# class-validator [![Build Status](https://travis-ci.org/typestack/class-validator.svg?branch=master)](https://travis-ci.org/typestack/class-validator) [![npm version](https://badge.fury.io/js/class-validator.svg)](https://badge.fury.io/js/class-validator) [![install size](https://packagephobia.now.sh/badge?p=class-validator)](https://packagephobia.now.sh/result?p=class-validator) [![Join the chat at https://gitter.im/typestack/class-validator](https://badges.gitter.im/typestack/class-validator.svg)](https://gitter.im/typestack/class-validator?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) 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 * [Installation](#installation) * [Usage](#usage) + [Validation errors](#validation-errors) + [Validation messages](#validation-messages) + [Validating arrays](#validating-arrays) + [Validating sets](#validating-sets) + [Validating maps](#validating-maps) + [Validating nested objects](#validating-nested-objects) + [Validating promises](#validating-promises) + [Inheriting Validation decorators](#inheriting-validation-decorators) + [Conditional validation](#conditional-validation) + [Whitelisting](#whitelisting) + [Passing context to decorators](#passing-context-to-decorators) + [Skipping missing properties](#skipping-missing-properties) + [Validation groups](#validation-groups) + [Custom validation classes](#custom-validation-classes) + [Custom validation decorators](#custom-validation-decorators) + [Using service container](#using-service-container) + [Synchronous validation](#synchronous-validation) + [Manual validation](#manual-validation) + [Validation decorators](#validation-decorators) + [Defining validation schema without decorators](#defining-validation-schema-without-decorators) + [Validating plain objects](#validating-plain-objects) * [Samples](#samples) * [Extensions](#extensions) * [Release notes](#release-notes) ## Installation ``` 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: ```javascript 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; } ``` > It's highly advised to set `forbidUnknownValues: true` as it will prevent unknown objects from passing validation. ## Validation errors The `validate` method returns an array of `ValidationError` objects. Each `ValidationError` is: ```javascript { target: Object; // Object that was validated. property: string; // Object's property that haven't pass validation. value: any; // Value that haven't pass a validation. constraints?: { // Constraints that failed validation with error messages. [type: string]: string; }; children?: ValidationError[]; // Contains all nested validation errors of the property } ``` In our case, when we validated a Post object, we have such an array of `ValidationError` objects: ```javascript [{ target: /* post object */, property: "title", value: "Hello", constraints: { length: "$property must be longer than or equal to 10 characters" } }, { target: /* post object */, property: "text", value: "this is a great post about hell world", constraints: { contains: "text must contain a hello string" } }, // and other errors ] ``` If you don't want a `target` to be exposed in validation errors, there is a special option when you use validator: ```javascript validator.validate(post, { validationError: { target: false } }); ``` This is especially useful when you send errors back over http, and you most probably don't want to expose the whole target object. ## Validation messages You can specify validation message in the decorator options and that message will be returned in the `ValidationError` returned by the `validate` method (in the case that validation for this field fails). ```javascript import {MinLength, MaxLength} from "class-validator"; export class Post { @MinLength(10, { message: "Title is too short" }) @MaxLength(50, { message: "Title is too long" }) title: string; } ``` There are few special tokens you can use in your messages: * `$value` - the value that is being validated * `$property` - name of the object's property being validated * `$target` - name of the object's class being validated * `$constraint1`, `$constraint2`, ... `$constraintN` - constraints defined by specific validation type Example of usage: ```javascript import {MinLength, MaxLength} from "class-validator"; export class Post { @MinLength(10, { // here, $constraint1 will be replaced with "10", and $value with actual supplied value message: "Title is too short. Minimal length is $constraint1 characters, but actual is $value" }) @MaxLength(50, { // here, $constraint1 will be replaced with "50", and $value with actual supplied value message: "Title is too long. Maximal length is $constraint1 characters, but actual is $value" }) title: string; } ``` Also you can provide a