Rails API parameter validation

Add this line to your application's Gemfile:

gem 'rosebud'

And then execute:

$ bundle

Or install it yourself as:

$ gem install rosebud

Just include Rosebud in your Rails controller.

class Api::V1::SomeController < Api::V1::ApplicationController
  include Rosebud
end

To validate parameters specify a params block and choose whether the params are required or optional.

class Api::V1::SomeController < Api::V1::ApplicationController
  include Rosebud

  params do
    requires :name
    optional :phone_number, regex: /\d{10}/, default: '5555555555'
  end

  ...

end

It's also possible to define validations for a specific action.

class Api::V1::SomeController < Api::V1::ApplicationController
  include Rosebud

  params :create do
    ...
  end

  def create
    ...
  end
end

When a parameter error is raised a JSON response will be rendered.

{
  "error":       "missing_parameter",
  "description": "missing parameter: name"
}

Currently the only validators that ship with Rosebud are presence, regex and type. If you need other validators you can create your own.

class MyLengthValidator < Rosebud::Validator
  def validate_param(name, value, options)
    if value.length <= options
      error!(:length, param: name, length: value.length, max_length: options)
    end
  end
end

Rosebud::Validations.register_validator!(:length, MyLengthValidator)

Rosebud uses the Errawr::Rails gem to raise and render localised errors. Add your custom error message to your locale file.

en:
  errawr:
    length:
      message: %{length} characters is too long for %{param}, should be less than or equal to %{max_length}
      http_status: 400
      metadata:
        additional_info: Kick him in the shins!

Add a validation using your custom validator:

class Api::V1::SomeController < Api::V1::ApplicationController
  include Rosebud

  params :create do
    requires :name, length: 2
  end

  def create
    ...
  end
end

The following error will be rendered for the name parameter when provided with a value of abc:

{
  "error":       "length",
  "description": "3 characters is too long for name, should be less than or equal to 2",
  "additional_info": "Kick him in the shins!"
}

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Rosebud is maintained and funded by Sticksnleaves

Thanks to all of our contributors