April 2016

smartphone money

This roundup of mobile developer news has a theme: making money with your apps, with both practical advice and tutorials, as well as bigger-picture discussions of the topic.

under the radar

Under the Radar is David Smith and Marco Arment’s podcast on indie iOS app development. They make sure that none of their podcasts runs longer than half an hour. Their latest podcast, the 21st in the series, is titled App Store Rejection, in which they provide suggestions on how to avoid rejections from Apple’s App Store review staff, and what to do when your app gets rejected.

Their two previous podcasts also cover the App Store: Improving the App Store, Part 1 and Improving the App Store, Part 2.

angry birds

I had no idea that mobile games were a bigger business than PC and console gaming. Here are the sizes of the game markets, according to App Annie and IDC:

  • Mobile games are a $34.8 billion market worldwide,
  • PC/Mac games are a $29 billion market,
  • Console games are an $18.5 billion market, and
  • Games for handheld game devices are a $3 billion market.

At the time of writing,”Application Category Distribution” section of PocketGamer.biz’s App Store metrics page showed the following breakdown of apps:

  1. Games (527,017 active)
  2. Business (234,930 active)
  3. Education (210,991 active)
  4. Lifestyle (198,844 active)
  5. Entertainment (144,613 active)

They also report these numbers for app pricing:

  • Current Average App Price: $1.12
  • Current Average Game Price: $0.54
  • Current Average Overall Price: $0.99

android apps for sale

Ray Wenderlich’s site may have started out as iOS-specific, but they’ve expanded their coverage to include Android and Unity development. Their latest Android article is titled Android App Distribution Tutorial: From Zero to Google Play Store, and it shows you how to get your newly-created Android app into Google Play’s store.

google play and app store

App Annie, the mobile app analytics service, published their inaugural app economy forecast a couple of months ago, where they make the following predictions:

  • This year, the global app market is expected to grow 24% and hit $51 billion in gross revenues across all app stores
  • The global app market will exceed $100 billion is gross revenues by 2020
  • China surpassed the US in mobile app downloads last year, and is expected to surpass them in app spending this year.

in-app purchase

In-app purchases can help you generate more money with your apps, and this article can help you with setting them up on iOS apps: In-App Purchase Tutorial: Getting Started.

life and death in the app store

In case you missed it, The Verge recently published Life and Death in the App Store, an article which on one level is the story of Pixite, a mobile development shop that had some early successes and is now treading water, and on another level is the story of the changes in the app market between its inception less than a decade ago and the present day, and what that means for developers who plan to make a living off it.


tsa randomizer

About 150 airports in the U.S. have TSA PreCheck, an expedited security line for pre-screened travellers. If you fly often, you’ll find it very convenient as the line’s usually short, and you can forego having to remove your shoes, jacket, and belt, as well as having to separate your laptop and “3-1-1 liquids” from the rest of your carry-on luggage. There is a price to be paid for this — a registration fee, along with providing the U.S. Customs and Border Protection agency enough info to do a background check on you, and there’s an interview as well. If you’re an American or Canadian with a NEXUS card, you’re already in the TSA PreCheck program.

Even the pre-screened people going through TSA PreCheck get some additional random screening every now and again. The TSA PreCheck line often has two lanes, one on the left, one on the right, and they pick people for additional security screenings from one of them. In order to keep people from trying to guess which line that is, the TSA commissioned the development of a “randomizer”, which is an iPad app that randomly determines which line you should use.

The video below shows the randomizer in action:

The app would make a good “iPad programming 101” assignment; a newbie developer should be able to complete it in a day, and someone with even a couple of months’ of experience should be able to complete it in an hour.

Developer Kevin Burke wondered how much the TSA paid to have the app developed. As a government agency, they’d have put out an RFP to companies that do contracts for government work, and none of them come cheap. He filed a Freedom of Information Act request, and mirabile dictu, he got some answers in the form of two documents:

Here’s the most eye-catching part of the contract:

total award amount

Burke posted his findings online, and Pratheek Rabala, who does interactive graphics for TIME, pointed out that not only the information was readily available to the public, but that the payment shown above was just one in a series of payments totalling $1.4 million.

It turns out that the $1.4 million dollars covers the cost of a larger project, which includes other mobile applications, software to support an “enhanced staffing model” for the TSA, and all the project management that such an undertaking requires.

