} else {
// If validation fails, show the form again with error messages
echo validation_errors(400);
}

<?php
$form_attr = [
'class' => 'highlight-errors',
];
echo form_open($form_location, $form_attr);

echo form_label('Name');
echo form_input('name', $name, array("placeholder" => "Enter Name"));

/**
* Handle submitted record data.
*
* @return void
*/
public function submit(): void {
$this->module('trongate_security');
$this->trongate_security->_make_sure_allowed();

// $submit = post('submit', true);
$submit = 'Submit'; // crude bypass

if ($submit === 'Submit') {

$this->validation->set_rules('task_name', 'Task Name', 'required|min_length[2]|max_length[255]');

$result = $this->validation->run();

if ($result === true) {

$update_id = (int) segment(3);
$data = $this->get_data_from_post();
$data['completed'] = ($data['completed'] === 1 ? 1 : 0);

if ($data['completed']) {
$data['date_completed'] = date('Y-m-d');
} else {
$data['date_completed'] = null;
}

if ($update_id > 0) {
//update an existing record
$this->model->update($update_id, $data, 'tasks');
$flash_msg = 'The record was successfully updated';
} else {
//insert the new record
$update_id = $this->model->insert($data, 'tasks');
$flash_msg = 'The record was successfully created';
}

set_flashdata($flash_msg);
redirect('tasks/show/' . $update_id);
} else {
//form submission error
echo validation_errors(400);
// $this->create();
}
}
}

<h1><?= $headline ?></h1>
<?= validation_errors() ?>
<div class="card">
<div class="card-heading">
Task Details
</div>
<div class="card-body">
<?php
$form_attr = [
'mx-post' => $form_location,
'class' => 'highlight-errors'
];
echo form_open('#', $form_attr);
echo form_label('Task Name');
echo form_input('task_name', $task_name, array("placeholder" => "Enter Task Name"));
echo '<div>';
echo 'Completed ';
echo form_checkbox('completed', 1, $checked = $completed);
echo '</div>';
echo form_submit('submit', 'Submit');
echo anchor($cancel_url, 'Cancel', array('class' => 'button alt'));
echo form_close();
?>
</div>
</div>