How to prevent text from being pasted in TextField with Javascript

Question

I am new to Javascript and trying to write a program to prevent text from being copied into textfield. the following is my code

function dontpaste()
{
  alert("hello");
  return true;
}

<input type="text" name="name" id="name" onpaste="dontpaste()">

The method is getting called. But the text gets copied after alert. Even

document.getElementById('name').value="";

is not working. Even tried with

return false;

for the method, still the text gets copied.

What needs to be done so that the method is called but text is not copied?

What are you actually trying to do? Similar to sites that disable right-clicking, behaviors like these only serve to annoy — they're trivial to disable by the user. — Etheryte, Apr 02 '21 at 15:28
Does this answer your question? [Disable pasting text into HTML form](https://stackoverflow.com/questions/1226574/disable-pasting-text-into-html-form) see this answer : https://stackoverflow.com/a/8797443/9977151 you can pass `event` to `dontpaste` and then use `preventDefault` — ATP, Apr 02 '21 at 15:36

score 1 · Answer 1 · answered Apr 02 '21 at 15:55

This won't pass the event parameter doing it like this

<input type="text" name="name" id="name" onpaste="dontpaste()">

Change it to

<input type="text" name="name" id="name">
document.getElementById("name").addEventListener("paste", dontpaste);

then use event.preventDefault(); inside dontpaste function to block the default paste functionality.

Working example where paste doesn't work.

function dontpaste(event)
{
  event.preventDefault();
}

document.getElementById("name").addEventListener("paste", dontpaste);

<input type="text" name="name" id="name">

*technically* you can still get at the event via `this.event.preventDefault()`. But that's a bit gross. — , Apr 02 '21 at 16:00

1 Answers1