objectschema.js

Advanced strongly-typed JavaScript object.

This is a light weight open source package for the server and browser (using module bundler). The source code is available on GitHub where you can also find our issue tracker.

Features

• Simple and intuitive API
• TypeScript ready
• Field type casting
• Custom field data types
• Field dynamic default value
• Field dynamic fake value
• Field value transformation with getter and setter
• Document serialization and filtering
• Document nesting with support for self referencing
• Change tracking, data commits and rollbacks
• Advanced field validation
• Built-in and custom validators

Related Projects

• Contextable.js: Simple, unopinionated and minimalist framework for creating context objects with support for unopinionated ORM, object schemas, type casting, validation and error handling and more.
• Validatable.js: A library for synchronous and asynchronous validation.
• Handleable.js: A library for synchronous and asynchronous error handling.
• Typeable.js: A library for checking and casting types.

Installation

Run the command below to install the package.

$ npm install --save objectschema

This package uses promises thus you need to use Promise polyfill when promises are not supported.

Introduction

// TODO

Getting Started

This package provides two core classes:

• Document represents strongly-typed data object with fields.
• Field represents a document property.

It's all about creating models.

The Simplest Model

We will be using TypeScript for code examples for the rest of the docs. If you haven't picked it up, you should!

Creating a model is pretty straightforward. Just define a class which extends from Document.

import {Document} from 'objectschema';

class User extends Document { // User model
  public name: string; // class property

  public constructor (data = {}, options = {}) {
    super(data, options);
    this.defineField('name'); // field definition for class property `name`
    this.populate(data); // populating document
  }
}

Now, you can use it like this:

let user = new User({
  name: 'John Smith'
});

console.log('User Name:', user.name); // => 'John Smith'

Context

Context-aware Models

Defining models.

class User extends Document {}

class Context extends Document { // Application context
  public constructor () {
    super();
    this.defineModel(User); // defines a new class which extends User
  }

  public echo () {
    return `Hello World`;
  }
}

Usage example:

let context = new Context();
let user = new context.User(); // new instance of context-aware user model
console.log(user.context.echo()); // how you would access the context from an instance method
console.log(User.context.echo()); // how you would access the context from a static method

Application Settings

import {Document} from 'objectschema';
import {MongoClient} from 'mongodb';

class Context extends Document { // Application context
  public settings: Object; // application settings

  public constructor (settings = {}, options = {}) {
    super(null, options);
    this.settings = Object.freeze(settings); // storing application settings
  }
}

HTTP Server

Database Connection

class Context extends Document { // Application context
  public db: string; // class property

  public constructor (settings = {}, options = {}) {
    ...
    this.mongo = null; // initializing variable for MongoDB connection
  }

  public async connect (): this {
    this.mongo = await MongoClient.connect(this.settings.mongo); // connecting to MongoDB
  }

  public async disconnect (): this {
    await this.mongo.close(); // closing MongoDB connection
    this.mongo = null;
  }
}

let ctx = new Context();
ctx.connect(); // application started

API

This package consists of two core classes:

• Document represents strongly-typed data object with fields.
• Field represents a document property.

This package uses typeable.js for data type casting. Many common data types and array types are supported, but we can also use custom types. Please check package's website for a list of supported types and further information.

Validation is handled by validatable.js. The package provides many built-in validators, allows adding custom validators and overriding existing ones. When a document is created all validators share field's context thus we can write context-aware checks. Please see package's website for details.

Document

A document is an advanced strongly-typed JavaScript object where properties are instances of the Field class.

Document(data, {parent})

Strongly-typed JavaScript object.

| Option | Type | Required | Default | Description |--------|------|----------|---------|------------ | data | Object | No | - | Initial data object. | parent | Document | No | - | Parent document instance (for nesting).

class Model extends Document {
  constructor (data, options) {
    super(data, options);

    this.defineField('name', {
      type: 'String', // field type casting
      get (v) { return v }, // custom getter
      set (v) { return v }, // custom setter
      validate: [ // value validations
        { // validator recipe (check validatable.js for more)
          validator: 'presence', // validator name
          message: 'must be present' // error message
        }
      ],
      defaultValue: 'Noname', // field default value (value or function)
      fakeValue: 'Noname', // field fake value (value or function)
    });

    this.populate(data);
    this.commit();
  }
}

Properties

Document.prototype.options: Object

Document options.

