Adding Animated Effects to iOS App Using UIKit Dynamics

In the recent tutorials, it has been underlined that iOS 7 has brought along great new features. Many new frameworks, libraries and APIs have been exposed to developers, letting them create modern and engaging applications and attract more users. One of them is the UIKit Dynamics library, integrated right into the UIKit framework, allowing the implementation of real physics in the most simple manner ever possible.

UIKit Dynamics is a brand new library shipped in iOS 7, and to those who haven’t used it or ever read about it, it might sounds hard to work with. However, the truth is totally different, and through this tutorial I’ll make an effort to present how easy it has been done to add realism to an app without having deep knowledge of physics, math and of course libraries or frameworks like Core Animation. People who have already worked with such technologies, they’ll find UIKit Dynamics a really handy tool, as it takes away all the hassle and effort that was just described.

uikit dynamics featured

Before we proceed in the details of the tutorial, let’s get to know some necessary stuff of the UIKit Dynamics, and let’s meet some of its most important classes that always play significant role when implementing it. So, let me start by saying that by being the UIKit Dynamics part of the UIKit framework, there’s no need to add any extra framework in order to use it. It’s always there, ready to be used at any time when the UIKit is imported into a project. It can be applied to any UIView object, or a subclass of it (such as UIButton or UILabel). The heart of this library is the UIDynamicAnimator class, and behind it there is hidden a physics engine, implemented and built right into the UIKit framework. It is responsible for producing the animation that will attach all the desired realistic effects to an app. However, even though the UIDynamicAnimator class is the core of the UIKit Dynamics, it doesn’t do anything on its own. Objects of some other classes must be added to it, named behaviors, or programmatically speaking, UIDynamicBehaviors. A UIKit Dynamics behavior actually represents a physical behavior of the real world in the programming world, and it specifies the realistic effects provided by UIKit Dynamics to developers. The classes related to behaviors, along with a short description, are the following:
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iOS Programming 101: Adding Section and Index List in UITableView

Recently, a reader asked me how to add an index list in a UITableView. As some of you may have the same question, I thought it’s better to write a post to share the solution. An indexed table view is more or less as the plain-styled table view that we’ve covered at the very beginning of our iOS programming course. The only difference is that it includes an index on the right side of the table view. Indexed table is very common in iOS apps. The most well-known example is the built-in Contacts app on iPhone. By offering an index scrolling, users are allowed to access a particular section of the table instantly without scrolling through each section.

If you’ve followed our UITableView tutorial, you should know how to implement an UITableView. Basically, to add sections and an index list in the UITableView, you need to deal with these methods as defined in UITableViewDataSource protocol:

  • numberOfSectionsInTableView: method – returns the total number of sections in the table view. Usually we set the number of section to 1. If you want to have multiple sections, set this value to a larger number.
  • titleForHeaderInSection: method – returns the header titles for different sections. This method is optional if you do not assign titles for the section.
  • numberOfRowsInSection: method – returns the total number of rows in a specific section
  • cellForRowAtIndexPath: method – this method shouldn’t be new to you if you know how to display data in UITableView. It returns the table data for a particular section.
  • sectionIndexTitlesForTableView: method – returns the indexed titles that appear in the index list on the right side of the table view. For example, you can return an array of strings containing “A” to “Z”.
  • sectionForSectionIndexTitle: method – returns the section index that the table view should jump to when user taps a particular index.

There’s no better way to explain the implementation than showing an example. As usual, we’ll build a simple app together and you should get a better idea of index list in a minute.
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Introduction to Objective-C Blocks

In programming, what differentiates a good developer from a great developer is the way each one takes advantage of the programming tools he or she offered by the used language. Objective-C, the official language for developing applications for iPhone, iPad and Mac OS, is a multi-featured one, and as a relative to C, very powerful. New developers have a lot to explore when starting working with it, while advanced programmers have always something new to learn, as there are numerous supported programming aspects. One of them, is the capability to write code using Blocks.

Blocks do not consist of a new programming discovery in Objective-C. They exist in other programming languages too (such as Javascript) with other names, such as Closures. In iOS, they first-appeared in version 4.0, and since then they’ve known great acceptance and usage. In subsequent iOS versions, Apple re-wrote or updated many framework methods so they adopt blocks, and it seems that blocks are going to be partly the future of the way code is written. But what are they all about really?

