Add pause to handle rate limit when reached

R/ct_perform_request.R

@@ -11,18 +11,29 @@
 ct_perform_request <- function(req, requests_per_second = 10 / 60, verbose = FALSE) {
 
     if (verbose) {
-      cli::cli_inform(c("i" = "Performing request, which can take a few seconds, depending on the amount of data queried"))
+      cli::cli_inform(c("i" = "Performing request, which can take a few seconds, depending on the amount of data queried."))
+    }
+
+    comtrade_is_transient <- function(resp) {
+      httr2::resp_status(resp) == 403 &&
+        httr2::resp_header(resp, "Retry-After") != "0"
+    }
+
+    comtrade_after <- function(resp) {
+      time <- as.numeric(httr2::resp_header(resp, "Retry-After"))
     }
 
     resp <- req |>
       httr2::req_error(body = comtrade_error_body) |>
       httr2::req_throttle(rate = requests_per_second) |>
-      httr2::req_retry(max_tries = 5) |>
+      httr2::req_retry(is_transient = comtrade_is_transient,
+                       after = comtrade_after) |>
       httr2::req_perform()
 
     if (verbose) {
-      cli::cli_inform(c("v" = "Got a response object from Comtrade. Use `process = F` if there is an error after this step to find issues with the response object."))
+      cli::cli_inform(c("v" = "Got a response object from UN Comtrade. Use `process = F` if there is an error after this step to find issues with the response object."))
     }
+
     return(resp)
   }