In this article, I will show you an example of how can you speedup development with code generation scripting.

How can you speed up development with scripted code generation?

For code generation, I usually use Python or Ruby as these languages have a lot of libs for the generation of boilerplate code. And also these languages are first-class citizenship on macOS.

Real-life example: I had a lot of color themes in an application and a lot of colors, my designer changed colors once every month and added a new theme once a year.

Information was provided in JSON format:

I had theme name and color type name with HEX code of color for light and dark modes.

So how should I convert this into the code?

In common situation you can transform hex into UIColor like that:

But it is really uncomfortable to use colors in this way. I prefer color literal because can see the color:

Сolor literal

Yeah, it is much better. Let’s do it this way.

First of all, we should create a swift file where our colors will be — “AppColors.generated.swift”.

After that, as we are using Ruby we should prepare a project for using Ruby.

  • Make sure Ruby and Gem are installed;
  • Call the bundle install command in the project’s iOS root folder — it will install the required gems;
  • Liquid is one of the required gems — we will use it for creating templates.

Also, we should have raw resources for colors — JSON with colors. Let’s name it “ios_colors.json”.

The liquid is very useful for preparing templates. Example of our template “ColorsTemplate.liquid”:

Now the most interesting process — writing script. I will just leave code on Ruby:

Ok, usually I save all scripts in the root directory as it is easy to use them. Name of our script file “convertColorsToStatic.rb”.

Let’s call in the terminal:

ruby convertColorsToStatic.rb

Voila:

Code Generation Script for iOS

Also I’m using scripts for creating events, feature toggles, strings, architecture components (for example, VIPER) and it saves me ton of time.

Latest articles here

Spring Boot vs. Quarkus: Which Java Framework to Choose?

Spring Boot vs. Quarkus: Which Java Framework to Choose?

If you have fallen for the hype that Java is going to retire, don’t jump to conclusions right away. Sure, some modern languages may be superior to...

API-First Development: The Key to Faster, More Reliable Software Delivery.

API-First Development: The Key to Faster, More Reliable Software Delivery

A shift occurred in the 2010s, when companies began to view APIs, Application Programming Interfaces, as an independent solution instead of only...

Android CI/CD boilerplate for publishing via Fastlane

How to Automate CI/CD for Android App with Boilerplate

Stop publishing your Android apps manually and start doing this fully automated at any stage.Mobile development, as well as any other software...

Go to blog