Dry::Metadata

WIP

Provides field level metadata for Dry-Validation and Dry-Struct.

Possible uses include the following:

• Form builders
• API builders
• Test Automation
• Generators
• Client side javascript (partial) validations

Installation

Add this line to your application's Gemfile:

gem 'dry-metadata'

And then execute:

$ bundle

Or install it yourself as:

$ gem install dry-metadata

Usage

With Dry Validation

require 'dry-validation'

UserSchema = Dry::Validation.Schema do
  required(:name).filled
  required(:age).maybe(:int?)
  required(:address).schema do
    required(:street).filled
    required(:city).filled
    optional(:zipcode).filled
  end
end

fields = Dry::Metadata::Fields.from_validation(UserSchema)

With Dry Struct

This is experimental - not all cases have been spec'ed yet. Please report any issues you find.

require 'dry-struct'
module Types
    include Dry::Types.module
end

class Address < Dry::Types::Struct
    attribute :street, Types::Strict::String
    attribute :city, Types::Strict::String
    attribute :zipcode, Types::Strict::String.optional
end

class UserStruct < Dry::Types::Struct
    attribute :name, Types::Strict::String
    attribute :age,  Types::Strict::Int
    attribute :address, Address
end

fields = Dry::Metadata::Fields.from_struct(UserStruct)

Metadata Fields Interface

fields.each do |field|
    puts field.name      # the name of the field
    puts field.required? # if the field is required
    puts field.optional? # if the field is !required
    puts field.types     # the array of valid types
    puts field.logic     # polish notation of the logic (minus custom rules)
    puts field.fields    # nested fields or []
end

# To fetch all required fields:
fields.required_fields

# To fetch all optional fields:
fields.optional_fields

# To fetch a single field by name:
fields[:age]

# To sort by name:
fields.sort

# To get an array of hash representations suitable to serialize:
fields.to_a

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec 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 tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/voomify/dry-metadata.

License

The gem is available as open source under the terms of the MIT License.