Getting Started with Visual Testing

There are tons of tools out there that help you make sure your app is functioning correctly. But how do test software from a purely visual standpoint?

Chances are you’re writing functional tests to check visual elements, or manually checking your UI whenever you push a change. If you are doing either of those things, then you know that they’re incredibly time-consuming and bugs still end up slipping through the cracks.

That’s where visual testing comes in.

Getting Started with Vue.js Navigation Guards to Restrict Access to Routes

You might remember that I had written a tutorial titled, Simple User Login in a Vue.js Web Application, which demonstrated how to navigate between routes and check a variable to determine if a user should in fact be allowed to be on a particular route. This previous tutorial focused on applying logic after the user had already completed the navigation process, rather than during or prior. While this is a good introduction to becoming familiar with the Vue.js router, it isn’t a realistic approach to handling user login and route restrictions.

The recommended approach is to use navigation guards, sometimes referred to as route guards.

In this tutorial, we’re going to see how to use Vuex with Vue.js navigation guards to protect certain pages within the application from unauthorized access.

Chaining JavaScript Promises While Sharing Parent Data

Typically when I’m working with RESTful APIs, the routes or endpoints return what I need, plus more, which would be too much data. However, recently I ended up working with an API where the responses were rather trim, resulting in the need to use many HTTP requests to various endpoints, rather than getting everything in a single request. To take it a step further, some of those HTTP requests depended on data from other requests creating a mess of asynchronous operations in JavaScript.

After consulting with my pal, Corbin Crutchley, we came up with a solution to what I needed, without creating chaos in my code. Remember, Corbin is a JavaScript professional, as demonstrated on the podcast we recorded together titled, Asynchronous JavaScript Development.

In this tutorial we’re going to see how to chain JavaScript promises, but also use data from parent links in the promise chain with child links in the same promise chain.

TPDP Episode #29: Asynchronous JavaScript Development

The latest episode of The Polyglot Developer Podcast has just published, this time focusing on the use of callbacks, promises, and async / await, in JavaScript.

This episode titled, Asynchronous JavaScript Development, is the twenty-ninth episode to appear on the show and it features Corbin Crutchley, an expert JavaScript developer and open source maintainer.

If you’ve ever struggled with wrapping your head around working with remote resources or blocking tasks in JavaScript, this episode should clear things up.

Image Cropping, Zooming, and Scaling with Angular and JavaScript

When building a web application there is a good chance you’re going to need to work with images eventually, even if it is something as simple as allowing a user to upload a profile image. In theory this is a simple task, but in reality, your website theme is probably anticipating images of a certain resolution or aspect ratio. If the user tries to upload an image that doesn’t meet your requirements, it might break your theme.

We’re going to see how to include image manipulation capabilities in your Angular application using the popular cropperjs JavaScript package.

Getting Started with Building Chatbots using AWS Lex and Node.js

Amazon and a lot of cloud vendors such as Microsoft and Google have services around machine learning (ML), artificial intelligence (AI), and virtual assistants. A popular one that might come to mind is Amazon Alexa, something I’ve written quite a few tutorials around over the years.

The concept around Alexa is simple. Provide the Alexa service some audio, have that audio converted into text or some other format that can be evaluated, execute some code, and respond with something to be spoken to the user. However, what if you didn’t necessarily want to use a virtual assistant with audio, but integrate as part of a chat application in the form of a chatbot?

In this tutorial we’re going to look at using Amazon Web Services (AWS) Lex, which is a service for adding conversational interfaces to your applications. If you’re coming from an Amazon Alexa background, the concepts will be similar as AWS Lex shares the same deep learning technologies.

Password Hashing and JWTs for NativeScript Apps with an Express.js Backend

When building an application that allows users to have accounts, you have to ensure that access to these accounts is secure. When building a user account system, an important factor to keep in mind is how passwords are stored. Storing passwords as plain text is a complete rookie move that leaves your users vulnerable to all sorts of data breaches.

The best way to protect passwords is to employ hashing and salting and in this tutorial, we’ll show you exactly how to do this. We’ll also show you how to generate JSON Web Tokens (JWT) on a Node.js server backend that can be used to authenticate and authorize users, as well as how to store those tokens on the client NativeScript application.