Document.prototype.parent: Document

Parent document instance.

Document.prototype.root: Document

The first document instance in a tree of documents.

Methods

Document.prototype.applyErrors(errors): Document

Deeply populates fields with the provided errors.

doc.applyErrors([
  {
    path: ['books', 1, 'title'], // field path
    errors: [
      {
        validator: 'presence',
        message: 'is required',
        code: 422
      }
    ]
  }
]);

Document.prototype.clear(): Document

Sets all document fields to null.

Document.prototype.clone(): Document

Returns a new Document instance which is the exact copy of the original.

Document.prototype.collect(handler): Array

Scrolls through document fields and collects results.

| Option | Type | Required | Default | Description |--------|------|----------|---------|------------ | handler | Function | Yes | - | A handler method which is executed for each field.

Document.prototype.collectErrors(): Array

Returns a list of errors for all the fields ({path, errors}[]).

doc.collectErrors(); // => {path: ['name'], errors: [{validator: 'absence', message: 'must be blank', code: 422}]}

Document.prototype.commit(): Document

Sets initial value of each document field to the current value of a field. This is how field change tracking is restarted.

Document.prototype.defineField(name, {type, get, set, defaultValue, fakeValue, validate}): Void

Defines a new document property.

| Option | Type | Required | Default | Description |--------|------|----------|---------|------------ | name | String | Yes | - | Property name. | type | String, Document | No | - | Data type (pass a Document to create a nested structure; check typeable.js for more). | get | Function | No | - | Custom getter. | set | Function | No | - | Custom setter. | defaultValue | Any | No | - | Field default value. | fakeValue | Any | No | - | Field fake value. | validate | Array | No | - | List of validation recipies (check validatable.js for more).

Document.prototype.defineType(name, converter): Void

Defines a custom data type.

| Option | Type | Required | Default | Description |--------|------|----------|---------|------------ | name | String | Yes | - | Type name. | converter | Function | Yes | - | Type converter.

Document.prototype.defineValidator(name, handler): Void

Defines a custom validator.

| Option | Type | Required | Default | Description |--------|------|----------|---------|------------ | name | String | Yes | - | Validator name. | handler | Function, Promise | Yes | - | Validator handler.

Document.prototype.equals(value): Boolean

Returns true when the provided value represents an object with the same fields as the document itself.

Document.prototype.failFast(fail): Void

Configures validator to stop field validation on the first error.

| Option | Type | Required | Default | Description |--------|------|----------|---------|------------ | fail | Boolean | No | false | Stops field validation on the first error when set to true.

Document.prototype.fake(): Document

Sets each document field to its fake value if a fake value generator is registered, otherwise the default value is used.

Document.prototype.filter(handler): Object

Converts a document into serialized data object with only the keys that pass the test.

| Option | Type | Required | Default | Description |--------|------|----------|---------|------------ | handler | Function | Yes | - | A function to test each key value. If the function returns true then the key is included in the returned object.

Document.prototype.flatten(): Array

Converts the document into an array of fields.

Document.prototype.getField(...keys): Field

Returns a class instance of a field at path.

| Option | Type | Required | Default | Description |--------|------|----------|---------|------------ | keys | Array | Yes | - | Path to a field (e.g. ['book', 0, 'title']).

Document.prototype.hasErrors(): Boolean

Returns true when no errors exist (inverse of isValid()). Make sure that you call the validate() method first.

Document.prototype.hasField(...keys): Boolean

Returns true when a field path exists.

| Option | Type | Required | Default | Description |--------|------|----------|---------|------------ | keys | Array | Yes | - | Path to a field (e.g. ['book', 0, 'title']).

Document.prototype.isChanged(): Boolean

Returns true if at least one document field has been changed.

