README

class-validator

!Build Status




Allows use of decorator and non-decorator based validation.
Internally uses [validator.js][1] to perform validation.
Class-validator works on both browser and node.js platforms.

 Table of Contents

- class-validator
  - Table of Contents
  - Installation
  - Usage
    - Passing options
  - Validation errors
  - Validation messages
  - Validating arrays
  - Validating sets
  - Validating maps
  - Validating nested objects
  - Validating promises
  - Inheriting Validation decorators
  - Conditional validation
  - Whitelisting
  - Passing context to decorators
  - Skipping missing properties
  - Validation groups
  - Custom validation classes
  - Custom validation decorators
  - Using service container
  - Synchronous validation
  - Manual validation
  - Validation decorators
  - Defining validation schema without decorators
  - Validating plain objects
  - Samples
  - Extensions
  - Release notes
  - Contributing

 Installation

sh
npm install class-validator --save


 Note: Please use at least npm@6 when using class-validator. From npm@6 the dependency tree is flattened, which is required by class-validator to function properly.

 Usage

Create your class and put some validation decorators on the properties you want to validate:

typescript
import {
  validate,
  validateOrReject,
  Contains,
  IsInt,
  Length,
  IsEmail,
  IsFQDN,
  IsDate,
  Min,
  Max,
} from 'class-validator';

export class Post {
  @Length(10, 20)
  title: string;

  @Contains('hello')
  text: string;

  @IsInt()
  @Min(0)
  @Max(10)
  rating: number;

  @IsEmail()
  email: string;

  @IsFQDN()
  site: string;

  @IsDate()
  createDate: Date;
}

let post = new Post();
post.title = 'Hello'; // should not pass
post.text = 'this is a great post about hell world'; // should not pass
post.rating = 11; // should not pass
post.email = 'google.com'; // should not pass
post.site = 'googlecom'; // should not pass

validate(post).then(errors = {
  // errors is an array of validation errors
  if (errors.length  0) {
    console.log('validation failed. errors: ', errors);
  } else {
    console.log('validation succeed');
  }
});

validateOrReject(post).catch(errors = {
  console.log('Promise rejected (validation failed). Errors: ', errors);
});
// or
async function validateOrRejectExample(input) {
  try {
    await validateOrReject(input);
  } catch (errors) {
    console.log('Caught promise rejection (validation failed). Errors: ', errors);
  }
}


 Passing options

The validate function optionally expects a ValidatorOptions object as a second parameter:

ts
export interface ValidatorOptions {
  skipMissingProperties?: boolean;
  whitelist?: boolean;
  forbidNonWhitelisted?: boolean;
  groups?: string[];
  dismissDefaultMessages?: boolean;
  validationError?: {
    target?: boolean;
    value?: boolean;
  };

  forbidUnknownValues?: boolean;
  stopAtFirstError?: boolean;
}


 IMPORTANT
 The forbidUnknownValues value is set to true by default and it is