module Chef::Mixin::ConvertToClassName

Public Instance Methods

constantize(camel_cased_word) click to toggle source

Tries to find a constant with the name specified in the argument string.

'Module'.constantize     # => Module
'Test::Unit'.constantize # => Test::Unit

The name is assumed to be the one of a top-level constant, no matter whether it starts with “::” or not. No lexical context is taken into account:

C = 'outside'
module M
  C = 'inside'
  C               # => 'inside'
  'C'.constantize # => 'outside', same as ::C
end

NameError is raised when the name is not in CamelCase or the constant is unknown.

# File lib/chef/mixin/convert_to_class_name.rb, line 93
def constantize(camel_cased_word)
  names = camel_cased_word.split("::")

  # Trigger a built-in NameError exception including the ill-formed constant in the message.
  Object.const_get(camel_cased_word) if names.empty?

  # Remove the first blank element in case of '::ClassName' notation.
  names.shift if names.size > 1 && names.first.empty?

  names.inject(Object) do |constant, name|
    if constant == Object
      constant.const_get(name)
    else
      candidate = constant.const_get(name)
      next candidate if constant.const_defined?(name, false)
      next candidate unless Object.const_defined?(name)

      # Go down the ancestors to check if it is owned directly. The check
      # stops when we reach Object or the end of ancestors tree.
      constant = constant.ancestors.inject do |const, ancestor|
        break const    if ancestor == Object
        break ancestor if ancestor.const_defined?(name, false)
        const
      end

      # owner is in Object, so raise
      constant.const_get(name, false)
    end
  end
end
convert_to_class_name(str) click to toggle source
# File lib/chef/mixin/convert_to_class_name.rb, line 25
def convert_to_class_name(str)
  str = normalize_snake_case_name(str)
  rname = nil
  regexp = %r{^(.+?)(_(.+))?$}

  mn = str.match(regexp)
  if mn
    rname = mn[1].capitalize

    while mn && mn[3]
      mn = mn[3].match(regexp)
      rname << mn[1].capitalize if mn
    end
  end

  rname
end
convert_to_snake_case(str, namespace = nil) click to toggle source
# File lib/chef/mixin/convert_to_class_name.rb, line 43
def convert_to_snake_case(str, namespace = nil)
  str = str.dup
  str.sub!(/^#{namespace}(\:\:)?/, "") if namespace
  str.gsub!(/[A-Z]/) { |s| "_" + s }
  str.downcase!
  str.sub!(/^\_/, "")
  str
end
filename_to_qualified_string(base, filename) click to toggle source
# File lib/chef/mixin/convert_to_class_name.rb, line 64
def filename_to_qualified_string(base, filename)
  file_base = File.basename(filename, ".rb")
  str = base.to_s + (file_base == "default" ? "" : "_#{file_base}")
  normalize_snake_case_name(str)
end
normalize_snake_case_name(str) click to toggle source
# File lib/chef/mixin/convert_to_class_name.rb, line 52
def normalize_snake_case_name(str)
  str = str.dup
  str.gsub!(/[^A-Za-z0-9_]/, "_")
  str.gsub!(/^(_+)?/, "")
  str
end
snake_case_basename(str) click to toggle source
# File lib/chef/mixin/convert_to_class_name.rb, line 59
def snake_case_basename(str)
  with_namespace = convert_to_snake_case(str)
  with_namespace.split("::").last.sub(/^_/, "")
end