v0.13.0: Interceptors

[mr-linch]

Interceptors are used to modify or process the request before it is sent to the server and the response before it is returned to the caller. It's like a [tgb.Middleware], but for outgoing requests.

All interceptors should be registered on the client before the request is made.

client := tg.New("<TOKEN>",
  tg.WithClientInterceptors(
    tg.Interceptor(func(ctx context.Context, req *tg.Request, dst any, invoker tg.InterceptorInvoker) error {
      started := time.Now()

      // before request
      err := invoker(ctx, req, dst)
      // after request

      log.Print("call %s took %s", req.Method, time.Since(started))

      return err
    }),
  ),
)

Arguments of the interceptor are:

• ctx - context of the request;
• req - request object tg.Request;
• dst - pointer to destination for the response, can be nil if the request is made with DoVoid method;
• invoker - function for calling the next interceptor or the actual request.

Contrib package has some useful interceptors:

• InterceptorRetryFloodError - retry request if the server returns a flood error. Parameters can be customized via options;
• InterceptorRetryInternalServerError - retry request if the server returns an error. Parameters can be customized via options;
• InterceptorMethodFilter - call underlying interceptor only for specified methods;
• InterceptorDefaultParseMethod - set default parse_mode for messages if not specified.

Interceptors are called in the order they are registered.

Example of using retry flood interceptor: examples/retry-flood

Full Changelog: v0.12.0...v0.13.0

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This discussion was created from the release v0.13.0: Interceptors.