All you need to know Accessibility | iOS SDK | Swift

Why does Accessibility matter?

First thing first, it always feels good to know that even if your work is small but it’s making a huge difference in someone’s life. 🙂 There are millions of smartphone users all around the world with some sort of disability. Enabling accessibility into the software system ease them in interacting with it.

And on the other hand, if you’re working for any government agency you have to implement it because of 508 compliance (which says that any technology or software product must be accessible to all users).

Accessibility domains?

– Vision: a vision challenge that makes focusing difficult, color blindness or total blind.
– Hearing: difficulty hearing sound, partial hearing loss or maybe deaf.
– Physical and motor skills: difficulty when it comes to tapping the interface or holding a device.
– Learning and Literacy: hard to understand a complex user interface or hard to remember a sequence of step to do a certain task.

Image from Apple.

What is VoiceOver?

A screen reading tool that helps the user to interact with the application without seeing the screen. The feature is designed for those who have vision problems. Navigate to Settings/Accessibility/VoiceOver.

VoiceOver: Gestures?

Enable the VoiceOver to try this out.
– Single tap: Tap anywhere, VoiceOver will start speaking information as per the accessibility attributes (find more later).
– Swipe right or left: Try swipe right/left VoiceOver will navigate you through all items on the screen while reading them aloud. Right for forward/down and Left for reverse/up.
-Double Tap: is to tap on a selected item.
– Single swipe down: is to spell out the focused item.
– Three finger swipe: For page views to navigate forwards or backward

Accessibility attributes?

Core attributes that VoiceOver will use to provide information to the user.
– Label: way to identify the view (like settings button, profile image) VoiceOver will speak the same when the item will be selected.
– Traits: way to identify the element state, usage or behaviour (like a button is selected.) 
– Hint: way to describe the action of an element (like Go to detail).
– Frame: frame of the element within the screen.
– Value: The value of element like a slider bar.
– AccessibilityLanguage: The language code that the element label value, hint should be spoken. 

How to debug accessibility attributes?

Accessibility inspector is a tool given by Apple to debug your app (Navigate to Xcode/Open Developer Tool/Accessibility Inspector). Where developer can choose the target, enable the pointer to debug the view.

Accessibility Notification?

Animation or layout changes are a visual feedback to the user as a response of the action taken, Use announcements notification to provide an update (other options are layoutChanged, screenChanged delegates).

Target Touch Size?

As per Apple human interface guidelines it is recommended to maintain a tappable area of 44x44pt (minimum) for all controls in the application.

What is Dynamic Type?

Functionality that allows the users to dynamically adjust the size of text, images (choose their preferred text size). iOS app will adopt the text/image size as per user preference. (Apple Developer documentation)

Setup Smart Invert Colors?

Need to set `accessibilityIgnoresInvertColors` property to enable or prevent a control from inverting it’s colours. (Navigate to Setting/General/Accessibility/Display Accommodations/Invert Colors).

Thanks for reading this.

Swift Keynote: Enumeration

  • An enumeration defines a common type for a group of related values and enables you to work with those values in a type-safe way within your code.   
    Or when a property can have its value only out of a defined set, enum is the solution which complimentary provides type-safety and auto-completion at compile time.
  • Enumerations can define initializers to provide an initial case value; can be extended to expand their functionality beyond their original implementation; can have functions and can conform to protocols to provide standard functionality.
  • Enums can have nested enums and associated values. 

    Screen Shot 2018-07-20 at 12.33.54 AM.png

  • Enums can be recursive: A recursive enumeration is an enumeration that has another instance of the enumeration as the associated value for one or more of the enumeration cases. “Indirect” keyword is used to inform the compiler about recursion.

    Screen Shot 2018-07-20 at 1.19.49 AM.png

  • Each enum case’s rawValue depends upon the raw type taken and if no raw type is not taken than rawValue wouldn’t be available. Swift’s enums don’t bound to use only integer type as a raw type, you can use StringsCharacters or even Floats instead.

Happy Coding!!

Creating and Distributing iOS Frameworks | Swift | Tips & Tricks

Why do we need to create frameworks? because it has three major purposes mentioned below and also you can share your code with your team, other developer or iOS community.

  • Code encapsulation
  • Code modularity
  • Code reuse

Let’s create the iOS framework.

Screen Shot 2018-02-05 at 8.24.50 PM

Now just give some meta-data about your framework like name, organization, identifier etc (I hope you’re already aware of it).

Screen Shot 2018-02-05 at 8.26.54 PM.png

We’re good to go till now. Just add the files that you want to keep within your framework.

add

Build the framework project to make sure that you get build succeeded with no build warnings or errors.

Things that you need to take care.

  • Make sure to check Copy items if needed, so that the files actually copy into the new project instead of just adding a reference. Frameworks need their own code, not references, to be independent.
  • Double-check that each of the files has Target Membership in ThreeRingControl to make sure they appear in the final framework. You can see this in the File Inspector for each file.
  • Double-check the access modifiers, while creating framework access modifiers plays very important roles.
  • if you’re creating Swift framework make sure you’re extending classes from NSObject otherwise it won’t reflect once you will import the framework.

