State machines are an old concept. They are a proven solution that provides a solid architectural foundation for application processes. In this article, I hope to provide an introduction to what they are and how they can be useful for a modern web or mobile application engineer. We’ll be focusing on one library in particular – xstate – and how it can allow anyone to easily leverage state machines for managing global or component state.
Let us present this scenario. You’re building a React application, and you’ve been tasked to build a registration form. Seems simple enough, you think at first, but then you start hearing the requirements. The application needs to have validation on each field, and each field needs to have certain requirements, such as being required, being a certain type of field, having a certain length, etc. Your form must also be easily created and have an easily adjusted state during its usage. At this point, something you originally thought would be quick and easy is seeming more and more time consuming and complicated!
Well, worry no more and look no further; the community has come to your rescue. In this post, we’re going to talk about using the form library called Formik and the validation library called Yup to build out a simple validation form inside of a ReactJS application.
You can’t read any technology trend news for the upcoming year without reading about Progressive Web Applications (PWA). PWA offers the ability to add native-like capabilities to your web application.
One of the core technologies of a PWA is the service worker, so I thought I would take us through a question and answer session on service workers. Service workers have been around for a while now, but the momentum in their use has picked up with the popularity of PWA. My goal here is for you to be able to understand what a service worker is, what you can do with it, and the limitations of a service worker.
Facial recognition is both amazing and horrifying. Some amazing things it can do is the ability to find missing children or seniors, using your face to unlock your phone, and being able to board an airplane faster.
In this blog post, I want to highlight some powerful tools and platforms that allow you to create distributed facial recognition systems with OpenCV and Azure’s Cognitive Services. By the end of this post, you will have a working face detector using OpenCV that can communicate with Azure’s Cognitive Services.
I used Python 3.7.4 and pip 19.2.3 for this project. You can view the code from this blog at https://github.com/dcandre/Dystopian-Future-At-Home.
There is a new exciting feature coming to JavaScript in the not-so-far future. That feature is Optional Chaining. At this moment, Optional Chaining is in Stage 3 of the TC39 process, so it’s in late stages of the process and will be here soonish.
In general terms, Optional Chaining is an approach to simplify JavaScript expressions for accessing deeply nested values, array items, and methods when there is a possibility that a reference may be missing.
In this blog, we give an introduction to Optional Chaining in JavaScript. We discuss what problems Optional Chaining solves, the various ways you can use it, and relatable code examples.