lib/key_tree.rb
# frozen_string_literal: true
require 'key_tree/forest'
require 'key_tree/loader'
require 'key_tree/refinements'
require 'key_tree/tree'
# Manage a tree of keys
#
# Example:
# kt=KeyTree[a: 1, b: { c: 2 }]
# kt["a"]
# -> 1
# kt["b.c"]
# -> 2
#
module KeyTree
using Refinements
class << self
def [](contents = {})
contents.to_key_wood
end
# Load a KeyTree from some external serialization
#
# load +type+: +serialization+
# load +key_prefix+, +type+: +serialization+
#
# +type+ is upcased to form a class name that should provide a
# +.load+ class method (like YAML or JSON does).
#
# If a +key_prefix+ is given, it will be prepended to the loaded data.
#
# Examples:
# load(:yaml, "---\na: 1\n")
# => {"a" => 1}
#
# load(:yaml, "---\nb: 2\n", prefix: 'a')
# => {"a.b" => 2}
#
def load(type, serialization, prefix: nil)
type = type.to_sym unless type.nil?
loader = Loader[type]
contents = loader.load(serialization)
contents = { prefix => contents } unless prefix.nil?
contents.to_key_wood.with_meta_data do |meta_data|
meta_data << { load: { type: type, loader: loader } }
meta_data << { load: { prefix: prefix } } unless prefix.nil?
end
end
# Open an external file and load contents into a KeyTree
# When the file basename begins with 'prefix@', the prefix
# is prepended to all keys in the filee.
def open(file_name)
type = File.extname(file_name)[/[^.]+/]
prefix = File.basename(file_name)[/(.+)@/, 1]
keytree = File.open(file_name, mode: 'rb:utf-8') do |file|
load_from_file(file, type, prefix)
end
return keytree unless block_given?
yield keytree
end
# Open all files in a directory and load their contents into
# a Forest of Trees, optionally following symlinks, and recursing.
def open_all(dir_name, follow_links: false, recurse: false)
Dir.children(dir_name).reduce(KeyTree::Forest.new) do |result, file|
path = File.join(dir_name, file)
next result if File.symlink?(path) && !follow_links
stat = File.stat(path)
# rubocop:disable Security/Open
next result << open(path) if stat.file?
# rubocop:enable Security/Open
next result unless recurse && stat.directory?
result << open_all(path, follow_links: follow_links, recurse: true)
end
end
private
def load_from_file(file, type, prefix)
load(type, file.read, prefix: prefix).with_meta_data do |meta_data|
file_path = file.path
meta_data << { file: { path: file_path,
name: File.basename(file_path),
dir: File.dirname(file_path) } }
end
end
end
end