Class: Glyph::Config

Inherits:
Object
  • Object
show all
Includes:
Utils
Defined in:
lib/glyph/config.rb

Overview

The Glyph::Config class is used (you don’t say!) to store configuration data. Essentially it wraps a Hash of Hashes and provides some useful methods to access keys and subkeys.

Instance Method Summary collapse

Methods included from Utils

#clean_xml_document, #complex_output?, #current_output_setting, #debug, #error, #file_copy, #file_load, #file_write, #info, #load_files_from_dir, #macro_alias?, #macro_aliases_for, #macro_definition_for, #macro_eq?, #msg, #multiple_output_files?, #project?, #run_external_command, #titled_sections, #warning, #with_files_from, #yaml_dump, #yaml_load

Constructor Details

#initialize(options = {}) ⇒ Config

Initializes the configuration with a hash of options:

  • :file (default: nil) - A YAML file to read data from

  • :data (default: {})- The initial contents

  • :resettable (default: false) - Whether the configuration can be reset (cleared) or not

  • :mutable (default: true) - Whether the configuration can be changed or not



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# File 'lib/glyph/config.rb', line 18

def initialize(options={})
  default_options = {:file => nil, :data => {}, :resettable => false, :mutable => true}
  @options = default_options.merge options
  @file = @options[:file]
  @data = @options[:data]
  read if @file
end

Instance Method Details

#get(setting) ⇒ Object

Returns a configuration setting

Examples:

cfg = Glyph::Config.new
cfg.get "system.quiet"              # true
cfg.get "test.test_value" # [1,2,3]

See Also:



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# File 'lib/glyph/config.rb', line 131

def get(setting)
  @data.instance_eval "self#{setting.to_s.split(".").map{|key| "[:#{key}]" }.join}" rescue nil
end

#merge(cfg) ⇒ Glyph::Config

Merges configuration data by applying Hash#merge to each sub-hash of data, recursively.

Raises:

  • (ArgumentError) —

    unless cfg is a Glyph::Config



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# File 'lib/glyph/config.rb', line 54

def merge(cfg)
  merge_or_update cfg, :merge
end

#read ⇒ Hash

Reads the contents of a file and stores them as configuration data

Raises:

  • (RuntimeError) —

    if self is not linked to a file or if the file does not contain a serialized Hash



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# File 'lib/glyph/config.rb', line 63

def read
  raise RuntimeError, "Configuration is not stored in a file." if @file.blank?
  if @file.exist? then 
    contents = yaml_load @file
    raise RuntimeError, "Invalid configuration file '#{@file}'" unless contents.is_a? Hash
    @data = contents
  else
    @data = {}
  end
  @data
end

#reset(hash = {}) ⇒ Hash

Resets all configuration data

Raises:

  • (RuntimeError) —

    unless the configuration is resettable or if no hash is passed



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# File 'lib/glyph/config.rb', line 36

def reset(hash={})
  raise RuntimeError, "Configuration cannot be reset" unless @options[:resettable]
  raise RuntimeError, "Configuration data is not stored in a Hash" unless hash.is_a? Hash
  @data = hash
end

#set(setting, value) ⇒ Object

Updates a configuration setting

Examples:

cfg = Glyph::Config.new
cfg.set "system.quiet", true                # Sets "system.quiet" => true
cfg.set "test.test_value", "[1,2,3]" # Sets :test => {:test_value => [1,2,3]}
cfg.set "system.quiet", "false"               # Sets "system.quiet" => false

Raises:

  • (RuntimeError) —

    unless the configuration is mutable

  • (ArgumentError) —

    if the setting refers to an invalid namespace



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# File 'lib/glyph/config.rb', line 87

def set(setting, value)
  raise RuntimeError, "Configuration cannot be changed" unless @options[:mutable]
  if value.is_a?(String) && value.match(/^(["'].*["']|:.+|\[.*\]|\{.*\}|true|false|nil)$/) then
    value = Kernel.instance_eval value
  end
  hash = @data
  path = setting.to_s.split(".").map{|s| s.intern}
  count = 1
  path.each do |s|
    if hash.has_key? s then
      if count == path.length then 
        # destination
        hash[s] = value
      else
        if hash[s].is_a?(Hash) then
          hash = hash[s]
          count +=1
        else
          raise ArgumentError, "Invalid namespace #{s}"
        end
      end
    else
      # key not found
      if count == path.length then # destination
        hash[s] = value
      else
        # create a new namespace
        hash[s] = {}
        hash = hash[s]
        count +=1
      end
    end
  end
  value
end

#to_hash ⇒ Hash

Returns the underlying data hash



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# File 'lib/glyph/config.rb', line 28

def to_hash
  @data
end

#update(cfg) ⇒ Object Also known as: merge!

Updates configuration data by applying Hash#update to each sub-hash of data, recursively.

Raises:

  • (ArgumentError) —

    unless cfg is a Glyph::Config



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# File 'lib/glyph/config.rb', line 46

def update(cfg)
  merge_or_update cfg, :update
end

#write ⇒ Object

Serialize configuration data and writes it to a file

Raises:

  • (RuntimeError) —

    if the configuration is not linked to a file



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# File 'lib/glyph/config.rb', line 137

def write
  raise RuntimeError, "Configuration is not stored in a file." if @file.blank?
  yaml_dump @file, @data
end