Question

I want the start_uploading function only to start if all the conditions are met and the file is uploading, right now the ‘loading’ message pops up for a split second when the form is submitted but it did not meet all the conditions to upload.

if(condtion){// don't start function} else

if(move_uploaded_file($_FILES['uploaded']['tmp_name'], $target)) {
  //now start function} else echo "error";

javascript

function start_Uploading(){
  document.getElementById('message').innerHTML = 'Loading... <br> Please Wait';
  return true;
}

and html

<form action="something.php" method="POST" enctype="multipart/form-data"
 onsubmit="start_Uploading();">    

Answer 1

Since you are checking for the condition to be true in php, I would simply only echo out the js method name if the condition is met.

Like so:

<?php
  if(true) $onsubmit = "start_Uploading();"; // Put actual condition in parantheses
  else $onsubmit = "";
?>

And then in your form:

<form action="something.php" method="POST" enctype="multipart/form-data"
onsubmit="<?php echo $onsubmit; ?>">

If the condition isn’t met, no method name will be provided and js simply won’t know what to look for on submit.