Codeigniter Callback functions for file validations are not working - codeigniter

Question

I've created validation rules for image uploading as follows.
$this->form_validation->set_rules('display_photo', 'Display Photo', 'callback_file_required|callback_file_size_max[1000]');
In controller I've included callback function as follows.
public function file_required($display_photo) {
if($_FILES[$display_photo]['size'] == 0) {
$this->form_validation->set_message('file_required', 'Upload a file.');
return false;
}
return true;
}
public function file_size_max($display_photo, $max_size) {
if($_FILES[$display_photo]['size'] > $max_size) {
$this->form_validation->set_message('file_size_max', 'This file exceeds max size.');
return false;
}
return true;
}
Only first rule is executing but not second rule. Please help me to find out the solution.

Answer 1

You should pass the file size limit in the config not in the validation rule.
Can u please paste the function or method that performs the upload ?

Answer 2

Not sure if you can use two callbacks on a single field when validation forms in CI. In any case you don't need to check the size to see if a file was uploaded. Use error code '4'
Solutions:
Check if the file was uploaded with if($_FILES[$display_photo]['error'] !== 4) // Error code 4 means no file was uploaded. So if it's not 4 then you have a file.
If you want to do multiple checks you can put them both in one single callback

Answer 3

$this->form_validation->set_rules('display_photo', 'Display Photo', 'callback_file_required_with_validation');
public function file_required_with_validation($display_photo) {
$max_size=1000;
if($_FILES[$display_photo]['size'] == 0) {
$this->form_validation->set_message('file_required', 'Upload a file.');
return false;
}
if($_FILES[$display_photo]['size'] > $max_size) {
$this->form_validation->set_message('file_size_max', 'This file exceeds max size.');
return false;
}
return true;
}

Answer 4

Pretty sure you need double underscore after 'callback' in your validation definition...
$this->form_validation->set_rules('display_photo', 'Display Photo', 'callback__file_required|callback__file_size_max[1000]');

Answer 5

One way - You can validate with JS before uploading the file:
<form method="post" enctype="multipart/form-data" action="upload.php">
<input type="file" name="file" id="file" />
<input type="submit" name="submit" value="Submit" />
</form>
<script>
document.forms[0].addEventListener('submit', function( evt ) {
var file = document.getElementById('file').files[0];
if(file && file.size < 10485760) { // 10 MB (this size is in bytes)
//Submit form
} else {
//Prevent default and display error
evt.preventDefault();
}
}, false);
</script>
Original Question is here
But if you want validate at server side, then server until does't know whenever we upload the file.