function, that returns a message. This allows you to create more granular messages: ```javascript import {MinLength, MaxLength, ValidationArguments} from "class-validator"; export class Post { @MinLength(10, { message: (args: ValidationArguments) => { if (args.value.length === 1) { return "Too short, minimum length is 1 character"; } else { return "Too short, minimum length is " + args.constraints[0] + " characters"; } } }) title: string; } ``` Message function accepts `ValidationArguments` which contains the following information: * `value` - the value that is being validated * `constraints` - array of constraints defined by specific validation type * `targetName` - name of the object's class being validated * `object` - object that is being validated * `property` - name of the object's property being validated ## Validating arrays If your field is an array and you want to perform validation of each item in the array you must specify a special `each: true` decorator option: ```javascript import {MinLength, MaxLength} from "class-validator"; export class Post { @MaxLength(20, { each: true }) tags: string[]; } ``` This will validate each item in `post.tags` array. ## Validating sets If your field is a set and you want to perform validation of each item in the set you must specify a special `each: true` decorator option: ```javascript import {MinLength, MaxLength} from "class-validator"; export class Post { @MaxLength(20, { each: true }) tags: Set; } ``` This will validate each item in `post.tags` set. ## Validating maps If your field is a map and you want to perform validation of each item in the map you must specify a special `each: true` decorator option: ```javascript import {MinLength, MaxLength} from "class-validator"; export class Post { @MaxLength(20, { each: true }) tags: Map; } ``` This will validate each item in `post.tags` map. ## Validating nested objects If your object contains nested objects and you want the validator to perform their validation too, then you need to use the `@ValidateNested()` decorator: ```javascript import {ValidateNested} from "class-validator"; export class Post { @ValidateNested() user: User; } ``` Please note that nested object *must* be an instance of a class, otherwise `@ValidateNested` won't know what class is target of validation. Check also [Validating plain objects](#validating-plain-objects). It also works with multi-dimensional array, like : ```javascript import {ValidateNested} from "class-validator"; export class Plan2D { @ValidateNested() matrix: Point[][]; } ``` ## Validating promises If your object contains property with `Promise`-returned value that should be validated, then you need to use the `@ValidatePromise()` decorator: ```javascript import {ValidatePromise, Min} from "class-validator"; export class Post { @Min(0) @ValidatePromise() userId: Promise; } ``` It also works great with `@ValidateNested` decorator: ```javascript import {ValidateNested, ValidatePromise} from "class-validator"; export class Post { @ValidateNested() @ValidatePromise() user: Promise; } ``` ## Inheriting Validation decorators When you define a subclass which extends from another one, the subclass will automatically inherit the parent's decorators. If a property is redefined in the descendant class decorators will be applied on it both from that and the base class. ```javascript import {validate} from "class-validator"; class BaseContent { @IsEmail() email: string; @IsString() password: string; } class User extends BaseContent { @MinLength(10) @MaxLength(20) name: string; @Contains("hello") welcome: string; @MinLength(20) password: string; } let user = new User(); user.email = "invalid email"; // inherited property user.password = "too short" // password wil be validated not only against IsString, but against MinLength as well user.name = "not valid"; user.welcome = "helo"; validate(user).then(errors => { // ... }); // it will return errors for email, title and text properties ``` ## Conditional validation The conditional validation decorator (`@ValidateIf`) can be used to ignore the validators on a property when the provided condition function returns false. The condition function takes the object being validated and must return a `boolean`. ```javascript import {ValidateIf, IsNotEmpty} from "class-validator"; export class Post { otherProperty:string; @ValidateIf(o => o.otherProperty === "value") @IsNotEmpty() example:string; } ``` In the example above, the validation rules applied to `example` won't be run unless the object's `otherProperty` is `"value"`. Note that when the condition is false all validation decorators are ignored, including `isDefined`. ## Whitelisting Even if your object is an instance of a validation class it can contain additional properties