Scalable Cloud Apps That Won't Keep You Up At

Night

Aaron Douglas @astralbodies Twitter/ADN

Red Arrow Labs - Milwaukee, WI

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So you have an app (or an idea)

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You want people to download and use it.

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Most apps need to integrate with

something.

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Because integration (collaboration) is

interesting

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Interesting apps = MOAR MONEY

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Why should I use the “Cloud”?

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Scalability & Infrastructure

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Cross Platform

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Our App Idea

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• Conference App

• Speakers

• Sessions

• Map

• Comments & Notes

• Photos

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• Still a hot mess with Core Data

• iOS and Mac only

• Hard to debug

Why not iCloud?

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Options

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We’re Going to Use Parse

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What Parse Provides

• Data storage - RESTful API & Native SDKs

• Queries

• ACLs / Users

• Cloud Code & Push Notifications

• File Storage

• In-App Purchases

• GeoPoints & Spatial Queries

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$ vi Podfilepod 'Parse'

$ pod install

Add To Your Project

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AppDelegate.m

#import <Parse/Parse.h>

...

[Parse setApplicationId:@"3lZSGBNTs03wQigx2apDHwUv6ZczMVaIib8nUz" clientKey:@"rstZrElVxBiB5tzsWn10QK9AfrRR0GkQQj16Hj"];

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Objects

• Session

• Schedule

• Speaker

• Attendee Notes

• Attendee Schedule

• ... and on and on

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PFObject

• Key-Value pairs

• Schema-less

• JSON data types: NSString, NSNumber, NSDate, NSData, NSArray, NSDictionary

• Associations - 1:1, 1:N, N:N

• objectId, updatedAt, createdAt

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PFObject

PFObject *speaker = [PFObject objectWithClassName:@"Speaker"]; [speaker setObject:@"Marty" forKey:@"firstName"]; [speaker setObject:@"McFly" forKey:@"lastName"]; [speaker setObject:@"Hill Valley, CA" forKey:@"location"]; NSLog(@"Object ID before save: %@", speaker.objectId); [speaker save]; // MAGIC HAPPENS HERE NSLog(@"Object ID after save: %@", speaker.objectId);

2013-03-03 16:19:08.923 CocoaConfParse[4803:c07] Object ID before save: (null)2013-03-03 16:19:09.468 CocoaConfParse[4803:c07] Object ID after save: 6iXsTrvWd0

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Back on Parse.com...

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Refresh

[speaker refresh];

[speaker refresh:&error];

[speaker refreshInBackgroundWithBlock:^(PFObject *object, NSError *error) { // Code}];

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Removing Data

[speaker removeObjectForKey:@"favoriteStarWarsCharacter"]; [speaker deleteInBackground];

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Relationships

PFObject *session = [PFObject objectWithoutDataWithClassName:@"Session" objectId:@"6iXsTrvWd0"];

[sessionComment setObject:session forKey:@"session"];

PFObject *session = [sessionComment objectForKey:@"session"];

[session fetchIfNeededInBackgroundWithBlock:^(PFObject *object, NSError *error) { NSString *title = [post objectForKey:@"title"];}];

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Query by ID

PFQuery *query = [PFQuery queryWithClassName:@"Speaker"]; PFObject *object = [query getObjectWithId:@"jFgtbb2aCb"]; NSLog(@"Name: %@ %@", object[@"firstName"], object[@"lastName"]);

2013-03-03 17:08:52.484 CocoaConfParse[6892:c07] Name: Marty McFly

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Querying PFQuery *query = [PFQuery queryWithClassName:@"Speaker"]; [query whereKey:@"lastName" equalTo:@"McFly"]; query.cachePolicy = kPFCachePolicyNetworkElseCache; PFObject *object = [query getFirstObject]; NSLog(@"Name: %@ %@", object[@"firstName"], object[@"lastName"]);

