Building Accessible JavaScript Interfaces: A Sudoku Case Study
As a developer, creating an engaging and interactive web application is only half the battle. Ensuring that it is accessible to everyone, including those with disabilities, is just as important. In this article, we will explore the process of building an accessible JavaScript interface using a simple Sudoku game as a case study.
Planning for Accessibility
Retrofitting accessibility into an existing interface can be challenging and time-consuming. Therefore, it’s essential to plan for accessibility from the start. One approach is to follow the POUR principles:
- Perceivable: All users should be able to perceive the interface.
- Operable: All users should be able to operate the interface.
- Understandable: The interface should be simple and intuitive.
- Robust: The interface should work across various browsers and assistive technologies.
Designing the Sudoku Game
For our Sudoku game, we need to convey information about the game board to users who may not be able to see it. We can achieve this by using a notation system to describe the game board. Our notation system consists of four squares, each containing four cells. We use a simple XY coordinate system to identify each cell.
Building the Game
To build the game, we use standard HTML controls and apply CSS for visual effects. We use 16 <input type="number"> elements to create the game board, which allows users to enter numbers. We also use <div> tags to group cells into squares and a CSS Grid Layout to organize the game board.
Selecting Color and Size
We choose colors that provide sufficient contrast for users with low-color vision. We use black and white for the game board and reserve colors like sky blue, reddish-purple, and yellow for highlighting correct and incorrect cells. We also ensure that the text size is at least 16 CSS pixels and use a line height of 1.35 to make the text more readable.
Incorporating Assistance with WAI-ARIA
We use WAI-ARIA attributes to provide additional information for screen readers. We add aria-label attributes to each cell to describe its position on the game board. We also use aria-live attributes to announce changes to the game board.
Adding Interactivity
We add JavaScript functions to make the game interactive. We allow users to check if the game board is completed correctly, show the full solution, restart the game, and highlight correct and incorrect cells.
Testing for Accessibility
We test the game for accessibility using keyboard-only navigation and screen readers like NVDA. We ensure that the game can be fully