Class: Puppet::Util::Feature

Inherits:
Object
  • Object
show all
Defined in:
lib/puppet/util/feature.rb

Overview

API:

  • public

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(path) ⇒ Feature

Create a new feature collection.

API:

  • public



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# File 'lib/puppet/util/feature.rb', line 45

def initialize(path)
  @path = path
  @results = {}
  @loader = Puppet::Util::Autoload.new(self, @path)
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method, *args) ⇒ Object

API:

  • public



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# File 'lib/puppet/util/feature.rb', line 55

def method_missing(method, *args)
  return super unless method.to_s =~ /\?$/

  feature = method.to_s.sub(/\?$/, '')
  @loader.load(feature)

  respond_to?(method) && self.send(method)
end

Instance Attribute Details

#path ⇒ Object (readonly)

API:

  • public



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# File 'lib/puppet/util/feature.rb', line 4

def path
  @path
end

Instance Method Details

#add(name, options = {}) ⇒ Object

Create a new feature test. You have to pass the feature name, and it must be unique. You can either provide a block that will get executed immediately to determine if the feature is present, or you can pass an option to determine it. Currently, the only supported option is ‘libs’ (must be passed as a symbol), which will make sure that each lib loads successfully.

API:

  • public



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# File 'lib/puppet/util/feature.rb', line 13

def add(name, options = {})
  method = name.to_s + "?"
  @results.delete(name)

  if block_given?
    begin
      result = yield
    rescue StandardError,ScriptError => detail
      warn "Failed to load feature test for #{name}: #{detail}"
      result = false
    end
    @results[name] = result
  end

  meta_def(method) do
    # we return a cached result if:
    #  * if a block is given (and we just evaluated it above)
    #  * if we already have a positive result
    #  * if we've tested this feature before and it failed, but we're
    #    configured to always cache
    if block_given?     ||
        @results[name]  ||
        (@results.has_key?(name) && (Puppet[:always_cache_features] || !Puppet[:always_retry_plugins]))
      @results[name]
    else
      @results[name] = test(name, options)
      @results[name]
    end
  end
end

#load ⇒ Object

API:

  • public



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# File 'lib/puppet/util/feature.rb', line 51

def load
  @loader.loadall
end

#test(name, options) ⇒ Object

Actually test whether the feature is present. We only want to test when someone asks for the feature, so we don’t unnecessarily load files.

API:

  • public



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# File 'lib/puppet/util/feature.rb', line 67

def test(name, options)
  return true unless ary = options[:libs]
  ary = [ary] unless ary.is_a?(Array)

  ary.each do |lib|
    return false unless load_library(lib, name)
  end

  # We loaded all of the required libraries
  true
end