The TSA, when asked, pointed out that the “development costs for the TSA Randomizer Application were $47,400 in total.”

With that in mind, it’s time to fire up Xcode and start on the path to that sweet, sweet government contract money. Why should IBM have all the fun?

If you’re new to iOS programming or even programming in general, the TSA Randomizer app is a good starter project. You might want to try writing it on your own before following the steps below. Here’s a hint that should help — you’ll need to know how to do these things in order to write the app:

  • How to generate a random number
  • How to display an image on the screen
  • How to change the contents of an image on the screen
  • How to know when the user has tapped on the screen

How to write the app

xcode icon

Open up Xcode and do the FileNewProject… dance. As you may have already suspected, you’re going to specify that this is a Single View Application:

tsa 01

Give the project a name (I called mine TSARandomizer), and select iPad from the Devices drop-down menu:

tsa 02

Once you’ve chosen a place to save the project and it’s been written to disk, you’ll be taken to the General page for your project. Under Device Orientation, make sure that Portrait is checked and that all other orientations are unchecked:

tsa 04

Click the screenshot to see it at full size.

Edit ViewController.swift and change its contents to the following:

This is all the logic needed to make the app work. The displayRandomizedArrow method is currently set so that 50% of the time, the left arrow is selected, and the other 50% of the time, the right arrow appears. You can adjust this to taste.

Time to build what little user interface there is. Open Main.storyboard and put an Image View control on the view. This will contain the arrows. We want it to fill up the screen, so set its constraints so that all its sides are 20 pixels from the view:

tsa 05

Click the screenshot to see it at full size.

In our code, we have an outlet variable named arrowImageView. We need to connect it to the image view we just added. Select the view and open the Connections Inspector. Drag from the circle to the right of New Referencing Outlet to the View Controller icon above the view, as shown in the screenshot below.

tsa 06

Click the screenshot to see it at full size.

Select arrowImageView from the pop-up menu that appears.

tsa 07

Click the screenshot to see it at full size.

Finally, we need to add the arrow images to our app: arrow-left.png and arrow-right.png. Open Assets.xcassets and drag the left-arrow and right-arrow images into it.

tsa 08

Click the screenshot to see it at full size.

Fire it up in the simulator or deploy it to your iPad, and start bidding on some TSA RFP’s — you’ve got a functioning TSA randomizer app!

xcode download

I’ve zipped up my project and made it available for download (it’s a mere 300KB zipped). Enjoy!

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xamarin forms

One of the big changes that came from Microsoft’s acquisition of the cross-platform development tool company Xamarin is that their IDE, which once required a subscription fee for a version for building non-trivial projects, is now free-as-in-beer for the following:

  • individual developers,
  • small professional teams (5 or fewer users in an organization that isn’t considered an “enterprise”, which Microsoft defines an organization with more than 250 PCs or makes more than US$1 million in annual revenues),
  • open source projects (that is, projects released under Open Source Initiative-approved licences),
  • use in on-line or in-person classroom training and education, and
  • use in academic research projects

If Windows is your development platform, Xamarin’s cross-platform mobile dev tools come baked into all editions of Visual Studio, even the free-as-in-beer Community Edition, which you can download from the Visual Studio page. If your preferred development platform is Mac OS, Xamarin Studio, a full-featured stand-alone IDE that borrows a few tricks from Visual Studio. In this article, I’ll take you on a quick tour of Xamarin Studio Community, as seen on my MacBook Pro, iPhone 6S, and Moto G running Android Marshmallow.

The installation process is pretty straightforward, and the length of time it takes will depend largely on your internet connection speed. Here’s a screenshot that I took of the installer at the start of the process:

xamarin installer

Once installed, I did the oh-so-familiar FileNewSolution… dance and was presented with this window:

xamarin 2016 01

Note the options offered in the left column:

  • Cross-platform development, which you can do in one of two ways:
    • Using Xamarin.Forms, a “universal” UI framework that allows you to target a single cross-platform UI that tries to be a native as possible on both Android and iOS, and
    • a more “traditional” way, where you write Android- and iOS-specific UI code while writing common logic that both with use
  • iOS apps,
  • Android apps,
  • Mac applications, and
  • “other” applications, which include:
    • console projects,
    • GTK# 2.0 projects,
    • NUnit libraries,
    • F# tutorials,
    • ASP.NET and ASP.NET MVC projects