Well, a block is a self-contained, autonomous code fragment, existing always into the scope of another programming structure, as for example the body of a method. The code on the block can “interact” with the world out of it, but what takes place in the block is not visible to the scope out of it. Also, blocks can modify the values of variables being out of its body using a special way (we’ll see more later). Blocks have two great features:

  1. They can be executed in a later time, and not when the code of the scope they have been implemented is being executed.
  2. Their usage leads eventually to a much cleaner and tidier code writing, as they can be used instead of delegate methods, written just in one place and not spread to many files.
Introduction to Blocks

Focusing even more on the second feature, blocks offer a nice solution for creating callbacks instead of delegates, as they are declared and implemented directly to the point of the code where they are invoked. Using blocks, there is no need to adopt protocols, or implementing delegate methods that lead to much more code in a class. The best thing though, is that the callback procedure can directly access and use any variables existing locally in the scope where the block has been defined, so the need of passing data like we do in callback methods is eliminated. However, blocks cannot totally replace delegates as they cannot be used for every purpose. The best practice is to make combination of both, and that can be achieved both by following some simple rules and using the experience obtained in time.
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How To Import Contacts Using Address Book Framework

One of the most well-known and most used feature of iPhone devices to all users, developers or not, is the Address Book. For those who use a lot the device as a phone (rather than a mobile mini computer), all important and vital information they need exist in their contacts. Till today, many applications have been developed, and even more can be built that make use the device’s address book data.

Apple makes developers’ life easy, as it provides frameworks that allow to access the address book and deal with its records. Knowing how to work with address book and how to perform some basic tasks (at least), is a knowledge necessary to all developers, as either sooner or later they’ll come in need of integrating address book info into their applications.

Before we proceed to take a tour on the most important aspects of the address book framework through a demo application, it would be a nice idea to make an introductory discussion first that will make easier to everyone to comprehend what comes next in this tutorial. So, keep reading and surely you’ll find some pretty interesting stuff as food for thinking and study.

How To Scan QR Code Using AVFoundation Framework

iOS 7 brings a wealth of new features that set it apart from all other mobile operating systems. Both major additions and minor improvements have been made, offering developers new or updated frameworks and APIs to work with, and the opportunity to provide single users with a much richer experience. The AVFoundation framework is just one of them, as it has accepted great enhancements and new class additions that make even more tools available. One of the new features that the AVFoundation incorporates, is the ability to discover and read bar codes in real-time, and one of the supported bar code types that we especially interested in at this tutorial, is the QR Code.

A Quick Response Code (QR Code) is actually a two-dimensional (2D) barcode. Instead of the vertical lines like those that the well-known barcode contains, a QR Code can have its lines designed in both horizontal and vertical directions. The data that’s being encapsulated into such a code, is read by devices specificly designed for this job, or by smart devices (smartphones, tablets) using the appropriate software. A QR Code can store a great amount of data (in relation to the ordinary barcode), so there is a variety of information that can be encoded in it. Some typical content examples of a QR Code are:

  • URL
  • Phone number
  • Simple text
  • SMS text

QR Codes are used mainly for marketing reasons, but not only. One can create a QR Code to use on its website, or on any other place that may wants.

QRCode Featured

Thanks to iOS 7, creating applications that can scan and translate a QR Code has been really a piece of cake. So, if you have ever been tempted to create such an app, or you are just curious to learn more about all these, then just keep reading!

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Creating Hello World App Using Xcode 5 and Interface Builder

Update: As Apple released Xcode 6 and Swift, we’ve updated the Hello World tutorial here.

The Hello World tutorial was the first programming article written for our free programming course. We think it’s time to update the tutorial to make it fit for Xcode 5. Since the release of Xcode 5, we received quite a lot of queries (or complaints) about the Hello World tutorial. Here are some of them:

  • I tried to follow the tutorial but the procedures no longer work for Xcode 5.
  • Where is the Interface Builder?
  • How can I create the XIB file?