that are not defined. If you do not want to have such properties on your object, pass special flag to `validate` method: ```javascript import {validate} from "class-validator"; // ... validate(post, { whitelist: true }); ``` This will strip all properties that don't have any decorators. If no other decorator is suitable for your property, you can use @Allow decorator: ```javascript import {validate, Allow, Min} from "class-validator"; export class Post { @Allow() title: string; @Min(0) views: number; nonWhitelistedProperty: number; } let post = new Post(); post.title = 'Hello world!'; post.views = 420; post.nonWhitelistedProperty = 69; (post as any).anotherNonWhitelistedProperty = "something"; validate(post).then(errors => { // post.nonWhitelistedProperty is not defined // (post as any).anotherNonWhitelistedProperty is not defined ... }); ```` If you would rather to have an error thrown when any non-whitelisted properties are present, pass another flag to `validate` method: ```javascript import {validate} from "class-validator"; // ... validate(post, { whitelist: true, forbidNonWhitelisted: true }); ``` ## Passing context to decorators It's possible to pass a custom object to decorators which will be accessible on the `ValidationError` instance of the property if validation failed. ```ts import { validate } from 'class-validator'; class MyClass { @MinLength(32, { message: "EIC code must be at least 32 characters", context: { errorCode: 1003, developerNote: "The validated string must contain 32 or more characters." } }) eicCode: string; } const model = new MyClass(); validate(model).then(errors => { //errors[0].contexts['minLength'].errorCode === 1003 }); ``` ## Skipping missing properties Sometimes you may want to skip validation of the properties that do not exist in the validating object. This is usually desirable when you want to update some parts of the object, and want to validate only updated parts, but skip everything else, e.g. skip missing properties. In such situations you will need to pass a special flag to `validate` method: ```javascript import {validate} from "class-validator"; // ... validate(post, { skipMissingProperties: true }); ``` When skipping missing properties, sometimes you want not to skip all missing properties, some of them maybe required for you, even if skipMissingProperties is set to true. For such cases you should use `@IsDefined()` decorator. `@IsDefined()` is the only decorator that ignores `skipMissingProperties` option. ## Validation groups In different situations you may want to use different validation schemas of the same object. In such cases you can use validation groups. ```javascript import {validate, Min, Length} from "class-validator"; export class User { @Min(12, { groups: ["registration"] }) age: number; @Length(2, 20, { groups: ["registration", "admin"] }) name: string; } let user = new User(); user.age = 10; user.name = "Alex"; validate(user, { groups: ["registration"] }); // this will not pass validation validate(user, { groups: ["admin"] }); // this will pass validation validate(user, { groups: ["registration", "admin"] }); // this will not pass validation validate(user, { groups: undefined // the default }); // this will not pass validation since all properties get validated regardless of their groups validate(user, { groups: [] }); // this will not pass validation, (equivalent to 'groups: undefined', see above) ``` There is also a special flag `always: true` in validation options that you can use. This flag says that this validation must be applied always no matter which group is used. ## Custom validation classes If you have custom validation logic you can create a *Constraint class*: 1. First create a file, lets say `CustomTextLength.ts`, and define a new class: ```javascript import {ValidatorConstraint, ValidatorConstraintInterface, ValidationArguments} from "class-validator"; @ValidatorConstraint({ name: "customText", async: false }) export class CustomTextLength implements ValidatorConstraintInterface { validate(text: string, args: ValidationArguments) { return text.length > 1 && text.length < 10; // for async validations you must return a Promise here } defaultMessage(args: ValidationArguments) { // here you can provide default error message if validation failed return "Text ($value) is too short or too long!"; } } ``` We marked our class with `@ValidatorConstraint` decorator. You can also supply a validation constraint name - this name will be used as "error type" in ValidationError. If you will not supply a constraint name - it will be auto-generated. Our class must implement `ValidatorConstraintInterface` interface and its `validate` method, which defines validation logic. If validation succeeds, method returns true, otherwise false. Custom validator can be asynchronous, if you want to perform validation after some asynchronous operations, simply return a promise with boolean inside in `validate` method. Also we defined optional method `defaultMessage` which defines a default error message, in the case that the decorator's implementation doesn't set an error message. 