Search all existing functions for package dependencies? - r

I have a package that I wrote while learning R and its dependency list is quite long. I'm trying to trim it down, for two cases:
I switched to other approaches, and packages listed in Suggests simply aren't used at all.
Only one function out of my whole package relies on a given dependency, and I'd like to switch to an approach where it is loaded only when needed.
Is there an automated way to track down these two cases? I can think of two crude approaches (download the list of functions in all the dependent packages and automate a text search for them through my package's code, or load the package functions without loading the required packages and execute until there's an error), but neither seems particularly elegant or foolproof....

One way to check dependancies in all functions is to use the byte compiler because that will check for functions being available in the global workspace and issue a notice if it does not find said function.
So if you as an example use the na.locf function from the zoo package in any of your functions and then byte compile your function you will get a message like this:
Note: no visible global function definition for 'na.locf'
To correctly address it for byte compiling you would have to write it as zoo::na.locf
So a quick way to test all R functions in a library/package you could do something like this (assuming you didn't write the calls to other functions with the namespace):
Assuming your R files with the functions are in C:\SomeLibrary\ or subfolders there of and then you define a sourceing file as C:\SomeLibrary.r or similar containing:
if (!(as.numeric(R.Version()$major) >=2 && as.numeric(R.Version()$minor) >= 14.0)) {
stop("SomeLibrary needs version 2.14.0 or greater.")
}
if ("SomeLibrary" %in% search()) {
detach("SomeLibrary")
}
currentlyInWorkspace <- ls()
SomeLibrary <- new.env(parent=globalenv())
require("compiler",quietly=TRUE)
pathToLoad <- "C:/SomeLibraryFiles"
filesToSource <- file.path(pathToLoad,dir(pathToLoad,recursive=TRUE)[grepl(".*[\\.R|\\.r].*",dir(pathToLoad,recursive=TRUE))])
for (filename in filesToSource) {
tryCatch({
suppressWarnings(sys.source(filename, envir=SomeLibrary))
},error=function(ex) {
cat("Failed to source: ",filename,"\n")
print(ex)
})
}
for(SomeLibraryFunction in ls(SomeLibrary)) {
if (class(get(SomeLibraryFunction,envir=SomeLibrary))=="function") {
outText <- capture.output(with(SomeLibrary,assign(SomeLibraryFunction,cmpfun(get(SomeLibraryFunction)))))
if(length(outText)>0){
cat("The function ",SomeLibraryFunction," produced the following compile note(s):\n")
cat(outText,sep="\n")
cat("\n")
}
}
}
attach(SomeLibrary)
rm(list=ls()[!ls() %in% currentlyInWorkspace])
invisible(gc(verbose=FALSE,reset=TRUE))
Then start up R with no preloaded packages and source in C:\SomeLibrary.r
And then you should get notes from cmpfun for any call to a function in a package that's not part of the base packages and doesn't have a fully qualified namespace defined.