Thanks for reading.

STUPID principles | Quick Notes

Recent blog: SOLID vs STUPID

STUPID principles and yes this may hurt your feeling but yes if you are following this you are writing stupid code.

Singleton

Well known design pattern, but mostly understood one as well. Like me, people are also fighting with Singleton syndrome. In that case, whenever we create a class we create it Singleton but why? That is definability not cool. Singleton also considered anti-patterns. We should think and avoid if possible because the program using Singleton are hard to test because of global state, with the global state they hide their dependencies.

Tight Coupling

Avoiding static things is important to avoid tight coupling. If it’s there then making a change in one module requires to changes another module too. Now it’s really difficult to reuse and difficult to test.

Untestability

Testing is not hard, what you think? We don’t write test case may be because we don’t have the time or the code we are writing is bad because of tight coupling?

Premature Optimization

One of my favorite quote from Donald Knuth, premature is the root of all evil. There are only cost and no benefits. Actually optimised code is much complex as compared to just writing a loop.

Indescriptive Naming

That’s what I like most and I try to follow as much as possible. Name of your class, variables or methods should be clear because at the end of the day human is only going to read because programming languages are for human not for computers, computers can understand 0 or 1 very well.

Duplication

That’s bad. Writing same code again and again so don’t repeat yourself, keep it simple and strong. Write Code only once.

Thank you for reading the quick introduction of STUPID principles, next will be SOLID principles.

Signs of wrong architecture? | Quick Notes

Recently I have got one iOS Application codebase to review and it always gives a thought, where to start?

Here are the 3 important first steps for me that I always do.

find . -type f -exec wc -l {} + | sort -n

Execute the terminal command in your project location, it will give you count of number of lines, like mentioned below

3000 ./ViewControllers/DashboardVC.swift
5655 ./AppDelegate.swift

where 3000/5655 is the lines of code.

Second, I track are we using Appdelete directly?

grep -rnw . -e "UIApplication.shared"

Last, but not the least. Swift/Objective-C dependency visualizer. It creates object dependency graphs and gives you the clear picture.

Screen Shot 2017-11-22 at 5.33.12 PM

Thanks for reading. I hope it was quick and informative for you.

How to Respond to an Authentication Challenge | iOS

How to Respond to an Authentication Challenge

If a session requires authentication it creates authentication challenge

 URLSession:task:didReceiveChallenge:completionHandler: 

in order for the connection to continue, the delegate has three options.

  • Provide authentication credentials
  • Attempt to continue without credentails
  • Cancel the authentication request.

NSURLProtectionSpace will give all information about the authentication type and failure if any attempts failed earlier.

Providing Credentials

To attempt to authenticate, the application should create an NSURLCredential object with authentication information of the form expected by the server. You can determine the server’s authentication method by calling authenticationMethod on the protection space.

  • HTTP basic authentication (NSURLAuthenticationMethodHTTPBasic) requires a user name and password. P
  • HTTP digest authentication (NSURLAuthenticationMethodHTTPDigest), like basic authentication, requires a user name and password.withcredentialWithUser:password:persistence:.
  • Client certificate authentication (NSURLAuthenticationMethodClientCertificate) requires the system identity and all certificates needed to authenticate with the server. Create an NSURLCredential object.
  • Server trust authentication (NSURLAuthenticationMethodServerTrust) requires a trust provided by the protection space of the authentication challenge.

Continuing Without Credentials

If the delegate chooses not to provide a credential for the authentication challenge, it can attempt to continue without one.

NSURLSessionAuthChallengePerformDefaultHandling processes the request as though the delegate did not provide a delegate method to handle the challenge.

  • NSURLSessionAuthChallengeRejectProtectionSpace rejects the challenge. Depending on the authentication types allowed by the server’s response, the URL loading class may call this delegate method more than once, for additional protection spaces.

Canceling the Connection

The delegate may also choose to cancel the authentication challenge, by passing NSURLSessionAuthChallengeCancelAuthenticationChallenge to the provided completion handler block.

Dependency Injection | Swift | Quick Note

A short answer is, it’s scary terms for a very simple idea!!! See this lines of code.

class Engine {

}

class Car {
    let engine: Engine? = nil
    init() {
        self.engine = Engine()
    }
}

we are creating dependency internally but the object can be also received from outside with lots of benefits like the object become instantly testable, Testing becomes possible without any frameworks, No runtime effects, This makes the whole system more loosely coupled.

class Car {
    let engine: Engine? = nil
    init(engine: Engine) {
        self.engine = engine
    }
}

There are three common types of dependency injections.

Setter, Interface, Constructor based.

In iOS Constructor based is preferable one, it’s when dependency passed to the client in the initializer and don’t change during the whole client life and the biggest advantage of this type could be that it makes the violation of the single responsibility programming principle, if an object takes all dependencies in the initializer and if it has more than three parameters so it means refactoring is needed.

Thanks for reading!!!