I have a complex object of this type:
class Person {
constructor(name, age, country) {
this.name = name;
this.age = age;
this.country = country;
}
setName(name) {
if (name !== null) this.name = name;
}
setAge(age) {
if (age !== null) this.age = age;
}
setCountry(country) {
if (country !== null) this.country = country;
}
getName() {
return this.name;
}
// ...
}
let person = new Person('Paul', 27, 'Haïti'); // needs to save this Object
console.log(person);So I would like to know if anyone has an idea on how I can store this Object so that I can access it the next time I open the browser. localStorage doesn't work.
localStorage does work - you just need to use it properly
I added a toJSON method on the class - this returns an array with the constructor parameter values in the right order
class Person {
constructor(name, age, country) {
this.name = name;
this.age = age;
this.country = country;
}
toJSON() {
return [this.name, this.age, this.country];
}
setName(name) {
if (name !== null) this.name = name;
}
setAge(age) {
if (age !== null) this.age = age;
}
setCountry(country) {
if (country !== null) this.country = country;
}
getName() {
return this.name;
}
}
To save
const person = new Person("John", 23, "Aussie");
localStorage.setItem('test', JSON.stringify(person));
To load
const revivedPerson = new Person(...JSON.parse(localStorage.getItem('test')));
You don't have to make the toJSON method, but it makes for simple code (if you never need to JSON.stringify an instance of Person)
I'd add a static method to the class, that can take a plain object and return an instance of the class in return. You can use Object.create and Object.assign for that.
Demo:
class Person {
constructor(name, age, country) {
this.name = name;
this.age = age;
this.country = country;
}
static from(obj) {
return Object.assign(Object.create(this.prototype), obj);
}
getName() {
return this.name;
}
// ...
}
// Demo
let person = new Person('Paul', 27, 'Haïti');
let serialised = JSON.stringify(person);
// ... write/read serialised to/from localStorage ...
// and then:
let person2 = Person.from(JSON.parse(serialised));
console.log(person2.getName());