DryStructParser

Generate a readable hash from a dry-struct for easier manipulation

The gem is still work in progress and is not yet fully tested.

Installation

Add this line to your application's Gemfile:

gem 'dry_struct_parser'

And then execute:

bundle install

Usage

Parsing a Dry::Struct

Lets say we have the following Dry::Struct definition:

class DTO1 < Dry::Struct
    attribute :dto1_field, Types::String
end

class DTO2 < Dry::Struct
    attribute :dto2_field, Types::String
end

class DTO < Dry::Struct
    attribute :dynamic_dto, DTO1 | DTO2
end
parser = DryStructParser::StructSchemaParser.new

parser.call(DTO)
=> {
     "dynamic_dto": [ # ARRAY
       {
         "type": "hash",
         "required": true,
         "nullable": false,
         "keys": {
           "dto1_field": {
             "type": "string",
             "required": true,
             "nullable": false
           }
         }
       },
       {
         "type": "hash",
         "required": true,
         "nullable": false,
         "keys": {
           "dto2_field": {
             "type": "string",
             "required": true,
             "nullable": false
           }
         }
       }
     ]
   }

The required key depends on whether we define the field as attribute or attribute?

For more complex types, for example DTO1 | DTO2 or Types::Array.of(DTO1 | DTO2), the parser converts the field value to an array of both schemas.

Overriding fields

You can also modify the fields by passing a block after the .call() method.

DryStructParser::StructSchemaParser.new.call(DTO) do |it|
  # types = string/integer/hash/array
  
  # Remove a field
  its.keys = it.keys.except(:field_name) 
  
  # Add new field on root level
  it.keys[:new_field_name] = { type: type, required: true/false, nullable: true/false } 
  
  # Add a new field in nested hash/array
  it.keys[:nested_field][:keys][:new_field_name] = { 
    type: type, required: true/false, nullable: true/false
  }
  
  # Remove a field in nested hash/array
  it.keys = it.keys[:nested_field][:keys].except(:field_name)
  
  # Add an array or hash
  it.keys[:nested_field] = { 
    type: "array/hash", required: true/false, nullable:  true/false, keys: {
      # List all nested fields
      new_field: { type: :type, required: true/false, nullable: true/false }
    }
  }
  
  # Add an Array of primitive types, type field needs to be the element type(string, integer, float), 
  and add an array: true flag
  
  it.keys[:array_field_name] = { 
    type: type, array: true, required: true/false, nullable:  true/false 
  }
  
end

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/Jane-Terziev/dry_struct_parser. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License

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

Code of Conduct

Everyone interacting in the DryStructParser project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.