Related

Loading libraries for use in an specific environment in R

I have written some functions to facilitate repeated tasks among my R projects. I am trying to use an environment to load them easily but also prevent them from appearing when I use ls() or delete them with rm(list=ls()).
As a dummy example I have an environment loader function in a file that I can just source from my current project and an additional file for each specialized environment I want to have.
currentProject.R
environments/env_loader.R
environments/colors_env.R
env_loader.R
.environmentLoader <- function(env_file, env_name='my_env') {
sys.source(env_file, envir=attach(NULL, name=env_name))
}
path <- dirname(sys.frame(1)$ofile) # this script's path
#
# Automatically load
.environmentLoader(paste(path, 'colors_env.R', sep='/'), env_name='my_colors')
colors_env.R
library(RColorBrewer) # this doesn't work
# Return a list of colors
dummyColors <- function(n) {
require(RColorBrewer) # This doesn't work
return(brewer.pal(n, 'Blues'))
}
CurrentProject.R
source('./environments/env_loader.R')
# Get a list of 5 colors
dummyColors(5)
This works great except when my functions require me to load a library. In my example, I need to load the RColorBrewer library to use the brewer.pal function in colors_env.R, but the way is now I just get an error Error in brewer.pal(n, "Blues") : could not find function "brewer.pal".
I tried just using library(RColorBrewer) or using require inside my dummyColors function or adding stuff like evalq(library("RColorBrewer"), envir=parent.env(environment())) to the colors_env.R file but it doesn't work. Any suggestions?
If you are using similar functions across projects, I would recommend creating an R package. It's essentially what you're doing in many ways, but you don't have reinvent a lot of the loading mechanisms, etc. Hadley Wickham's book R Packages is very good for this topic. It doesn't need to be a completely fully built out, CRAN ready sort of thing. You can just create a personal package with misc. functions you frequently use.
That being said, the solution for your specific question would be to explicitly use the namespace to call the function.
dummyColors <- function(n) {
require(RColorBrewer) # This doesn't work
return(RColorBrewer::brewer.pal(n, 'Blues'))
}
Create a package and then run it. Use kitten to build the boilerplate, copy your file to it, optionally build it if you want a .tar.gz file or omit that step if you don't need it and finally install it. Then test it out. We have assumed colors_env.R, shown in the question, is in current directory.
(Note that require should always be within an if so that if it does not load then the error is caught. If not within an if use library which will guarantee an error message in that case.)
# create package
library(devtools)
library(pkgKitten)
kitten("colors")
file.copy("colors_env.R", "./colors/R")
build("colors") # optional = will create colors_1.0.tar.gz
install("colors")
# test
library(colors)
dummyColors(5)
## Loading required package: RColorBrewer
## [1] "#EFF3FF" "#BDD7E7" "#6BAED6" "#3182BD" "#08519C"

How to decorate and overwrite all functions in a R local package

I have developed a local package with 150+ functions and would like to build a dictionary of input/output formats (mostly nested tibbles) over all functions.
Since I have testthat tests written, I would like to decorate every function of the package with:
write_in_out_formats_decorator <- function(f){
wrapper <- function(...) {
res <- f(...)
# Write arguments and results formats in some files
return(res)
}
return(wrapper)
}
Then I would run my tests and retrieve all the format files.
My problem is that I cannot figure out how to decorate my functions inside a testthat context.
I tried the package tinsel : https://github.com/nteetor/tinsel
but the source_decoratees function does not seem to do the trick since testthat runs tests using the functions from package namespace and source functions are not taken into account.
So I thought about something in a setup.R before tests run:
for (funcname in package_funcnames) {
func <- get(funcname, envir = asNamespace(my_package))
# decorate my function here
decorated_func <- func ...
assignInNamespace(funcname, decorated_func, ns = my_package)
}
I have tried several things like creating a helper namespace to store my original functions and have:
decorated_func <- write_in_out_formats_decorator(helper_ns::func)
No success so far... I feel a bit lost.
Would someone have an idea of how this can be done?

