How to implement a mechanism to prevent multiple clicks of a button (e.g., 'Buy' on an exchange or 'Order a taxi') so that the action is performed only once?

To protect against multiple button presses and ensure an action is performed only once, several approaches can be used:

1. Frontend button blocking: After the first click, the button becomes disabled to prevent the user from clicking again.

const button = document.getElementById('buyButton');
button.addEventListener('click', () => {
  button.disabled = true;
  // send request to server
});

2. Debounce or throttling: Limit the frequency of handler calls to ignore repeated clicks within a short period.

3. Transaction ID: Generate a unique ID for each operation and send it to the server, which will check if such an operation has already been performed.

4. Server-side protection: The most reliable method is to verify on the server that an action with such an ID or parameters is not executed again (e.g., check by unique order or session).

Combining client-side button blocking with server-side verification provides reliable protection against repeated clicks.