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I am currently trying to convert my received JSON Object into a TypeScript class with the same attributes and I cannot get it to work. What am I doing wrong?
Employee Class
export class Employee{ firstname: string; lastname: string; birthdate: Date; maxWorkHours: number; department: string; permissions: string; typeOfEmployee: string; note: string; lastUpdate: Date; } Employee String
{ "department": "<anystring>", "typeOfEmployee": "<anystring>", "firstname": "<anystring>", "lastname": "<anystring>", "birthdate": "<anydate>", "maxWorkHours": <anynumber>, "username": "<anystring>", "permissions": "<anystring>", "lastUpdate": "<anydate>" //I will add note later } My Attempt
let e: Employee = new Employee(); Object.assign(e, { "department": "<anystring>", "typeOfEmployee": "<anystring>", "firstname": "<anystring>", "lastname": "<anystring>", "birthdate": "<anydate>", "maxWorkHours": 3, "username": "<anystring>", "permissions": "<anystring>", "lastUpdate": "<anydate>" }); console.log(e); Link to Typescript Playground
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const value = pick(JSON. parse('{"name": "Bob", "error": false}'), { name: String, error: Boolean, }); Now value will be typed, since String and Boolean are both "transformers" in the sense they take input and return a typed output. Furthermore, the value will actually be that type.
To parse a JSON object to a TypeScript object, we use the JSON. parse method. interface Employee { departmentId: number; permissionsId: number; maxWorkHours: number; employeeId: number; firstName: string; lastName: string; } const jsonObj: any = JSON.
You will just have to construct your Typescript object passing the json data in the constructor. In your ajax callback, you receive a company: onReceiveCompany( jsonCompany : any ) { let newCompany = new Company( jsonCompany ); // call the methods on your newCompany object ... }
We can create a JSON object in TYPESCRIPT dynamically. There are two types of objects in TypeScript. A Plain Object that we achieve with json. parse() which results in the plain object, and the TypeScript Class, which returns the Class Object.
If you use a TypeScript interface instead of a class, things are simpler:
export interface Employee { typeOfEmployee_id: number; department_id: number; permissions_id: number; maxWorkHours: number; employee_id: number; firstname: string; lastname: string; username: string; birthdate: Date; lastUpdate: Date; } let jsonObj: any = JSON.parse(employeeString); // string to generic object first let employee: Employee = <Employee>jsonObj; If you want a class, however, simple casting won't work. For example:
class Foo { name: string; public pump() { } } let jsonObj: any = JSON.parse('{ "name":"hello" }'); let fObj: Foo = <Foo>jsonObj; fObj.pump(); // crash, method is undefined! For a class, you'll have to write a constructor which accepts a JSON string/object and then iterate through the properties to assign each member manually, like this:
class Foo { name: string; constructor(jsonStr: string) { let jsonObj: any = JSON.parse(jsonStr); for (let prop in jsonObj) { this[prop] = jsonObj[prop]; } } } let fObj: Foo = new Foo(theJsonString); If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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