R: Is a directory the project root?

root_criterion {rprojroot}

R Documentation

Is a directory the project root?

Description

Objects of the root_criterion class decide if a given directory is a project root.

Usage

root_criterion(testfun, desc, subdir = NULL)

is.root_criterion(x)

as.root_criterion(x)

## S3 method for class 'character'
as.root_criterion(x)

## S3 method for class 'root_criterion'
as.root_criterion(x)

## S3 method for class 'root_criterion'
x | y

has_file(filepath, contents = NULL, n = -1L)

has_dir(filepath)

has_file_pattern(pattern, contents = NULL, n = -1L)

has_dirname(dirname, subdir = NULL)

Arguments

`testfun`	A function with one parameter that returns `TRUE` if the directory specified by this parameter is the project root, and `FALSE` otherwise. Can also be a list of such functions.
`desc`	A textual description of the test criterion, of the same length as `testfun`
`subdir`	Subdirectories to start the search in, if found
`x`	An object
`y`	An object
`filepath`	File path (can contain directories)
`contents`	Regular expression to match the file contents
`n`	integer. The (maximal) number of lines to read. Negative values indicate that one should read up to the end of input on the connection.
`pattern`	Regular expression to match the file name
`dirname`	A directory name, without subdirectories

Details

Construct criteria using root_criterion in a very general fashion by specifying a function with a path argument, and a description.

The as.root_criterion function accepts objects of class root_criterion, and character values; the latter will be converted to criteria using has_file.

Root criteria can be combined with the | operator. The result is a composite root criterion that requires either of the original criteria to match.

The has_file function constructs a criterion that checks for the existence of a specific file (which itself can be in a subdirectory of the root) with specific contents.

The has_dir function constructs a criterion that checks for the existence of a specific directory.

The has_file_pattern function constructs a criterion that checks for the existence of a file that matches a pattern, with specific contents.

The has_dirname function constructs a criterion that checks if the base::dirname() has a specific name.

Value

An S3 object of class root_criterion wit the following members:

testfun: The testfun argument
desc: The desc argument
subdir: The subdir argument
find_file: A function with ... argument that returns for a path relative to the root specified by this criterion. The optional path argument specifies the starting directory, which defaults to ".".
make_fix_file: A function with a path argument that returns a function that finds paths relative to the root. For a criterion cr, the result of cr$make_fix_file(".")(...) is identical to cr$find_file(...). The function created by make_fix_file can be saved to a variable to be more independent of the current working directory.

Examples

root_criterion(function(path) file.exists(file.path(path, "somefile")), "has somefile")
has_file("DESCRIPTION")
is_r_package
is_r_package$find_file
## Not run: 
is_r_package$make_fix_file(".")

## End(Not run)

[Package rprojroot version 1.2 Index]