For this walkthrough, I’m going to go with Xamarin.Forms to write something to deploy to both Android and iOS. When you do this, you’re presented with a couple of configuration dialogs, shown below. I’m going to name my project Magic8Ball

xamarin 2016 02

xamarin 2016 03

Once past the configuration dialogs, you’re presented with your project. Xamarin Studio’s interface is a pretty standard IDE: solution tree in the left column, editor in the upper right-hand quadrant, and debug and console panes below the editor:

xamarin 2016 04

If you look at the left-hand solution tree column, you should notice that it’s divided into three parts:

  1. Magic8Ball, the main project
  2. Magic8Ball.Droid, the Android-specific parts of the solution, and
  3. Magic8Ball.iOS, the iOS-specific parts of the solution.

Right now, Magic8Ball.iOS is marked in bold, which indicates that it’s the startup project. If you were to run the app right now with an iOS simulator as the target, here’s what you’d see:

xamarin 2016 05

Left-clicking on Magic8Ball.Droid and selecting Set As Startup Project makes it the startup project…

xamarin 2016 06

…and here’s what it looks like on the emulator. Note that Xamarin’s Android projects, by default, use a dark color scheme (which you can change with a simple configuration tweak):

xamarin 2016 09

In the newly-created “Hello World” template that you get when you first create a Xamarin.Forms solution, everything happens in the Application class instance. In the case of my app, that instance lives in Magic8Ball.cs. Not how the entire UI is set up in the constructor, App():

I changed the code to pass off the UI creation to a view class that I’m calling MainPage:

I decided to create a class called EightBall to handle all the predictions. Using File → New → File…, I was presented with the New File dialog, where I selected General on the left-hand column and Empty Class in the center column:

xamarin empty class

Here’s the contents of the file as given to me by Xamarin…

…and here it is once I’d filled it in:

With the model class done, it was time for a view class, created with File → New → File… again. This time, I selected Forms from the left-hand column, and Forms ContentPage from the center column, specifying that I wanted a ContentPage, an onscreen container for containing a single view. It’s often used to represent a “screen” in an app:

xamarin new file

Here’s the contents of the file when initially generated by Xamarin…

…and here it is once I’ve defined my user interface and added a reference to the EightBall class:

…and that’s it — we have a basic “Magic 8-Ball” app! Here’s what it looks like running on iOS 9…

ios 8ball screen shot

Screenshot taken on my iPhone 6S running iOS 9.2.

…and here’s what it looks like running on Android Marshmallow:

android 8ball screen shot

Screenshot taken on my Moto G (second generation) running Android Marshmallow (6.0).

xamarin download

You can download the project (70KB zipped) to try it for yourself.

More about Xamarin

creating mobile apps with xamarin forms

Charles Petzold, the guy who literally wrote the book on Windows development, was commissioned to write a book on building cross-platform mobile apps with Xamarin.Forms. At 27 chapters and nearly 1,200 pages, Creating Mobile Apps with Xamarin.Forms is the most complete document on the topic, and it’s free-as-in-beer to download. You’ll definitely want to get your hands on this.


For those of you looking for an online course, edX is offering a course called Introduction to Xamarin.Forms. It’s an introductory-level course, and is available for free. However, if you’d like to get a “Verified Certificate” for completing the course, you can apply for one for a mere $25.

build 2016

The two videos below, shot at Microsoft’s recent Build 2016 conference, show more about Xamarin and its tools in action. Here’s the shorter one (27:19 long)…

…and here’s the longer one, running at one hour, which features a complete session from the conference, Cross-Platform Mobile with Xamarin:


optimistic weather app

Screenshots from the Optimistic Weather app. Click the image to see the app in the App Store.

According to comScore, two of the top 25 most-used mobile apps were weather apps, namely the Weather Channel app (#16) and the Weather Channel widget (#20). This makes sense, as a weather app fits at least two, if not three, of the book Tapworthy says are the mobile users’ mindsets when they launch an app:

  1. I’m bored
  2. I’m local
  3. I’m micro-tasking

Weather apps are great programming exercises, as they combine a number of different features, including fetching information from online sources, and geolocation. In this series, we’ll build a weather app from scratch, starting with a simple, no-user-interface, only-developers-could-love, bare-bones weather app, and over time, turn it into something better.

