Nostradamus Predicting Maelstroms


    0.2.3 • Public • Published



    Give your object and models schemas

    Build Status browser support




    $ npm install draft --save


    $ component install jwerle/draft


    $ bower install draft


    <script type="text/javascript" src=""></script>


    Creating a model with draft is as simple as passing it a schema descriptor

    var User = draft({ name: String, email: String })
      , Post = draft({ owner: Object, content: String })
    var werle = new User({ name: 'werle', email: '' })
      , post  = new Post({ owner: werle, content: "I like draft :)"})


    draft(descriptor, options)

    Creates a schema form a descriptor and returns a model constructor


    var Post = draft({
      owner    : User,
      comments : [Comment],
      content  : String,
      created  : Date,
      updated  : Date


    Schema(descriptor, options)

    Schema constructor

    • descriptor - An object defining a descriptor for the schema instance
    • options - An object of options:
    • strict - Strict mode. Model from schema will be frozen from schema updates after instantiation. (Default: true)


    var schema = new draft.Schema({
      name: String,
      email: String

    .add(key, descriptor)

    Adds an object to the schema tree

    • key - A key used to identify the property in the schema
    • descriptor - An object descriptor or constructor function


    schema.add({ age: Number });

    .static(name, func)

    Creates a static function on the schema's model constructor

    • name - The name of the static function
    • func - The actual function


    var siteSchema = new draft.Schema({
      name : String,
      url  : String
    siteSchema.static('createSites', function createSites (map) {
      return Object.keys(map).map(function (site) {
        return new this({ name: site, url: map[site] });
      }, this);
    // create Site model
    var Site = siteSchema.createModel();
    var sites = Site.createSites({
      'google'  : "",
      'github'  : "",
      'twitter' : "",
    sites[0].name; // 'google'
    sites[0].url; // ''
    sites[1].name; // 'github'
    sites[1].url; // ''


    Creates a constructor from the defined schema


    var schema = new draft.Schema({
      name  : String,
      email : String
    var User = schema.createModel();
    var user = new User({ name: 'werle', email: '' });


    Accepts an object of data and passes it to the Model constructor from the Schema instance

    • data - An object of data to pass to the schema instance model constructor


    var schema = new draft.Schema({
      name   : String,
      albums : [Album],
      fans   : [Fan]
    var bob ={
      name: 'bob',
      albums: [new Album({ name: "Sun Is Shining" }), new Album({ name: "Roots of a Legend" }) ],
      fans: [sally, frank, joe]

    using schema descriptors

    A schema descriptor is a key to type descriptor object. The key for each property on the object represents a possible key on a model instance created from the schema instance.

    A simple example of a schema who defines a model which accepts an object that defines a single property name of the type string

    new draft.Schema({ name : String })

    A more advanced example would be to define the descriptor object for the property:

    new draft.Schema({
      name: { type: String }


    Tree(descriptor, options)

    Tree constructor. Creates an object tree for a schema. This is used for aggregating types

    A tree instance is intended to be used with a schema

    • descriptor - A schema descriptor used to define the tree.
    • options - An object of options. If present and array is set to true then an array is returned who's prototype is an instance of the tree .


    var tree = new draft.Tree({
      name: String
    // is an instance of draft.Type who's constructor is a String constructor; // { Constructor: [Function: String] }

    .add(parent, key, descriptor)

    Adds a key to the tree on a given parent tree. Defaults to 'this' as the parent if one is not provided.

    • parent - The parent tree object in which the descriptor is added to by the provided key. Defaults to the tree instance caller.
    • key - The key of the item in the tree to add
    • descriptor - The object descriptor for the key being added to the tree


    var tree = new draft.Tree({
      domain: String
    tree.add('subdomains', {});
    tree.subdomains; // {} (Tree instance)
    tree.add(tree.subdomains, 'primary', String);
    tree.subdomains.primary; // { Constructor: [Function: String] }
    tree.add(tree.subdomains, 'secondary', String);
    tree.subdomains.secondary; // { Constructor: [Function: String] }
    tree.subdomains.add('cdn', String);
    tree.subdomains.cdn; // { Constructor: [Function: String] }
    tree.add('host', String);; // { Constructor: [Function: String] }


    Type(Constructor, descriptor)

    Type constructor. Creates a Type used in a Tree instance for a Schema instance. It is meant to provide methods for validation and coercion.

    • Constructor - A valid type constructor who will NEVER be invoked with the new operator
    • descriptor - A valid schema constructor


    var stringType = new draft.Type(String);
    stringType.coerce(123); // '123'
    var numberType = new draft.Type(Number);
    numberType.coerce('123'); // 123
    var booleanType = new draft.Type(Boolean);
    booleanType.coerce(1); // true
    booleanType.coerce(0); // false

    Creating a custom type

    var customType = new draft.Type(function CustomType (value) {
      return {
        toString: function () {
          return value.toString();
        valueOf: function () {
          return value;
        add: function (n) {
          return CustomType(value + n);
        sub: function (n) {
          return CustomType(value - n);
    +customType.coerce(4).add(5); // 9
    +customType.coerce(10).sub(9); // 1
    customType.coerce('j').add('o').add('e').toString(); // 'joe'


    Returns a string representation of a Type instance


    someType.toString(); // '[object Type]'


    Returns the valueOf return value from the original constructor on the Type instance

    var someType.valueOf(); // some value


    Default getter that coerces a value. This method that can be implemented by the descriptor. Defaults to .coerce()

    var stringType = new draft.Type(String)
    stringType.get(12345); // '12345'


    Default setter that coerces a value. This method that can be implemented by the descriptor. Defaults to .coerce()

    var stringType = new draft.Type(String)
    stringType.set(12345); // '12345'


    Validates a defined type. It performs instance of checks on values that are not primitive. Primitive inputs are validated with a 'typeof' check

    • input - Mixed input to validate against the type


    var numberType = new draft.Type(Number)
    numberType.validate('123'); // false
    numberType.validate(true); // false
    numberType.validate(123); // true


    Coerces a given input with the set Constructor type

    • input - Input to coerce to a type


    var booleanType = new draft.Type(Boolean)
    booleanType.coerce(1); // true
    booleanType.coerce(123); // true
    booleanType.coerce(0); // false
    booleanType.coerce(null); // false
    booleanType.coerce(); // false


    Model(data, schema)

    Base constructor for all created Model instances. Usually a Model constructor is created from a schema, but passing a schema to a Model constructor works too.

    • data - An object of data is validated against the schema used to create the Model
    • schema - An instance of a schema.


    var schema = new draft.Schema({
      name: String,
      email: String
    var user = new draft.Model({ name: 'werle', email: '' }, schema);


    Refreshes the state of the model based on its schema


    Sets data on the model based on the schema


    Returns a plain object representation of the model


    Called with JSON.stringify


    Returns a string representation of a Model instance


    Returns a value representation of a Model instance



    Define a schema for an object with types. Strict mode default

    var draft = require('draft')
    var schema = new draft.Schema({
      name : String,
      profile : {
        email : String,
        age : Number

    Create a model constructor from the schema defaulting to strict mode

    var User = schema.createModel();

    Instantiate the model passing in an object. In strict mode all properties on an object must be defined in the schema that was used to create it

    var user = new User({
      name: 'werle',
      profile: { email: '' },
      somePropertyNotInSchema: 'someValue'

    Only values in the schema were set on the object // werle //
    user.somePropertyNotInSchema // undefined


    • write more tests
    • document more




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