Add some setters for custom.Message

telethon/utils.py

@@ -6,10 +6,12 @@ import math
 import mimetypes
 import os
 import re
+import struct
 import types
 from collections import UserList
 from mimetypes import guess_extension
 
+from .tl import TLObject
 from .tl.types import (
     Channel, ChannelForbidden, Chat, ChatEmpty, ChatForbidden, ChatFull,
     ChatPhoto, InputPeerChannel, InputPeerChat, InputPeerUser, InputPeerEmpty,
@@ -500,6 +502,44 @@ def _fix_peer_id(peer_id):
     return int(peer_id)
 
 
+def add_surrogate(text):
+    return ''.join(
+        # SMP -> Surrogate Pairs (Telegram offsets are calculated with these).
+        # See https://en.wikipedia.org/wiki/Plane_(Unicode)#Overview for more.
+        ''.join(chr(y) for y in struct.unpack('<HH', x.encode('utf-16le')))
+        if (0x10000 <= ord(x) <= 0x10FFFF) else x for x in text
+    )
+
+
+def del_surrogate(text):
+    return text.encode('utf-16', 'surrogatepass').decode('utf-16')
+
+
+def get_inner_text(text, entity):
+    """
+    Gets the inner text that's surrounded by the given entity or entities.
+    For instance: text = 'hey!', entity = MessageEntityBold(2, 2) -> 'y!'.
+
+    :param text: the original text.
+    :param entity: the entity or entities that must be matched.
+    :return: a single result or a list of the text surrounded by the entities.
+    """
+    if isinstance(entity, TLObject):
+        entity = (entity,)
+        multiple = True
+    else:
+        multiple = False
+
+    text = add_surrogate(text)
+    result = []
+    for e in entity:
+        start = e.offset
+        end = e.offset + e.length
+        result.append(del_surrogate(text[start:end]))
+
+    return result if multiple else result[0]
+
+
 def get_peer_id(peer):
     """
     Finds the ID of the given peer, and converts it to the "bot api" format