2. Then you can use your new validation constraint in your class: ```javascript import {Validate} from "class-validator"; import {CustomTextLength} from "./CustomTextLength"; export class Post { @Validate(CustomTextLength, { message: "Title is too short or long!" }) title: string; } ``` Here we set our newly created `CustomTextLength` validation constraint for `Post.title`. 3. And use validator as usual: ```javascript import {validate} from "class-validator"; validate(post).then(errors => { // ... }); ``` You can also pass constraints to your validator, like this: ```javascript import {Validate} from "class-validator"; import {CustomTextLength} from "./CustomTextLength"; export class Post { @Validate(CustomTextLength, [3, 20], { message: "Wrong post title" }) title: string; } ``` And use them from `validationArguments` object: ```javascript import {ValidationArguments, ValidatorConstraint, ValidatorConstraintInterface} from "class-validator"; @ValidatorConstraint() export class CustomTextLength implements ValidatorConstraintInterface { validate(text: string, validationArguments: ValidationArguments) { return text.length > validationArguments.constraints[0] && text.length < validationArguments.constraints[1]; } } ``` ## Custom validation decorators You can also create a custom decorators. Its the most elegant way of using a custom validations. Lets create a decorator called `@IsLongerThan`: 1. Create a decorator itself: ```javascript import {registerDecorator, ValidationOptions, ValidationArguments} from "class-validator"; export function IsLongerThan(property: string, validationOptions?: ValidationOptions) { return function (object: Object, propertyName: string) { registerDecorator({ name: "isLongerThan", target: object.constructor, propertyName: propertyName, constraints: [property], options: validationOptions, validator: { validate(value: any, args: ValidationArguments) { const [relatedPropertyName] = args.constraints; const relatedValue = (args.object as any)[relatedPropertyName]; return typeof value === "string" && typeof relatedValue === "string" && value.length > relatedValue.length; // you can return a Promise here as well, if you want to make async validation } } }); }; } ``` 2. Put it to use: ```javascript import {IsLongerThan} from "./IsLongerThan"; export class Post { title: string; @IsLongerThan("title", { /* you can also use additional validation options, like "groups" in your custom validation decorators. "each" is not supported */ message: "Text must be longer than the title" }) text: string; } ``` In your custom decorators you can also use `ValidationConstraint`. Lets create another custom validation decorator called `IsUserAlreadyExist`: 1. Create a ValidationConstraint and decorator: ```javascript import {registerDecorator, ValidationOptions, ValidatorConstraint, ValidatorConstraintInterface, ValidationArguments} from "class-validator"; @ValidatorConstraint({ async: true }) export class IsUserAlreadyExistConstraint implements ValidatorConstraintInterface { validate(userName: any, args: ValidationArguments) { return UserRepository.findOneByName(userName).then(user => { if (user) return false; return true; }); } } export function IsUserAlreadyExist(validationOptions?: ValidationOptions) { return function (object: Object, propertyName: string) { registerDecorator({ target: object.constructor, propertyName: propertyName, options: validationOptions, constraints: [], validator: IsUserAlreadyExistConstraint }); }; } ``` note that we marked our constraint that it will by async by adding `{ async: true }` in validation options. 2. And put it to use: ```javascript import {IsUserAlreadyExist} from "./IsUserAlreadyExist"; export class User { @IsUserAlreadyExist({ message: "User $value already exists. Choose another name." }) name: string; } ``` ## Using service container Validator supports service container in the case if want to inject dependencies into your custom validator constraint classes. Here is example how to integrate it with [typedi][2]: ```javascript import {Container} from "typedi"; import {useContainer, Validator} from "class-validator"; // do this somewhere in the global application level: useContainer(Container); let validator = Container.get(Validator); // now everywhere you can inject Validator class which will go from the container // also you can inject classes using constructor injection into your custom