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rr-package
General Douglas MacArthur
General Douglas MacArthur

Reputation: 37

R Package passing function through to new function

I'm creating a new package as a learning exercise. I've selected a few functions that serve the purpose I need and want to bundle them together into a single, new, package that I can then apply gWidgets to to make them GUI driven.

Finding documentation on how to pass existing functions has been pretty sparse and I am a novice at this. Any assistance would be appreciated.

I've added the necessary imports in my Description using usethis:use_package() updated the NAMESPACE (using Roxygen) and created the .R files using a Stackoverflow as a framework. a sample .R looks like this:

#'ODBC list drivers
#'
#'@export
odbcListDrivers <- function() {
odbc::odbcListDrivers()
}

This Works. But when it comes to the point I need to pass information with a more advanced function:

#'    
#' u/export    
#'    
DBconnect <- function() {    
DBI::dbConnect()    
}

I get an unused argument error when I try to run the test code.

con <- DBconnect(RMySQL::MySQL(),    
+ dbname = "sakila",    
+ host = "192.168.50.71",    
+ port = 49153,    
+ user = "root",    
+ password = "Camplovers01")

Error in DBconnect(RMySQL::MySQL(), dbname = "sakila", host = "192.168.50.71", :    
unused arguments (dbname = "sakila", host = "192.168.50.71", port = 49153, user = "root", password = "Camplovers01")

The question then is when I pass a function like above how can I make sure I pass the correct arguments? Function I am trying to pass

Upvotes: 0

Views: 58

Answers (1)

General Douglas MacArthur
General Douglas MacArthur

Reputation: 37

Ok, asked and then answered by myself. The answer is in the error, unused arguments. I need to place the arguments from the source function in the function I create. These will pass through to the original function and return the correct response. The odbcListDrivers worked as it had no arguments to pass or expect. Example Old .R file

#'    
#' u/export    
#'    
DBconnect <- function() {    
DBI::dbConnect()    
}

This of course fails as was the reason for my question. New .R file

#'
#' @export
#'
DBconnect <- function(dsn = NULL,
                      ...,
                      timezone = "UTC",
                      timezone_out = "UTC",
                      encoding = "",
                      bigint = c("integer64", "integer", "numeric", "character"),
                      timeout = Inf,
                      driver = NULL,
                      server = NULL,
                      database = NULL,
                      uid = NULL,
                      pwd = NULL,
                      dbms.name = NULL,
                      .connection_string = NULL) {
  DBI::dbConnect()
}

Finding the arguments of the function was a simple matter of reviewing the .R file in the GitHub repo for the Package in question.

Upvotes: 0

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