This first article looks at where we’ll get the weather data for our app and signing up for a free subscription to that weather source. We’ll then retrieve weather data from that source, first manually, then programatically. At the end of this article, you’ll have a very basic weather app; it won’t have a user interface, and the way it presents information is more developer-friendly than user-friendly, but it will perform a key task: retrieve the current weather for a specified location.

Step 1: Get an OpenWeatherMap API key for current weather data


There are a number of weather APIs to choose from, and for this tutorial, we’ll use OpenWeatherMap’s API. It’s simple to use, and you can make up to 60 calls a minute on their free API subscription plan, which should be more than enough for testing purposes and personal use.

If you go to OpenWeatherMap’s API page (pictured below), you’ll see that they offer all sorts of weather data. For this app, which answers the question “What’s the weather like right now for a given place?”, we’ll use their current weather data API. Click on the API doc button under Current weather data:

openweathermap apis

and you’ll be taken to this page. Under the Free column, click the Get API key and Start button:

openweathermap current weather api

which will take you to yet another page. Click the Sign up button…

opernweathermap sign up

…which takes you to a page where you provide a little info:

openweathermap create account form

Once you’ve submitted your info, you’ll have created an OpenWeatherMap account. You’ll be sent to a page that shows your API key (pictured below). If you ever need to look up this hey again, you can log into the site and click on the Home link near the upper right-hand corner of the page, which will take you to your account information, which includes your API key.

openweathermap api key

Copy the API key, and get ready to use it in the next step!

Step 2: Test your API key using your browser

OpenWeatherMap’s current weather data API accepts calls in the format shown below:


Note the parts in italics; you’ll replace those:

  • CityNameGoesHere is replaced with the name of the city whose current weather data you want to fetch, and
  • YourAPIKeyGoesHere is replaced with your API key.

For example, if you want the weather for Tampa, and your API key is abcdef1234567890 (don’t bother using this key; it’s not real and for example purposes only), you’d use this call:


Try constructing your own call, using the format above, along with Tampa for the city and your API key after the part that goes APPID=, and enter it into your browser’s address bar. You should be taken to a very plain page displaying something that looks something like the text below:

{"coord":{"lon":-82.46,"lat":27.95},"weather":[{"id":803,"main":"Clouds","description":"broken clouds","icon":"04n"}],"base":"cmc stations","main":{"temp":296.75,"pressure":1018,"humidity":94,"temp_min":295.15,"temp_max":298.15},"wind":{"speed":1.5},"clouds":{"all":75},"dt":1459224301,"sys":{"type":1,"id":721,"message":0.0078,"country":"US","sunrise":1459250563,"sunset":1459295181},"id":4174757,"name":"Tampa","cod":200}

What you’re looking is current weather data, formatted in JSON. Here’s the same data, reformatted so that it’s a little bit easier to read:

The data that OpenWeatherMap returns is a JSON dictionary. Its keys are:

