Object Definition

The standard library for schema and type definition in Meta-System.

Features

This library contains the typescript type definition and two functions to both validate if your type definition is properly declared, and if a given object adheres to such object definition.

For information on how to define such objects, go to the Meta-System Documentation.

API Reference

Object Definition Type

You should use this type in your application if you use Typescript and you are writing the definitions by hand in your code. To do so, just import ObjectDefinition from the index file of the library.

isObjectDefinition : Function

This function validates the object definition to see if it has the correct interface. If the definition is badly formatted, the function throws.

const goodDefinition = {/*definition here*/};
const badDefinition = {/*definition here*/};

isObjectDefinition(goodDefinition); // OK
isObjectDefinition(badDefinition); // THROWS

validateObject : Function

The validateObject function checks whether a given object adheres to another given ObjectDefinition. The function returns an object with a property errors, which is an array contaning data about errors found during validation. It is empty if the object is properly delcared.

const objectTypeDefinition = {
  name: { type: "string" },
  age: { type: "number" },
  hobbies: { type: "array", subtype: "string" }
};

const goodObject = {
  name: "John Doe",
  age: 33,
  hobbies: [ "piano", "swimming" ];
};

const badObject = {
  name: "Mary Ferry",
  age: 27,
  hobbies: [ "bowling", false ]
};

console.log(validateObject(goodObject, objectTypeDefinition))
  // { errors: [] }

console.log(validateObject(badObject, objectTypeDefinition))
  // { errors: [{ path: 'hobbies.1', error: 'Array subtype not respected: string' }] }