Module: Mixins::Datadir

Defined in:
lib/mixins/datadir.rb

Overview

Adds a #data_dir method and a DATA_DIR constant to extended objects. These will be set to the ‘Pathname` to the data directory distributed with a gem of the name derived from the `#name` of the extended object. Prefers environmental override, Gem path, then local filesystem pathing.

This can also be called manually if the including class name doesn’t match the gem, or something else esoteric.

require 'mixins'

class Acme
    extend Mixins::Datadir
end

# When loading from checked-out source
Rhizos.data_dir
# => #<Pathname:../data/acme>

# With ACME_DATADIR=/path/to/data set in the environment before Ruby starts:
Rhizos.data_dir
# => #<Pathname:/path/to/data>

# When installed via gem
Rhizos.data_dir
# => #<Pathname:/path/to/lib/ruby/gems/3.4.0/gems/acme-1.0.0/data/acme>

Class Method Summary collapse

Class Method Details

.extended(obj) ⇒ Object

Extend hook: Set up the ‘data_dir` accessor and the `DATA_DIR` constant



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# File 'lib/mixins/datadir.rb', line 42

def self::extended( obj )
	name = obj.name.downcase.gsub( '::', '-' )
	dir = self.find_datadir( name )

	obj.const_set( :DATA_DIR, dir )
	obj.singleton_class.attr_accessor :data_dir
	obj.data_dir = dir
end

.find_datadir(gemname, env: nil) ⇒ Object

Return a pathname object for the gem data directory. Use the ‘<gemname>_DATADIR` environment variable if it’s set, or the data directory of the loaded gem if there is one. If neither of those are set, fall back to a relative path of ‘../../data/<gemname>`. You can override which environment variable is used for the override by setting env.



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# File 'lib/mixins/datadir.rb', line 58

def self::find_datadir( gemname, env: nil )
	unless env
		comps = gemname.split( '-' )
		env = comps.size > 1 ? comps.last : comps.first
		env = "%s_DATADIR" % [ env.upcase ]
	end

	loaded_gemspec = Gem.loaded_specs[ gemname ]

	dir = if ENV[ env ]
			Pathname( ENV[ env ] )
		elsif loaded_gemspec && File.exist?( loaded_gemspec.datadir )
			Pathname( loaded_gemspec.datadir )
		else
			caller_path = caller_locations( 2, 1 ).first.absolute_path
			Pathname( caller_path ).dirname.parent + "data/#{gemname}"
		end

	return dir
end