How to detect if user has blocked camera?

Question

How can I detect if user has blocked camera in browser?

I have tried this:

navigator.mediaDevices.getUserMedia(constraints)
  .then(function(stream) {
    console.log(stream)
  })
  .catch(function(err) {
    console.log(error)
  });

But I get

VM1267:1 Uncaught ReferenceError: constraints is not defined

https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices/getUserMedia

I am assuming I should target this exception NotAllowedError .

Thanks.

Answer 1

You need to actually specify the constraints :

navigator.mediaDevices.getUserMedia({ audio: true, video: true })
  .then(function(stream) {
    console.log(stream)
  })
  .catch(function(err) {
    console.log(error)
  });

The MDN page you linked to in your question has more information.