Our next step is about adding the ability to create new chats. We have the ChatsPage
and the authentication system, but we need to hook them up some how. Let's define the initial User
schema which will be used to retrieve its relevant information in our application:
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type?: MessageType
ownership?: string;
}
export interface User extends Meteor.User {
profile?: Profile;
}
Meteor
comes with a built-in users collection, defined as Meteor.users
, but since we're using Observables
vastly, we will wrap our collection with one:
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import { MongoObservable } from 'meteor-rxjs';
import { Meteor } from 'meteor/meteor';
import { User } from '../models';
export const Users = MongoObservable.fromExisting<User>(Meteor.users);
For accessibility, we're gonna export the collection from the index
file as well:
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export * from './chats';
export * from './messages';
export * from './users';
We will be using Ionic
's modal dialog to show the chat creation view. The first thing we're gonna do would be implementing the component itself, along with its view and stylesheet:
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import { Component, OnInit } from '@angular/core';
import { Chats, Users } from 'api/collections';
import { User } from 'api/models';
import { AlertController, ViewController } from 'ionic-angular';
import { MeteorObservable } from 'meteor-rxjs';
import { _ } from 'meteor/underscore';
import { Observable, Subscription } from 'rxjs';
@Component({
selector: 'new-chat',
templateUrl: 'new-chat.html'
})
export class NewChatComponent implements OnInit {
senderId: string;
users: Observable<User[]>;
usersSubscription: Subscription;
constructor(
private alertCtrl: AlertController,
private viewCtrl: ViewController
) {
this.senderId = Meteor.userId();
}
ngOnInit() {
this.loadUsers();
}
addChat(user): void {
MeteorObservable.call('addChat', user._id).subscribe({
next: () => {
this.viewCtrl.dismiss();
},
error: (e: Error) => {
this.viewCtrl.dismiss().then(() => {
this.handleError(e);
});
}
});
}
loadUsers(): void {
this.users = this.findUsers();
}
findUsers(): Observable<User[]> {
// Find all belonging chats
return Chats.find({
memberIds: this.senderId
}, {
fields: {
memberIds: 1
}
})
// Invoke merge-map with an empty array in case no chat found
.startWith([])
.mergeMap((chats) => {
// Get all userIDs who we're chatting with
const receiverIds = _.chain(chats)
.pluck('memberIds')
.flatten()
.concat(this.senderId)
.value();
// Find all users which are not in belonging chats
return Users.find({
_id: { $nin: receiverIds }
})
// Invoke map with an empty array in case no user found
.startWith([]);
});
}
handleError(e: Error): void {
console.error(e);
const alert = this.alertCtrl.create({
buttons: ['OK'],
message: e.message,
title: 'Oops!'
});
alert.present();
}
}
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<ion-header>
<ion-toolbar color="whatsapp">
<ion-title>New Chat</ion-title>
<ion-buttons left>
<button ion-button class="dismiss-button" (click)="viewCtrl.dismiss()"><ion-icon name="close"></ion-icon></button>
</ion-buttons>
<ion-buttons end>
<button ion-button class="search-button"><ion-icon name="search"></ion-icon></button>
</ion-buttons>
</ion-toolbar>
</ion-header>
<ion-content class="new-chat">
<ion-list class="users">
<button ion-item *ngFor="let user of users | async" class="user" (click)="addChat(user)">
<img class="user-picture" [src]="user.profile.picture">
<h2 class="user-name">{{user.profile.name}}</h2>
</button>
</ion-list>
</ion-content>
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.new-chat {
.user-picture {
border-radius: 50%;
width: 50px;
float: left;
}
.user-name {
margin-left: 20px;
margin-top: 25px;
transform: translate(0, -50%);
float: left;
}
}
The dialog should contain a list of all the users whose chat does not exist yet. Once we click on one of these users we should be demoted to the chats view with the new chat we've just created.
The dialog should be revealed whenever we click on one of the options in the options pop-over, therefore, we will implement the necessary handler:
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import { Component, OnInit } from '@angular/core';
import { Chats, Messages } from 'api/collections';
import { Chat } from 'api/models';
import { NavController, PopoverController, ModalController } from 'ionic-angular';
import { Observable } from 'rxjs';
import { MessagesPage } from '../messages/messages';
import { ChatsOptionsComponent } from './chats-options';
import { NewChatComponent } from './new-chat';
@Component({
templateUrl: 'chats.html'
...some lines skipped...
constructor(
private navCtrl: NavController,
private popoverCtrl: PopoverController,
private modalCtrl: ModalController) {
}
addChat(): void {
const modal = this.modalCtrl.create(NewChatComponent);
modal.present();
}
ngOnInit() {
...some lines skipped...
).zone();
}
showMessages(chat): void {
this.navCtrl.push(MessagesPage, {chat});
}
And bind it to the click
event:
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Chats
</ion-title>
<ion-buttons end>
<button ion-button icon-only class="add-chat-button" (click)="addChat()">
<ion-icon name="person-add"></ion-icon>
</button>
<button ion-button icon-only class="options-button" (click)="showOptions()">
We will import the newly created component in the app's NgModule
as well, so it can be recognized properly:
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import { MomentModule } from 'angular2-moment';
import { IonicApp, IonicModule, IonicErrorHandler } from 'ionic-angular';
import { ChatsPage } from '../pages/chats/chats';
import { NewChatComponent } from '../pages/chats/new-chat';
import { ChatsOptionsComponent } from '../pages/chats/chats-options';
import { LoginPage } from '../pages/login/login';
import { MessagesPage } from '../pages/messages/messages';
...some lines skipped...
