Get value of a submitted form without submit button

Question

I'm trying to upload an image without submit button. My code works fine for submiting without button.

My HTML code

<form name="service_image_form" method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
 Add new image <input name="userfile" type="file" id="userfile" onchange="return subForm()" /> 
</form>

<script>
function subForm() {
document.service_image_form.submit();
};
</script>

But I'm little confused in retriving data at PHP. In php I tried something like this to retrieve data.

if (isset($_POST['service_image_form']))
{
echo "working";
}

Here I'm trying to echo "working" just for confirmation. If my condition works then then I can save my image to server and db. I know its very simple but stumbed here for a while. surfed lots of links, but no idea. Please help me out with this.

I know if I had a submit button with name="submit" then I can retrive like this

 if(isset($_POST['submit']))
 {
 upload code comes here..
 }

I dont wan't submit button..

Answer 1

To check if a post request is made:

if($_SERVER['REQUEST_METHOD']=='POST'){
    echo "working";
}

Note that uploaded files data will be in the $_FILES superglobal, not $_POST , and as mentioned by Fred, you will need to add the enctype attribute on your form

Answer 2

You need to add enctype attribute into your for like this

<form name="myform" method="post" enctype="multipart/form-data" action="<?php echo $_SERVER['PHP_SELF']; ?>">
 Add new image <input name="userfile" type="file" id="userfile" onchange="return subForm()" /> 
</form>

And in your php you get the uploaded files using the $_FILE

<?php
if ($_FILES['userfile']['error'] > 0) {
  echo $_FILES['userfile']['error'];
} else {
  echo 'Name: ' . $_FILES['userfile']['name'];
  echo 'Temp file location in: ' . $_FILES['userfile']['tmp_name'];
}
?>

Answer 3

So basically you are trying to check if upload is correct, right? Well, it's not how it's done.

PHP has great manual for that http://php.net/manual/pl/features.file-upload.php

You miss:

• correct form encoding, add attribute enctype="multipart/form-data" to your form tag
• your file will be placed in $_FILES['userfile'] variable
• you can check $_FILES['userfile']['error'] to determine if upload was successful (if so, it will be equal to constant UPLOAD_ERR_OK, 0)

After that you are good to go, you can find all the details here http://php.net/manual/pl/features.file-upload.post-method.php it's pretty straightforward.