Class: FlexConf

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Includes:
Enumerable
Defined in:
lib/flexconf.rb

Overview

A simple but flexible configuration class.

Instance Method Summary collapse

Constructor Details

#initialize(hash) ⇒ FlexConf #initialize(yaml_file, opts) ⇒ FlexConf #initialize ⇒ FlexConf

Loads configuration from the supplied source(s).

Overloads:

  • #initialize(hash) ⇒ FlexConf

    Reads the supplied hash as the entire configuration. No options are handled; you’ll have to make sure the data you provide contains everything you intend it to.

    Parameters:

    • source (Hash) —

      The configuration data you want to provide.

  • #initialize(yaml_file, opts) ⇒ FlexConf

    Loads the given YAML file and optional overrides.

    Parameters:

    • source (String, Hash) —

      A YAML filename. The file must be in the current directory or a complete path must be given.

    • opts (optional, Hash) —

      Specifies ways in which the supplied data can be overridden. Overrides are processed in the following order:

      1. `:scope` (limit the source configuration namespace)
2. `:local` (secondary '*_local.yml' file)
3. `:override` (hash supplied in code)
4. `:environment` (environment variables)

    Options Hash (opts):

    • :override (Hash) —

      A hash which will be merged over the source configuration.

    • :local (String, Boolean) —

      A second YAML file containing local data (presumably outside source control). No error is raised if this file does not exist. A value of ‘true’ appends ‘_local` to the source file’s base name, e.g. ‘config_local.yml`.

    • :environment (Array, Boolean) —

      If given an array of environment variable names, FlexConf will lowercase the names and then inject or override them into the configuration. Nested values can be marked by a double underscore (i.e. ‘FOO__BAR’ would set a value at [:foo]). A value of ‘true’ scans all environment variables, but will only override existing values (e.g. an existing config value at [:aws_access_key] could be overridden by the AWS_ACCESS_KEY environment variable.)

      (Use with caution! Casually setting ‘:environment => true’ if you have configuration variables such as [:home] or [:path] could have undesired results.)

    • :scope (String, Symbol) —

      Limits the configuration to the values beneath the given top-level key in the YAML source file. Useful for Rails-style environment configurations (‘development’, ‘production’, etc.) Local, environment, and hash overrides are unaffected; they are assumed to be already within the intended scope.

  • #initialize ⇒ FlexConf

    With no parameters, takes a common default case and acts as if you had run ‘FlexConf.new(’config.yml’, :local => ‘config_local.yml’, :environment => true)‘. Raises an exception if ’config.yml’ does not exist.



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# File 'lib/flexconf.rb', line 50

def initialize(source=nil, options=nil)
  @data = {}
  case source
  when /.*\.yml/
    source_data = YAML.load_file(source)
    if options && options[:scope]
      flexify scoped(source_data, options[:scope])
    else
      flexify source_data
    end
    handle_overrides(source, options) if options
  when Hash
    flexify source
  when nil
    if File.exists?('config.yml')
      initialize('config.yml', :local => 'config_local.yml', :environment => true)
    else
      raise ArgumentError, "FlexConf can't load: no configuration was given and there is no config.yml file to default to."  
    end
  end
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, *args, &block) ⇒ Object (private) 



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# File 'lib/flexconf.rb', line 184

def method_missing(name, *args, &block)
  self.has_key?(name) ? self[name] : super
end

Instance Method Details

#[](key) ⇒ Object

Returns the value for the given key, which can be a string or a symbol. Named keys can also be accessed via method calls (i.e. ‘config.foo`). Nested configurations are returned as FlexConf objects.



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# File 'lib/flexconf.rb', line 75

def [](key)
  @data[normalize_key(key)]
end

#has_key?(key) ⇒ Boolean

Returns true if the given configuration value exists.

Returns:

  • (Boolean) 


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# File 'lib/flexconf.rb', line 80

def has_key?(key)
  @data.has_key? normalize_key(key)
end