#xcode 7

Become an Advanced iOS 9 App Developer For Only $19

Those who want to move into the app development field will find ample opportunities to earn a high salary and express your creativity. But if you want to get into this exciting sector, you have to receive the right education first, and it isn’t always possible to take good courses at local schools, especially if you’re pressed for time or on a tight budget.

That’s where online learning can come…

Become an Advanced iOS 9 App Developer For Only $19

Those who want to move into the app development field will find ample opportunities to earn a high salary and express your creativity. But if you want to get into this exciting sector, you have to receive the right education first, and it isn’t always possible to take good courses at local schools, especially if you’re pressed for time or on a tight budget.

That’s where online learning can come…

Become an Advanced iOS 9 App Developer For Only $19

Those who want to move into the app development field will find ample opportunities to earn a high salary and express your creativity. But if you want to get into this exciting sector, you have to receive the right education first, and it isn’t always possible to take good courses at local schools, especially if you’re pressed for time or on a tight budget.

That’s where online learning can come…

I’ve been wanting to get into iPhone app development for some time now. I bought an online course from Udemy and considering the amount of time it would take me to learn the SWIFT coding language, I thought long and hard about hiring a freelancer to do the coding work for me. That would leave me all the time in the world to focus on the design, management, and commercial delivery of the app. Over time I realized that bootstrapping and maintaining my savings was the way to go and that learning to code would be a worthwhile investment for this career path. After all, you can’t run a business effectively without understanding the operations and the ins and outs of its products. 

Given that, I decided to suck it up and blow through the course. 

Xcode: More Design, Less Coding

Xcode is Apple’s platform for developing apps. Much like the Unity and Unreal Engine game development platforms, Xcode has been around long enough for it to evolve into a more visual design experience than a purely coding experience. This makes app development so much more fun, especially for people like me who are lacking in coding skills. A third of the work is taken care of by simply dragging and dropping preset UI elements (buttons, images, tables, toolbars, etc.) and checking off options.

There’s also a humongous online community to leverage from. If you can’t figure out how to do something, just Google it and 99% of the time you will find either a tutorial or a forum discussion with detailed solutions.

BLOGpost 25 January 2016

I'd like to share my work with you. I'm interested to know what you --- the reader --- make of my work, and my conclusions.

The sudokuSoft analyticalEngine. I've used sudoku puzzles ---published in local and national newspapers, books and websites --- to test the development and coding of a sudoku puzzle solver application I'm scripting. I'm using the Swift programming language within Apple's Xcode scripting environment. I call my sudoku puzzle solver application The sudokuSoft Analytical Engine.

The analyticalEngine software automatically solves and analyses any sudoku puzzle, including those with more than one solution. The analysis it generates shows a step-by-step route from initial conditions through to solution outcome using six algorithmic methods. It can also solve very tough puzzles which require more powerful algorithmic methods.

The six methods I have developed and implemented in the software, I label as followed:

(1) Markup; (2) Fetch Unique Integer; (3) Fetch Hidden integer; (4) pairPurge;  (5) singleBlockPurge; and (6) Nudge

Solving a Sudoku puzzle begins with the mark up stage of the puzzle solution (algorithm method 1).

Markup finds all possible numbers in void cells by compiling a database derived from row, column, and 9x9 cell box initial condition information (the board). This database comprises the missing integers on which the puzzle's solution relies.

Next, the software exhausts a search for single integers in void cells in each row, column and box using the markup database.  Specifically, there are two sorts of single integer search. There is a search for a unique integer, and a search for a hidden integer.

A unique integer is a single integer in any markup cell (Fetch Unique Integer algorithm; method 2). A hidden integer is a single integer hidden among more than one integer in any markup cell (Fetch Hidden integer algorithm; method 3).

The sudokuSoft Analytical Engine searches next for identical pair-pair sets in any row, column and box, and deletes all identical pair-pair set integers from the same row, column and box markup cells (pairPurge algorithm; method 4).

Next, the sudokuSoft package is set to undertake a second exhaustive search for single integers in cells in row, column and box generated by the application of the search for identical pair-pair sets (methods 2 and 3). The sudokuSoft package again undertakes a second exhaustive search for identical pair-pair sets, and deletes all identical pair-pair set integers from the same row, column and box (pairPurge algorithm; method 4).

Finally, the sudokuSoft package searches for identical single-pair sets in any row, column and box, and deletes all identical single-pair set integers from the same row, column and box (singleBlockPurge algorithm; method 5).

The sudokuSoft package is set to iterate these methods until the puzzle is solved. Most valid sudoku board puzzles are solved by iterating the application of the first five methods. Easier puzzles are usually resolved and solved using the first three methods. More difficult puzzles are solved using method 4. Tougher puzzles require application of method 5.

But, a few boards will remain unresolved by exhaustive application of these first five algorithms. These boards require an additional method. And there is debate about whether this additional sixth method is a method at all. Some say it is only a guess.

I have written code to emulate a guess. I call this additional sixth method a nudge because it searches out a key integer pair which unlocks the board and enables solution.

Most puzzles in books, newspapers and  websites have one solution which does not involve a guess. I want to say: sudoku puzzles which involve a guess are not valid sudoku puzzles.

What do you, the reader, think?

Do you want to beta test the sudokuSoft analyticalEngine?

If you do, then contact me.

The code in this post was tested with Xcode Version 7.2 (7C68).

