Learn Dry Validation in Ruby On Rails – P1

First, I will introduce about Dry Validation

• dry-validation is the validation data library provided by DSL, it works with any input data, whether it is a hash, an array or an object containing deep nested data.
• Validations are expressed through Contract object . A Contract will define a schema with basic data check types and any applicable rules . Contract rules are only applied once the values ​​they are based on are passed through the basic schema data check types.
• Using it will be much faster than using ActiveRecord/ActiveModel::Validations , strong-parameters .
• To be able to use it in your project we need to install it first by adding the gem 'dry-validation' the gem 'dry-validation' of the ROR project.

Let’s begin to learn the basics of this library:

1. Type Validate Basic

• Some types of check validate commonly used in dry I can mention:

2. Schemas

• It can be said that Schemas is an important part of dry-validation , it will process the data before it is validated by the rules (and what rules are below I will learn more) and Schemas can provide Error message in the most detailed way
• rules here can understand that I will validate the data in a more specific way (the data needs to be logically validated) that the gem validate types do not support.

Define a basic schema

• To define a schema we will use the schema method:

• Above we have created a Contact with the required use which means the input must have email , the age and value of the email must be string and the value of age must be integer
• Now, we will try to apply the Contract we just created:

Defining a Schema with Params required

• To define a schema for validating HTTP parameters , we will use the params method:

• The main difference between params and schema is simply that params will implement params enforced rules before applying rules . In the rules section we will learn more clearly.

Define a schema with json required

• We can use json to define an appropriate schema for validating JSON data:

Reuse schema from other schema

• We can use a schema is or multiple schema by passing it into schema we define. For example:

Custom Types for Schema

• When we define the schema using param or json , we can handle the value of the input data the way we want, for example:

Thank you for reading my article

Reference: Dry Validation