2013-03-03 17:08:52.484 CocoaConfParse[6892:c07] Name: Marty McFly

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Queries

• NSPredicate

• 1000 records max (100 default)

• Relational queries

• Cache policies

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Asynchronous

PFObject *speaker = ...;

[speaker save]; [speaker saveEventually]; [speaker saveInBackground];

[speaker saveInBackgroundWithBlock: ^(BOOL succeeded, NSError *error){}];

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Users[PFUser enableAutomaticUser]; PFUser *currentUser = [PFUser currentUser];[currentUser setObject:[NSDate date] forKey:@"lastLaunched"];[currentUser saveInBackground];

PFUser *user = [PFUser user];user.username = @"martymcfly";user.password = @"awesomesauce";[user signUpInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {

}]; [PFUser logInWithUsernameInBackground:@"martymcfly" password:@"awesomesauce" block:^(PFUser *user, NSError *error) {

}];

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ACLs

PFObject *feedback = [PFObject objectWithClassName:@"SessionFeedback"]; [feedback setObject:@"I enjoyed it." forKey:@"comment"];

feedback.ACL = [PFACL ACLWithUser:[PFUser currentUser]];

[feedback saveInBackground];

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Built-In Views

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App Structure

• Where does Parse start & end?

• Service Layers

• Parse everywhere

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Data Transfer Objects

• Map PFObject to some object in your code

• Parse is contract/schema-free

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Push Notifications

• Still requires APN setup

• Simplifies addressing & registration

• Cross platform (Android & iOS)

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- (void)application:(UIApplication *)applicationdidRegisterForRemoteNotificationsWithDeviceToken:(NSData *)deviceToken{ // Store the deviceToken in the current // Installation and save it to Parse. PFInstallation *currentInstallation = [PFInstallation currentInstallation];

[currentInstallation setDeviceTokenFromData:deviceToken]; [currentInstallation saveInBackground];}

Push Registration

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Channels

PFInstallation *currentInstallation = [PFInstallation currentInstallation]; [currentInstallation addUniqueObject:@"Speakers" forKey:@"channels"]; [currentInstallation saveInBackground];

PFPush *push = [[PFPush alloc] init]; [push setChannel:@"Speakers"]; [push setMessage:@"Thanks for all the fish!"]; [push sendPushInBackground];

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In-App Purchases

• Wraps StoreKit

• Receipt verification

• Asset download

• PFProductTableViewController

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What about server-side calls?

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• Create new speakers & sessions

• Attendees register preferences

• Push notifications when session changes

• Welcome emails

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Cloud Code lets you deploy server-side code

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Cloud Code

• RESTful API

• JavaScript Language

• Triggers & Validation

• Modules

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$ curl -s https://www.parse.com/downloads/cloud_code/installer.sh | sudo /bin/bash

$ parse new CocoaConfCloudCodeEmail: astralbodies@gmail.comPassword:1:CocoaConfSelect an App:1

$ cd CocoaConfCloudCode

Installing the CL Tool

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Parse.Cloud.define("numberOfSpeakers", function(request, response) {  var query = new Parse.Query("Speaker");  query.find({    success: function(results) {      response.success(results.count);    },    error: function() {      response.error("Speaker lookup failed");    }  });});

$ vi cloud/sessions.js

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$ parse deploy$ curl -X POST \  -H "X-Parse-Application-Id: MN28ox..." \  -H "X-Parse-REST-API-Key: RItKo..." \  -H "Content-Type: application/json" \  -d '{}' \  https://api.parse.com/1/functions/numberOfSpeakers

{  "result": 1}

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Modules

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Cloud Code

• Still in its infancy

• No scheduled events

• Take a look at iron.io

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Cost

• Free (1 million API requests / Pushes / 1GB)

• $199/month (15mil / 5mil / 10GB)

• Enterprise >$199

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Portability

• Import

• Export

• Service layer to abstract

• Never really want to lock into a technology

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Code

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Questions?

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