  • coord: A dictionary containing the geographic coordinates for the weather data, with the following keys:
    • lon: Longitude, in degrees
    • lat: Latitude, in degrees
  • weather: An array that usually contains a single dictionary containing the qualitative data about the weather. The dictionary contains the following keys:
    • id: The condition code for the current weather. You can find a list of weather condition codes on this page (you’ll need to scroll down to the section marked Weather condition codes).
    • main: The general category for the current weather. This is usually a single word such as Clear, Clouds, Rain, Thunderstorm, Snow, and so on.
    • description: A slightly longer description of the current weather. Where main may specify Clouds, this value may be few clouds, broken clouds, scattered clouds, etc.
    • icon: The name of the icon for the current weather. You can find a list of icons and their names on this page (you’ll need to scroll down to the section marked Weather icons).
  • base: This is described in the API documentation as an “internal parameter” and probably useful only to OpenWeatherMap’s developers.
  • main: A dictionary containing the quantitative data about the weather. The dictionary contains the following keys:
    • temp: The current temperature, expressed in Kelvin by default.
    • pressure: Atmospheric pressure, expressed in hPa (hectopascal, which is equivalent to 1 millibar). This is the pressure at sea level, if there’s no data for the atmospheric pressure at sea level or ground level.
    • humidity: Humidity, expressed as a percentage.
    • temp_min: Minimum temperature at the moment — the deviation from the current temperature, which you’ll find in large metropolitan areas, expressed in Kelvin by default.
    • temp_max: Maximum temperature at the moment — the deviation from the current temperature, which you’ll find in large metropolitan areas, expressed in Kelvin by default.
    • sea_level: Atmospheric pressure at sea level, expressed in hPa (hectopascal, which is equivalent to 1 millibar).
    • grnd_level: Atmospheric pressure at ground level, expressed in hPa (hectopascal, which is equivalent to 1 millibar).
  • wind: A dictionary containing data about the wind, with the following keys:
    • speed: The wind speed, expressed in meters per second by default.
    • deg: The direction that the wind is coming from, expressed in degrees.
  • clouds: A dictionary containing data about cloud cover, with the following keys:
    • all: The amount of cloud cover, expressed as a percentage.
  • dt: The time when the weather data was provided, in UTC, formatted as Unix time (number of seconds since January 1, 1970, 00:00:00 UTC).
  • sys: A dictionary containing system information, as well as a number of useful items. It contains these keys:
    • type: This is described in the API documentation as an “internal parameter” and probably useful only to OpenWeatherMap’s developers.
    • id: This is described in the API documentation as an “internal parameter” and probably useful only to OpenWeatherMap’s developers.
    • message: This is described in the API documentation as an “internal parameter” and probably useful only to OpenWeatherMap’s developers.
    • country: The two-letter ISO country code for the weather data’s location. Useful when you want to be sure that you’re getting the weather for St. Petersburg in the U.S. or in Russia.
    • sunrise: The time when the sun will rise at the weather data’s location, in UTC, formatted as Unix time (number of seconds since January 1, 1970, 00:00:00 UTC).
    • sunset: The time when the sun will set at the weather data’s location, in UTC, formatted as Unix time (number of seconds since January 1, 1970, 00:00:00 UTC).
  • id: OpenWeatherMap’s internal ID number for the city corresponding to the weather data’s location.
  • name: OpenWeatherMap’s internal name for the city corresponding to the weather data’s location.
  • cod: This is described in the API documentation as an “internal parameter” and probably useful only to OpenWeatherMap’s developers.

Once you’ve confirmed that you can manually get current weather forecasts using your API key and browser, let’s do it programatically with an app.

Step 3: Create a basic app to get the data from OpenWeatherMap

new single view application

Start a new project by doing the FileNewProject… dance and then selecting Single View Application.

Our first iteration won’t have any user interface. It’ll simply try to communicate with OpenWeatherMap, and print the results to the console. Once we’ve confirmed that we’ve got our API communications code working, we’ll add a simple user interface, and I’ll leave making it fancier as an exercise for you.

Many tutorials are happy to stick all the code in a view controller in order to keep the tutorial simple. While it may make writing the tutorial simpler, I think it results in cluttered view controllers and teaches bad programming habits. I’d much rather keep the code in the view controller limited to handling user interactions and put what some people call the “business logic” of our app — in this case, the code that communicates with OpenWeatherMap and extracts weather data from what it sends back — into a separate model class.

With that in mind, we’ll create a new class by selecting FileNewFile… from the menu bar, then selecting Swift File:

new swift class

Give the new file the name WeatherGetter.swift. It will be the home of a class we’ll call WeatherGetter, which will house the code to communicate with OpenWeatherMap and provide the weather data that the view controller will eventually use.

Change the contents of WeatherGetter.swift so that it contains the following code:

You’ve probably figured out that you should replace the string YOUR API KEY HERE with the API key that you got in step 1 and used in step 2. You’re probably eager to see this code in action, so we’ll defer the explanation of how it works until we’ve got the app up and running.

We now need to create an instance of the WeatherGetter class and call its getWeather() method. We’ll do it in the viewDidLoad() method of the view controller:

Now that we’ve got the WeatherGetter class and a way to instantiate and use it, let’s run the app. Remember that right now, it doesn’t have a user interface, and outputs everything using print statements, which will appear in the output pane of XCode’s debug area:

all output will appear here

Step 4: Run the app (and tweak it)

Run the app. You’ll see some disappointing text in the debug area’s output pane that will be similar to this:

