Many Downloads with gatoRs

Due to GBIF’s API timeout error, if you want to download a bunch of records for a bunch of species, you have to you have to add a retry in your download loop. Here we demonstrate how to add a retry with the gatoRs::gators_download() function.

Retry Function

This is a modified function from JT Miller. Here you have a nameset which is a list of lists (see below), an ith value, and the retry count. Note, here failed_name_holder must be defined outside of the function.

# Build a retry_downloader function that proceeds to try if an API error occurs
failed_names_holder <- list() 
retry_download <- function(nameset, i, retry_count) {
  if(retry_count >= 11) { # Allow up to 11 attempts
    failed_names_holder[[i]] <<- c(nameset[[i]][1], 
                                   "Maximum retries exceeded", 
                                   format(Sys.time(), "%a %b %d %X %Y")) 
    return(NULL) # Null otherwise 
  } 
  tryCatch({
    gators.download <- gatoRs::gators_download(synonyms.list = nameset[[i]], 
                                              write.file = TRUE, 
                                              filename = paste0("data/", 
                                                                gsub(" ", "_", nameset[[i]][1]), ".csv"))
    return(gators.download) # Return the gators.download
  },
  error = function(e) { # create error report
    if (e$message != "No records found.") { # If errors besides the following occurs, retry
      Sys.sleep(retry_count*30)  
      print(paste("Download attempt", retry_count + 1, "for", nameset[[i]][1], 
                  "failed. Retrying with delay", print(retry_count*30), "second delay"))
      return(retry_download(nameset, i, retry_count + 1))  # Retry the download
    } else {
     failed_names_holder[[i]] <<- c(nameset[[i]][1], e, format(Sys.time(), "%a %b %d %X %Y"))
      return(NULL)
    }
  })
  
}

Use the Retry Function

Here we define a namelist where the 1st object is the accepted name. We then use the retry function to download. If the failed_name_holder includes any lines, we then inspect this list.

name_list <- list(Shortia_galacifolia = c("Shortia galacifolia", 
                                            "Sherwoodia galacifolia"),
                  Galax_urceolata = c("Galax urceolata", 
                                      "Galax aphylla"),
                  Pyxidanthera_barbulata = c("Pyxidanthera barbulata",
                                             "Pyxidanthera barbulata var. barbulata"),
                  Pyxidanthera_brevifolia = c("Pyxidanthera brevifolia", 
                                              "Pyxidanthera barbulata var. brevifolia"))



for(i in 1:length(name_list)){
   retry_download(name_list, i, 0) # 0 initializes the download count
}

## Inspect failed names
failed_names_table <- as.data.frame(do.call(rbind, failed_names_holder)) # unpack the f
if(length(failed_names_table) > 0){
  colnames(failed_names_table)[1] <- "name" # Assign column headers
  colnames(failed_names_table)[2] <- "errorType"
  colnames(failed_names_table)[3] <- "systemTime"
}