/**
* Class to handle user data access with localStorage.
* Provides methods for retrieving, adding, updating, and deleting user data.
*/
class UserDataAccess {
///////////////////////////////////////////////
// PRIVATE INSTANCE VARIABLES (start with #)
///////////////////////////////////////////////
/**
* Dummy data to populate the localStorage database.
* @type {Array<{id: number, firstName: string, lastName: string, email: string}>}
*/
#dummyData = [
{id: 1, firstName: "Jane", lastName: "Doe", email: "jdoe@acme.com"},
{id: 2, firstName: "Tony", lastName: "Thompsom", email: "tony@acme.com"},
{id: 3, firstName: "Jesse", lastName: "Jones", email: "jesse@acme.com"},
{id: 4, firstName: "Bob", lastName: "Doe", email: "jdoe@acme.com"},
{id: 5, firstName: "ToM", lastName: "Thompsom", email: "tony@acme.com"},
{id: 6, firstName: "Susie", lastName: "Jones", email: "jesse@acme.com"}
];
////////////////////////////////////
// CONSTRUCTOR
////////////////////////////////////
/**
* Initializes the UserDataAccess instance. Checks if the "userData" key exists in localStorage,
* if not, initializes it with the dummy data.
*/
constructor() {
if (!localStorage.getItem("userData")) {
localStorage.setItem("userData", JSON.stringify(this.#dummyData));
}
}
////////////////////////////////////
// PUBLIC METHODS
////////////////////////////////////
/**
* Retrieves all users from localStorage.
* @returns {Array<{id: number, firstName: string, lastName: string, email: string}>} List of users.
*/
getAllUsers() {
const str = localStorage.getItem("userData");
const users = JSON.parse(str);
return users;
}
/**
* Retrieves a user by their ID from localStorage.
* @param {number} id - The ID of the user to retrieve.
* @returns {Object|null} The user object if found, else null.
*/
getUserById(id) {
const str = localStorage.getItem("userData");
const users = JSON.parse(str);
const user = users.find((u) => u.id == id);
return user || null;
}
/**
* Inserts a new user into the localStorage database.
* @param {Object} newUser - The user object to insert.
* @param {number} newUser.id - The user's ID (automatically assigned).
* @param {string} newUser.firstName - The user's first name.
* @param {string} newUser.lastName - The user's last name.
* @param {string} newUser.email - The user's email address.
*/
insertUser(newUser) {
newUser.id = this.#getMaxId() + 1;
const str = localStorage.getItem("userData");
const users = JSON.parse(str);
users.push(newUser);
localStorage.setItem("userData", JSON.stringify(users));
}
/**
* Updates an existing user in the localStorage database.
* @param {Object} updatedUser - The user object to update.
* @param {number} updatedUser.id - The ID of the user to update.
* @param {string} updatedUser.firstName - The updated first name.
* @param {string} updatedUser.lastName - The updated last name.
* @param {string} updatedUser.email - The updated email.
*/
updateUser(updatedUser) {
const str = localStorage.getItem("userData");
const users = JSON.parse(str);
const indexOfUserToUpdate = users.findIndex(user => updatedUser.id == user.id);
users[indexOfUserToUpdate] = updatedUser;
localStorage.setItem("userData", JSON.stringify(users));
}
/**
* Deletes a user from the localStorage database by their ID.
* @param {number} id - The ID of the user to delete.
*/
deleteUser(id) {
const str = localStorage.getItem("userData");
const users = JSON.parse(str);
const indexOfUserToDelete = users.findIndex(u => u.id == id);
users.splice(indexOfUserToDelete, 1);
localStorage.setItem("userData", JSON.stringify(users));
}
////////////////////////////////////
// PRIVATE METHODS (start with #)
////////////////////////////////////
/**
* Private method to find the maximum user ID in the localStorage database.
* @returns {number} The highest user ID currently stored.
*/
#getMaxId() {
const str = localStorage.getItem("userData");
const users = JSON.parse(str);
let maxId = 0;
for (let i = 0; i < users.length; i++) {
if (users[i].id > maxId) {
maxId = users[i].id;
}
}
return maxId;
}
}