Package 'path.chain'

path.chain: Concise Structure for Chainable Paths

Description

The aim of this package is to provide tools, which allow us to represent directory structure as nested R objects. It can be easily saved as .yaml files so that we can later load it and use in our project.

Author(s)

Krzysztof Joachimiak

---

Access path_chain object

Description

Access path_chain object

Usage

## S3 method for class 'path_chain'
node$child

Arguments

node	path_chain
child	nested path_chain name

Value

path_chain or character, if path indicates leaf of structure tree

Examples

#' If we want to create our chain manually, we have start from the leaves
level2.b <- path_link("fileA.RData")
level2.a <- path_link("fileB.RData")
level1   <- path_link("data", list(level2.a = level2.a , level2.b = level2.b))
root     <- path_link("files", list(level1))
# Print root path
root$.
# Print file path using chaining
root$data$level2.a

---

Prepare list to be saved as config .yaml file

Description

This function is provided to keep compatibility with 'config' package, which requires existence of default key. Additionally, we can at once wrap our structure with some other keys, in order to not to mix directory structur with different keys.

Usage

as_config(x, config = "default", wrap = "dirs", ...)

## S3 method for class 'path_chain'
as_config(x, config = "default", wrap = "dirs",
  ..., root.name = "root.dir")

## S3 method for class 'list'
as_config(x, config = "default", wrap = "dirs", ...)

Arguments

x	list with directory structure
config	configuration name
wrap	key name to wrap directory structure
...	additional arguments (not used at the moment)
root.name	key for root directory (for path_chain only)

Value

list compatible with 'config' package

Examples

library(magrittr)
# Initalizaing sample directory
tmp <- create_temp_dir("files")
create_sample_dir(tmp, override = TRUE)
full_path_chain(tmp, "kRoot", naming_k) %>%
   list(kDirs = .) %>%
   list(default = .) %>%
   yaml::write_yaml(temp_path("config.yaml"))
# We can simply use such function
full_path_chain(tmp, "kRoot", naming_k) %>%
   as_config("default", "kDirs") %>%
   yaml::write_yaml(temp_path("config.yaml"))

---

Create chainable path

Description

This function always treats first object in the nested list as a subdirectory root path

Usage

as_path_chain(nested.list, root.name = "kRoot")

Arguments

nested.list	'list' object with nested lists/strings inside
root.name	key for root directory

Value

path_chain object

Examples

library(magrittr)
# Manually created nested list
nested.list <- list(kRoot = "root", "file1.txt", list("subdir", "file2.csv"))
chainable.path <- as_path_chain(nested.list)
class(chainable.path)
chainable.path$.
chainable.path$subdir$files2.csv
# Nested list from config file
tmp <- create_temp_dir("files")
create_sample_dir(tmp, override = TRUE)
fs::dir_tree(tmp)
path_chain(tmp, naming = naming_k) %>%
  as.list(root.name = "kRoot") %>%
  as_config("default", "kDirs") %>%
  yaml::write_yaml(temp_path("config.yaml"))
chainable.path <- config::get("kDirs", "defaul", temp_path("config.yaml")) %>%
 as_path_chain()
class(chainable.path)
chainable.path$.
chainable.path$kData$kExample1

---

Convert object of type 'path_chain' to list

Description

Convert object of type 'path_chain' to list

Usage

## S3 method for class 'path_chain'
as.list(x, ..., root.name = "root.dir")

Arguments

x	a path_chain object
...	elipsis for API consistency, does nothing
root.name	key for root directory; default: 'root.dir'

Examples

tmp <- create_temp_dir("files")
create_sample_dir(tmp)
path.chain <- path_chain(tmp)
as.list(path.chain)

---

Create sample directory

Description

Creates sample nested directory to test and learn path.chain package

Usage

create_sample_dir(path = "files", override = FALSE)

Arguments

path	path for the new sample folder
override	boolean: override folder if it already exists

Examples

tmp <- create_temp_dir("files")
create_sample_dir(tmp, override = TRUE)
list.files(tmp, all.files = TRUE, recursive = TRUE, include.dirs = TRUE)
fs::dir_tree(tmp)

---

Create temporary diectory and return its name

Description

Create temporary diectory and return its name

Usage

create_temp_dir(..., warn = FALSE, recursive = FALSE,
  fsep = .Platform$file.sep)

Arguments

...	arbitrary character objects
warn	warn, if folder already exists
recursive	ogical. Should elements of the path other than the last be created? If true, like the Unix command mkdir -p
fsep	the path separator to use

Examples

# Simply create and return temporal directory
create_temp_dir()
# Create temp dir and return concatenated path
# Keep in mind, that 'files' and 'report_2020.xls' will not be created.
create_temp_dir("files", "report_2020.xls")

---

Construct path to file without doubled separators

Description

Construct path to file without doubled separators

Usage

file_path(..., fsep = .Platform$file.sep)

Arguments

...	character vectors
fsep	the path separator to use

Value

character file path

Examples

file.path("files/", "data/", "cars.RData")
file_path("files/", "data/", "cars.RData")

---

Full path chain

Description

'full_path_chain' represents another approach to creating chainable paths In contrast to 'path_chain', this functon creates just a list with nested list with full paths as a leaves.

