Search/check values in YAML document with Ruby

Question

my goal:

check if yaml document include value for specific key using ypath/xpath

select value for specified key using ypath/xpath

document yaml:

app:
    name: xxx
    version: xxx
description:
    author:
        name: xxx
        surname: xxx
        email: xxx@xxx.xx

what was checked:*

google

stackoverflow

Ruby API (YAML::DBM as one of methods it provide is select)

example:

Module::Class.select('description/author/name')
Module::Class.select('*/name')
Module::Class.isset?('*/name')

Answer 1

Since there are no up-to-date YPath implementations around, I would suggest to give a chance ActiveSupport and Nokogiri:

yml = LOAD_YML_WITH_YOUR_PREFERRED_YAML_ENGINE

# ActiveSupport adds a to_xml method to Hash
xml = yml.to_xml(:root => 'yaml')

doc = Nokogiri::XML(xml)
doc.xpath("description/author/name").map do |name|
  puts [name['key'], name['value']]
end

Answer 2

Use yaml:

require 'yaml'
yml = YAML.load_file('your_file.yml')

Now yml is a hash. You can use it like one. Here is a simple and ugly solution for what you try:

if !yml["description"].nil? && !yml["description"]["author"].nil? && !yml["description"]["author"]["name"].nil? && !yml["description"]["author"]["name"].empty?
  puts "An author is set!"
end