LoginPage,
VerificationPage,
ProfilePage,
ChatsOptionsComponent,
NewChatComponent
],
imports: [
IonicModule.forRoot(MyApp),
...some lines skipped...
LoginPage,
VerificationPage,
ProfilePage,
ChatsOptionsComponent,
NewChatComponent
],
providers: [
{provide: ErrorHandler, useClass: IonicErrorHandler},
We're also required to implement the appropriate Meteor
method which will be the actually handler for feeding our data-base with newly created chats:
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});
Meteor.methods({
addChat(receiverId: string): void {
if (!this.userId) {
throw new Meteor.Error('unauthorized',
'User must be logged-in to create a new chat');
}
check(receiverId, nonEmptyString);
if (receiverId === this.userId) {
throw new Meteor.Error('illegal-receiver',
'Receiver must be different than the current logged in user');
}
const chatExists = !!Chats.collection.find({
memberIds: { $all: [this.userId, receiverId] }
}).count();
if (chatExists) {
throw new Meteor.Error('chat-exists',
'Chat already exists');
}
const chat = {
memberIds: [this.userId, receiverId]
};
Chats.insert(chat);
},
updateProfile(profile: Profile): void {
if (!this.userId) throw new Meteor.Error('unauthorized',
'User must be logged-in to create a new chat');
As you can see, a chat is inserted with an additional memberIds
field. Whenever we have such a change we should update the model's schema accordingly, in this case we're talking about adding the memberIds
field, like so:
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title?: string;
picture?: string;
lastMessage?: Message;
memberIds?: string[];
}
export interface Message {
Thanks to our new-chat dialog, we can create chats dynamically with no need in initial fabrication. Let's replace the chats fabrication with users fabrication in the Meteor server:
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import * as moment from 'moment';
import { MessageType } from './models';
import { Accounts } from 'meteor/accounts-base';
import { Users } from './collections/users';
Meteor.startup(() => {
if (Meteor.settings) {
...some lines skipped...
SMS.twilio = Meteor.settings['twilio'];
}
if (Users.collection.find().count() > 0) {
return;
}
Accounts.createUserWithPhone({
phone: '+972540000001',
profile: {
name: 'Ethan Gonzalez',
picture: 'https://randomuser.me/api/portraits/men/1.jpg'
}
});
Accounts.createUserWithPhone({
phone: '+972540000002',
profile: {
name: 'Bryan Wallace',
picture: 'https://randomuser.me/api/portraits/lego/1.jpg'
}
});
Accounts.createUserWithPhone({
phone: '+972540000003',
profile: {
name: 'Avery Stewart',
picture: 'https://randomuser.me/api/portraits/women/1.jpg'
}
});
Accounts.createUserWithPhone({
phone: '+972540000004',
profile: {
name: 'Katie Peterson',
picture: 'https://randomuser.me/api/portraits/women/2.jpg'
}
});
Accounts.createUserWithPhone({
phone: '+972540000005',
profile: {
name: 'Ray Edwards',
picture: 'https://randomuser.me/api/portraits/men/2.jpg'
}
});
});
Since we've changed the data fabrication method, the chat's title and picture are not hard-coded anymore, therefore, any additional data should be fetched in the components themselves:
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import { Component, OnInit } from '@angular/core';
import { Chats, Messages, Users } from 'api/collections';
import { Chat, Message } from 'api/models';
import { NavController, PopoverController, ModalController } from 'ionic-angular';
import { MeteorObservable } from 'meteor-rxjs';
import { Observable, Subscriber } from 'rxjs';
import { MessagesPage } from '../messages/messages';
import { ChatsOptionsComponent } from './chats-options';
import { NewChatComponent } from './new-chat';
...some lines skipped...
})
export class ChatsPage implements OnInit {
chats;
senderId: string;
constructor(
private navCtrl: NavController,
private popoverCtrl: PopoverController,
private modalCtrl: ModalController) {
this.senderId = Meteor.userId();
}
addChat(): void {
...some lines skipped...
}
ngOnInit() {
this.chats = this.findChats();
}
findChats(): Observable<Chat[]> {
// Find chats and transform them
return Chats.find().map(chats => {
chats.forEach(chat => {
chat.title = '';
chat.picture = '';
const receiverId = chat.memberIds.find(memberId => memberId !== this.senderId);
const receiver = Users.findOne(receiverId);
if (receiver) {
chat.title = receiver.profile.name;
chat.picture = receiver.profile.picture;
}
// This will make the last message reactive
this.findLastChatMessage(chat._id).subscribe((message) => {
chat.lastMessage = message;
});
});
return chats;
});
}
findLastChatMessage(chatId: string): Observable<Message> {
return Observable.create((observer: Subscriber<Message>) => {
const chatExists = () => !!Chats.findOne(chatId);
// Re-compute until chat is removed
MeteorObservable.autorun().takeWhile(chatExists).subscribe(() => {
Messages.find({ chatId }, {
sort: { createdAt: -1 }
}).subscribe({
next: (messages) => {
// Invoke subscription with the last message found
if (!messages.length) {
return;
}
const lastMessage = messages[0];
observer.next(lastMessage);
},
error: (e) => {
observer.error(e);
},
complete: () => {
observer.complete();
}
});
});
});
}
showMessages(chat): void {
this.navCtrl.push(MessagesPage, {chat});
Now we want our changes to take effect. We will reset the database so next time we run our Meteor
server the users will be fabricated. To reset the database, first make sure the Meteor
server is stopped , and then type the following command:
api$ meteor reset
Now, as soon as you start the server, new users should be fabricated and inserted into the database:
$ npm run api