Refactor async initialization in ProgressBarManager (#16)

Co-authored-by: openhands <openhands@all-hands.dev>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Paillat <me@paillat.dev>

README.md

@@ -79,24 +79,21 @@ from discord_progress_bar import ProgressBarManager
 # Create a Discord bot with emoji caching enabled
 bot = discord.Bot(cache_app_emojis=True)
 
-progress_bar_manager = None
-progress_bar = None
+# Create the progress bar manager (doesn't load emojis yet)
+progress_manager = ProgressBarManager(bot)
 
 @bot.event
 async def on_ready():
-    """Initialize the ProgressBarManager when the bot is ready."""
-    global progress_bar_manager, progress_bar
+    """Load emojis when the bot is ready."""
+    await progress_manager.load()
+    print(f"Logged in as {bot.user}")
 
-    # Initialize the progress bar manager
-    progress_bar_manager = await ProgressBarManager(bot)
-    # Get a progress bar with the "green" style
-    progress_bar = await progress_bar_manager.progress_bar("green")
-
-@bot.slash_command()
+@bot.command()
 async def show_progress(ctx, percent: float = 0.5):
     """Display a progress bar with the specified percentage."""
 
-    await ctx.respond(f"Progress: {progress_bar.partial(percent)}")
+    progress_bar = await progress_manager.progress_bar("green", length=10)
+    await ctx.send(f"Progress: {progress_bar.partial(percent)}")
 
 # Run your bot
 bot.run("YOUR_TOKEN")
@@ -233,14 +230,22 @@ This is required for the `ProgressBarManager` to properly load and manage emojis
 
 ### Progress Bar Manager Initialization
 
-Initialize the `ProgressBarManager` after your bot is ready:
+Create a `ProgressBarManager` instance when your bot starts, and load emojis in the
+`on_ready` event:
 
 ```python
-@discord.Cog.listener()
-async def on_ready(self) -> None:
-    self.progress_bar_manager = await ProgressBarManager(self.bot)
+# Create the manager (doesn't load emojis yet)
+progress_manager = ProgressBarManager(bot)
+
+@bot.event
+async def on_ready():
+    """Load emojis from the server after the bot is ready."""
+    await progress_manager.load()
 ```
 
+This approach ensures that your bot can properly initialize and load emojis once it's
+connected to Discord.
+
 ### Custom Progress Bar Styles
 
 You can create custom progress bar styles by providing your own emoji images:

examples/basic.py

@@ -17,22 +17,27 @@ bot = discord.Bot(cache_app_emojis=True)
 class MyCog(discord.Cog):
     def __init__(self, bot: discord.Bot) -> None:
         self.bot: discord.Bot = bot
-        self.progress_bar_manager: ProgressBarManager
-        self.progress_bar: ProgressBar
+        self.progress_bar_manager: ProgressBarManager = ProgressBarManager(self.bot)
+        self.progress_bar: ProgressBar | None = None
 
     @discord.Cog.listener()
     async def on_ready(self) -> None:
         print(f"Logged in as {bot.user} (ID: {bot.user.id})")  # pyright: ignore [reportOptionalMemberAccess]
         print("------")
-        self.progress_bar_manager = await ProgressBarManager(self.bot)
+        await self.progress_bar_manager.load()
         self.progress_bar = await self.progress_bar_manager.progress_bar("green", length=10)
         print("Progress bar manager loaded.")
 
     @discord.slash_command()  # pyright: ignore [reportUntypedFunctionDecorator]
     async def get_progress_bar(self, ctx: discord.ApplicationContext, percent: float | None = None) -> None:
         """Send a progress bar message."""
-        if percent is None:
+        if not self.progress_bar:
+            await ctx.respond("Progress bar manager is not loaded yet.")
+            return
+
+        if percent is None or percent > 1:
             percent = 1
+
         await ctx.respond(f"Progress: {self.progress_bar.partial(percent)}")
 
 

src/discord_progress_bar/progress_bar.py

@@ -2,7 +2,7 @@
 # SPDX-License-Identifier: MIT
 
 from collections import defaultdict
-from typing import Self, cast
+from typing import cast
 
 import aiofile
 import aiohttp
@@ -67,20 +67,25 @@ class ProgressBarManager:
     def __init__(self, bot: discord.Bot) -> None:
         self._bot: discord.Bot = bot
         self._emojis: dict[str, ProgressBarEmojiMapping] = defaultdict(dict)
-
-    async def __new__(cls, bot: discord.Bot) -> Self:
-        obj = super().__new__(cls)
-        obj.__init__(bot)
-        await obj.load()
-        return obj
+        self._loaded: bool = False
 
     async def load(self) -> None:
-        await self._bot.wait_until_ready()
+        """Load emojis from the Discord server.
+
+        This method should be called after the bot is ready.
+        Typically called in your bot's on_ready event.
+        """
         for emoji in self._bot.app_emojis:
             if emoji.name.startswith("pb_"):
                 key: str = emoji.name.split("_")[1]
                 part: ProgressBarPart = cast("ProgressBarPart", int(emoji.name.split("_")[2]))
                 self._emojis[key][part] = emoji
+        self._loaded = True
+
+    @property
+    def loaded(self) -> bool:
+        """Check if the manager has been loaded."""
+        return self._loaded
 
     async def create_emojis_from_urls(self, name: str, emojis: ProgressBarUrlMapping) -> None:
         async with aiohttp.ClientSession() as session:
@@ -107,9 +112,27 @@ class ProgressBarManager:
             self._emojis[name][key] = emoji
 
     async def progress_bar(self, name: str, *, length: int = 5) -> ProgressBar:
+        """Get a progress bar by name.
+
+        Args:
+            name: The name of the progress bar.
+            length: The length of the progress bar (default is 5).
+
+        Returns:
+            A ProgressBar instance with the specified emojis.
+
+        Raises:
+            ValueError: If the progress bar is not found
+            RuntimeError: If the manager is not loaded.
+
+        """
+        if not self.loaded:
+            raise RuntimeError("ProgressBarManager has not been loaded yet. Call load() first.")
+
         if name not in self._emojis:
             if default := DEFAULT_PROGRESS_BARS.get(name):
                 await self.create_emojis_from_urls(name, default)
             else:
                 raise ValueError(f"Progress bar {name} not found.")
+
         return ProgressBar(self._emojis[name], length=length)