Array Decorator ​

The Array decorator allows for the validation of array properties within classes, ensuring they meet specific criteria such as length and uniqueness, and even applying custom validation to each element.

Properties ​

• minLength: number - Specifies the minimum length the array must have.
• maxLength: number - Defines the maximum length allowed for the array.
• unique: boolean - Ensures all elements in the array are unique.
• validator: ValidatorFunction<T> - A custom validation function to apply to each element in the array.

Usage ​

To use the Array, apply it to array properties in your class, specifying the desired validation constraints.

Example ​

import { ClassValidator, Array } from "rest-data-validator";

@ClassValidator
class ShoppingCart {
  @Array({
    minLength: 1,
    unique: true,
    validator: (item) => {
      // Custom validation logic for each item
      return item.price > 0
        ? { isValid: true }
        : { isValid: false, errors: ["Price must be greater than 0"] };
    },
  })
  items: Array<{ id: number; price: number }>;
}

In this example, the items array must have at least one item, each item must be unique, and every item must satisfy the custom validation condition (price greater than 0).

Applying Array ​

To apply the Array, you need to decorate your class property with @Array and provide the necessary validation options. This enables a declarative approach to specifying validation logic directly within your class models.

The Array is a powerful tool for ensuring data integrity for array properties, supporting both simple constraints and complex, element-wise validation.