Load complete package — load

load_all() loads a package. It roughly simulates what happens when a package is installed and loaded with library(), without having to first install the package. It:

Loads all data files in data/. See load_data() for more details.
Sources all R files in the R directory, storing results in environment that behaves like a regular package namespace. See load_code() for more details.
Adds a shim from system.file() to shim_system.file() in the imports environment of the package. This ensures that system.file() works with both development and installed packages despite their differing directory structures.
Adds shims from help() and ? to shim_help() and shim_question() to make it easier to preview development documentation.
Compiles any C, C++, or Fortran code in the src/ directory and connects the generated DLL into R. See pkgbuild::compile_dll() for more details.
Loads any compiled translations in inst/po.
Runs .onAttach(), .onLoad() and .onUnload() functions at the correct times.
If you use testthat, will load all test helpers so you can access them interactively. devtools sets the DEVTOOLS_LOAD environment variable to the package name to let you check whether the helpers are run during package loading.

is_loading() returns TRUE when it is called while load_all() is running. This may be useful e.g. in .onLoad hooks. A package loaded with load_all() can be identified with is_dev_package().

Usage

load_all(
  path = ".",
  reset = TRUE,
  recompile = FALSE,
  export_all = TRUE,
  helpers = TRUE,
  quiet = FALSE,
  ...
)

Arguments

path: Path to a package, or within a package.
reset: This is no longer supported because preserving the namespace requires unlocking its environment, which is no longer possible in recent versions of R.
recompile: DEPRECATED. force a recompile of DLL from source code, if present. This is equivalent to running pkgbuild::clean_dll() before load_all()
export_all: If TRUE (the default), export all objects. If FALSE, export only the objects that are listed as exports in the NAMESPACE file.
helpers: if TRUE loads testthat test helpers.
quiet: if TRUE suppresses output from this function.
...: Additional arguments passed to pkgload::load_all().

Differences to regular loading

load_all() tries its best to reproduce the behaviour of loadNamespace() and library(). However it deviates from normal package loading in several ways.

load_all() doesn't install the package to a library, so system.file() doesn't work. pkgload fixes this for the package itself installing a shim, shim_system.file(). However, this shim is not visible to third party packages, so they will fail if they attempt to find files within your package. One potential workaround is to use fs::path_package() instead of system.file(), since that understands the mechanisms that devtools uses to load packages.
load_all() loads all packages referenced in Imports at load time, but loadNamespace() and library() only load package dependencies as they are needed.
load_all() copies all objects (not just the ones listed as exports) into the package environment. This is useful during development because it makes internal objects easy to access. To export only the objects listed as exports, use export_all = FALSE. This more closely simulates behavior when loading an installed package with library(), and can be useful for checking for missing exports.

Controlling the debug compiler flags

load_all() delegates to pkgbuild::compile_dll() to perform the actual compilation, during which by default some debug compiler flags are appended. If you would like to produce an optimized build instead, you can opt out by either using debug = FALSE, setting the pkg.build_extra_flags option to FALSE, or setting the PKG_BUILD_EXTRA_FLAGS environment variable to FALSE. For further details see the Details section in pkgbuild::compile_dll().

Examples

if (FALSE) { # \dontrun{
# Load the package in the current directory
load_all("./")

# Running again loads changed files
load_all("./")

# With export_all=FALSE, only objects listed as exports in NAMESPACE
# are exported
load_all("./", export_all = FALSE)
} # }