JavaScript

Using Decorators to Declaratively Extend Functions

The decorator pattern gained fame in the object-oriented world after being featured in the classic 1994 Gang of Four book, Design Patterns. Since then, it’s been used extensively in traditional object-oriented programming as an alternative to inheritance. What’s really going on behind the scenes though, is composition, which means decorators are also great for cleaning up some functional programming boilerplate.

We’re going to look at decorators in JavaScript, along with some proposed syntax sugar coming in ES2017 that will make it easier to use them. Read more on Using Decorators to Declaratively Extend Functions…

GraphQL + Apollo – Part 2: Building a Server

In this series, we are taking a dive into GraphQL through the lens of the Apollo toolchain. Part 1 of the series explains some core concepts of GraphQL and introduces Apollo as a GraphQL solution. In this post, we will take a closer look at building a GraphQL server with Apollo tools. Part 3 will take a look at the Apollo Client libraries and implement an example client. Read more on GraphQL + Apollo – Part 2: Building a Server…

GraphQL + Apollo – Part 1: An Introduction

This past September, I attended the Strange Loop conference in St. Louis. Among the plethora of great talks that I attended was one about GraphQL, given by Lee Byron. This talk, supplemented by a great deal of research, convinced me that I should use GraphQL in the project that I started a couple of months ago.
Read more on GraphQL + Apollo – Part 1: An Introduction…

Lazy Sequences with ECMAScript 6 Generators

Generators are an ES6 feature that started receiving a lot of attention a few years ago because of their potential to ease some of the pain associated with writing asynchronous code. However, with the emergent async/await proposal (mere syntax sugar around generators and promises), some of the shine has worn off, and generators aren’t getting the same amount of attention they used to.

This is a shame, because even if you disregard their uses in asynchronous code, generators are still pretty cool in their own right. I’m going to explore some of the ways you can use them to implement lazy sequences.
Read more on Lazy Sequences with ECMAScript 6 Generators…

Pixels and Palettes: Extracting Color Palettes From Images

Color palettes are usually carefully hand-selected to reflect a desired design aesthetic. Although there have been some attempts to procedurally generate palettes, automated palette creation is very difficult. It’s easy to choose some random colors, but generating a coherent and aesthetically pleasing palette in an automated way is not easy.
Read more on Pixels and Palettes: Extracting Color Palettes From Images…

Sharing Web Data with iOS Using WKWebView

I recently helped develop a native iOS app for a client that sells software to many different educational organizations. We wrote the app in Swift, and it interacts with our client’s pre-existing web API.

One challenge we faced was that many of our client’s customers require single-account, multiple-login (SAML) support through their own web portals. To support SAML, we needed an easy way to pass a user’s API credentials from a web page to our iOS application. In this post, I’ll show how this can be accomplished using WKWebView.
Read more on Sharing Web Data with iOS Using WKWebView…

Take Your Emacs to the Next Level by Writing Custom Packages

I wrote recently about using Emacs as a JavaScript development environment. One of my chief complaints was the inability to easily run JavaScript tests from within Emacs. I practice TDD frequently, and having to context-switch out of the editor I’m using to run tests is a big annoyance for me.

I knew it was possible to do what I wanted from within Emacs, as evidenced by other test runner modes like RSpec-mode. Armed with that knowledge, I decided to go through the process of learning enough Emacs Lisp to make a Mocha test runner. In the process, I learned a lot about developing Emacs packages and ended up with a really useful tool, so I thought I would share some of the things I learned.
Read more on Take Your Emacs to the Next Level by Writing Custom Packages…

Avoiding “Undefined is Not a Function” with Constants

How many times have you come across JavaScript’s “Undefined is not a function”? Too many. JavaScript is known for being so flexible that it’s easy to create unintentional bugs.

One way we can add structure to JavaScript code is to make a habit of using constants. Constants pair well in JavaScript with JS’s powerful object data structure, and they can prevent all kinds of problems, Read more on Avoiding “Undefined is Not a Function” with Constants…