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This is the third part of the series on Higher-Order Components. In the first tutorial, we started from ground zero. We learned the basics of ES6 syntax, higher-order functions, and higher-order components.  The higher-order component pattern is useful for creating abstract components—you can use them to share data (state and behavior) with your existing components. In the second part of the series, I demonstrated practical examples of code using this pattern. This includes protected routes, creating a configurable generic container, attaching a loading indicator to a component, etc.  In this tutorial, we will have a look at some best practices and dos and don'ts that you should look into while writing HOCs.  Introduction React previously had something called Mixins, which worked great with the  React.createClass method. Mixins allowed developers to share code between components. However, they had some drawbacks, and the idea was dropped eventually. Mixins were ...

An app's credibility today highly depends on how the user's private data is managed. The Android stack has many powerful APIs surrounding credential and key storage, with specific features only available in certain versions. This short series will start off with a simple approach to get up and running by looking at the storage system and how to encrypt and store sensitive data via a user-supplied passcode. In the second tutorial, we will look at more complex ways of protecting keys and credentials. The Basics The first question to think about is how much data you actually need to acquire. A good approach is to avoid storing private data if you don't really have to. For data that you must store, the Android architecture is ready to help. Since 6.0 Marshmellow, full-disk encryption is enabled by default, for devices with the capability. Files and SharedPreferences that are saved by the app are automatically set with the MODE_PRIVATE constant. This means the data can be a...

In this article, we'll go through mutators and accessors of the Eloquent ORM in the Laravel web framework. After the introduction, we'll go through a handful of examples to understand these concepts. In Laravel, mutators and accessors allow you to alter data before it's saved to and fetched from a database. To be specific, the mutator allows you to alter data before it's saved to a database. On the other hand, the accessor allows you to alter data after it's fetched from a database. In fact, the Laravel model is the central place where you can create mutator and accessor methods. And of course, it's nice to have all your modifications in a single place rather than scattered over different places. Create Accessors and Mutators in a Model Class As you're familiar with the basic concept of mutators and accessors now, we'll go ahead and develop a real-world example to demonstrate it. I assume that you're aware of the Eloquent model in Laravel, and w...

Overview JSON is one of the most popular serialization formats. It is human readable, reasonably concise, and can be parsed easily by any web application using JavaScript. Go as a modern programming language has first-class support for JSON serialization in its standard library.  But there are some nooks and crannies. In this tutorial you'll learn how to effectively serialize and deserialize arbitrary as well as structured data to/from JSON. You will also learn how to deal with advanced scenarios such as serialization enums. The json Package Go supports several serialization formats in the encoding package of its standard library. One of these is the popular JSON format. You serialize Golang values using the Marshal() function into a slice of bytes. You deserialize a slice of bytes into a Golang value using the Unmarshal() function. It's that simple. The following terms are equivalent in the context of this article: Serialization/Encoding/Marshalling Deserialization/Deco...

The multiprocessing package supports spawning processes using an API similar to the threading module. It also offers both local and remote concurrency. This tutorial will discuss multiprocessing in Python and how to use multiprocessing to communicate between processes and perform synchronization between processes, as well as logging. Introduction to Multiprocessing Multiprocessing works by creating a Process object and then calling its start() method as shown below. from multiprocessing import Process def greeting(): print 'hello world' if __name__ == '__main__': p = Process(target=greeting) p.start() p.join() In the example code above, we first import the Process class and then instantiate the Process object with the greeting function which we want to run. We then tell the process to begin using the start() method, and we finally complete the process with the join() method.  Additionally, you can also pass arguments to the function by prov...

In this article, we are going to explore the basics of event management in Laravel. It's one of the important features that you, as a developer, should have in your arsenal in your desired framework. As we move on, we'll also grab this opportunity to create a real-world example of a custom event and listener, and that's the ultimate goal of this article as well. The concept of events in Laravel is based on a very popular software design pattern—the observer pattern. In this pattern, the system is supposed to raise events when something happens, and you could define listeners that listen to these events and react accordingly. It's a really useful feature in a way that allows you to decouple components in a system that otherwise would have resulted in tightly coupled code. For example, say you want to notify all modules in a system when someone logs into your site. Thus, it allows them to react to this login event, whether it's about sending an email or in-app notif...

Mocking is a library for testing in Python. It allows you to replace parts of your system under test with mock objects and make assertions about how they have been used. This tutorial will discuss in detail what mocking is and how to use it in Python applications. What Is Mocking? Mocking is a library for testing in Python which allows you to replace parts of your system under test with mock objects and make assertions about how they have been used. In Python, mocking is accomplished by replacing parts of your system with mock objects using the unittest.mock module. This module contains a number of useful classes and functions, namely the patch function (as decorator and context manager) and the MagicMock class. These two components are very important in achieving mocking in Python. A mock function call usually returns a predefined value immediately.  A mock object's attributes and methods are defined in the test as well, without creating the real object. Mocking also allows y...