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A Resource Collection

Source: R/class_resource.R
multi_resource.Rd

The multi_resource can be used to permit sourcing package information from multiple resources.

Usage

multi_resource(
  package = NA_character_,
  version = NA_character_,
  id = next_id(),
  md5 = NA_character_,
  resources = list()
)

Arguments

package

character(1L) Package name. Optional, but should be provided if possible.

version

character(1L) Package version, provided as a string.

id

integer(1L) optional id used for tracking resources throughout execution. Generally not provided directly, as new objects automatically get a unique identifier. For example, the package source code from a repo_resource() may be downloaded to add a source_archive_resource() and add it to a new multi_resource(). Because all of these represent the same package, they retain the same id. Primarily the id is used for isolating temporary files.

md5

character(1L) md5 digest of the package source code tarball. This is not generally provided directly, but is instead derived when acquiring resources.

resources

list of resources

Details

Most prominently, these are exposed when a pkg() is assumed from a character value. With only a package name, val.meter will search for resources from acceptable sources according to your policy. If more than one acceptable resource is discovered, they are combined into a multi_resource.

During data derivation, each of the bundled resources is used to attempt to derive package data. The package only raises an error when no resource can successfully derive the expected data.

See also

Other resources: cran_repo_resource(), git_resource(), install_resource(), local_resource(), local_source_resource(), mock_resource(), remote_resource(), repo_resource(), resource(), source_archive_resource(), source_code_resource(), unknown_resource()