Validation

Overview

Validation ensures data integrity and business rules.

Example

Required: Validates that a field is not null, empty, or whitespace.
OneAtLeastRequired: Ensures at least one field from a list is provided.
FailIf: Throws exception when a condition is true.
In/Contains: Validates a value exists in a list.

C#JavaTypeScriptPython

C#

Rule.Required(userId, "userId");
Rule.ValidateEmail(email);
Rule.In(type, PlanType.All);

Java

Rule.required(userId, "userId");
Rule.validateEmail(email);
Rule.in(type, PlanType.All);

TypeScript

rule.required(userId, "userId");
rule.validateEmail(email);
rule.isIn(type, PlanType.All);

Python

Rule.required(user_id, "user_id")
Rule.validate_email(email)
Rule.contains(PlanType.All, type)

Validation Levels

Controllers: Validate required inputs and types.
Service: Validate business rules.
Middlewares: Validate security and authorization rules.