The list goes on and on. Xcode 5 promotes the use of Storyboard instead of Interface Builder. When you create a new Xcode project using the Single View template, it defaults to Storyboard. There is no XIB file generated.

HelloWorld App Featured

We’ve completely updated the Hello World tutorial for Xcode 5. However, we intend to use Interface Builder to build the project. It doesn’t mean we prefer Interface Builder over Storyboard, which is great. We just want you to learn both.

Enter the Hello World tutorial for Xcode 5.
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Customizing Navigation Bar and Status Bar in iOS 7

Like many of you, I have been very busy upgrading my apps to make them fit for iOS 7. The latest version of iOS introduces lots of visual changes. From a developer’s perspective, the navigation bar and status bar are two noticeable changes that need to cater. The status bar is now transparent, that means the navigation bar behind it shows through. In some cases, the background image for a navigation bar can extend up behind the status bar.

Some time ago, I’ve written a tutorial about how to customize a navigation bar. I think it’s time to revisit the customization and see how it is done in iOS 7. Here are some of the tips and tricks that you’ll find in this article:

  • Setting the background color of navigation bar
  • Using background image in navigation bar
  • Customizing the color of back button
  • Changing the font of navigation bar title
  • Adding multiple bar button items
  • Changing the style of status bar
  • Hiding the status bar
custom navigation bar iOS 7

You’ll need Xcode 5 to properly execute the code as presented in this tutorial. So if you’re still using older versions of Xcode, make sure you upgrade to Xcode 5 before running the sample Xcode project.
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iOS Localization Tutorial: Localize Your Apps to Support Multiple Languages

Editor’s note: This week let’s talk about localization. In brief, localization is a process to adapt a product to a particular language. Not all iPhone users can read or write English. If you just release your app in English, it may be ignored by user from other parts of the world. In this tutorial, Ziad will go through the localization process with you. You’ll see how easy you can localize an app and make it available in multiple languages by using the built-in function of Xcode and iOS API.

Update: If you’re using Xcode 6, please check out the updated localisation tutorial.

Enter the iOS localization tutorial.

The iOS devices including iPhone and iPad are available globally. Obviously, iOS users are from different countries and speak different languages. To deliver a great user experience, you may want to make your app available in multiple languages. The process of adapting an app to support a particular language is usually known as localization.

Xcode has the built-in support of localization. So it’s fairly easy for developer to internationalize an app through the localization feature and some API calls.

Localization Feature Photo

Some people think of localization as the same process of translation. That’s partially correct. Translating static or visible text is just part of the localization process. Localization involves other elements such as images, graphics and sound. You’ll also need to handle the different display format of numeric values, as well as, date and time.

In this tutorial, we’ll show you the step-by-step on how to localize the storyboard file, strings, images and app name. As usual, we’ll demonstrate the process by building a simple app and make it available in French.
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How To Fetch and Parse JSON Using iOS SDK

Editor’s Note: This week, Ziad Tamim will show you how to fetch and parse JSON. In this tutorial, we will be focusing on adding JSON support to your iOS apps by demonstrating how to create a simple app using Meetup API. The tutorial may be a bit complicated than other tutorials we covered before. You’re expected to have basic knowledge of JSON and design patterns.

Enter the JSON programming tutorial.

First, what’s JSON? JSON (short for JavaScript Object Notation) is a text-based, lightweight and easy way for storing and exchanging data. It’s commonly used for representing structural data and data interchange in client-server applications, serving as an alternative to XML. A lot of the services we use everyday have JSON-based APIs. Most of the iOS apps including Twitter, Facebook and Flick send data to their backend web services in JSON format.

iOS Programming 101: How To Create Email with Attachment

A year ago, we wrote a short tutorial to show you how to send email using MessageUI framework. Some asked how to attach a photo, PDF document or Powerpoint in the email. Instead of replying every email individually, we think it’s better to write another short how-to tutorial.

The MessageUI framework has made it really easy to send email in your apps. If you’ve read the official document of MessageUI framework, you know the MFMailComposeViewController class already provides a method called “addAttachmentData:” to add any types of files as an attachment. In this short tutorial, like other articles of our iOS Programming 101 series, we’ll write a simple app and demonstrate the usage of the method.