class Webgen::Configuration

Stores the configuration for a webgen website.

Configuration options can be created by using the #define_option method:

config.define_option "my.new.option", 'default value'

and later accessed or set using the accessor methods [] and []=. A validation block can also be specified when defining an option. This validation block is called when a new value should be set and it should return the (possibly changed) value to be set:

config.define_option "my.new.option", 'default value' do |val|
  raise "Option must be a string" unless val.kind_of?(String)
  val.upcase
end

*Note*: When a Configuration object is dumped (via Marshal), the option validator procs are not dumped and can therefore not be restored!

Attributes

options[R]

Contains all the defined configuration options.

Public Class Methods

new() click to toggle source

Create a new Configuration object.

# File lib/webgen/configuration.rb, line 54
def initialize
  @options = {}
  @values = {}
end

Public Instance Methods

[](name) click to toggle source

Return the value for the configuration option name.

# File lib/webgen/configuration.rb, line 104
def [](name)
  if @options.has_key?(name)
    if frozen?
      @values.has_key?(name) ? @values[name] : @options[name].dupped_default
    else
      @values[name] = @options[name].dupped_default unless @values.has_key?(name)
      @values[name]
    end
  else
    raise Error, "Configuration option '#{name}' does not exist"
  end
end

[]=(name, value) click to toggle source

Use value as value for the configuration option name.

# File lib/webgen/configuration.rb, line 118
def []=(name, value)
  if @options.has_key?(name)
    begin
      @values[name] = (@options[name].validator ? @options[name].validator.call(value) : value)
    rescue
      raise Error, "Problem setting configuration option '#{name}': #{$!.message}", $!.backtrace
    end
  else
    raise Error, "Configuration option '#{name}' does not exist"
  end
end

define_option(name, default, &validator) click to toggle source

Define a new option name with a default value of default.

If a validation block is provided, it is called with the new value when one is set and should return a (possibly altered) value to be set.

# File lib/webgen/configuration.rb, line 87
def define_option(name, default, &validator)
  if @options.has_key?(name)
    raise ArgumentError, "Configuration option '#{name}' has already be defined"
  else
    @options[name] = Option.new
    @options[name].default = default.freeze
    @options[name].validator = validator.freeze
    @options[name].freeze
  end
end

load_from_file(filename) click to toggle source

Load the configuration values.

If filename is a String, it is treated as the name of the configuration file from which the values should be loaded. If filename responds to #read, it is treated as an IO object from which the values should be loaded.

The configuration needs to be in YAML format. More specifically, it needs to contain a YAML hash which is further processed by set_values.

Returns an array with all unknown configuration options.

# File lib/webgen/configuration.rb, line 170
def load_from_file(filename)
  data = if String === filename || filename.respond_to?(:read)
           begin
             YAML::load(String === filename ? File.read(filename) : filename.read) || {}
           rescue RuntimeError, ArgumentError, SyntaxError, YAML::SyntaxError => e
             raise Error, "Problem parsing configuration data (it needs to contain a YAML hash): #{e.message}", e.backtrace
           end
         else
           raise ArgumentError, "Need a String or IO object, not a #{filename.class}"
         end
  raise Error, 'Structure of configuration file is invalid, it has to be a Hash' unless data.kind_of?(Hash)
  set_values(data)
end

option?(name) click to toggle source

Return true if the given option exists.

# File lib/webgen/configuration.rb, line 99
def option?(name)
  @options.has_key?(name)
end

set_values(values) click to toggle source

Set the configuration values from the Hash values.

The hash can either contain full configuration option names or namespaced option names, ie. in YAML format:

my.option: value

website:
  lang: en
  url: my_url

The above hash will set the option 'my.option' to value, 'website.lang' to en and 'website.url' to my_url.

Returns an array with all unknown configuration options.

# File lib/webgen/configuration.rb, line 145
def set_values(values)
  unknown_options = []
  process = proc do |name, value|
    if @options.has_key?(name)
      self[name] = value
    elsif value.kind_of?(Hash)
      value.each {|k,v| process.call("#{name}.#{k}", v)}
    else
      unknown_options << name
    end
  end
  values.each(&process)
  unknown_options
end