Module: Puppet::Util::ClassGen

Included in:
Reports, Type
Defined in:
lib/puppet/util/classgen.rb

Overview

This is a utility module for generating classes.

Constant Summary

Instance Method Summary (collapse)

Methods included from Puppet::Util

exit_on_fail, #exit_on_fail, which, #which

Instance Method Details

- (Object) genconst_string(name, options) (private) private

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Generates the constant to create or remove.



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# File 'lib/puppet/util/classgen.rb', line 88

def genconst_string(name, options)
  unless const = options[:constant]
    prefix = options[:prefix] || ""
    const = prefix + name2const(name)
  end

  const
end

- (Object) genthing(name, type, options, block) (private) private

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

This does the actual work of creating our class or module. It’s just a slightly abstract version of genclass.



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# File 'lib/puppet/util/classgen.rb', line 100

def genthing(name, type, options, block)
  options = symbolize_options(options)

  name = name.to_s.downcase.intern

  if type == Module
    #evalmethod = :module_eval
    evalmethod = :class_eval
    # Create the class, with the correct name.
    klass = Module.new do
      class << self
        attr_reader :name
      end
      @name = name
    end
  else
    options[:parent] ||= self
    evalmethod = :class_eval
    # Create the class, with the correct name.
    klass = Class.new(options[:parent]) do
      @name = name
    end
  end

  # Create the constant as appropriation.
  handleclassconst(klass, name, options)

  # Initialize any necessary variables.
  initclass(klass, options)

  block ||= options[:block]

  # Evaluate the passed block if there is one.  This should usually
  # define all of the work.
  klass.send(evalmethod, &block) if block

  klass.postinit if klass.respond_to? :postinit

  # Store the class in hashes or arrays or whatever.
  storeclass(klass, name, options)

  klass
end

- (Object) handleclassconst(klass, name, options) (private) private

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Handle the setting and/or removing of the associated constant.



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# File 'lib/puppet/util/classgen.rb', line 161

def handleclassconst(klass, name, options)
  const = genconst_string(name, options)

  if is_constant_defined?(const)
    if options[:overwrite]
      Puppet.info "Redefining #{name} in #{self}"
      remove_const(const)
    else
      raise Puppet::ConstantAlreadyDefined,
        "Class #{const} is already defined in #{self}"
    end
  end
  const_set(const, klass)

  const
end

- (Object) initclass(klass, options) (private) private

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Perform the initializations on the class.



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# File 'lib/puppet/util/classgen.rb', line 181

def initclass(klass, options)
  klass.initvars if klass.respond_to? :initvars

  if attrs = options[:attributes]
    attrs.each do |param, value|
      method = param.to_s + "="
      klass.send(method, value) if klass.respond_to? method
    end
  end

  [:include, :extend].each do |method|
    if set = options[method]
      set = [set] unless set.is_a?(Array)
      set.each do |mod|
        klass.send(method, mod)
      end
    end
  end

  klass.preinit if klass.respond_to? :preinit
end

- (Boolean) is_constant_defined?(const) (private) private

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

const_defined? in Ruby 1.9 behaves differently in terms of which class hierarchy it polls for nested namespaces

See http://redmine.ruby-lang.org/issues/show/1915

Returns:

  • (Boolean) 


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# File 'lib/puppet/util/classgen.rb', line 150

def is_constant_defined?(const)
  if ::RUBY_VERSION =~ /1.9/
    const_defined?(const, false)
  else
    const_defined?(const)
  end
end

- (Object) name2const(name) (private) private

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Convert our name to a constant.



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# File 'lib/puppet/util/classgen.rb', line 205

def name2const(name)
  name.to_s.capitalize
end

- (Object) storeclass(klass, klassname, options) (private) private

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Store the class in the appropriate places.



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# File 'lib/puppet/util/classgen.rb', line 211

def storeclass(klass, klassname, options)
  if hash = options[:hash]
    if hash.include? klassname and ! options[:overwrite]
      raise Puppet::SubclassAlreadyDefined,
        "Already a generated class named #{klassname}"
    end

    hash[klassname] = klass
  end

  # If we were told to stick it in a hash, then do so
  if array = options[:array]
    if (klass.respond_to? :name and
            array.find { |c| c.name == klassname } and
            ! options[:overwrite])
      raise Puppet::SubclassAlreadyDefined,
        "Already a generated class named #{klassname}"
    end

    array << klass
  end
end