Introducation

This library fully uses the advantages of decorators, make it smooth to write validation rules. This projects aims to be foundation component for the rest of @t2ee projects. It provides dependency injection and auto configuration functionalities.

Installation

npm i reflect-metadata @t2ee/core @t2ee/validation -S

Usage

Example usage with @t2ee/vader

class Message {
    @NotNull
    @Min(4)
    message: string;
}

@Path('/')
@Component
class Controller {

    @POST
    @Path('/say')
    say(@Valid @Body message: Message) {
        // message should be at least 4 characters long
    }
}

Example Custom Rule

const IsEmail = CustomRule('IsEmail', 'should be valid email');
@ValidationRule('IsEmail')
class IsEmailRule implements Rule {
    validate(value: any, parameter: any, meta, AutoWireMeta, args: any[]): boolean {
        return /[\d\w]*\@[\d\w]*\.[\w]*/.test(value);
    }
}

OR

const IsEmail = Pattern(/[\d\w]*\@[\d\w]*\.[\w]*/);

API

@Valid

@Valid is an essential decorator, it validates all the rules associated with a type. Without @Valid, validations will not be triggered.

@CustomRule

CustomRule(name: string, error: string, parameter?: any) , returns a PropertyDecorator. This binds necessary metadata to the class

@ValidationRule and Rule

@ValidationRule(name: string) inject your implementation of a rule to the ValidationProvider, where your rules are resolved, parsed and validated.

Rule is a interface guides you how should it be implmeented for a ValidationRule.

Rules

@Length, @Max and @Min

@NotNull

Any value shuold pass validation if the value is not null nor undefined.

@Pattern

It only validates the regex when value is string and not null nor undefined.