impress/app/javascript/wardrobe-2020/components/useCurrentUser.js

// Read the current user ID once from the <meta> tags, and use that forever!
const currentUserId = readCurrentUserId();

function useCurrentUser() {
	if (currentUserId == null) {
		return {
			isLoggedIn: false,
			id: null,
		};
	}

	return {
		isLoggedIn: true,
		id: currentUserId,
	};
}

function readCurrentUserId() {
	try {
		const element = document.querySelector("meta[name=dti-current-user-id]");
		const value = element.getAttribute("content");
		if (value === "null") {
			return null;
		}
		return value;
	} catch (error) {
		console.error(
			`[readCurrentUserId] Couldn't read user ID, using null instead`,
			error,
		);
		return null;
	}
}

export default useCurrentUser;