revalidator

A cross-browser / node.js validator used by resourceful and flatiron.

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. This option is used for lx-valid format extensions and additional custom formats. Those are stored in here. ( 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. ( default: undefined )
• deleteUnknownProperties: Deletes all properties from object which are not declared in the schema. ( default: false )
• convert: Converts a property by the format defined in the schema. Modifies the original object. ( default: undefined )
• trim: Trims all properties of type string. Modifies the original object. ( default: false )
• strictRequired: Sets validity of empty string to false. ( default: false )

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 empty

{ required: true }

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 }

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 then expected value number of items

{ minItems: 2 }

maxItems

Value must contains less then expected value 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 value

{ 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' }
{ format: ['ip-address', 'ipv6'] }

conform

Value must conform to constraint denoted by expected value

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

{
  name: {
    type: 'string'
  },
  verifiedName: {
    type: 'string',
    conform: function (actual, original) {
      if (actual === original.name) {
        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 message 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'
}

Convert option

Converts a property by the format defined in the schema and returns the converted object in the result.

var data = {
  birthdate: '1979-03-01T15:55:00.000Z'
};

var schema = {
  properties: {
    birthdate: {
      type: 'string',
      format: 'date-time'
    }
  }
};

var convertFn = function(format, value) {
  if (format === 'date-time') {
    return new Date(value);
  }

  return value;
};

var result = validate(data, schema, {convert: convertFn});

// birthdate was converted
typeof result.convertedObject === 'object';
typeof result.convertedObject.birthdate === 'object';

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

License: Apache 2.0