class Contact {
constructor(name, email) {
this.name = name;
this.email = email;
}
}
class ContactManager {
constructor() {
// when we build the contact manager, it
// has an empty list of contacts
this.listOfContacts = [];
}
// Will erase all contacts
empty() {
this.listOfContacts = [];
}
add(contact) {
this.listOfContacts.push(contact);
}
remove(contact) {
for(let i = 0; i < this.listOfContacts.length; i++) {
var c = this.listOfContacts[i];
if(c.email === contact.email) {
// remove the contact at index i
this.listOfContacts.splice(i, i);
// stop/exit the loop
break;
}
}
}
sort() {
// As our array contains objects, we need to pass as argument
// a method that can compare two contacts.
// we use for that a class method, similar to the distance(p1, p2)
// method we saw in the ES6 Point class in module 4
// We always call such methods using the name of the class followed
// by the dot operator
this.listOfContacts.sort(ContactManager.compareByName);
}
// class method for comparing two contacts by name
static compareByName(c1, c2) {
// JavaScript has builtin capabilities for comparing strings
// in alphabetical order
if (c1.name < c2.name)
return -1;
if (c1.name > c2.name)
return 1;
return 0;
}
printContactsToConsole() {
if(this.listOfContacts.length === 0) {
console.log("EMPTY LIST!");
return;
}
this.listOfContacts.forEach(function(c) {
console.log(c.name);
});
}
load() {
if(localStorage.contacts !== undefined) {
// the array of contacts is saved in JSON, let's convert
// it back to a reak JavaScript object.
this.listOfContacts = JSON.parse(localStorage.contacts);
}
}
save() {
// We can only save strings in local Storage. So, let's convert
// ou array of contacts to JSON
localStorage.contacts = JSON.stringify(this.listOfContacts);
}
}
var cm = new ContactManager();
var c1 = new Contact("Jimi Hendrix", "jimi@rip.com");
var c2 = new Contact("Robert Fripp", "robert.fripp@kingcrimson.com");
var c3 = new Contact("Angus Young", "angus@acdc.com");
var c4 = new Contact("Arnold Schwarzenneger", "T2@terminator.com");
console.log("--- Adding 4 contacts ---")
cm.add(c1);
cm.add(c2);
cm.add(c3);
cm.add(c4);
cm.printContactsToConsole();
// trying to remove c2
console.log("--- Removing the second one! ---");
cm.remove(c2);
cm.printContactsToConsole();
console.log("--- Sorting contacts ---");
cm.sort();
cm.printContactsToConsole();
console.log("--- Saving contacts to local storage ---");
cm.save();
console.log("--- Emptying the list of contacts ---");
cm.empty();
cm.printContactsToConsole();
console.log("--- Loading contacts from local storage ---");
cm.load();
cm.printContactsToConsole();
console.log("Do you notice: contacts have all been restored!");
JS.Classes.Objects.Contact manager version 2 with load/save to LocalStorage
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