attach_source: Source R files in an attached environment

In envir: Manage R Environments Better

Source R files in an attached environment

Description

Source R files in an attached environment

Usage

attach_source(
  ...,
  name = as_tidy_env_name(c(...), prefix = "source:"),
  recursive = FALSE,
  pos = 2L,
  chdir = FALSE,
  warn.conflicts = TRUE,
  mask.ok = NULL
)

Arguments

...	filepaths to R files, or paths to directories containing R files.
name	A string, the name for the attached environment. By default, the name is constructed from paths supplied to .... If the requested name is not on the search path, a new environment of this name is attached.
recursive	If directories are passed to ..., whether to search them recursively.
pos	The position where to attach the environment, if creating a new one. If an environment of name already exists, pos is ignored.
chdir	logical. if TRUE, the R working directory is temporarily changed to the directory containing the file(s) being sourced.
warn.conflicts	logical. If TRUE (the default), print warnings about objects in the attached environment that that are masking or masked by other objects of the same name.
mask.ok	character vector of names of objects that can mask objects on the search path without signaling a warning if warn.conflicts is TRUE

Value

The attached environment, invisibly.

Note

One subtlety that is sometimes important: packages attached after this environment is created will be not on the symbol search path for the environment where the R source is evaluated. The search path of the environment the R files are sourced in is tail(search(), -pos).

This means that, for example, if you source a script that calls library(), the code in that script will not "see" the functions from the newly attached packages. This is by design. However, if you want to source scripts that call library and define new functions, and you want those new functions to "see" the library attached packages, here are 3 ways to do that:

1. Attach all the packages you want before attaching the script:

   library(foo); library(bar)
   attach_source("my_script.R")
   

2. Modify the default pos argument to library, so all new packages attach after your script:

   envir:::set_default_library_pos(after = "source:my_script.R")
   attach_source("my_script.R")
   

3. This is the likely the most preferred solution. Instead of sourcing files directly in the attached environment, source the files into a new environment that inherits from .Globalenv, and then copy over everything to the attached environment.

   attach_eval({
     import_from("my_script.R")
   })
   

See Also

import_from, set_library_default_pos

envir documentation built on Sept. 22, 2022, 5:07 p.m.