How do I check uploaded file is empty? - php

Question

I am attempting to do some validation on uploaded images. When I check to see if any images have been selected and uploaded it should return an error message if no images have been uploaded. But in my method it always returns false.
Heres the method:
class event{
private $dbh;
private $post_data;
public function __construct($post_data, PDO $dbh){
$this->dbh = $dbh;
$this->post_data = array_map('trim', $post_data);
}
public function checkValidImages(){
$errors = array();
if(empty($this->post_data['event-images'])){
$errors[] = 'Please select at least one image to upload.';
}
if(count($errors) > 0){
return $errors;
}else{
return FALSE;
}
}
and calling it here:
// Check all images are valid
$images = new event($_FILES, $dbh);
var_dump($imageErrors = $images->checkValidImages());
The var_dump() returns bool(false).
heres the form:
<form name="submit-event" action="submit-event.php" method="post" enctype="multipart/form-data">
<div class="large-12 columns no-padding">
<p>Select images for this event</p><br />
<input type="file" class="right" name="event-images[]" size="50" multiple="multiple" />
</div>
</form>
So why is my method returning false even when I don't select any images.

Answer 1

When an HTML file input is left empty, the browser will still submit the name of the form element, so you will still get that entry in the $_FILES array, but with an error code of UPLOAD_ERR_NO_FILE and a filename of "".
You should check the error code anyway as lots of things can go wrong. So your validation code becomes something like:
$numOkayFiles = 0;
$numIntendedFiles = 0;
foreach ($_FILES['event-images']['error'] as $errorCode) {
$numIntendedFiles += ($errorCode != UPLOAD_ERR_NO_FILE);
switch ($errorCode) {
case UPLOAD_ERR_OK:
$numOkayFiles++;
break;
case UPLOAD_ERR_INI_SIZE:
case UPLOAD_ERR_FORM_SIZE:
$errors[] = 'Your file was bigger than the maximum allowed size.';
break;
case UPLOAD_ERR_NO_FILE:
// ignore
break;
default:
$errors[] = 'A problem occured during file upload.';
}
}
if ($numIntendedFiles == 0) {
$errors[] = 'Please select at least one image to upload.';
}