Bearer tokens serve as a form of access token authentication, providing a secure method for authorizing API requests. They are typically included in the Authorization header of HTTP requests and grant access to protected resources.

We can bolster the security of loading our images using bearer tokens. Common SDWebImage’s extension method we use to load an image into UIImageView is:

imageView.sd_setImage(with: url, placeholderImage: nil, options: [.refreshCached]) { (image, error, cacheType, url) in
//Handle if required
}

How do we pass a bearer token in SDWebImage?

Making UIScrollView Scrollable with Keyboard in iOS

Register for Keyboard Notifications

Register for keyboard notifications in view controller. These notifications will inform us when the keyboard shows and hides.

NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(_:)), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(_:)), name: UIResponder.keyboardWillHideNotification, object: nil)

When it comes to programmatically creating custom UITableViewCells, there's a common stumbling block that developers often encounter. It's the scenario where you add a button to the cell, but the target action doesn't get triggered when the button is pressed. While there could be several factors contributing to this issue, I'll delve into one of the fundamental design flaws that can lead to such behavior.

The crux of the problem often lies in the way we add subviews to our custom cell programmatically. A common practice is to add the subviews directly to the cell itself. However, this approach can cause unexpected behavior, including the failure of target action calls when a button is pressed.

override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        
        addSubview(button)
        button.addTarget(self, action: #selector(didTapButton), for: .touchUpInside)
}

So, what's the solution? Let's dive into it.

To convert the string literal into an array of strings, we use the map function on the string literal.

In order to crawl a large text file containing URLs, I required a method that would allow me to specify and read only a certain range of lines, without having to load the entire file into memory. To achieve this, I utilized the islice() function from Python's itertools module: itertools.islice()

Here is a code snippet that demonstrates this:

In Swift most sequence collections provides removeAll(where:) - an efficient way to remove at once multiple items matching the coditional logic from collection.

Very common user experience we come across when using UITextField and UITextview is to limit the number of characters.

For UITextField:

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    if (textField.text?.count ?? 0) +  (string.count - range.length) >= characterLimit{
        return false
    }
    
    return true
}

For UITextView:

There is always a need to sort an array. What if array consists of custom objects? How do we sort array of custom objects by a property value? Let us find out!

const array = [
    { name: 'John', order: '2' },
    { name: 'Jack', order: '1' },
    { name: 'James', order: '10' }
]

In my localhost server, remote push notifications worked fine. It had stopped working on the production server. I have designed a neat system to separate the development environment from production mode for testing remote push notifications. Different certificates are used automatically based on the running environment. Device tokens are stored in a database based on the nature of the iOS app’s distribution. It ensures sandbox mode uses debug-version of device tokens else we will be running often into the “Baddevice Token” response from the apns server.

The system is well-tested with time. Remote push notifications stopped working in production mode all of sudden. I am not using the third-party service to manage our push notifications. I have our well-designed and well-tested middleware to manage push notifications. It follows a modern recommendation from apple to use http/2 to process all requests to apns server. Many good tutorials out there on the subject. I will share my troubleshooting experience and its solutions.

I turned on the verbose settings to display every information of cURL execution. It gives insight on if the connection is going through the apns server and what response we get.

CURLOPT_VERBOSE => true