Swift Weekly – Issue 06 – The Swift Runtime (Part 4) – Generics

Generics are pretty cool. They let us do complicated stuff that many programmers don’t want to deal with sometimes and want to stick with traditional means of achieving the same goals but using basic ideas in OOP. In this edition of Swift Weekly, I won’t teach you about generics eventhough you may just see the examples and learn generics anyways. What I will teach you however is how generics are compiled at the assembly level buy the Swift compiler.

I am going to use the release version of the code to make sure the output assembly is as optimized as possible so that the optimization level is set to -O in the output when your Swift files are being compiled. Also my swift -versionshows this:

Swift version 1.1 (swift-600.0.54.20)
Target: x86_64-apple-darwin14.0.0

I am using the latest beta of Xcode, aka Version 6.2 (6C86e). Let’s get started.

Note: I am going to get rid of some of the assembly code that is not relevant to the main point of this week’s objective.

Continue reading this article on GitHub.

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iOS 8 Swift Programming Cookbook (50% off)

Hi guys and gals,

iOS 8 Swift Programming Cookbook is 50% off today only. Grab yours here.

That link includes the code so make sure that you either click that link or include the code DEAL upon checkout. Just check your basket to ensure you got the 50% off. Good luck.

Swift Weekly – Issue 05 – The Builder Pattern and Fluent Interface

A few weeks ago I started checking out some Wikipedia articles about various s/e design patterns and came across theBuilder pattern which is a Creational GoF pattern. Then as you know, I cannot just read one article in one sitting. I have to click every link that the article leads to, so I stumbled upon the article about Fluent Interfaces and I could then see the possibilities.

Note: Fluent Interfaces have nothing to do with IB or a visual interface that is displayed on the screen at all. Fluent interfaces are the way that we can write our software to ensure they are… well… fluent. Read on to understand how this works.

I don’t think fluent interfaces are the same as the builder pattern. I don’t really think fluent interface is actually a pattern at all. I believe that fluent interfaces are a concept, and a kick ass one at that. I think mixing fluent interfaces and the builder pattern will allos us to build Swift classes that are amazingly simple to use, instead of the classic OOP designs that we see on pretty much every Apple class these days. I wish Apple could read this article and (ehem), just update their iOS SDK classes for instance to use fluent interfaces and the builder pattern.

If you want to write your Swift apps in the most kick ass way, continue reading. I think this article will help you a lot not only in learning more about Swift, but also writing some really crazy code that will make your life and those around you much easier.

Click here to read the full article on GitHub.

Getting the most out of your WiFi dongle data plan (The definitive guide)

I am currently facing a situation where I need to carry out my work while I am connected to a WiFi dongle. I have spent about £20 for 6GB of data that can be used for up to 3 months, whichever comes first. So I have now learnt a lot of tricks on how to minimize my data usage and save money. Here, I want to share with you some of these tricks.

Trick 1 – Disabled images in your browser

If you view the web without images, your browser does not have to load those images from the internet so you will save A LOT of data. Every browser is different so I cannot tell you how to do that on every browser. Here is how to disable the loading of images on Safari on OS X:

  1. Go to Safari Preferences
  2. Go to the Advance tab
  3. At the bottom of the Advance tab, find the “Show Develop menu in menu bar”
  4. Then close the preferences window
  5. Go to the newly-shown Develop menu and choose Disable Images

That’s it. Some websites will not look nice without images and that just shows you how some web developers have now become too reliant on using images! Their fault really.

Trick 2 – Use Git commands carefully

I use Git through the terminal and two of the most useful commands that I use quite often are git fetch and git rebase. Now, git fetch, will fetch every new branch and all change-sets from the server and brings it into your local machine. What you want to do is to replace git fetch with the following command:

git fetch origin NAME OF BRANCH

So if you are on a branch named “ios7” and you want to just bring the remote changes on that branch to your local repo, do this:

git fetch origin ios7

git rebase origin/ios7

Now you got only the changes in that branch and you rebased to the latest changes

Trick 3 – Use Adblock… A LOT

Install Adblock on your browser and go to your popular websites and start blocking anything that looks useless and will consume your data. So just start blocking all content that is irrelevant.

Trick 4 – Disable Flash

I don’t have to explain this. Flash videos are memory, CPU and data hungry. They consume your battery so fast it is unbelievable. Just disable Flash to make sure your browser will not try to load those darn Flash videos for you.

