JsonPathAttribute

JsonPathAttribute is a simple but powerful object mapper to map JSON or Hash data into Ruby objects, using JsonPath.

Although this gem has been released fairly recently, it was originally developed for Beequip and a very similar version has been used for a few years.

Given a JSON (or Ruby hash) like this:

{
  "post": {
    "title": "How to drive on snow?",
    "body": "Just use a low gear and slowly build up speed",
    "likes": 12,
    "comments": [
      {
        "body": "Thank you for the tip! It is very useful.",
        "user": {
          "name": "Charles Careful"
        }
      }
    ]
  }
}

You can include JsonPathAttribute to a Ruby class:

class Post
  include JsonPathAttribute

  json_path_attribute :title, path: 'post.title'
  json_path_attribute :likes, path: 'post.likes', type: :integer
  json_path_attribute :comments, path: 'post.comments[*]', type: Comment, array: true
end

class Comment
  include JsonPathAttribute

  json_path_attribute :body, path: 'body'
  json_path_attribute :name, path: 'user.name'
end

And it gets parsed like this

post = Post.parse(json) # => <Post:...>
post.title # => "How to drive on snow?"
post.body # => "Just use a low gear and slowly build up speed"
post.likes # => 12
post.comments # => [#<Comment:0x000000011e4354d0 @body="Thank you for the tip! It is very useful.", @name="Charles Careful">]

Install the gem and add to the application's Gemfile by executing:

bundle add json_path_attribute

If bundler is not being used to manage dependencies, install the gem by executing:

gem install json_path_attribute

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/BEEQUIP/json_path_attribute.

Thanks to the original authors jdongelmans and jandintel.

Also thanks to joshbuddy for creating JsonPath.