Class: DrySchemaRails::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/dry_schema_rails/base.rb

Overview

Base class serves as a foundational class designed to encapsulate common functionalities associated with schema definitions. It provides a blueprint for creating new schema classes efficiently and consistently.

The core mechanism of this class hinges on the ‘class_attribute` called `_schema_proc`, which stores the schema’s definition as a proc. This proc gets executed in the context of ‘Dry::Schema` to define the schema.

Example Usage:

To create a new schema, simply inherit from the Base class and provide the schema definition inside a block passed to the ‘schema` class method.

Example:

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

user_params = { username: "John", email: "[email protected]", age: 25 }
result = UserSchema.params.call(user_params)
OR
result = UserSchema.call(user_params)

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

This approach allows for the creation of multiple schema classes in a concise and consistent manner, all inheriting common functionality from the base Base class.

Class Attribute Summary collapse

Class Method Summary collapse

Class Attribute Details

._schema_proc ⇒ Object 



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# File 'lib/dry_schema_rails/base.rb', line 42

def _schema_proc
  @_schema_proc ||= -> {}
end

Class Method Details

.call(*args) ⇒ Dry::Schema::Result

Returns the schema matching result.

Returns:

  • (Dry::Schema::Result) —

    the schema matching result



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# File 'lib/dry_schema_rails/base.rb', line 49

def call(*args)
  params.call(*args)
end

.params ⇒ Dry::Schema::Params Also known as: contract

Using to create custom validators easy.

Example:

UserSchema = Class.new(DrySchemaRails) do
  schema do
    required(:name).filled(:string)
    required(:email).filled(:string)
  end
end

class UserValidator < Dry::Validation::Contract
  params UserSchema.params
  # OR
  params UserSchema.contract

  rule(:name) do
    key.failure('name is too short') if value.length < 3
  end
end

validation = UserSchema.params

Returns:

  • (Dry::Schema::Params) —

    the schema definition



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# File 'lib/dry_schema_rails/base.rb', line 77

def params
  Dry::Schema.Params(&_schema_proc)
end

.schema(&block) ⇒ Proc

Using in rails controllers.

Example:

UserSchema = Class.new(BaseSchema) do
  schema do
    required(:name).filled(:string)
    optional(:email).filled(:string)
  end
end

class ApplicationController < ActionController::Base
  before_action do
     if safe_params&.failure?
      render json: { errors: safe_params.errors.to_h }, status: :bad_request
     end
  end
end

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

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

Returns:

  • (Proc) —

    the schema definition



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# File 'lib/dry_schema_rails/base.rb', line 112

def schema(&block)
  if block_given?
    self._schema_proc = block
  else
    _schema_proc
  end
end