Webcam does not go to page

I want to do face recognition on the web but no image. How to fix this problem.I don't know exactly where the problem is. Please help me

  function view() {

  document.getElementById("face-login").style.display = 'none';

  stream();
  logger("Wait...");

  socket.on("stream", function (data) {
    var img = document.getElementById("img");
    img.style.display = 'block';
    img.src = data['img'];

    var devRect = document.getElementById("face-detect");
    var rect = data['rectFace'];
    if(Object.keys(rect).length !== 0) {
      devRect.style.display = 'block';
      devRect.style.top = rect.y + 'px';
      devRect.style.left = rect.x + 'px';
      devRect.style.width = rect.w + 'px';
      devRect.style.height = rect.h + 'px';

    } else {
      devRect.style.display = 'none';
    }
  });

  socket.on("stream-end", function (data) {
    $("#face-login").hide();
    $("#face-detect").hide();
    logger("Verifying user...");
    socket.emit("verify-user", '');
  });

  socket.on("verify-user", function (data) {
    $("#face-detect").hide();
    logger("verified, " + data['name'] + ", accouracy: " + data['accouracy']);
    console.log(data)
    if(data['id']) {
      $("#face-login").hide();
      $.post("/login", {'auth_key': data['auth_key']}, function(data) {
        location.reload();
      })
    } else {
      $("#face-login").show();
    }
  });
}

No error but does not function

if(Object.keys(rect).length !== 0)

rect variable null