ValidatorConstraint-s ``` ## Synchronous validation If you want to perform a simple non async validation you can use `validateSync` method instead of regular `validate` method. It has the same arguments as `validate` method. But note, this method **ignores** all async validations you have. ## Manual validation There are several method exist in the Validator that allows to perform non-decorator based validation: ```javascript import {isEmpty, isBoolean} from "class-validator"; isEmpty(value); isBoolean(value); ``` ## Validation decorators | Decorator | Description | |-------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------| | **Common validation decorators** | | `@IsDefined(value: any)` | Checks if value is defined (!== undefined, !== null). This is the only decorator that ignores skipMissingProperties option. | | `@IsOptional()` | Checks if given value is empty (=== null, === undefined) and if so, ignores all the validators on the property. | | `@Equals(comparison: any)` | Checks if value equals ("===") comparison. | | `@NotEquals(comparison: any)` | Checks if value not equal ("!==") comparison. | | `@IsEmpty()` | Checks if given value is empty (=== '', === null, === undefined). | | `@IsNotEmpty()` | Checks if given value is not empty (!== '', !== null, !== undefined). | | `@IsIn(values: any[])` | Checks if value is in a array of allowed values. | | `@IsNotIn(values: any[])` | Checks if value is not in a array of disallowed values. | | **Type validation decorators** | | `@IsBoolean()` | Checks if a value is a boolean. | | `@IsDate()` | Checks if the value is a date. | | `@IsString()` | Checks if the string is a string. | | `@IsNumber(options: IsNumberOptions)` | Checks if the value is a number. | | `@IsInt()` | Checks if the value is an integer number. | | `@IsArray()` | Checks if the value is an array | | `@IsEnum(entity: object)` | Checks if the value is an valid enum | | **Number validation decorators** | | `@IsDivisibleBy(num: number)` | Checks if the value is a number that's divisible by another. | | `@IsPositive()` | Checks if the value is a positive number greater than zero. | | `@IsNegative()` | Checks if the value is a negative number smaller than zero. | | `@Min(min: number)` | Checks if the given number is greater than or equal to given number. | | `@Max(max: number)` | Checks if the given number is less than or equal to given number. | | **Date validation decorators** | | `@MinDate(date: Date)` | Checks if the value is a date that's after the specified date. | | `@MaxDate(date: Date)` | Checks if the value is a date that's before the specified date. | | | **String-type validation decorators** | | `@IsBooleanString()` | Checks if a string is a boolean (e.g. is "true" or "false"). | | `@IsDateString()` | Checks if a string is a complete representation of a date (e.g. "2017-06-07T14:34:08.700Z", "2017-06-07T14:34:08.700 or "2017-06-07T14:34:08+04:00"). | | `@IsNumberString(options?: IsNumericOptions)` | Checks if a string is a number. | | **String validation decorators** | | `@Contains(seed: string)` | Checks if the string contains the seed. | | `@NotContains(seed: string)` | Checks if the string not contains the seed. | | `@IsAlpha()` | Checks if the string contains only letters (a-zA-Z). | | `@IsAlphanumeric()` | Checks if the string contains only letters and numbers. | `@IsDecimal(options?: IsDecimalOptions)` | Checks if the string is a valid decimal value. Default IsDecimalOptions are `force_decimal=False`, `decimal_digits: '1,'`, `locale: 'en-US',` | | `@IsAscii()` | Checks if the string contains ASCII chars only. | | `@IsBase32()` | Checks if a string is base32 encoded. | | `@IsBase64()` | Checks if a string is base64 encoded. | | `@IsIBAN()` | Checks if a string is a IBAN (International Bank Account Number). | | `@IsBIC()` | Checks if a string is a BIC (Bank Identification Code) or SWIFT code. | | `@IsByteLength(min: number, max?: number)` | Checks if the string's length (in bytes) falls in a range. | | `@IsCreditCard()` | Checks if the string is a credit card. | | `@IsCurrency(options?: IsCurrencyOptions)` | Checks if the string is a valid currency amount. | | `@IsEthereumAddress()` | Checks if the string is an Ethereum address using basic regex. Does not validate address checksums. | | `@IsBtcAddress()` | Checks if the string is a valid BTC address. | | `@IsDataURI()` | Checks if the string is a data uri format. | | `@IsEmail(options?: IsEmailOptions)` | Checks if the string is an email. | | `@IsFQDN(options?: IsFQDNOptions)` | Checks if the string is a fully qualified domain name (e.g. domain.com). | | `@IsFullWidth()` | Checks if the string contains any full-width chars. | | `@IsHalfWidth()` | Checks if the string contains any half-width