A developer created a custom link to change the appearance of a page programmatically. They made use of the event onMouseDown to trigger the action. By doing so they violated Success Criterion 2.1.1 Keyboard because the link cannot be activated from the keyboard, and Success Criterion 2.5.2 Pointer Cancellation because the action is triggered before releasing the mouse button leaving the user without an option to cancel the navigation if they clicked by mistake.

Try to modify the JavaScript event used.

Note: For a website to be accessible, all user actions must be accessible from the keyboard! By default, any element that is not supposed to do an action when clicked is not focusable with the keyboard. That means that a website that sets click listeners on elements like <div>, is not accessible. Setting a tabindex on such elements can fix this issue

Note2: A proper navigation implementation also updates the history API of the browser to support the back/forward buttons and provides a proper href. Do not use this routing example in real websites.