Advanced

Error Handling

The library signals unsuccessful Bot API requests and other arbitrary errors during the Bot API calls.

(tbot/set-webhook mybot nil)
=>
{:ok false,
 :error_code 400,
 :description "Bad Request: bad webhook: Failed to resolve host: No address associated with hostname",
 :error #error{...}}

Upon any exception, it is passed either:

• along with the Bot API response (in a form of Clojure map) in case the request was unsuccessful in terms of the Bot API, or
• just as {:error ex} map in all other situations when we're unable to retrieve a response body.

It's up to you to decide on how to react to an error in each particular case.

The usual choices are:

• to just log (w/ :error_code and :description), or
• to retry (if the :parameters as present), or
• to rethrow the :error object.

NOTE: In asynchronous code, where callbacks can be/are processed on a different thread there is no sense in re-throwing exceptions. See the next section for details on how to make an async Telegram Bot API request with the telegrambot-lib.

Making Asynchronous Calls

Basically, you have to pass an :async true parameter along with the bot to make any function end up with firing an asynchronous request. The only difference is that the function returns immediately, with a regular core.async channel to take the response (or error result) from later on.

Here's how such a call may look like:

;; Option 1: temporarily modify the bot map for a particular async request
(tbot/send-message (assoc mybot :async true)
                   {:chat_id 280000000 :text "Drop-and-run!"})

;; Option 2: use a global/shared bot map for all asynchronous requests
(def my-async-bot (tbot/create {:async true}))

(tbot/send-message my-async-bot 280000000 "Drop-and-run!")

In either case you'll get a similar response — a core.async channel to take from later on:

=>
#object[clojure.core.async.impl.channels.ManyToManyChannel 0x3d059861 "clojure.core.async.impl.channels.ManyToManyChannel@3d059861"]