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Validating JSON data and Introspecting a Model

Concerto provides a JSON serialization for instances of a model, and APIs to validate JSON data against a model.

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const { ModelManager, Concerto } = require('@accordproject/concerto-core');

try {
// create the model manager, used to manage a consistent set of
// related models
const mm = new ModelManager();

// add a CTO file (as a string) to the model manager
mm.addModel(`namespace test@1.0.0

abstract concept Person
o String firstName
o String lastName

concept Driver extends Person {
o String favoriteColor

concept Car identified by vin
o String vin
o Person owner

// create the Concerto instance to validate data
// against the model and to introspect the model
// the Concerto instance is bound to a model manager
const concerto = new Concerto(mm);

// define some sample data, consistent with the model
const data = {
$class: "test@1.0.0.Car",
vin: "abc123",
owner: {
$class: "test@1.0.0.Driver",
firstName: "John",
lastName: "Doe",
favoriteColor: "Blue"

// validate the data
console.log('Valid data!')

// get the type declaration for the data
const typeDeclaration = concerto.getTypeDeclaration(data);

// get the fully-qualified name for the type declaration
const fqn = typeDeclaration.getFullyQualifiedName();
// iterate over each of the properties of the type declaration
typeDeclaration.getProperties().forEach(p => console.log(`- ${p.getName()} : ${p.getFullyQualifiedTypeName()}`));
catch (err) {

These APIs allow you to examine the declared properties, super types and meta-properies for a modelled type.