R/begin.R

In easyr: Helpful Functions from Oliver Wyman Actuarial Consulting

#' Begin
#' 
#' Perform common operations before running a script. Includes clearing environment objects, disabling scientific notation, loading common packages, and setting the working directory to the location of the current file.
#'
#' @param wd Path to set as working directory. If blank, the location of the current file open in RStudio will be used if available. If FALSE, the working directory will not be changed.
#' @param load Packages to load. If not available, they'll be installed.
#' @param keep Environment objects to keep. If blank, all objects will be removed from the environment.
#' @param scipen Do scientific notation in output?
#' @param verbose Print information about what the function is doing?
#' @param repos choose the URL to install from.
#'
#' @export
#'
#' @examples
#' 
#' begin()
begin = function(
  wd = NULL, 
  load = c( 'magrittr', 'dplyr' ),
  keep = NULL,
  scipen = FALSE,
  verbose = TRUE,
  repos = 'http://cran.us.r-project.org'
){
  
  # check if attempting to keep any objects not in environment
  envobjs = ls( all.names = TRUE, envir = parent.frame() )
  if( length(keep) > 0 ){
    missing = setdiff( keep, envobjs )
    if( length( missing ) > 0 ) stop(glue::glue('
        Attempted to keep objects not in the environment: [{cc(missing, sep = ", ")}]. Error easyr::begin E911.
    ')) 
  }

  # clear objects not set to keep
  rm( list = setdiff( envobjs, keep ), envir = parent.frame() )
  if( verbose ) if( length(keep) > 0 ){ 
    cat(glue::glue( 'Cleared all objects from the environment except: [{cc(keep, sep = ", ")}]. \n' ))
  } else {
    cat(glue::glue( 'Cleared all objects from the environment. \n' ))
  }
  
  # set working directcory.
  
    # use tryCatch since this will error out if it isn't being run in RStudio.
    if( is.null( wd ) ) wd = tryCatch(
      dirname( rstudioapi::getSourceEditorContext()$path ),
      error = function(e) FALSE
    )
    
    if( !is.logical(wd) || wd == TRUE ){
      setwd( wd )
      if( verbose ) cat( 'Set workspace to [', wd, ']. \n' )
    }
  
  # no scientific notation
  if( ! scipen ){
    options( scipen = 999 )
    if( verbose ) cat( 'Disabled scientific notation. \n' )
  }
  
  # load common packages.
  if( length( load ) > 0 ){
    easyr::usepkg( load, repos = repos)
    if( verbose ) cat( 'Loaded: [', paste0( load, collapse = ', ' ), ']. \n' )
  }
  
  # run functions.
  if( dir.exists( 'functions' ) ){
    easyr::runfolder( 'functions', verbose = verbose )
  }
  if( dir.exists( 'fun' ) ){
    easyr::runfolder( 'fun', verbose = verbose )
  }

}