Package Registry

packageRegistry provides ways to create query package specific registries.

packageRegistry(
  regname = NULL,
  quiet = FALSE,
  entry = FALSE,
  update = !entry,
  package = topenv(parent.frame())
)

packageRegistries(regname = NULL, package = NULL, primary = FALSE)

hasPackageRegistry(regname = NULL, package)

setPackageRegistry(
  regname,
  regobj,
  description = "",
  entrydesc = NA,
  ...,
  package = topenv(parent.frame()),
  overwrite = FALSE
)

setPackageRegistryEntry(
  regname,
  key,
  ...,
  overwrite = FALSE,
  verbose = FALSE,
  where = topenv(parent.frame()),
  msg = NULL
)

Arguments

regname	Name of a sub-registry, used as its identifier.
quiet	a logical that indicates that one should return the (meta-)registry if it exists, or NULL otherwise, without throwing any error.
entry	logical that indicates if the corresponding meta registry entry should be directly returned, without any other processing.
update	logical that indicates if the package registry should be updated, by adding/removing entries from other loaded/unloaded packages.
package	package where to store or look for the registry.
primary	logical that indicates if only primary registries should be listed.
regobj	a registry object or a single character string that indicates the class of the objects that are stored in the sub-registry. See details for the list of the sub-registry's fields in this latter case.
description	short description line about the registry. It is recommended to provide such description as it makes clearer the purpose of the registry. This description is shown when the registry object is printed/formated/listed.
entrydesc	human readable description that is used in log messages when registering/removing entries.
...	named values used to set extra information about the new registry, that are stored in the corresponding fields of the meta-registry. Currently not used, as no extra field other than 'description' is defined.
overwrite	a logical that indicate if an existing registry with the same should be overwritten if it exists.
key	entry identifier.
verbose	a logical that indicates if verbosity should be toggle on.
where	package name or namespace that owns the registry.
msg	addon message to print at the end of the output log line, when verbose=TRUE.

Value

a registry object or NULL (see argument quiet).

Details

Package registries are organised in a meta-registry (a registry of registries) within a package's namespace. Each registry can be used to store sets of built-in or user-defined objects in an organised way, e.g. algorithms or datasets.

A package meta-registry is a registry object, whose entries are registry objects themselves. A sub-registry entry is defined by the following fields:

key

The sub-registry's accession key/identifier (a character string).

regobj

The sub-registry itself (a registry object)

description

Human readable description of the purpose of the registry (a character string)

description

Short human readable description of the type of entries (a character string)

package

owner package, which is forced to be the package in which the meta registry is defined.

parent

The name of the package that holds the parent registry, which we call the primary package. This field is non empty for cross-package registries, i.e. registries that derive from primary package's own registry. Their entries are defined when (lazy-)loading the dependent package's namespace.

Note that this function cannot be called from the global environment, but from a package namespace, e.g., when a package is lazy-loaded on installation or loaded via the function load_all from the devtools package.

Functions

• packageRegistries: lists registries from loaded packages.

• hasPackageRegistry: tells if a given package has a meta-registry or a given registry.

• setPackageRegistry: creates a package-specific registry within a package.

  Each package sub-registry has its own set of fields. Sub-registries defined by passing a character string in argument regobj of setPackageRegistry have the following fields: 'key' and 'object'

• setPackageRegistryEntry: adds an entry in a package registry.