How to find out if I am using a package

My R script has evolved over many months with many additions and subtractions. It is long and rambling and I would like to find out which packages I am actually using in the code so I can start deleting library() references. Is there a way of finding redundant dependencies in my R script?
I saw this question so I tried:
library(mvbutils)
library(MyPackage)
library(dplyr)
foodweb( funs=find.funs( asNamespace( 'EndoMineR')), where=
asNamespace( 'EndoMineR'), prune='filter')
But that really tells me where I am using a function from a package whereas I don't necessarily remember which functions I have used from which package.
I tried packrat but this is looking for projects whereas mine is a directory of scripts I am trying to build into a package.
To do this you first parse your file and then use getAnywhere to check for each terminal token in which namespace it is defined. Compare the result with the searchpath and you will have the answer. I compiled a function that takes a filename as argument and returns the packages which are used in the file. Note that it can only find packages that are loaded when the function is executed, so be sure to load all "candidates" first.
findUsedPackages <- function(sourcefile) {
## get parse tree
parse_data <- getParseData(parse(sourcefile))
## extract terminal tokens
terminal_tokens <- parse_data[parse_data$terminal == TRUE, "text"]
## get loaded packages/namespaces
search_path <- search()
## helper function to find the package a token belongs to
findPackage <- function(token) {
## get info where the token is defined
token_info <- getAnywhere(token)
##return the package the comes first in the search path
token_info$where[which.min(match(token_info$where, search_path))]
}
packages <- lapply(unique(terminal_tokens), findPackage)
##remove elements that do not belong to a loaded namespace
packages <- packages[sapply(packages, length) > 0]
packages <- do.call(c, packages)
packages <- unique(packages)
##do not return base and .GlobalEnv
packages[-which(packages %in% c("package:base", ".GlobalEnv"))]
}

Extended R package can't correctly communicate with its 'parent' R package

I am trying to build a package that extends another package. However at its most basic level I am doing something wrong. I build a simple example that presents the same issue:
I have two packages, packageA and packageB. packageA has a single R file in the R folder that reads:
local.env.A <- new.env()
setVal <- function()
{
local.env.A$test <- 1
}
getVal <- function()
{
if(!exists("test", envir = local.env.A)) stop("test does not exist")
return(local.env.A$test)
}
For packageB I have the following single R file in the R folder:
# refers to package A
setVal()
getValinA <- function()
{
return(getVal())
}
I want both packageA and packageB to be available for end users, therefore I set packageB to depend on packageA (in the description file). When packageB is loaded, e.g. by means of library(packageB) I expect it to run setVal() and thus set the test value. However, if I next try to get the value that was set by means of getValinA(), it throws me the stop:
> library(packageB)
Loading required package: PackageA
> getValinA()
Error in getVal() : test does not exist
I am pretty sure it is related to environments, but I am not sure how. Please help!
With thanks to #Roland. The answer was very simple. I was under the impression (assumptions assumptions assumptions!) that when you perform library(packageB) it would load all the actions within it, in my case perform the setVal() function. This is however not the case. If you wish this function to be performed you need to place this within the function .onLoad:
.onLoad <- function(libname, pkgname)
{
setVal()
}
By convention you place this .onload function in an R file called zzz.R. Reason being that if you do not specifically collate your R scripts it will load alphabetically, and it makes sense to perform your actions when at least all the functions in your package are loaded.

Dealing with conflicting namespaces in R (same function names in different packages): reset precedence of a package namespace

The name conflicts between namespaces from different packages in R can be dangerous, and the use of package::function is unfortunately not generalized in R...
Isn't there a function that can reset the precedence of a package namespace over all the others currently loaded?
Surely we can detach and then reload the package, but isn't there any other, more practical (one-command) way?
Because I often end up with many packages and name conflicts in my R sessions, I use the following function to do that:
set_precedence <- function(pckg) {
pckg <- deparse(substitute(pckg))
detach(paste("package", pckg, sep = ":"), unload=TRUE, character.only=TRUE)
library(pckg, character.only=TRUE)
}
# Example
set_precedence(dplyr)
No built-in way to achieve this in a single command?
Or a way that doesn't imply detaching and reloading the package, in case it is heavy to load, and working directly on namespaces?
Here's a way that do not reload the package and work directly on the environments/namespaces.
Just replace your library() call with attachNamespace():
set_precedence <- function(pkg) {
detach(paste0("package:", pkg), character.only = TRUE)
attachNamespace(pkg)
}
set_precedence('utils')
# now utils is in pos #2 in `search()`
I would suggest taking a look at the conflicted package.
Prefix the package name with a double colon: <package>::<function>()
For instance:
ggplot2::ggplot(data=data, ggplot2::aes(x=x)) +
ggplot2::geom_histogram()
More typing, but I feel so much less anxious using R now that I have found this.

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