Add get_chat_preview method and ChatPreview object

docs/source/pyrogram/Client.rst

@@ -74,6 +74,7 @@ Chats
 
     join_chat
     leave_chat
+    get_chat_preview
     kick_chat_member
     unban_chat_member
     restrict_chat_member

docs/source/pyrogram/Types.rst

@@ -12,6 +12,7 @@ Users & Chats
     User
     UserStatus
     Chat
+    ChatPreview
     ChatPhoto
     ChatMember
     ChatMembers
@@ -82,6 +83,9 @@ Input Media
 .. autoclass:: Chat
     :members:
 
+.. autoclass:: ChatPreview
+    :members:
+
 .. autoclass:: ChatPhoto
     :members:
 

pyrogram/__init__.py

@@ -32,7 +32,7 @@ from .client.types import (
     Location, Message, MessageEntity, Dialog, Dialogs, Photo, PhotoSize, Sticker, User, UserStatus,
     UserProfilePhotos, Venue, Animation, Video, VideoNote, Voice, CallbackQuery, Messages, ForceReply,
     InlineKeyboardButton, InlineKeyboardMarkup, KeyboardButton, ReplyKeyboardMarkup, ReplyKeyboardRemove,
-    Poll, PollOption
+    Poll, PollOption, ChatPreview
 )
 from .client import (
     Client, ChatAction, ParseMode, Emoji,

pyrogram/client/methods/chats/__init__.py

@@ -22,6 +22,7 @@ from .get_chat import GetChat
 from .get_chat_member import GetChatMember
 from .get_chat_members import GetChatMembers
 from .get_chat_members_count import GetChatMembersCount
+from .get_chat_preview import GetChatPreview
 from .get_dialogs import GetDialogs
 from .join_chat import JoinChat
 from .kick_chat_member import KickChatMember
@@ -54,6 +55,7 @@ class Chats(
     PinChatMessage,
     UnpinChatMessage,
     GetDialogs,
-    GetChatMembersCount
+    GetChatMembersCount,
+    GetChatPreview
 ):
     pass

pyrogram/client/methods/chats/get_chat_preview.py

@@ -0,0 +1,63 @@
+# Pyrogram - Telegram MTProto API Client Library for Python
+# Copyright (C) 2017-2019 Dan Tès <https://github.com/delivrance>
+#
+# This file is part of Pyrogram.
+#
+# Pyrogram is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published
+# by the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Pyrogram is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with Pyrogram.  If not, see <http://www.gnu.org/licenses/>.
+
+import pyrogram
+from pyrogram.api import functions, types
+from ...ext import BaseClient
+
+
+class GetChatPreview(BaseClient):
+    def get_chat_preview(self,
+                         invite_link: str):
+        """Use this method to get the preview of a chat using the invite link.
+
+        This method only returns a chat preview, if you want to join a chat use :meth:`join_chat`
+
+        Args:
+            invite_link (``str``):
+                Unique identifier for the target chat in form of *t.me/joinchat/* links.
+
+        Returns:
+            Either :obj:`Chat` or :obj:`ChatPreview`, depending on whether you already joined the chat or not.
+
+        Raises:
+            :class:`Error <pyrogram.Error>` in case of a Telegram RPC error.
+            ``ValueError`` in case of an invalid invite_link.
+        """
+        match = self.INVITE_LINK_RE.match(invite_link)
+
+        if match:
+            r = self.send(
+                functions.messages.CheckChatInvite(
+                    hash=match.group(1)
+                )
+            )
+
+            if isinstance(r, types.ChatInvite):
+                return pyrogram.ChatPreview._parse(self, r)
+
+            if isinstance(r, types.ChatInviteAlready):
+                chat = r.chat
+
+                if isinstance(chat, types.Chat):
+                    return pyrogram.Chat._parse_chat_chat(self, chat)
+
+                if isinstance(chat, types.Channel):
+                    return pyrogram.Chat._parse_channel_chat(self, chat)
+        else:
+            raise ValueError("The invite_link is invalid")

pyrogram/client/types/__init__.py

@@ -35,5 +35,5 @@ from .messages_and_media import (
 )
 from .user_and_chats import (
     Chat, ChatMember, ChatMembers, ChatPhoto,
-    Dialog, Dialogs, User, UserStatus
+    Dialog, Dialogs, User, UserStatus, ChatPreview
 )

pyrogram/client/types/user_and_chats/__init__.py

@@ -20,6 +20,7 @@ from .chat import Chat
 from .chat_member import ChatMember
 from .chat_members import ChatMembers
 from .chat_photo import ChatPhoto
+from .chat_preview import ChatPreview
 from .dialog import Dialog
 from .dialogs import Dialogs
 from .user import User

pyrogram/client/types/user_and_chats/chat_preview.py

@@ -0,0 +1,78 @@
+# Pyrogram - Telegram MTProto API Client Library for Python
+# Copyright (C) 2017-2019 Dan Tès <https://github.com/delivrance>
+#
+# This file is part of Pyrogram.
+#
+# Pyrogram is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published
+# by the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Pyrogram is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with Pyrogram.  If not, see <http://www.gnu.org/licenses/>.
+
+from typing import List
+
+import pyrogram
+from pyrogram.api import types
+from .chat_photo import ChatPhoto
+from ..pyrogram_type import PyrogramType
+from ..user_and_chats.user import User
+
+
+class ChatPreview(PyrogramType):
+    """This object represents a chat preview.
+
+    Args:
+        title (``str``):
+            Title of the chat.
+
+        photo (:obj:`ChatPhoto`):
+            Chat photo. Suitable for downloads only.
+
+        type (``str``):
+            Type of chat, can be either, "group", "supergroup" or "channel".
+
+        members_count (``int``):
+            Chat members count.
+
+        members (List of :obj:`User`, *optional*):
+            Preview of some of the chat members.
+    """
+
+    def __init__(self,
+                 *,
+                 client: "pyrogram.client.ext.BaseClient",
+                 title: str,
+                 photo: ChatPhoto,
+                 type: str,
+                 members_count: int,
+                 members: List[User] = None):
+        super().__init__(client)
+
+        self.title = title
+        self.photo = photo
+        self.type = type
+        self.members_count = members_count
+        self.members = members
+
+    @staticmethod
+    def _parse(client, chat_invite: types.ChatInvite) -> "ChatPreview":
+        return ChatPreview(
+            title=chat_invite.title,
+            photo=ChatPhoto._parse(client, chat_invite.photo),
+            type=("group" if not chat_invite.channel else
+                  "channel" if chat_invite.broadcast else
+                  "supergroup"),
+            members_count=chat_invite.participants_count,
+            members=[User._parse(client, user) for user in chat_invite.participants] or None,
+            client=client
+        )
+
+    # TODO: Maybe just merge this object into Chat itself by adding the "members" field.
+    #  get_chat can be used as well instead of get_chat_preview