encode-and-decode.mdx

name	Encode and Decode JSON Objects
route	/encode-and-decode

Behind the scenes

The Sdkgen uses 2 functions to parse JSON objects received through the API calls into Custom Types defined in .sdkgen files. Those functions are encode and decode

Decode

Signature:

decode(typeTable: TypeTable, path: string, type: TypeDescription, value: any)

• TypeTable: generated table containing all Custom Types in the API.
• path: a context for error messages. If the attribute validation fails there will be a message like Invalid type at path.attr
• type: name of the Custom Type you want to parse the JSON
• value: the JSON to be convertible

Example:

// Suppose there is a Custom Type named User
import { api } from "./generated/api";
const obj = {first_name: "Doug", last_name: "Dog", birthDate: "1998-05-31"};
const user = decode(api.astJson.typeTable, "user", "User", obj);
user.birthDate // Date object on 1998 May 31

Encode

Signature

encode(typeTable: TypeTable, path: string, type: TypeDescription, value: any): any

• TypeTable: generated table containing all Custom Types in the API.
• path: a context for error messages. If the attribute validation fails there will be a message like Invalid type at path.attr
• type: name of the Custom Type you want to parse the JSON
• value: your Custom Type that should be converted to JSON

// Suppose there is a Custom Type named User
import { api } from "./generated/api";

api.fn.processUser = async (ctx, { user }) => {
    const obj = encode(api.astJson.typeTable, "user", "User", user);
    obj // JSON object
};