The accompanying source code can be found at github.com/mczenko/UsingSwiftFrameworksFromObjectiveC

When working with legacy iOS products it may happens that you need to integrate with main application target that contains only Objective-C code. You want to take advantage of Swift but you want this nicely separated from the old legacy code. Creating a framework that will contain your Swift code is the answer.

There is no something like a Swift framework. A framework can include both Objective-C and Swift code. In this short post we focus on a framework containing only Swift code.

If you want to share your Swift code, a framework is necessary. You can't just use a static library as they do not support Swift code.

The following steps describe the whole process of creating a framework and adding it to an Objective-C-only target.

If you want to follow with the source code from github.com/mczenko/UsingSwiftFrameworksFromObjectiveC please clone the repository and checkout the very first commit with comment Initial commit. (commit 73e8dde) and then follow the steps. The last commit corresponds to the final state.

Step 1 - add a taget

Select your project in the Project Navigator and create a new target:

and name it ExampleSwiftFramework:

Step 2 - make the tests logical

The idea of Logical Unit Tests is less widely used in the Xcode community, but you can still make sure that your framework tests execute only against your framework code without depending on the application code (no application instance, no app delegate, no views, etc). Even though Apple does not seem to distinguish anymore between application unit tests and logic unit tests, the latter is what we want here: your tests working only with the Swift code in your framework. For this to work you need to make sure that the Host Application seeting for the ExampleSwiftFrameworkTests is set to None:

Logic unit tests cannot be run on the device. They may only run in the simulator.

Step 3 - add example framework class

Now inside our example framework, add an example swift class:

import Foundation class ExampleSwiftFrameworkClass { let message: String init(withHelloMessage message: String) { self.message = message } func sayHello() -> String { return self.message } }

The tests for this class can be found in the ExampleSwiftFrameworkTests.swift file in the ExampleSwiftFrameworkTests target.

Step 4 - referring to the Swift framework from the main application target

Now, let's try to reference the ExampleSwiftFrameworkClass from our main application target - which does not contain any Objective-C code.

We will be modifying the viewDidLoad method of the ViewController class from the main application target. You will quickly realise that Xcode code completion does not work for our class - in this case it right - our class is not visible yet in the main application target.

To make our class visible you need to import the module it comes from. Add the following line somewhere on the top of your ViewController.m file:

@import ExampleSwiftFramework;

You may realise that the Xcode's completion already recognized the module, but the our ExampleSwiftFrameworkClass remains invisible to Xcode. To fix this, we need to do two things:

Mark your Swift framework class with @objc annotation, and make it inheritting from NSObject (if you do not, compiler will tell you that you can't use @objc annotation otherwise).

Make sure your class, the constructor, and the method you want to access from another target are public. The default visibility is internal which means your class and all its methods are accessible to any other class from the same target. But our framework and our main application are from different targets - that's why we need to use public for access control.

After the modifications, our ExampleSwiftFrameworkClass should look like this:

@objc public class ExampleSwiftFrameworkClass : NSObject { let message: String public init(withHelloMessage message: String) { self.message = message } public func sayHello() -> String { return self.message } }

If you try to run the app or the application tests (not framework tests) you may be surprised seeing that the app crashes with the following log output:

dyld: Library not loaded: @rpath/libswiftCore.dylib Referenced from: /Users/usename/Library/Developer/Xcode/DerivedData/UsingSwiftFrameworksFromObjectiveC-befsyfovlmeizgeypzhxolfxbaco/Build/Products/Debug-iphonesimulator/ExampleSwiftFramework.framework/ExampleSwiftFramework Reason: image not found

Xcode is quite intelligent in fixing most of the stuff for us (we will discuss this still in more details below), but there are somethings we have to take care for ourselves.

Step 5 - Fixing the missing reference to libswiftCore.dylib

If you are building an app that does not use Swift but embeds content such as a framework that does, Xcode will not include these libraries in your app. As a result, your app will crash upon launching...

The text quoted above comes from the Technical Q&A QA1881 Embedding Content with Swift in Objective-C. As resultion it instructs to set Embedded Content Contains Swift Code build setting to YES for the target that does not include Swift code itself but depends on a framework that does use Swift. Additionally, it recommends setting the Embedded Content Contains Swift Code to NO for the dependent framework target so that we do not get multiple copies of Swift libraries in the app.

In our example therefore, the only target where we need to set Embedded Content Contains Swift Code to YES is the main application target UsingSwiftFrameworksFromObjectiveC:

Other settings

We mentioned already that Xcode takes care for pretty mych everything. In some cases, however, especially when you deal with a legacy project, it may turn out handy to know what else may require our attention. We summarize the important points below:

Main application target - UsingSwiftFrameworksFromObjectiveC. We have to make sure that target depends on the framework, the framework is included in the Link Binary With Libraries build phase, and that the Embed Frameworks build phase contains the framework with the Destination set to Frameworks:

The framework - ExampleSwiftFramework target. In our case we do not want it to depend on the main application target UsingSwiftFrameworksFromObjectiveC:

ExampleSwiftFrameworkTests target. It depends on ExampleSwiftFramework only and includes ExampleSwiftFramework in the Link Binary With Libraries build phase:

Additional references

Technical Q&A QA1881 v2 - Embedding Content with Swift in Objective-C

Swift and Objective-C in the Same Project

How to Create a Framework for iOS