Creating a PDF file from HTML can be done using iText Java library. iText has an add-on that enables converting HTML to PDF document. This post shows how to use iText to convert HTML to PDF.

Kotlin auto-generates a field referencing a class property within its accessors "get() or set()". This field is called a backing field and it will be generated if a property uses the default accessors implementation or if one of the accessors references it through field identifier

Inheritance is a common solution for code reusability. Extending class implementation will allow subclasses to inherit implemented members e.g. functions and properties. Delegation design pattern, however, is an alternative solution to inheritance. Delegation pattern uses object composition to achieve code reusability. Kotlin provides native support for this pattern where a class can delegate implementation to a specified object. In this post we will explain delegation design pattern and see it in action usign Kotlin.

Backpropagation is a technique used for training neural network. There are many resources explaining the technique, but this post will explain backpropagation with concrete example in a very detailed colorful steps.

ConnectivityManager class can be used to answer queries about network connectivity status. It can also notifiy applications when network connectivity status changes using NetworkCallback.

Sending data to the cloud is a common task in mobile applications. Here we will consume an open REST service to practice sending data in JSON format to a cloud server. We will use HttpURLConnection to make an HTTP POST request to the server.

Long-running task such as CPU intensive work, writing a file to disk or network request should NOT run on the main thread. Android, for example, will throw a NetworkOnMainThreadException if you try to perform an HTTP reqeust on the main thread. To resolve this issue, we can use Kotlin coroutine to perform long-running task on a separate thread. This post shows how to perform a non-blocking HTTP reqest using HttpUrlConnection and Kotlin coroutine.