath(language_file).stem
+        with open(language_file, 'r', encoding='utf8') as file:
+            language_translations[language_code] = json.load(file)
+    return language_translations

app/internal/utilities.py

@@ -0,0 +1,30 @@
+from typing import Any, Dict
+
+from fastapi import Request
+from fastapi.templating import Jinja2Templates
+
+from app.dependencies import templates
+from app.internal import languages
+
+
+def get_template_response(html_file_name: str, request: Request,
+                          variables: Dict[str, Any] = None) -> Jinja2Templates:
+    """Creates and returns a Jinja2Templates object with a result dictionary
+    containing three parts: the request object, a variables dictionary,
+    and a translation dictionary.
+
+    Args:
+        html_file_name (str): the name of the html file.
+        request (Request): a FastApi Request object.
+        variables (Dict[str, Any]): an optional variables dictionary used
+        in the html file.
+
+    Returns:
+        Jinja2Templates: a Jinja2Templates response object.
+    """
+    translations = languages.get_translation_words()
+    result = {"request": request,
+              "variables": variables,
+              "localized": translations,
+              }
+    return templates.TemplateResponse(html_file_name, result)

app/languages/en.json

@@ -0,0 +1,31 @@
+{
+  "website_title": "Calendar",
+  "calendar_button": "Calendar",
+  "home_button": "Home",
+  "profile_button": "Profile",
+  "sign_in_button": "Sign In",
+  "sign_up_button": "Sign Up",
+  "agenda_button": "Agenda",
+  "edit_full_name_button": "Edit full name",
+  "edit_email_button": "Edit email",
+  "edit_photo_button": "Edit photo",
+  "edit_description_button": "Edit description",
+  "update_full_name_title": "Update full name",
+  "update_email_title": "Update email",
+  "update_photo_title": "Upload photo",
+  "update_description_title": "Update description",
+  "save_changes_button": "Save changes",
+  "settings_button": "Settings",
+  "features_title": "Features",
+  "export_calendar_button": "Export my calendar",
+  "upcoming_event_on_date": "Upcoming event on {date}",
+  "from_button": "From",
+  "to_button": "to",
+  "get_agenda_button": "Get Agenda",
+  "agenda_today": "Today",
+  "agenda_next_week": "Next week",
+  "agenda_next_month": "Next month",
+  "agenda_invalid_date": "Start date is greater than end date",
+  "no_events_found": "No events found...",
+  "test_word": "test"
+}

app/languages/he.json

@@ -0,0 +1,31 @@
+{
+  "website_title": "Calendar",
+  "calendar_button": "Calendar",
+  "home_button": "Home",
+  "profile_button": "פרופיל",
+  "sign_in_button": "Sign In",
+  "sign_up_button": "Sign Up",
+  "agenda_button": "Agenda",
+  "edit_full_name_button": "ערוך שם מלא",
+  "edit_email_button": "ערוך אימייל",
+  "edit_photo_button": "ערוך תמונה",
+  "edit_description_button": "ערוך תיאור",
+  "update_full_name_title": "עדכן שם מלא",
+  "update_email_title": "עדכן אימייל",
+  "update_photo_title": "עדכן תמונה",
+  "update_description_title": "עדכן תיאור",
+  "save_changes_button": "שמור שינויים",
+  "settings_button": "הגדרות",
+  "features_title": "Features",
+  "export_calendar_button": "Export my calendar",
+  "upcoming_event_on_date": "Upcoming event on {date}",
+  "from_button": "מ",
+  "to_button": "עד",
+  "get_agenda_button": "Get Agenda",
+  "agenda_today": "היום",
+  "agenda_next_week": "שבוע הבא",
+  "agenda_next_month": "חודש הבא",
+  "agenda_invalid_date": "Start date is greater than end date",
+  "no_events_found": "לא נמצאו אירועים...",
+  "test_word": "בדיקה"
+}

app/main.py

@@ -3,10 +3,9 @@
 
 from app.database import models
 from app.database.database import engine
-from app.dependencies import (
-    MEDIA_PATH, STATIC_PATH, templates)
-from app.routers import agenda, event, profile, email
-
+from app.dependencies import MEDIA_PATH, STATIC_PATH
+from app.internal.utilities import get_template_response
+from app.routers import agenda, email, event, profile
 
 models.Base.metadata.create_all(bind=engine)
 
@@ -22,8 +21,4 @@
 
 @app.get("/")
 async def home(request: Request):
-    return templates.TemplateResponse("home.html", {
-        "request": request,
-        "message": "Hello, World!"
-
-    })
+    return get_template_response("home.html", request)

app/routers/agenda.py

@@ -7,9 +7,8 @@
 from sqlalchemy.orm import Session
 
 from app.database.database import get_db
-from app.dependencies import templates
 from app.internal import agenda_events
-
+from app.internal.utilities import get_template_response
 
 router = APIRouter()
 
@@ -18,7 +17,7 @@ def calc_dates_range_for_agenda(
         start: Optional[date],
         end: Optional[date],
         days: Optional[int]
-        ) -> Tuple[date, date]:
+) -> Tuple[date, date]:
     """Create start and end dates eccording to the parameters in the page."""
     if days is not None:
         start = date.today()
@@ -36,27 +35,28 @@ def agenda(
         start_date: Optional[date] = None,
         end_date: Optional[date] = None,
         days: Optional[int] = None
-        ) -> Jinja2Templates:
+) -> Jinja2Templates:
     """Route for the agenda page, using dates range or exact amount of days."""
 
-    user_id = 1   # there is no user session yet, so I use user id- 1.
+    user_id = 1  # there is no user session yet, so I use user id- 1.
     start_date, end_date = calc_dates_range_for_agenda(
         start_date, end_date, days
-        )
+    )
 
     events_objects = agenda_events.get_events_per_dates(
         db, user_id, start_date, end_date
-        )
+    )
     events = defaultdict(list)
     for event_obj in events_objects:
         event_duration = agenda_events.get_time_delta_string(
             event_obj.start, event_obj.end
-            )
+        )
         events[event_obj.start.date()].append((event_obj, event_duration))
 
-    return templates.TemplateResponse("agenda.html", {
-        "request": request,
+    variables = {
         "events": events,
         "start_date": start_date,
-        "end_date": end_date
-    })
+        "end_date": end_date,
+    }
+
+    return get_template_response("agenda.html", request, variables)

app/routers/event.py

@@ -1,6 +1,6 @@
 from fastapi import APIRouter, Request
 
-from app.dependencies import templates
+from app.internal.utilities import get_template_response
 
 router = APIRouter(
     prefix="/event",
@@ -11,11 +11,10 @@
 
 @router.get("/edit")
 async def eventedit(request: Request):
-    return templates.TemplateResponse("event/eventedit.html",
-                                      {"request": request})
+    return get_template_response("event/eventedit.html", request)
 
 
 @router.get("/view/{id}")
 async def eventview(request: Request, id: int):
-    return templates.TemplateResponse("event/eventview.html",
-                                      {"request": request, "event_id": id})
+    variables = {"event_id": id}
+    return get_template_response("event/eventview.html", request, variables)