2016-04-02 09:03:42.316 SimpleWeather[51150:6547853] App Transport Security has blocked a cleartext HTTP (http://) resource load since it is insecure. Temporary exceptions can be configured via your app's Info.plist file.
Error Domain=NSURLErrorDomain Code=-1022 "The resource could not be loaded because the App Transport Security policy requires the use of a secure connection." UserInfo={NSUnderlyingError=0x7f89ab201e20 {Error Domain=kCFErrorDomainCFNetwork Code=-1022 "(null)"}, NSErrorFailingURLStringKey=http://api.openweathermap.org/data/2.5/weather?q=Tampa&APPID=***YOUR_APP_ID_HERE***, NSErrorFailingURLKey=http://api.openweathermap.org/data/2.5/weather?q=Tampa&APPID=***YOUR_APP_ID_HERE***, NSLocalizedDescription=The resource could not be loaded because the App Transport Security policy requires the use of a secure connection.}

We’ve just run into a security feature of iOS networking that by default requires HTTP connections to be of the secure and encrypted HTTPS variety. Someday, all HTTP communication will be done as HTTPS, but that day hasn’t come yet.

The first thing we should do is see if we can communicate with OpenWeatherMap using HTTPS. Let’s try changing the URL in WeatherGetter.swift so that it starts with https: instead of http:

If we run the app again, we get a different, but equally disappointing message in the debug output pane:

Error Domain=NSURLErrorDomain Code=-1004 "Could not connect to the server." UserInfo={NSUnderlyingError=0x7fd6940016c0 {Error Domain=kCFErrorDomainCFNetwork Code=-1004 "(null)" UserInfo={_kCFStreamErrorCodeKey=61, _kCFStreamErrorDomainKey=1}}, NSErrorFailingURLStringKey=https://api.openweathermap.org/data/2.5/weather?q=Tampa&APPID=***YOUR_APP_ID_HERE***, NSErrorFailingURLKey=https://api.openweathermap.org/data/2.5/weather?q=Tampa&APPID=***YOUR_APP_ID_HERE***, _kCFStreamErrorDomainKey=1, _kCFStreamErrorCodeKey=61, NSLocalizedDescription=Could not connect to the server.}

So now we know that OpenWeatherMap doesn’t accept HTTPS connection requests. Luckily for us, we can change the default connection security policy for our app so that iOS allows it to communicate using plain HTTP. We can do this by adding a couple of extra rows to Info.plist:

click on ifo.plist

Click the screen shot to see it at full size.

Info.plist is an XML file that contains configuration information, and it’s included in every iOS project. In order to make it more readable, Xcode presents it in a nice list interface. If you prefer, you can edit it in its plain XML form by right-clicking on Info.plist in the Project Navigator and selecting Open As → Source Code in the menu that appears.

To enable our app to use plain HTTP communication, we want to do two things in Info.plist:

  1. Add a new dictionary item with the key App Transport Security Settings
  2. Add an item to the App Transport Security Settings dictionary with the key Allow Arbitrary Loads and the boolean value YES

Rather than describe how you do this, I made a video of the process that should be pretty easy to follow:

In the end, you should have this as part of your Info.plist:

app transport security settings

Once that’s done, don’t forget to change the URL in WeatherGetter.swift so that it starts with http: and not https:

Now try running the app. If you’re connected to the internet and OpenWeatherMap.org’s server is running normally, you should see something like the following in the debug output pane:

<7b22636f 6f726422 3a7b226c 6f6e223a 2d38322e 34362c22 6c617422 3a32372e 39357d2c 22776561 74686572 223a5b7b 22696422 3a323131 2c226d61 696e223a 22546875 6e646572 73746f72 6d222c22 64657363 72697074 696f6e22 3a227468 756e6465 7273746f 726d222c 2269636f 6e223a22 31316422 7d2c7b22 6964223a 3530302c 226d6169 6e223a22 5261696e 222c2264 65736372 69707469 6f6e223a 226c6967 68742072 61696e22 2c226963 6f6e223a 22313064 227d2c7b 22696422 3a373031 2c226d61 696e223a 224d6973 74222c22 64657363 72697074 696f6e22 3a226d69 7374222c 2269636f 6e223a22 35306422 7d5d2c22 62617365 223a2263 6d632073 74617469 6f6e7322 2c226d61 696e223a 7b227465 6d70223a 3239372e 35332c22 70726573 73757265 223a3130 31342c22 68756d69 64697479 223a3838 2c227465 6d705f6d 696e223a 3239362e 31352c22 74656d70 5f6d6178 223a3239 382e3135 7d2c2277 696e6422 3a7b2273 70656564 223a352e 312c2264 6567223a 3138307d 2c22636c 6f756473 223a7b22 616c6c22 3a39307d 2c226474 223a3134 35393630 39363832 2c227379 73223a7b 22747970 65223a31 2c226964 223a3732 352c226d 65737361 6765223a 302e3030 35392c22 636f756e 74727922 3a225553 222c2273 756e7269 7365223a 31343539 35393538 36332c22 73756e73 6574223a 31343539 36343039 32337d2c 22696422 3a343137 34373537 2c226e61 6d65223a 2254616d 7061222c 22636f64 223a3230 307d>

