Add a global context

The global context will be used by other parts of the code in the
future, to store information related to the current execution.

Author: pietroalbini

botogram/context.py

@@ -0,0 +1,55 @@
+# Copyright (c) 2015-2017 The Botogram Authors (see AUTHORS)
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+#   The above copyright notice and this permission notice shall be included in
+#   all copies or substantial portions of the Software.
+#
+#   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+#   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+#   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+#   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+#   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+#   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+#   DEALINGS IN THE SOFTWARE.
+
+import threading
+
+
+_local = threading.local()
+_local._botogram_context = []
+
+
+class Context:
+    """Context of an hook call"""
+
+    def __init__(self, bot, hook, update):
+        self.bot = bot
+        self.hook = hook
+        self.update = update
+
+    def __enter__(self):
+        _local._botogram_context.append(self)
+
+    def __exit__(self, *_):
+        _local._botogram_context.pop()
+
+    def component_name(self):
+        """Get the name of the current component"""
+        return self.hook.component.component_name
+
+    def chat(self):
+        """Get the current chat"""
+        if self.update:
+            return self.update.chat()
+
+
+def ctx():
+    """Get the current context"""
+    if _local._botogram_context:
+        return _local._botogram_context[-1]

botogram/hooks.py

@@ -20,6 +20,7 @@
 import re
 
 from .callbacks import hashed_callback_name
+from .context import Context
 
 
 class Hook:
@@ -53,9 +54,10 @@ def _after_init(self, args):
 
     def call(self, bot, update):
         """Call the hook"""
-        if self._only_texts and update.message.text is None:
-            return
-        return self._call(bot, update)
+        with Context(bot, self, update):
+            if self._only_texts and update.message.text is None:
+                return
+            return self._call(bot, update)
 
     def _call(self, bot, update):
         """*Actually* call the hook"""
@@ -217,28 +219,30 @@ def _after_init(self, args):
         )
 
     def call(self, bot, update, name, data):
-        if not update.callback_query:
-            return
-        q = update.callback_query
+        with Context(bot, self, update):
+            if not update.callback_query:
+                return
+            q = update.callback_query
 
-        if name != self._name:
-            return
+            if name != self._name:
+                return
 
-        bot._call(
-            self.func, self.component_id, query=q, chat=q.message.chat,
-            message=q.message, data=data,
-        )
+            bot._call(
+                self.func, self.component_id, query=q, chat=q.message.chat,
+                message=q.message, data=data,
+            )
 
-        update.callback_query._maybe_send_noop()
-        return True
+            update.callback_query._maybe_send_noop()
+            return True
 
 
 class ChatUnavailableHook(Hook):
     """Underlying hook for @bot.chat_unavailable"""
 
     def call(self, bot, chat_id, reason):
-        return bot._call(self.func, self.component_id, chat_id=chat_id,
-                         reason=reason)
+        with Context(bot, self, None):
+            return bot._call(self.func, self.component_id, chat_id=chat_id,
+                             reason=reason)
 
 
 class MessageEditedHook(Hook):
@@ -272,4 +276,5 @@ class TimerHook(Hook):
     """Underlying hook for a timer"""
 
     def call(self, bot):
-        return bot._call(self.func, self.component_id)
+        with Context(bot, self, None):
+            return bot._call(self.func, self.component_id)

botogram/objects/updates.py

@@ -30,6 +30,8 @@ class Update(BaseObject):
     https://core.telegram.org/bots/api#update
     """
 
+    # Please update the chat method below when adding new types, thanks!
+
     required = {
         "update_id": int,
     }
@@ -42,6 +44,25 @@ class Update(BaseObject):
     }
     _check_equality_ = "update_id"
 
+    def chat(self):
+        """Get the chat related to this update"""
+        if self.message is not None:
+            return self.message.chat
+
+        if self.edited_message is not None:
+            return self.edited_message.chat
+
+        if self.channel_post is not None:
+            return self.channel_post.chat
+
+        if self.edited_channel_post is not None:
+            return self.edited_channel_post.chat
+
+        if self.callback_query is not None:
+            return self.callback_query.message.chat
+
+        raise NotImplementedError
+
 
 # Shortcut for the Updates type
 Updates = multiple(Update)