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SpaDES.core (version 2.0.5)

convertToPackage: Convert standard module code into an R package

Description

EXPERIMENTAL -- USE WITH CAUTION. This function will only create the necessary source files so that all the code can be used (and installed) like an R package. This function does not install anything (e.g., devtools::install). After running this function, simInit will automatically detect that this is now a package and will load the functions (via pkgload::load_all) from the source files. This will have the effect that it emulates the "non-package" behaviour of a SpaDES module exactly. After running this function, current tests show no impact on module behaviour, other than event-level and module-level Caching will show changes and will be rerun. Function-level Caching appears unaffected. In other words, this should cause no changes to running the module code via simInit and spades.

Usage

convertToPackage(
  module = NULL,
  path = getOption("spades.modulePath"),
  buildDocuments = TRUE
)

Value

Invoked for its side effects. There will be a new or modified DESCRIPTION file in the root directory of the module. Any functions that were in the main module script (i.e., the .R file whose filename is the name of the module and is in the root directory of the module) will be moved to individual .R files in the R folder. Any function with a dot prefix will have the dot removed in its respective filename, but the function name is unaffected.

Currently, SpaDES.core does not install the package under any circumstances. It will load it via pkgdown::load_all, and optionally (option("spades.moduleDocument" = TRUE)) build documentation via roxygen2::roxygenise within the simInit call. This means that any modifications to source code will be read in during the simInit call, as is the practice when a module is not a package.

invoked for the side effect of converting a module to a package

Arguments

module

Character string of module name, without path

path

Character string of modulePath. Defaults to getOption("spades.modulePath").

buildDocuments

A logical. If TRUE, the default, then the documentation will be built, if any exists, using roxygen2::roxygenise.

Exported functions

The only function that will be exported by default is the doEvent.xxx, where xxx is the module name. If any other module is to be exported, it must be explicitly exported with e.g., @export, and then building the NAMESPACE file, e.g., via devtools::document(moduleRootPath). NOTE: as long as all the functions are being used inside each other, and they all can be traced back to a call in doEvent.xxx, then there is no need to export anything else.

DESCRIPTION

The DESCRIPTION file that is created (destroying any existing DESCRIPTION file) with this function will have several elements that a user may wish to change. Notably, all packages that were in reqdPkgs in the SpaDES module metadata will be in the Imports section of the DESCRIPTION. To accommodate the need to see these functions, a new R script, imports.R will be created with @import for each package in reqdPkgs of the module metadata. However, if a module already has used @importFrom for importing a function from a package, then the generic @import will be omitted for that (those) package(s). So, a user should likely follow standard R package best practices and use @importFrom to identify the specific functions that are required within external packages, thereby limiting function name collisions (and the warnings that come with them).

Other elements of a standard DESCRIPTION file that will be missing or possibly inappropriately short are Title, Description, URL, BugReports.

Installing as a package

There is no need to "install" the source code as a package because simInit will load it on the fly. But, there may be reasons to install it, e.g., to have access to individual functions, help manual, running tests etc. To do this, simply use the devtools::install(pathToModuleRoot). Even if it is installed, simInit will nevertheless run pkgload::load_all to ensure the spades call will be using the current source code.

Details

This will move all functions that are not already in an .R file in the R folder into that folder, one function per file, including the doEvent.xxx function. It will not touch any other functions already in the "R" folder. It will also create and fill a minimal DESCRIPTION file. This will leave the defineModule function call as the only code in the main module file. This defineModule and a doEvent.xxx are the only 2 elements that are required for an R package to be considered a SpaDES module. With these changes, the module should still function normally, but will be able to act like an R package, e.g., for writing function documentation with roxygen2, using the testthat infrastructure, etc.

This function is intended to be run once for a module that was created using the "standard" SpaDES module structure (e.g., from a newModule call). There is currently no way to "revert" the changes from R (though it can be done using version control utilities if all files are under version control, e.g., GitHub). Currently SpaDES.core identifies a module as being a package if it has a DESCRIPTION file, or if it has been installed to the .libPaths() e.g., via devtools::install or the like. So one can simply remove the package from .libPaths and delete the DESCRIPTION file and SpaDES.core will treat it as a normal module.

Examples

Run this code
if (requireNamespace("ggplot2") && requireNamespace("pkgload") ) {
  tmpdir <- tempdir2()
  newModule("test", tmpdir, open = FALSE)
  convertToPackage("test", path = tmpdir)
  pkgload::load_all(file.path(tmpdir, "test"))
  pkgload::unload("test")
}

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