Document.prototype.isNested(): Boolean

Returns true if nested fields exist.

Document.prototype.isValid(): Boolean

Returns true when all document fields are valid (inverse of hasErrors()). Make sure that you call the validate() method first.

Document.prototype.invalidate(): Document

Clears errors on all fields.

Document.prototype.populate(data): Document

Applies data to a document.

| Option | Type | Required | Default | Description |--------|------|----------|---------|------------ | data | Object | Yes | - | Data object.

Document.prototype.reset(): Document

Sets each document field to its default value.

Document.prototype.rollback(): Document

Sets each document field to its initial value (last committed value). This is how you can discharge document changes.

Document.prototype.scroll(handler): Integer

Scrolls through document fields and executes a handler on each field.

| Option | Type | Required | Default | Description |--------|------|----------|---------|------------ | handler | Function | Yes | - | A handler method which is executed for each field.

Document.prototype.serialize(): Object

Converts a document into serialized data object.

Document.prototype.validate({quiet}): Promise(Document)

Validates document fields and throws an error if not all fields are valid unless the quiet is set to true.

| Option | Type | Required | Default | Description |--------|------|----------|---------|------------ | quiet | Boolean | No | false | When set to true, a validation error is thrown.

try {
  await doc.validate(); // throws a validation error when invalid fields exist
}
catch (e) {
  // `e` is a 422 validation error
}

Field

Every document field is an instance of the Field class.

Field({type, get, set, defaultValue, fakeValue, validate}, {owner, validators, failFast})

A document field.

| Option | Type | Required | Default | Description |--------|------|----------|---------|------------ | type | String, Document | No | - | Data type (pass a Document to create a nested structure; check typeable.js for more). | get | Function | No | - | Custom getter. | set | Function | No | - | Custom setter. | defaultValue | Any | No | - | Field default value. | fakeValue | Any | No | - | Field fake value. | validate | Array | No | - | List of validation recipies (check validatable.js for more). | owner | Document | No | - | An instance of a Document which owns the field. | validators | Object | No | - | Custom validators (check validatable.js for more) | failFast | Boolean | No | false | Stops validation on the first error when set to true.

Properties

Field.prototype.defaultValue: Any

A getter which returns the default field value.

Field.prototype.errors: Object[];

List of field errors (sets the validate method).

Field.prototype.fakeValue: Any

A getter which returns a fake field value.

Field.prototype.initialValue: Any

A getter which returns the last commited field value.

Field.prototype.options: Object

A getter which returns field options.

Field.prototype.owner: Document

A getter which returns a reference to a Document instance on which the field is defined.

Field.prototype.recipe: Object

A getter which returns a field recipe object.

Field.prototype.type: Any

A getter which returns field type (set to Document for a nested structure).

Field.prototype.value: Any

Field current value (the actula document's property).

Methods

Field.prototype.clear(): Field

Sets field and related sub fields to null.

Field.prototype.commit(): Field

Sets initial value to the current value. This is how field change tracking is restarted.

Field.prototype.equals(value): Boolean

Returns true when the provided value represents an object that looks the same.

Field.prototype.fake(): Field

Sets field to a generated fake value.

Field.prototype.hasErrors(): Boolean

Returns true when no errors exist (inverse of isValid()). Make sure that you call the validate() method first.

Field.prototype.isChanged(): Boolean

Returns true if the field or at least one sub field have been changed.

Field.prototype.isNested(): Boolean

Returns true if the field is a nested document.

Field.prototype.isValid(): Boolean

Returns true if the field and all sub fields are valid (inverse of hasErrors()). Make sure that you call the validate() method first.

Field.prototype.invalidate(): Field

Clears the errors field on all fields (the reverse of validate()).

Field.prototype.reset(): Field

Sets the field to its default value.

Field.prototype.rollback(): Field

Sets the field to its initial value (last committed value). This is how you can discharge field's changes.

Field.prototype.validate(): Promise(Field)

Validates the value and populates the errors property with errors.

License (MIT)

Copyright (c) 2016 Kristijan Sedlak <[email protected]>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.