Welcome to this course on Networking and Security in iOS Applications. Our focus in this course is very practitioner oriented. We want to get you up and running using social networking integration with single sign-on, basic OAuth2 functionality, secure JSON web APIs, cryptographically secured push notifications, and secure data storage so that you can get apps into the iTunes ecosystem and out into the marketplace. This course will have several code sessions in which we walk you through the process of building apps, some of which you will also build for peer review assignments. Interspersed with the tutorials we will take time-outs to cover the basics of some concepts that might be mysterious without a more formal treatment. Our hope is that you come out of this course knowing more (of course!) and having several projects that you can refer to in the future when you want to incorporate these techniques into your apps - your personal app toolbox. The intensity picks up from the previous course in this Specialization, so get ready!

Now it's time to consider what we are going to do if we want to work with web services that aren't deeply integrated into iOS. There are hundreds (thousands?!?!) of them. Most of them require authentication via the OAuth 2.0 protocol. In this week's lessons we will walk through an example of getting a photo from Instagram on behalf of a user. This week is also a code tutorial in preparation for your peer review assignment, but in the middle we need to step back from coding to cover some basics: How do we use a UIImageView? What is OAuth 2.0 anyway? What is JSON and how do we read it? What's the big deal about http vs https anyway?

In this week we will look at several aspects of push notifications. Those are those alerts that show up at the top of your iOS interface when an app wants to get your attention. There are several ways that they can be initiated. They can be initiated from an app on a local device, or they can be initiated by a remote server somewhere on the internet. Obtaining permission to post those notifications requires lots of steps, certificates, passwords etc. We'll walk you through it all. This week we start with a high-level overview of the iOS app lifecycle. Then we will do three code tutorials. The first will be the one that you will need to do the peer-review assessment. It's a basic countdown timer that sends a notification at a specific time. The second will show you how to make it all fancy with custom actions. The final one will be for remote notifications. Since remote notifications require an Apple developer account ($$$) we won't assess you on it, but if you have one you can try it out on your own and add it to your personal app toolbox.