Trick 5 – Stop watching videos on websites

Do not go to YouTube and other streaming video websites. They are very data hungry no matter how low you have set the quality of the videos. Watch videos when you are on a proper broadband, not on a tiny WiFi dongle.

Trick 6 – Subscribe to websites with push notifications

I read MacRumors quite a lot. I go to their website probably 3-4 times a day. But instead of doing that, it’s best that you subscribe to push notifications from news websites that offer that service. Then you can get push messages directly to your OS X desktop of new content that get posted on those websites instead of going there every time you want to check the news. A push notification will only contain the new article, not the whole website. But if you go and browse the website, you are viewing everything that is on the front page at least, hopefully without the images, as one of the tricks you learnt earlier!

Trick 7 – Stop opening a browser page ever time you think you’ve lost your internet connection

We all do this. When we think we have no internet connection, which can happen on a daily commute on a Wifi dongle, we open our browsers and navigate to our favorite website. If the website loads, we go “Aha, it works”. Instead of that, do this:

  1. Open Terminal
  2. Type this: ping http://www.apple.com

Once you see ICMP packets going and coming back, you know at least ICMP is working and you are almost 99.99% sure that your internet works.

Trick 8 – Do not preload top hits in your browser

Users of Safari or most modern browsers know that when they type in the search field for anything, a few “suggested” websites and terms will appear automatically. For instance, if you start typing “blood”, in your search field in your browser, you may get suggested words such as “blood pressure”, “check your blood sugar level”, and etc. Every time you type something in your browser’s search field, your browser will hit your search engine and look for suggested words and links. This will take battery and will use your internet. To disable this in Safari, follow these steps:

  1. Open Safari Preferences
  2. Go to the Privacy tab
  3. In the “Smart search field” area, click the “Prevent search engine from providing suggestions”
  4. In the same area, click the “Do not preload Top Hit in the background”

Okay that is it for now. These are all the tricks I have up my sleeves for saving you some data usage on your WiFi dongle. If you have any other tips that you believe are worth sharing with others, please let me know and I will include them here.

Enjoy

Jenkins doesn’t load under OS X Mountain Lion (or Server)? Here is the fix!

Answer: your machine doesn’t have Java installed on it. This happened to me. Jenkins installed fine, but then when I opened it on its default port of 8080, nothing happened.

To fix it, open Terminal and type “java” without the quotation marks.

This will tell you that you have to have Java SE installed on your computer and then will download and install Java SE automatically for you. Done! 🙂

Network-Connect 2 Macs

I was looking for a way to connect my two Mac Minis and transfer files between them, see the other Mac’s desktop and etc.

People were suggesting, FireWire, Thunderbolt cables, etc. Save your money. None of that really works.

The solution? Good old Gigabit Ethernet (CAT5E) cable and connect the two Macs together. Even if you have the latest MacBook Pro or MacBook Air that don’t have Gigabit Ethernet ports, there are Ethernet to USB cables that you can get from Apple which will do the job for you. So you still use the ethernet cable but at both ends or 1 end use the Ethernet to USB cable. Easy peasy.

In case you don’t know what an Ethernet cable looks like, it’s like this:

Image

String enums in Objective-C

Note: I have written a newer and better solution to this problem in a new video, which you can watch by clicking here.

Sooo a lot of programmers think enumeration items cannot be strings, and they are right, BUT, there is a BUT. You have to understand that C strings that are made out of 4 characters, each of which is 1 byte long, constitute a memory address that is 4 bytes long, or just the equivalent of int, NSInteger or whatever you want to call it.

So if you put a value such as ‘Good’ for the enumeration item, in fact, the compiler will translate the values of ‘G’, ‘o’, ‘o’ and ‘d’ as their numerical values and will generate a hexadecimal value and put it as the integral value of the enumeration item.

Let’s say we want to say “Good”, or “Nice” all in enumeration items in C. Here is the example, this code runs fine in Objective-C for iOS or OS X as well:

Screen Shot 2013-03-24 at 19.30.24

The output of this is the string “dooG” printed to the screen if you run this on an iPhone device for instance. The reason is the bytes are obviously reversed as the string ‘Good’ has the letter ‘d’ as the lowest byte and that ends up being at the first byte of the string so we end up with “dooG”. That’s not good though, is it? So we just have to swap the bytes around to get the proper string:

Screen Shot 2013-03-24 at 19.31.08

Easy peasy, aye? The highlighted line is very important. That line swaps the order of bytes in the integer. Also note that I am using the calloc function as it will not only allocate the memory but also set the byte values to 0x00 in the memory for us so we don’t have to do it manually or with another procedure.