Dynamic Component Focus Management with Template Refs in Vue

Template refs in Vue provide a powerful mechanism to directly access DOM elements or components. This challenge focuses on leveraging template refs to dynamically manage focus within a Vue component, specifically targeting a dynamically rendered list of input elements. This is a common requirement in forms and interactive interfaces where you need to programmatically set focus to specific elements based on user actions or application state.

Problem Description

You are tasked with creating a Vue component called DynamicFocusList that renders a list of input elements dynamically. The component should accept a items prop, which is an array of strings. Each string in the items array represents the label for an input element. The component must implement a method called focusNextInput that, when called, programmatically sets focus to the next input element in the list. If the currently focused input is the last element, focusNextInput should set focus to the first input element. You must use template refs to access the input elements.

Key Requirements:

• Dynamically render input elements based on the items prop.
• Use template refs (ref) to access each input element.
• Implement the focusNextInput method to cycle focus through the input elements.
• Handle the edge case where the currently focused input is the last element in the list.
• The component should be written in TypeScript.

Expected Behavior:

• The component should render a list of input elements, each with a label derived from the items prop.
• Initially, no input element should have focus.
• Calling focusNextInput should move focus to the next input element in the list.
• Calling focusNextInput when the last input element has focus should move focus to the first input element.

Edge Cases to Consider:

• Empty items array: The component should render no input elements.
• items array with a single element: Calling focusNextInput should cycle focus back to the same element.
• Input elements are not immediately available in the DOM (e.g., due to asynchronous rendering). The focus should be set only when the element is present.

Examples

Example 1:

Input: items = ["Name", "Email", "Phone"]
Output: A list of three input elements with labels "Name", "Email", and "Phone".  Calling focusNextInput three times will cycle focus through these elements, returning to "Name" on the fourth call.
Explanation: The component dynamically renders three input elements. The focusNextInput method iterates through the refs and sets focus to the next element in the array.

Example 2:

Input: items = ["Address"]
Output: A single input element with label "Address". Calling focusNextInput repeatedly will keep focus on the same element.
Explanation: The component renders a single input element. focusNextInput cycles back to the same element.

Example 3:

Input: items = []
Output: No input elements are rendered.
Explanation: The component handles the edge case of an empty items array gracefully.

Constraints

• The component must be written in TypeScript.
• The focusNextInput method must be implemented.
• The solution must use template refs to access the input elements.
• The component should be reasonably performant (avoid unnecessary DOM manipulations).
• The component should be well-structured and readable.

Notes

• Consider using nextSibling or similar DOM traversal methods to find the next input element.
• You may need to use setTimeout or requestAnimationFrame to ensure the input elements are fully rendered before attempting to set focus. This is particularly important if the rendering is asynchronous.
• Think about how to handle the case where an input element might be removed from the DOM (e.g., due to conditional rendering). You might need to update the list of refs accordingly.
• The focus should be set using the focus() method on the DOM element.
• The items prop is guaranteed to be an array of strings.