chars. | | `@IsVariableWidth()` | Checks if the string contains a mixture of full and half-width chars. | | `@IsHexColor()` | Checks if the string is a hexadecimal color. | | `@IsHSLColor()` | Checks if the string is an HSL (hue, saturation, lightness, optional alpha) color based on [CSS Colors Level 4 specification](https://developer.mozilla.org/en-US/docs/Web/CSS/color_value). | | `@IsRgbColor(options?: IsRgbOptions)` | Checks if the string is a rgb or rgba color. | | `@IsIdentityCard(locale?: string)` | Checks if the string is a valid identity card code. | | `@IsPassportNumber(countryCode?: string)` | Checks if the string is a valid passport number relative to a specific country code. | | `@IsPostalCode(locale?: string)` | Checks if the string is a postal code. | | `@IsHexadecimal()` | Checks if the string is a hexadecimal number. | | `@IsOctal()` | Checks if the string is a octal number. | | `@IsMACAddress(options?: IsMACAddressOptions)` | Checks if the string is a MAC Address. | | `@IsIP(version?: "4"\|"6")` | Checks if the string is an IP (version 4 or 6). | | `@IsPort()` | Check if the string is a valid port number. | | `@IsISBN(version?: "10"\|"13")` | Checks if the string is an ISBN (version 10 or 13). | | `@IsEAN()` | Checks if the string is an if the string is an EAN (European Article Number). | | `@IsISIN()` | Checks if the string is an ISIN (stock/security identifier). | | `@IsISO8601(options?: IsISO8601Options)` | Checks if the string is a valid ISO 8601 date. Use the option strict = true for additional checks for a valid date, e.g. invalidates dates like 2019-02-29. | | `@IsJSON()` | Checks if the string is valid JSON. | | `@IsJWT()` | Checks if the string is valid JWT. | | `@IsObject()` | Checks if the object is valid Object (null, functions, arrays will return false). | | `@IsNotEmptyObject()` | Checks if the object is not empty. | | `@IsLowercase()` | Checks if the string is lowercase. | | `@IsLatLong()` | Checks if the string is a valid latitude-longitude coordinate in the format lat,long | | `@IsLatitude()` | Checks if the string or number is a valid latitude coordinate | | `@IsLongitude()` | Checks if the string or number is a valid longitude coordinate | | `@IsMobilePhone(locale: string)` | Checks if the string is a mobile phone number. | | `@IsISO31661Alpha2()` | Checks if the string is a valid [ISO 3166-1 alpha-2](https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2) officially assigned country code. | | `@IsISO31661Alpha3()` | Checks if the string is a valid [ISO 3166-1 alpha-3](https://en.wikipedia.org/wiki/ISO_3166-1_alpha-3) officially assigned country code. | | `@IsLocale()` | Checks if the string is a locale. | | `@IsPhoneNumber(region: string)` | Checks if the string is a valid phone number. "region" accepts 2 characters uppercase country code (e.g. DE, US, CH).If users must enter the intl. prefix (e.g. +41), then you may pass "ZZ" or null as region. See [google-libphonenumber, metadata.js:countryCodeToRegionCodeMap on github](https://github.com/ruimarinho/google-libphonenumber/blob/1e46138878cff479aafe2ce62175c6c49cb58720/src/metadata.js#L33) | | `@IsMongoId()` | Checks if the string is a valid hex-encoded representation of a MongoDB ObjectId. | | `@IsMultibyte()` | Checks if the string contains one or more multibyte chars. | | `@IsNumberString(options?: IsNumericOptions)` | Checks if the string is numeric. | | `@IsSurrogatePair()` | Checks if the string contains any surrogate pairs chars. | | `@IsUrl(options?: IsURLOptions)` | Checks if the string is an url. | | `@IsMagnetURI()` | Checks if the string is a [magnet uri format](https://en.wikipedia.org/wiki/Magnet_URI_scheme). | | `@IsUUID(version?: "3"\|"4"\|"5"\|"all")` | Checks if the string is a UUID (version 3, 4, 5 or all ). | | `@IsFirebasePushId()` | Checks if the string is a [Firebase Push id](https://firebase.googleblog.com/2015/02/the-2120-ways-to-ensure-unique_68.html) | | `@IsUppercase()` | Checks if the string is uppercase. | | `@Length(min: number, max?: number)` | Checks if the string's length falls in a range. | | `@MinLength(min: number)` | Checks if the string's length is not less than given number. | | `@MaxLength(max: number)` | Checks if the string's length is not more than given number. | | `@Matches(pattern: RegExp, modifiers?: string)` | Checks if string matches the pattern. Either matches('foo', /foo/i) or matches('foo', 'foo', 'i'). | `@IsMilitaryTime()` | Checks if the string is a valid representation of military time in the format HH:MM. | | `@IsHash(algorithm: string)` | Checks if the string is a hash of type algorithm.