At least now we’re getting some data. Let’s make it a little more human-readable. In WeatherGetter.swift, let’s tweak the else clause so it looks like this:

Now, when we run the code — and assuming your internet connection and the OpenWeatherMap server are working — the output should look something like this:

Raw data:
<7b22636f 6f726422 3a7b226c 6f6e223a 2d38322e 34362c22 6c617422 3a32372e 39357d2c 22776561 74686572 223a5b7b 22696422 3a323131 2c226d61 696e223a 22546875 6e646572 73746f72 6d222c22 64657363 72697074 696f6e22 3a227468 756e6465 7273746f 726d222c 2269636f 6e223a22 31316422 7d2c7b22 6964223a 3530312c 226d6169 6e223a22 5261696e 222c2264 65736372 69707469 6f6e223a 226d6f64 65726174 65207261 696e222c 2269636f 6e223a22 31306422 7d2c7b22 6964223a 3730312c 226d6169 6e223a22 4d697374 222c2264 65736372 69707469 6f6e223a 226d6973 74222c22 69636f6e 223a2235 3064227d 5d2c2262 61736522 3a22636d 63207374 6174696f 6e73222c 226d6169 6e223a7b 2274656d 70223a32 39372e36 322c2270 72657373 75726522 3a313031 332c2268 756d6964 69747922 3a313030 2c227465 6d705f6d 696e223a 3239362e 31352c22 74656d70 5f6d6178 223a3239 392e3135 7d2c2277 696e6422 3a7b2273 70656564 223a342e 362c2264 6567223a 3138307d 2c22636c 6f756473 223a7b22 616c6c22 3a39307d 2c226474 223a3134 35393631 30323932 2c227379 73223a7b 22747970 65223a31 2c226964 223a3638 302c226d 65737361 6765223a 302e3030 34392c22 636f756e 74727922 3a225553 222c2273 756e7269 7365223a 31343539 35393538 36322c22 73756e73 6574223a 31343539 36343039 32337d2c 22696422 3a343137 34373537 2c226e61 6d65223a 2254616d 7061222c 22636f64 223a3230 307d>

Human-readable data:
{"coord":{"lon":-82.46,"lat":27.95},"weather":[{"id":211,"main":"Thunderstorm","description":"thunderstorm","icon":"11d"},{"id":501,"main":"Rain","description":"moderate rain","icon":"10d"},{"id":701,"main":"Mist","description":"mist","icon":"50d"}],"base":"cmc stations","main":{"temp":297.62,"pressure":1013,"humidity":100,"temp_min":296.15,"temp_max":299.15},"wind":{"speed":4.6,"deg":180},"clouds":{"all":90},"dt":1459610292,"sys":{"type":1,"id":680,"message":0.0049,"country":"US","sunrise":1459595862,"sunset":1459640923},"id":4174757,"name":"Tampa","cod":200}

As you can see, the stuff after “Human-readable data:” looks like the output you got when you manually got the weather data from OpenWeatherMap in step 2.

Step 5: Play with the app, and keep an eye open for the next installment in this series!

Here’s what your WeatherGetter.swift file should look like…

…here’s what ViewController.swift should look like…

…and if you prefer to edit Info.plist as raw XML, here’s what it should look like:

xcode download

You can also download the Xcode project — it’s a mere 33KB zipped.

Try some experiments. Here are a few of my suggestions:

  • What happens if you run the app in Airplane Mode?
  • What happens if you change the URL in WeatherGetter to a non-existent one, such as openweathermoop.org?
  • How would you go about extracting the weather information from the JSON returned by the server?
  • How would you display the weather information to the user?

