revalidator

A cross-browser / node.js validator with JSONSchema compatibility as the primary goal.

Example

The core of revalidator is simple and succinct: revalidator.validate(obj, schema):

  var revalidator = require('revalidator');

  console.dir(revalidator.validate(someObject, {
    properties: {
      url: {
        description: 'the url the object should be stored at',
        type: 'string',
        pattern: '^/[^#%&*{}\\:<>?\/+]+$',
        required: true
      },
      challenge: {
        description: 'a means of protecting data (insufficient for production, used as example)',
        type: 'string',
        minLength: 5
      },
      body: {
        description: 'what to store at the url',
        type: 'any',
        default: null
      }
    }
  }));

This will return with a value indicating if the obj conforms to the schema. If it does not, a descriptive object will be returned containing the errors encountered with validation.

  {
    valid: true // or false
    errors: [/* Array of errors if valid is false */]
  }

In the browser, the validation function is exposed on window.validate by simply including revalidator.js.

Installation

Installing npm (node package manager)

  $ curl http://npmjs.org/install.sh | sh

Installing revalidator

  $ [sudo] npm install revalidator

Usage

revalidator takes json-schema as input to validate objects.

revalidator.validate (obj, schema, options)

This will return with a value indicating if the obj conforms to the schema. If it does not, a descriptive object will be returned containing the errors encountered with validation.

{
  valid: true // or false
  errors: [/* Array of errors if valid is false */]
}

Available Options

• validateFormats: Enforce format constraints (default true)
• validateFormatsStrict: When validateFormats is true treat unrecognized formats as validation errors (default false)
• validateFormatExtensions: When validateFormats is true also validate formats defined in validate.formatExtensions (default true)
• additionalProperties: When additionalProperties is true allow additional unvisited properties on the object. (default true)
• cast: Enforce casting of some types (for integers/numbers are only supported) when it's possible, e.g. "42" => 42, but "forty2" => "forty2" for the integer type.

Schema

For a property an value is that which is given as input for validation where as an expected value is the value of the below fields

required

If true, the value should not be undefined

{ required: true }

allowEmpty

If false, the value must not be an empty string

{ allowEmpty: false }

type

The type of value should be equal to the expected value

{ type: 'string' }
{ type: 'number' }
{ type: 'integer' }
{ type: 'array' }
{ type: 'boolean' }
{ type: 'object' }
{ type: 'null' }
{ type: 'any' }
{ type: ['boolean', 'string'] }

pattern

The expected value regex needs to be satisfied by the value

{ pattern: /^[a-z]+$/ }

maxLength

The length of value must be greater than or equal to expected value

{ maxLength: 8 }

minLength

The length of value must be lesser than or equal to expected value

{ minLength: 8 }

minimum

Value must be greater than or equal to the expected value

{ minimum: 10 }

maximum

Value must be lesser than or equal to the expected value

{ maximum: 10 }

allowEmpty

Value may not be empty

{ allowEmpty: false }

exclusiveMinimum

Value must be greater than expected value

{ exclusiveMinimum: 9 }

exclusiveMaximum

Value must be lesser than expected value

{ exclusiveMaximum: 11 }

divisibleBy

Value must be divisible by expected value

{ divisibleBy: 5 }
{ divisibleBy: 0.5 }

minItems

Value must contain more than expected number of items

{ minItems: 2 }

maxItems

Value must contain fewer than expected number of items

{ maxItems: 5 }

uniqueItems

Value must hold a unique set of values

{ uniqueItems: true }

enum

Value must be present in the array of expected values

{ enum: ['month', 'year'] }

format

Value must be a valid format

{ format: 'url' }
{ format: 'email' }
{ format: 'ip-address' }
{ format: 'ipv6' }
{ format: 'date-time' }
{ format: 'date' }
{ format: 'time' }
{ format: 'color' }
{ format: 'host-name' }
{ format: 'utc-millisec' }
{ format: 'regex' }

conform

Value must conform to constraint denoted by expected value

{ conform: function (v) {
    if (v%3==1) return true;
    return false;
  }
}

dependencies

Value is valid only if the dependent value is valid

{
  town: { required: true, dependencies: 'country' },
  country: { maxLength: 3, required: true }
}

Nested Schema

We also allow nested schema

{
  properties: {
    title: {
      type: 'string',
      maxLength: 140,
      required: true
    },
    author: {
      type: 'object',
      required: true,
      properties: {
        name: {
          type: 'string',
          required: true
        },
        email: {
          type: 'string',
          format: 'email'
        }
      }
    }
  }
}

Custom Messages

We also allow custom messages for different constraints

{
  type: 'string',
  format: 'url'
  messages: {
    type: 'Not a string type',
    format: 'Expected format is a url'
  }

{
  conform: function () { ... },
  message: 'This can be used as a global message'
}

Tests

All tests are written with vows and should be run with npm:

  $ npm test

Author: Charlie Robbins, Alexis Sellier

Contributors: Fedor Indutny, Bradley Meck, Laurie Harper, Martijn Swaagman

License: Apache 2.0