|
| 1 | +# Provides feature definitions. |
| 2 | +module Puppet::Util::ProviderFeatures |
| 3 | + class ProviderFeature |
| 4 | + require 'puppet/util/methodhelper' |
| 5 | + require 'puppet/util' |
| 6 | + include Puppet::Util |
| 7 | + include Puppet::Util::MethodHelper |
| 8 | + attr_accessor :name, :docs, :methods |
| 9 | + def initialize(name, docs, hash) |
| 10 | + self.name = symbolize(name) |
| 11 | + self.docs = docs |
| 12 | + hash = symbolize_options(hash) |
| 13 | + set_options(hash) |
| 14 | + end |
| 15 | + end |
| 16 | + |
| 17 | + # Define one or more features. At a minimum, features require a name |
| 18 | + # and docs, and at this point they should also specify a list of methods |
| 19 | + # required to determine if the feature is present. |
| 20 | + def feature(name, docs, hash) |
| 21 | + @features ||= {} |
| 22 | + if @features.include?(name) |
| 23 | + raise Puppet::DevError, "Feature %s is already defined" % name |
| 24 | + end |
| 25 | + begin |
| 26 | + obj = ProviderFeature.new(name, docs, hash) |
| 27 | + @features[obj.name] = obj |
| 28 | + rescue ArgumentError => detail |
| 29 | + error = ArgumentError.new( |
| 30 | + "Could not create feature %s: %s" % [name, detail] |
| 31 | + ) |
| 32 | + error.set_backtrace(detail.backtrace) |
| 33 | + raise error |
| 34 | + end |
| 35 | + end |
| 36 | + |
| 37 | + # Return a hash of all feature documentation. |
| 38 | + def featuredocs |
| 39 | + str = "" |
| 40 | + @features ||= {} |
| 41 | + return nil if @features.empty? |
| 42 | + @features.each do |name, feature| |
| 43 | + doc = feature.docs.gsub(/\n\s+/, " ") |
| 44 | + str += " - **%s**: %s\n" % [name, doc] |
| 45 | + end |
| 46 | + str |
| 47 | + end |
| 48 | + |
| 49 | + # Generate a module that sets up the boolean methods to test for given |
| 50 | + # features. |
| 51 | + def feature_module |
| 52 | + unless defined? @feature_module |
| 53 | + @features ||= {} |
| 54 | + @feature_module = ::Module.new |
| 55 | + const_set("FeatureModule", @feature_module) |
| 56 | + features = @features |
| 57 | + # Create a feature? method that can be passed a feature name and |
| 58 | + # determine if the feature is present. |
| 59 | + @feature_module.send(:define_method, :feature?) do |name| |
| 60 | + method = name.to_s + "?" |
| 61 | + if respond_to?(method) and send(method) |
| 62 | + return true |
| 63 | + else |
| 64 | + return false |
| 65 | + end |
| 66 | + end |
| 67 | + |
| 68 | + # Create a method that will list all functional features. |
| 69 | + @feature_module.send(:define_method, :features) do |
| 70 | + return false unless defined?(features) |
| 71 | + features.keys.find_all { |n| feature?(n) }.sort { |a,b| |
| 72 | + a.to_s <=> b.to_s |
| 73 | + } |
| 74 | + end |
| 75 | + |
| 76 | + # Create a boolean method for each feature so you can test them |
| 77 | + # individually as you might need. |
| 78 | + @features.each do |name, feature| |
| 79 | + method = name.to_s + "?" |
| 80 | + @feature_module.send(:define_method, method) do |
| 81 | + set = nil |
| 82 | + feature.methods.each do |m| |
| 83 | + if is_a?(Class) |
| 84 | + unless public_method_defined?(m) |
| 85 | + set = false |
| 86 | + break |
| 87 | + end |
| 88 | + else |
| 89 | + unless respond_to?(m) |
| 90 | + set = false |
| 91 | + break |
| 92 | + end |
| 93 | + end |
| 94 | + end |
| 95 | + |
| 96 | + if set.nil? |
| 97 | + true |
| 98 | + else |
| 99 | + false |
| 100 | + end |
| 101 | + end |
| 102 | + end |
| 103 | + end |
| 104 | + @feature_module |
| 105 | + end |
| 106 | +end |
| 107 | + |
| 108 | +# $Id$ |
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