Type-R is the modern JS data framework to manage complex domain and UI application state. Features:

• It's mapped to JSON by default. The mapping can handle sophisticated scenarios with nested JSON and relations by id, and can be easily customized for every particular attribute or class.
• All changes are observable, happens in the scope of transactions, and there's the fine-grained change events system.
• Validation is performed on the first access to the validation error and never happens twice for unchanged data.
• Everything is typed at run-time and is protected from improper updates. The shape of generated JSON and data classes is guaranteed to match the definitions.
• It still looks like regular JS classes and is freaking fast. Type-R data structures are about 10 times faster than Backbone models and collections.

Data layer is defined as a superposition of three kinds of building blocks:

• Record classes with typed attributes.
• Ordered collections of records.
• Stores are records with a set of collections in its attributes used to resolve id-references in JSON.
• IOEndpoints is an entity encapsulating I/O transport which represent the persistent collection of records.

Type-R is completely unopinionated on the client-server transport protocol and the view layer technology. It's your perfect M and VM in modern MVVM or MVC architecture.

import { define, Record } from 'type-r' // Define email attribute type with encapsulated validation check. const Email = String.has.check( x => x! || x.indexOf( '@' ) >= 0, 'Invalid email' ); @define class User extends Record { static attributes = { name : String.isRequired, // should not be empty for the record to be valid. email : Email.isRequired } } @define class Message extends Record { static attributes = { created : Date // = new Date() author : User, // aggregated User record. to : User.Collection, // aggregating collection of users subject : '', body : '' } } const msg = new Message(); assert( !msg.isValid() ); // Is not valid because msg.author has empty attributes // Listen for the changes in aggregation tree... msg.on( 'change', () => console.log( 'change!!!' ) ); msg.transaction( () => { // Prepare to make the sequence of changes on msg msg.author.name = 'John Dee'; // No 'change' event yet as we're in the transaction.  msg.author.email = 'dee@void.com'; assert( msg.isValid() ); // Now msg is valid as all of its attributes are valid. }); // Got single 'change!!!' message in the console.

Is packed as UMD and ES6 module. No peer dependencies are required.

npm install type-r --save-dev