Telegram sendPhoto method don't refresh

Question

I'm using a simple bot code which takes an Image from a php page created using:

header("Content-type: image/png");

and

imagepng();

Here is the bot code:

if ($text == "/photo") {
  $reply_markup = [
    "inline_keyboard" => [
      [
        [
          "text" => "Url",
          "url" => "https://google.com",
        ],
      ],
    ],
  ];
  sendPhoto($chat_id, "https://url.com/image.php?x=".urlencode($string), "Text", "HTML", false, $message_id, $reply_markup);
}



function sendPhoto($chat_id, $photo, $caption, $parse_mode = "default", $disable_notification = "default", $reply_to_message_id, $reply_markup) {

  global $config;

  if ($parse_mode == "default") $parse_mode = $config['parse_mode'];
  if ($disable_notification === "default") $disable_notification = $config['disable_notification'];

  $args = [
    "chat_id" => $chat_id,
    "photo" => $photo,
    "caption" => $caption,
    "parse_mode" => $parse_mode,
    "disable_notification" => $disable_notification,
  ];

  if (isset($reply_to_message_id)) $args["reply_to_message_id"] = $reply_to_message_id;
  if (isset($reply_markup)) $args["reply_markup"] = $reply_markup;

  return json_decode(http_request("sendPhoto", $args), true);
}

The code works fine and it sends the image correctly. But if I use the same url twice, it sends me the older version sent before.

For example i request ?x=photo and it prints photo.png correctly, after a while i request again photo(now the php page gives me another image) but bot sends me the older photo. It seems like it's cached on Telegram

Answer 1

Telegram might be caching it because it is receiving the same filename twice, Instead of sending the photo with the original name, you could generate a random filename so telegram doesn't cache it.