/**
* A class that handles user data operations in the localStorage database.
*/
class UserDataAccess {
///////////////////////////////////////////////
// PRIVATE INSTANCE VARIABLES (start with #)
///////////////////////////////////////////////
/**
* Dummy data used to populate localStorage if no user data is found.
* @private
* @type {Array<Object>}
*/
#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"}
];
////////////////////////////////////
// CONSTRUCTOR
////////////////////////////////////
/**
* Initializes the UserDataAccess instance.
* Checks if 'userData' is already 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 the localStorage.
* @returns {Array<Object>} List of all users in localStorage.
*/
getAllUsers(){
const str = localStorage.getItem("userData");
const users = JSON.parse(str);
return users;
}
/**
* Retrieves a user by their unique ID.
* @param {number} id - The ID of the user to retrieve.
* @returns {Object|null} The user object if found, or null if not found.
*/
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 ID of the new user.
* @param {string} newUser.firstName - The first name of the new user.
* @param {string} newUser.lastName - The last name of the new user.
* @param {string} newUser.email - The email address of the new user.
*/
insertUser(newUser){
// We really should validate newUser before inserting it!
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's data in the localStorage database.
* @param {Object} updatedUser - The user object with updated data.
* @param {number} updatedUser.id - The ID of the user to update.
* @param {string} updatedUser.firstName - The updated first name of the user.
* @param {string} updatedUser.lastName - The updated last name of the user.
* @param {string} updatedUser.email - The updated email address of the user.
*/
updateUser(updatedUser){
// We should validate updatedUser before putting it in the database
const str = localStorage.getItem("userData");
const users = JSON.parse(str);
const indexOfUserToUpdate = users.findIndex(u => updatedUser.id == u.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 indexOfUserToRemove = users.findIndex(u => id == u.id);
users.splice(indexOfUserToRemove,1);
localStorage.setItem("userData", JSON.stringify(users));
}
////////////////////////////////////
// PRIVATE METHODS (start with #)
////////////////////////////////////
/**
* Retrieves the highest user ID from the localStorage database.
* @private
* @returns {number} The highest user ID in the localStorage.
*/
#getMaxId(){
const str = localStorage.getItem("userData");
const users = JSON.parse(str);
let maxId = 0;
for(let x = 0; x < users.length; x++){
if(users[x].id > maxId){
maxId = users[x].id;
}
}
return maxId;
}
}