dry_schema_rails

Simplify Your Schema Management in Rails.

Description

DrySchemaRails is a lightweight gem that leverages dry-schema for defining schemas in a DRY and consistent manner across your Rails application. It encapsulates common schema definition functionalities, promoting a clean and easy-to-follow schema definition practice.

Key Features

• Concise Schema Definitions: Write compact and clear schema definitions using block syntax.
• Reusable Schemas: Create and reuse schema definitions across different parts of your application.
• Extendable: Easily extend and customize your schema definitions as per your requirements.

Installation

Add DrySchemaRails to your Gemfile and bundle.

gem 'dry_schema_rails'

Run

bundle install

Quick Usage Guide

1. Define Schema:

Define your schema classes with necessary validation rules in a block passed to schema.

   class UserSchema < DrySchemaRails::Base
     schema do
       required(:username).filled(:string)
       required(:email).filled(:string, format?: /@/)
       required(:age).filled(:integer, gt?: 18)
     end
   end

1. Use Schema:

Validate and sanitize parameters using defined schemas.

   user_params = { username: "John", email: "john@example.com", age: 25 }
   result = UserSchema.call(user_params)

   puts result.success?   # => true
   puts result.errors     # => {}

In-Depth Usage

Custom Validators

module User
  class CreateValidator < DrySchemaRails::Base
    params User::CreateSchema.params

    rule(:username) do
      key.failure('must be unique') if User.exists?(username: value)
    end

    rule(:email) do
      key.failure('must be in internation format') unless value.end_with?('.com')
    end 
  end
end

In Controllers

class UsersController < ApiController
  ...
  schema(:create, &UserSchema.schema) 

  # This checks maybe in base controller for reusability
  if safe_params&.failure?
    render json: { errors: safe_params.errors }, status: :unprocessable_entity
  end

  def create
    @user = User.create!(safe_params.output)
    render json: @user, status: :created
  end
  ...
end

Example Application: DrySchemaRailsDemo

Idea

Create a Rails application DrySchemaRailsDemo demonstrating the usage of DrySchemaRails in various common Rails use-cases: model validation, parameter validation in controllers, form object validation, etc.

Key Features:

• User Management: Simple CRUD for managing users with validations using defined schemas.
• API Endpoint: Demonstrate parameter validation for API endpoints.
• Form Object: Use schemas to validate form objects.

Implementation

1. Model and Schema:

Define User model and UserSchema for validating user attributes.

   class User < ApplicationRecord
     # your model code
   end

   class UserSchema < DrySchemaRails::Base
     schema do
       required(:username).filled(:string)
       # additional validations...
     end
   end

1. Controller Validation:

Implement validations in controllers and API endpoints using schema.

   class UsersController < ApplicationController
     def create
       validation = UserSchema.call(params.permit!.to_h)
       if validation.success?
         # handle success...
       else
         # handle failure...
       end
     end
   end

1. Form Object:

Define form objects validating data using schema before processing.

   class RegistrationForm
     def initialize(params)
       @params = params
     end

     def save
       validation = UserSchema.call(@params)
       if validation.success?
         User.create(validation.output)
       else
         # handle errors...
       end
     end
   end

Tests

Write tests for models, controllers, and form objects ensuring schema validations are applied and working as expected.

License

See LICENSE file.

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For more complex understanding you might adjust specifics to cater to the unique needs and standards of your app or team. For further details on dry-schema, visit Dry Schema.