Node object with validated, transformed & typecasted schema.

npm install node-schema-object
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Designed to enforce schema on Javascript objects. Allows you to specify type, transformation and validation of values via a set of attributes. Support for sub-schemas included.

npm install node-schema-object

For all features, run node with --harmony flag.

Very basic usage example

var SchemaObject = require('node-schema-object');

// Create User schema
var User = new SchemaObject({
  firstName: String,
  lastName: String,
  birthDate: Date

// Initialize instance of user
var user = new User({firstName: 'Scott', lastName: 'Hovestadt', birthDate: 'June 21, 1988'});

// Prints:
{ firstName: 'Scott',
  lastName: 'Hovestadt',
  birthDate: Tue Jun 21 1988 00:00:00 GMT-0700 (PDT) }

Advanced example

var SchemaObject = require('node-schema-object');

// Create custom basic type
// Type can be extended with more properties when defined
var NotEmptyString = {type: String, minLength: 1};

// Create sub-schema for user's Company
var Company = new SchemaObject({
  startDate: Date,
  endDate: Date,
  name: NotEmptyString

// Create User schema
var User = new SchemaObject({
  // Basic user information using custom type
  firstName: NotEmptyString,
  lastName: NotEmptyString,

  // "NotEmptyString" with only possible values as 'm' or 'f'
  gender: {type: NotEmptyString, enum: ['m', 'f']},

  // Index with sub-schema
  company: Company,

  // An array of Objects with an enforced type
  workHistory: [Company],

  // Create field which reflects other values but can't be directly modified
  fullName: {type: String, readOnly: true, default: function() {
    return (this.firstName + ' ' + this.lastName).trim();

// Initialize a new instance of the User with a value
var user = new User({firstName: 'Scott', lastName: 'Hovestadt', gender: 'm'});

// Set company name = 'My Company';

// The date is automatically typecast from String = 'June 1, 2010';

// Add company to work history
  name: 'Old Company',
  startDate: '01/12/2005',
  endDate: '01/20/2010'


// Prints:
{ firstName: 'Scott',
  lastName: 'Hovestadt',
  gender: 'm',
   { startDate: Tue Jun 01 2010 00:00:00 GMT-0700 (PDT),
     endDate: undefined,
     name: 'My Company' },
   [ { startDate: Wed Jan 12 2005 00:00:00 GMT-0800 (PST),
       endDate: Wed Jan 20 2010 00:00:00 GMT-0800 (PST),
       name: 'Old Company' } ],
  fullName: 'Scott Hovestadt' }


When you create the SchemaObject, you may pass a set of options as a second argument. These options allow you to fine-tune the behavior of your objects for specific needs.


Strict mode (default: true) allows you to specify what happens when an index is set on your SchemaObject that does not exist in the schema. If strict mode is on, the index will be ignored. If strict mode is off, the index will automatically be created in the schema when it's set with type "any".

With strict mode on (default):

var Profile = new SchemaObject({
  id: String
}, {
  strict: true

var profile = new Profile(); = 'abc123';
profile.customField = 'hello';

// Prints:
{ id: 'abc123' }

With strict mode off:

var Profile = new SchemaObject({
  id: String
}, {
  strict: false

var profile = new Profile(); = 'abc123';
profile.customField = 'hello';

// Prints:
{ id: 'abc123', customField: 'hello' }


When setting a value fails, an error is generated silently. Errors can be retrieved with getErrors() and cleared with clearErrors().

var Profile = new SchemaObject({
  id: {type: String, minLength: 5}

var profile = new Profile(); = '1234';


// Prints:
[ { errorMessage: 'String length too short to meet minLength requirement.',
    setValue: '1234',
    originalValue: undefined,
    fieldSchema: { name: 'id', type: 'string', minLength: 5 } } ]

// Clear all errors.


Supported types:

  • String
  • Number
  • Boolean
  • Date
  • Array (including types within Array)
  • Object (including typed SchemaObjects for sub-schemas)
  • 'alias'
  • 'any'

When a type is specified, it will be enforced. Typecasting is enforced on all types except 'any'. If a value cannot be typecasted to the correct type, the original value will remain untouched.

Types can be extended with a variety of attributes. Some attributes are type-specific and some apply to all types.

Custom types can be created by defining an object with type properties.

var NotEmptyString = {type: String, minLength: 1};
country: {type: NotEmptyString, default: 'USA'}

General attributes


Called immediately when value is set and before any typecast is done.

name: {type: String, transform: function(value) {
  // Modify the value here...
  return value;


Provide default value. You may pass value directly or pass a function which will be executed when the value is retrieved. The function is executed in the context of the object and can use "this" to access other properties.

country: {type: String, default: 'USA'}


If true, the value can be read but cannot be written to. This can be useful for creating fields that reflect other values.

fullName: {type: String, readOnly: true, default: function(value) {
  return (this.firstName + ' ' + this.lastName).trim();


If true, the value can be written to but isn't outputted as an index when toObject() is called. This can be useful for creating aliases that redirect to other indexes but aren't actually present on the object.

zip: String,
postalCode: {type: 'alias', invisible: true, index: 'zip'}
// this.postalCode = 12345 -> this.toObject() -> {zip: '12345'}



Called after value is typecast to string if value was successfully typecast but called before all validation.

postalCode: {type: String, stringTransform: function(string) {
  // Type will ALWAYS be String, so using string prototype is OK.
  return string.toUpperCase();


Validates string against Regular Expression. If string doesn't match, it's rejected.

memberCode: {type: String, regex: new RegExp('^([0-9A-Z]{4})$')}


Validates string against array of strings. If not present, it's rejected.

gender: {type: String, enum: ['m', 'f']}


Enforces minimum string length.

notEmpty: {type: String, minLength: 1}


Enforces maximum string length.

stateAbbrev: {type: String, maxLength: 2}


If true, clips string to maximum string length instead of rejecting string.

bio: {type: String, maxLength: 255, clip: true}



Number must be > min attribute or it's rejected.

positive: {type: Number, min: 0}


Number must be < max attribute or it's rejected.

negative: {type: Number, max: 0}



Ensures duplicate-free array, using === to test object equality.

emails: {type: Array, unique: true, arrayType: String}


Elements within the array will be typed to the attributes defined.

aliases: {type: Array, arrayType: {type: String, minLength: 1}}

An alternative shorthand version is also available -- wrap the properties within array brackets.

aliases: [{type: String, minLength: 1}]



Allows you to define a typed object.

company: {type: Object, objectType: {
  name: String

An alternative shorthand version is also available -- simply pass an instance of SchemaObject or a schema.

company: {
  name: String


index (required)

The index key of the property being aliased.

zip: String,
postalCode: {type: 'alias', alias: 'zip'}
// this.postalCode = 12345 -> this.toObject() -> {zip: '12345'}
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