get_message(): more examples

library(saferDev)

These examples may not work well here because of a particular environment. Please, copy-paste in a local environment.

Dataset

char1 <- "wilcox.test(c(1,1,3), c(1, 2, 4), paired = TRUE)" # string of a command to evaluate -> warning message
char2 <- "message('ahah')" # idem -> standard message
char3 <- "NOTGOOD" # idem -> error message
char4 <- "mean(2)" # idem -> no message

Dataset info

char1

## [1] "wilcox.test(c(1,1,3), c(1, 2, 4), paired = TRUE)"

char2

## [1] "message('ahah')"

char3

## [1] "NOTGOOD"

Simple example

# By default, get_message() returns the first error message of the evaluated string.
# Here no error message
get_message(data = char1)

## NULL

# Here no error message
get_message(data = char2)

## NULL

# Error message
get_message(data = char3)

## [1] "ERROR MESSAGE REPORTED:\nIn base::eval(expr = base::parse(text = data, file = \"\", n = NULL,  : \n  object 'NOTGOOD' not found\n"

Argument kind

# To get the last potential warning message.
get_message(data = char1, kind = "warning")

## [1] "WARNING MESSAGE REPORTED:\nIn wilcox.test.default(c(1, 1, 3), c(1, 2, 4), paired = TRUE): cannot compute exact p-value with zeroes\n"

# See that 2 warning messages are returned when evaluating char1.
 eval(parse(text = char1))

## Warning in wilcox.test.default(c(1, 1, 3), c(1, 2, 4), paired = TRUE): cannot
## compute exact p-value with ties

## Warning in wilcox.test.default(c(1, 1, 3), c(1, 2, 4), paired = TRUE): cannot
## compute exact p-value with zeroes

## 
##  Wilcoxon signed rank test with continuity correction
## 
## data:  c(1, 1, 3) and c(1, 2, 4)
## V = 0, p-value = 0.3458
## alternative hypothesis: true location shift is not equal to 0

# To get the last potential standart message (neither error nor warning).
get_message(data = char2, kind = "message")

## ahah

## NULL

Argument header

# To get the output message without header.
get_message(data = char3, header = FALSE)

## [1] "Error in base::eval(expr = base::parse(text = data, file = \"\", n = NULL,  : \n  object 'NOTGOOD' not found\n"

# To get the output message with header (by default).
get_message(data = char3, header = TRUE) 

## [1] "ERROR MESSAGE REPORTED:\nIn base::eval(expr = base::parse(text = data, file = \"\", n = NULL,  : \n  object 'NOTGOOD' not found\n"

Argument print_no

# Print a message when no "kind" message returned.
get_message(data = char1, print_no = TRUE)

## [1] "NO ERROR MESSAGE REPORTED"

# Example with potential returned warning message.
get_message(data = char2, kind = "warning", print_no = TRUE) 

## ahah

## [1] "NO WARNING MESSAGE REPORTED"

Argument text

# String added to the output message, even if nothing reported (when print_no = TRUE).
# Useful when used inside a function to name it.
get_message(data = char3, text = "IN MY EXECUTION") 

## [1] "ERROR MESSAGE REPORTED IN MY EXECUTION:\nIn base::eval(expr = base::parse(text = data, file = \"\", n = NULL,  : \n  object 'NOTGOOD' not found\n"

Argument env

# Evaluation only in the indicated environment.
get_message(data = char1, env = .GlobalEnv)

## NULL

get_message(data = char1, kind = "warning", env = asNamespace("stats"))

## [1] "WARNING MESSAGE REPORTED:\nIn wilcox.test.default(c(1, 1, 3), c(1, 2, 4), paired = TRUE): cannot compute exact p-value with zeroes\n"

Argument safer_check

# Safer checkings are performed before main code running.
get_message(data = char2, safer_check = TRUE)

## NULL

Argument lib_path

# The "NOTGOOD" path does not exists.
get_message(data = char2, lib_path = "NOTGOOD")

## Error: 
## 
## ================
## 
## ERROR IN saferDev::get_message().
## 
## THE DIRECTORY PATH INDICATED IN THE lib_path ARGUMENT DOES NOT EXIST:
## NOTGOOD
## 
## ================

Argument error_text

# Add a text in error messages returned by get_message().
get_message(
    data = char2, 
    lib_path = "NOTGOOD", 
    error_text = " === TEXT ADDED ==="
)

## Error: 
## 
## ================
## 
## ERROR IN saferDev::get_message() === TEXT ADDED ===
## 
## THE DIRECTORY PATH INDICATED IN THE lib_path ARGUMENT DOES NOT EXIST:
## NOTGOOD
## 
## ================

All the arguments

get_message(
    data = char1, # instruction to evaluate.
    kind = "warning", # kind of message to report.
    header = FALSE, # add a header in the returned message?
    print_no = TRUE, # print a message saying that nothing has to be reported?
    text = "IN A", # string added to the output message (even if nothing reported).
    env = NULL, # existing environment where to evaluate the instruction.
    safer_check = TRUE, # perform some "safer" checks (see https://github.com/safer-r)?
    lib_path = NULL, # where the required packages are if not in the default directories.
    error_text = "" # add information in error messages returned by the function.
)

## [1] "simpleWarning in wilcox.test.default(c(1, 1, 3), c(1, 2, 4), paired = TRUE): cannot compute exact p-value with zeroes\n"