Module: Sinatra::ConfigFile

Defined in:
lib/sinatra/config_file.rb

Overview

Sinatra::ConfigFile

Sinatra::ConfigFile is an extension that allows you to load the application’s configuration from YAML files. It automatically detects if the files contains specific environment settings and it will use the corresponding to the current one.

You can access those options through settings within the application. If you try to get the value for a setting that hasn’t been defined in the config file for the current environment, you will get whatever it was set to in the application.

Usage

Once you have written your configurations to a YAML file you can tell the extension to load them. See below for more information about how these files are interpreted.

For the examples, lets assume the following config.yml file:

greeting: Welcome to my file configurable application

Classic Application

require "sinatra"
require "sinatra/config_file"

config_file 'path/to/config.yml'

get '/' do
  @greeting = settings.greeting
  haml :index
end

# The rest of your classic application code goes here...

Modular Application

require "sinatra/base"
require "sinatra/config_file"

class MyApp < Sinatra::Base
  register Sinatra::ConfigFile

  config_file 'path/to/config.yml'

  get '/' do
    @greeting = settings.greeting
    haml :index
  end

  # The rest of your modular application code goes here...
end

Config File Format

In its most simple form this file is just a key-value list:

foo: bar
something: 42
nested:
  a: 1
  b: 2

But it also can provide specific environment configuration. There are two ways to do that: at the file level and at the setting level. They are illustrated, repsectively, as follows:

development:
  foo: development
  bar: bar
test:
  foo: test
  bar: bar
production:
  foo: production
  bar: bar

and

foo:
  development: development
  test: test
  production: production
bar: bar

In either case, settings.foo will return the environment name, and settings.bar will return "bar".

Be aware that if you have a different environment, besides development, test and production, you will also need to adjust the environments setting, otherwise the settings will not load. For instance, when you also have a staging environment:

set :environments, %w{development test production staging}

If you wish to provide defaults that may be shared among all the environments, this can be done by using one of the existing environments as the default using the YAML alias, and then overwriting values in the other environments:

development: &common_settings
  foo: 'foo'
  bar: 'bar'

production:
  <<: *common_settings
  bar: 'baz' # override the default value

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.registered(base) ⇒ Object

When the extension is registered sets the environments setting to the traditional environments: development, test and production.



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# File 'lib/sinatra/config_file.rb', line 119

def self.registered(base)
  base.set :environments, %w[test production development]
end

Instance Method Details

#config_file(*paths) ⇒ Object

Loads the configuration from the YAML files whose paths are passed as arguments, filtering the settings for the current environment. Note that these paths can actually be globs.



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# File 'lib/sinatra/config_file.rb', line 126

def config_file(*paths)
  Dir.chdir(root || '.') do
    paths.each do |pattern|
      Dir.glob(pattern) do |file|
        $stderr.puts "loading config file '#{file}'" if logging?
        document = IO.read(file)
        document = ERB.new(document).result if file.split('.').include?('erb')
        yaml = config_for_env(YAML.load(document)) || {}
        yaml.each_pair do |key, value|
          for_env = config_for_env(value)
          set key, for_env unless value and for_env.nil? and respond_to? key
        end
      end
    end
  end
end