Algorithm is one of `['md4', 'md5', 'sha1', 'sha256', 'sha384', 'sha512', 'ripemd128', 'ripemd160', 'tiger128', 'tiger160', 'tiger192', 'crc32', 'crc32b']` | | `@IsMimeType()` | Checks if the string matches to a valid [MIME type](https://en.wikipedia.org/wiki/Media_type) format | | `@IsSemVer()` | Checks if the string is a Semantic Versioning Specification (SemVer). | | `@IsISSN(options?: IsISSNOptions)` | Checks if the string is a ISSN. | | `@IsISRC()` | Checks if the string is a [ISRC](https://en.wikipedia.org/wiki/International_Standard_Recording_Code). | | `@IsRFC3339()` | Checks f the string is a valid [RFC 3339](https://tools.ietf.org/html/rfc3339) date. | | **Array validation decorators** | | `@ArrayContains(values: any[])` | Checks if array contains all values from the given array of values. | | `@ArrayNotContains(values: any[])` | Checks if array does not contain any of the given values. | | `@ArrayNotEmpty()` | Checks if given array is not empty. | | `@ArrayMinSize(min: number)` | Checks if array's length is as minimal this number. | | `@ArrayMaxSize(max: number)` | Checks if array's length is as maximal this number. | | `@ArrayUnique()` | Checks if all array's values are unique. Comparison for objects is reference-based. | | **Object validation decorators** | | `@IsInstance(value: any)` | Checks if the property is an instance of the passed value. | **Other decorators** | | `@Allow()` | Prevent stripping off the property when no other constraint is specified for it. | ## Defining validation schema without decorators You can define your validation schemas without decorators: * you can define it in the separate object * you can define it in the `.json` file This feature maybe useful in the cases if: * are using es5/es6 and don't have decorators available * you don't have a classes, and instead using interfaces * you don't want to use model at all * you want to have a validation schema separate of your model * you want beautiful json-schema based validation models * you simply hate decorators Here is an example of using it: 1. Create a schema object: ```javascript import {ValidationSchema} from "class-validator"; export let UserValidationSchema: ValidationSchema = { // using interface here is not required, its just for type-safety name: "myUserSchema", // this is required, and must be unique properties: { firstName: [{ type: "minLength", // validation type. All validation types are listed in ValidationTypes class. constraints: [2] }, { type: "maxLength", constraints: [20] }], lastName: [{ type: "minLength", constraints: [2] }, { type: "maxLength", constraints: [20] }], email: [{ type: "isEmail" }] } }; ``` Same schema can be provided in `.json` file, depend on your wish. 2. Register your schema: ```javascript import {registerSchema} from "class-validator"; import {UserValidationSchema} from "./UserValidationSchema"; registerSchema(UserValidationSchema); // if schema is in .json file, then you can simply do registerSchema(require("path-to-schema.json")); ``` Better to put this code in a global place, maybe when you bootstrap your application, for example in `app.ts`. 3. Validate your object using validation schema: ```javascript import {validate} from "class-validator"; const user = { firstName: "Johny", secondName: "Cage", email: "johny@cage.com" }; validate("myUserSchema", user).then(errors => { if (errors.length > 0) { console.log("Validation failed: ", errors); } else { console.log("Validation succeed."); } }); ``` That's it. Here `"myUserSchema"` is the name of our validation schema. `validate` method will perform validation based on this schema ## Validating plain objects Due to nature of the decorators, the validated object has to be instantiated using `new Class()` syntax. If you have your class defined using class-validator decorators and you want to validate plain JS object (literal object or returned by JSON.parse), you need to transform it to the class instance (e.g. using [class-transformer](https://github.com/pleerock/class-transformer)) or just use the [class-transformer-validator](https://github.com/19majkel94/class-transformer-validator) extension which can do that for you. ## Samples Take a look on samples in [./sample](https://github.com/pleerock/class-validator/tree/master/sample) for more examples of usages. ## Extensions There are several extensions that simplify class-validator integration with other modules: - [class-validator integration](https://github.com/19majkel94/class-transformer-validator) with [class-transformer](https://github.com/pleerock/class-transformer) - [class-validator-rule](https://github.com/yantrab/class-validator-rule) - [ngx-dynamic-form-builder](https://github.com/EndyKaufman/ngx-dynamic-form-builder) ## Release notes See information about breaking changes and release notes [here][3]. [1]: https://github.com/chriso/validator.js [2]: https://github.com/pleerock/typedi [3]: CHANGELOG.md