Usage

full_path_chain(path = ".", root.name = ".", naming = basename)

Arguments

path	root path
root.name	naming convention for root directory
naming	naming function

Value

list of lists and character objects

Examples

tmp <- create_temp_dir("files")
create_sample_dir(tmp, override = TRUE)
fs::dir_tree(tmp)
chainable.path <- full_path_chain(tmp)
chainable.path

---

Naming convention, which adds k prefix for each key, capitalizes and removes file extension

Description

Naming convention, which adds k prefix for each key, capitalizes and removes file extension

Usage

naming_k(path)

Arguments

path	full path or its element

Examples

library(magrittr)
naming_k("path/to/myfile.txt")
# Using with full_path_chain
tmp <- create_temp_dir("files")
create_sample_dir(tmp, override = TRUE)
full.path.chain <- full_path_chain(tmp, naming = naming_k)
full.path.chain
tmp <- create_temp_dir("files")
create_sample_dir(tmp)
# Using with path_chain / create_path_chain
path.chain <- path_chain(tmp, naming = naming_k)
path.chain %>%
  as.list()

---

Function called if path does not exists

Description

Function called if path does not exists

Usage

on_path_not_exists(fun)

Arguments

fun	a function, one-side formula or NULL; if missing, returns value of the path.chain.on.path.not.exists option

Examples

# We'll create an options backup for this example
old.options <- options()
on_path_not_exists(print)
on_path_not_exists()
options(old.options)

---

Function called to validate path correctness

Description

Function called to validate path correctness

Usage

on_validate_path(fun)

Arguments

fun	a function; if missing, returns value of the path.chain.on.path.not.exists option

Examples

# We'll create an options backup for this example
old.options <- options()
is_path_valid <- function(x) grepl("\\.fst", x)
on_validate_path(is_path_valid)
on_validate_path()
options(old.options)

---

Get directory structure and create path_chain object

Description

Returns 'path_chain' object, which reflects structure of the folder passed with 'path' param

Usage

path_chain(path, naming = basename)

Arguments

path	root of the directory structure
naming	function, which defines naming convention

Value

path_chain object

Examples

tmp <- create_temp_dir("files")
create_sample_dir(tmp, override = TRUE)
fs::dir_tree(tmp)
chainable.path <- path_chain(tmp)
chainable.path$data$persons.csv
# With customized naming convention
chainable.path <- path_chain(tmp, naming = naming_k)
chainable.path$kData$kPersons

---

Get children nodes, i.e. all the suddiectories in the given directory

Description

Get children nodes, i.e. all the suddiectories in the given directory

Usage

path_children(path.chain)

Arguments

path.chain

object of 'path_chain' class

Value

a list of 'path_chain' objects

Examples

tmp <- create_temp_dir("files")
create_sample_dir(tmp, override = TRUE)
path.chain <- path_chain(tmp)
path_children(path.chain)

---

Creates a link of path chain - a directory or a file

Description

It returns basic package's object: an object representing a link in the chain. Each link has the path_chain class - it can represents a one-element path chain

Usage

path_link(node = NULL, children = NULL)

Arguments

node	Current node name; character
children	list of children - path_chains

Value

path_chain object

Examples

# If we want to create our chain manually, we have start from the leaves
level2.b <- path_link("fileA.RData")
level2.a <- path_link("fileB.RData")
level1   <- path_link("data", list(level2.a = level2.a , level2.b = level2.b))
root     <- path_link("files", list(level1))
# Print root path
root$.
# Print file path using chaining
root$data$level2.a

---

Print path_chain object

Description

Print path_chain object

Usage

## S3 method for class 'path_chain'
print(x, ...)

Arguments

x	'path_chain' object
...	elipsis for API consistency, does nothing

Examples

level2.b <- path_link("fileA.RData")
level2.a <- path_link("fileB.RData")
level1   <- path_link("data", list(level2.a = level2.a , level2.b = level2.b))
root     <- path_link("files", list(level1))
print(root)

tmp <- create_temp_dir("files")
create_sample_dir(tmp, override = TRUE)
chainable.path <- path_chain(tmp)
print(chainable.path)

---

Construct path to file in a temporary directory

Description

Construct path to file in a temporary directory

Usage

temp_path(..., fsep = .Platform$file.sep)

Arguments

...	arbitrary character objects
fsep	the path separator to use.

Details

Be careful: if you call this function, it only creates a path for temporary file/dir. All the rest has to be created on your own, e.g. calling dir.create function.

Value

a path

Examples

temp_path("files", "report.csv")

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