In the next installment in this series, we’ll take a step back and cover “iOS/Swift networking 101”, taking a closer look at the various objects used inside the WeatherGetter class.


minion mic drop

For April Fool’s Day, Google added a “Send this email with a mic drop” button to Gmail, which is a button that allows the sender to have the last word in a conversation. For the first few hours of April 1, 2016, Gmail users starting a new email message saw this:

introducing gmail mic drop

If you were to send an email with the orange Send + mic drop button instead of the standard blue Send button, your email message gets sent with a couple of key changes:

  • It adds an animated GIF of the scene from the Minions movie where Bob the Minion, now King of England, ends a royal address with a “mic drop”, a gesture where a speaker, at the end of a performance or speech, drops the microphone on the ground as a way of saying “I was just so impressive, there’s no point in anyone speaking after me” or “I just won this debate or rap battle”, and
  • because the feature is supposed to give you the last word, it ensures that the sender NEVER sees any reply to the email.

When used jokingly among friends while discussing a trivial topic — say, a debate about the 1980s fantasy film Ladyhawke, just like the one in the novel Ready Player One — this feature can be pretty funny. It may strain relations if you use it to reply to a pro-Donald Trump mass email that your ultra-conservative vaguely racist aunt sent out to her large family cc: list.

The problem with the Send + mic drop button is that it’s all too easy to use it by accident. It’s located in about the same place as the plain Send button. The different color should be a dead give-away that something’s different, but given that web apps, especially Google web apps, change their user interfaces quite often, it’s all too easy for someone to click on the new button with unexpected, and possibly unpleasant results.

Here’s one complaint posted to the Gmail Help Forum, posted by someone identifying themselves as Allen Pashby:

will google give me a job

It reads:

Thanks to Mic Drop I just lost my job. I am a writer and had a deadline to meet. I sent my articles to my boss and never heard back from her. I inadvertently sent the email using the “Mic Drop” send button.There were corrections that needed to be made on my articles and I never received her replies. My boss took offense to the Mic Drop animation and assumed that I didn’t reply to her because I thought her input was petty (hence the Mic Drop). I just woke up to a very angry voicemail from her which is how I found out about this “hilarious” prank.

Google have since disabled their April Fool’s feature and have updated their blog post announcing it to start with the following paragraph:

UPDATE: Well, it looks like we pranked ourselves this year. 😟 Due to a bug, the Mic Drop feature inadvertently caused more headaches than laughs. We’re truly sorry. The feature has been turned off. If you are still seeing it, please reload your Gmail page.

Lessons you can learn

problem - opportunity

While I’ve found it instructional to learn from my own mistakes, it’s far more enjoyable and less stressful and embarrassing to learn from others’ mistakes. Here’s what you can take away from Google’s mic drop snafu:

  • When you’ve got a platform with a large number of users (the number that gets bandied about when talking about total Gmail users is one billion), you’re going to have a large number of use cases. Many people use Gmail as their primary business email tool, and there’s a good chance that a number of business conversations and relationships were derailed, at least temporarily, by a mic drop message.
  • People expect consistency, especially from tools they use daily, and when that consistency is broken, the experience is degraded. Remember what happened when Microsoft removed the start menu in Windows 8?
  • When you change your user interface often, people stop noticing user interface changes. As designer Douglas Bowman wrote when he resigned in 2009, their approach to design often takes a test-driven approach, where they present one group of users with one design, another group of users with an alternate design, and they choose the winning design based on user responses. This approach requires performing little experiments which involve making changes to the interfaces that users see. We’ve become so used to these changes that we often don’t notice them until they’re pointed out. Often, these changes are minor, such as the time they showed different users different shades of blue to see which one of 41 possible shades would perform better. However, in cases where the change in behavior is significant, such as with the mic drop, surprising the user can be problematic.
  • Warn users when you’re about to perform something “destructive” or radically different. Typically, when you’re about to delete a file, photo, or some other piece of data in an application, you’re presented with an “Are you really sure you want to do this?” message. Google could’ve made a similar message appear after the user pressed Send + mic drop button that explained what was about to happen and offered a way to cancel.
  • Nobody’s always alert. This feature was introduced at midnight Pacific time (GMT -7), April 1, 2016, which meant that for a lot of users, it was late at night or early in the morning, meaning that a lot of users were either working late or early, when alertness is low. Coupled with the fact that people stop noticing user interface changes when they change so often, this can lead to trouble.