What Is the Observer Pattern? The Observer Pattern is a software design pattern that establishes a one-to-many dependency between objects. Anytime the state of one of the objects (the “subject” or “observable”) changes, all of the other objects (“observers”) that depend on it are notified. Let’s use the example of users that have subscribed to receive offers from Envato…
Ensure High-Quality Android Code With Static Analysis Tools
In today’s tutorial, we’ll learn about how to ensure high-quality Android code in our projects using some static code analysis tools for Java. We’ll look at Checkstyle, FindBugs, PMD, and Android Studio Lint—all of them free and open source! What Are Static Code Analysis Tools? These are tools that parse and analyse your source code…
Android O: How to Use Notification Channels
Google has launched the first developer preview of the next Android version, currently code-named Android O (Oreo maybe?). Some exciting features were released, and one of them is Notification Channels. In this tutorial, we’ll explore this feature and build a simple app that demonstrates the functionalities it provides. What Are Notification Channels? Notification channels enable us app developers to…
Serverless Apps With Firebase Cloud Functions
Firebase’s goal is to help developers build better apps and grow them into successful businesses. By taking care of your app back-end or infrastructure, Firebase lets you focus on solving problems for your users. One of the new exciting features announced at the Google Cloud Next ’17 Conference this March for Firebase was Cloud Functions. In this tutorial,…
Code an Image Gallery Android App With Glide
1. What Is Glide? Glide is a popular open-source Android library for loading images, videos, and animated GIFs. With Glide, you can load and display media from many different sources, such as remote servers or the local file system. By default, Glide uses a custom implementation of HttpURLConnection to load images over the internet. However, Glide also provides plugins…
How to Make Calls and Use SMS in Android Apps
In this tutorial, you’ll learn about the Android Telephony and SMS API. You’ll learn how to make a call from your app and how to monitor phone call events, as well as how to send and receive SMS. 1. How to Make A Call To start off, I’ll show you how to initiate a call from…
Passwordless Authentication With Account Kit
About Account Kit What Is Passwordless Authentication? Passwordless authentication skips using a password for registration or login. Instead, user authentication is confirmed either with a one-time SMS verification code sent to the user’s phone or a one-time link to their email address. Why Use Passwordless Authentication? Seamless login and registration process for your users. Keeps…
Crash Reporting With Crashlytics
In Android, there is a high probability of your app crashing even after you have manually and automatically tested it. This can be due to factors such as incompatibility with different API levels, screen sizes, phone memory, hardware sensor availability, and vendors’ customization to suit their individual devices. Crashlytics will help you diagnose these problems.…
Quick Tip: Firebase Security Rules
Firebase Realtime Database security rules are how you secure your data from unauthorised users and protect your data structure. In this quick tip tutorial, I will explain how to configure your database security rules properly so that only authorised users have read or write access to data. I’ll also show you how to structure your…
Part 2: Sending Data With Retrofit 2 HTTP Client for Android
What Is Retrofit? Retrofit is a type-safe HTTP client for Android and Java. Retrofit makes it easy to connect to a REST web service by translating the API into Java interfaces. In this tutorial, I’ll show you how to use one of the most popular and often recommended HTTP libraries available for Android. So Why Use…