PackageCheck.R

PackageCheck <- function(USE_THESE_PACKAGES,
                         DEBUG = TRUE){
 
    if(DEBUG) message("PackageCheck: Function initialized  \n")

    if(any(USE_THESE_PACKAGES == "")){
         stop("PackageCheck: An empty string element was passed in USE_THESE_PACKAGES  \n")
    } 
    
    if(DEBUG) message("PackageCheck: Check for uninstalled packages  \n")

    FUNCTION_OUTPUT <- list()

    new_packages <- USE_THESE_PACKAGES[!(USE_THESE_PACKAGES %in% installed.packages()[,"Package"])]

    if(length(new_packages)) {
          
        install.packages(new_packages)

        if(DEBUG) message("PackageCheck: Importing all packages  \n")

        sapply(USE_THESE_PACKAGES[tolower(USE_THESE_PACKAGES) %in% tolower(.packages())], require, character.only = TRUE)

    } else {
      
        if(DEBUG) message("PackageCheck: Importing all packages  \n")

        sapply(USE_THESE_PACKAGES[tolower(USE_THESE_PACKAGES) %in% tolower(.packages())], require, character.only = TRUE)

    }

    if(DEBUG) message("PackageCheck: Collecting final output  \n")

    results <- data.table(package_name = names(sapply(USE_THESE_PACKAGES, require, character.only = TRUE)),
                          loaded = sapply(USE_THESE_PACKAGES, require, character.only = TRUE))

    FUNCTION_OUTPUT[["USE_THESE_PACKAGES"]] <- USE_THESE_PACKAGES
    FUNCTION_OUTPUT[["NEW_PACKAGES_TO_INSTALL"]] <- new_packages
    FUNCTION_OUTPUT[["ALREADY_LOADED"]] <- USE_THESE_PACKAGES[tolower(USE_THESE_PACKAGES) %in% tolower((.packages()))]
    FUNCTION_OUTPUT[["FINAL_PACKAGE_STATUS"]] <- results

    if(!is.null(results) || !nrow(results) == 0){
        if(DEBUG) message("PackageCheck: Package installation completed  \n")

        return(FUNCTION_OUTPUT)
    } else {
        stop("PackageCheck: Function returned an empty data set  \n")
    }
}