Extended YAML

ExtendedYAML adds a couple of additional features to the standard YAML library:

1. Each YAML file can extend (inherit from) other YAML files by specifying extends: other_file
2. YAML files are parsed for ERB tags.

It is a simpler reimplementation of yaml_extend.

$ gem install extended_yaml

Given this simple.yml file:

extends: subdir/production.yml

settings:
  host: localhost
  port: 80

which uses extends to load this subdir/production.yml file.

settings:
  host: example.com

We can now load the extended YAML file like this:

# Load an extended YAML
require 'extended_yaml'

p ExtendedYAML.load 'examples/simple.yml'
#=> {"settings"=>{"host"=>"localhost", "port"=>80}}

1. Arrays will be merged.
2. Nested hashes will be merged.
3. Other types of values will be overridden based on which loaded file was the last to define them.
4. ERB tags will be evaluated in all YAML files.
5. The extends option can use either a single file string, or an array. Extensions are optional.
6. Using * anywhere in the extends path will load multiple files with one call.
7. If you need to use a key that is named differently than extends, provide it using the key keyword argument:

   ExtendedYAML.load 'examples/simple.yml', key: 'include'

See the examples/master.yml file for additional information.