PHP required checkbox field - php

Question

I have a form with multiple checkboxes. I want to allow the user to select at least 1 in each checkbox field, if the user does not check any of the options in the checkbox, a message will display "You have to select at least one." How do I do it? I have here some of my codes:
<div>
<div><span class="font-2">Categories:</span></div>
</div>
<div class = "addinfo">
<?php $categories = array('Breakfast', 'Lunch', 'Dinner', 'Snack', 'Grill', 'Buffet', 'Fast Food');
$values = explode(',' , $row['categories']);
?>
<?php foreach($categories as $category) {
$cat='';
foreach($values as $value){
if($value == $category){
$cat ="checked";
}
?>
<input <?php echo $cat ?> type="checkbox" name="category[]" value="<?php echo $category?>"><?php echo $category?><br>
<?php }
}?>
</div>
form
<form method = "POST" action = "<?php echo base_url().'/index.php/AdminController/operation'?>">
AdminController
public function addResto(){
$this->load->model('AdminModel');
$this->AdminModel->insert();
$this->getRestos();
}
public function operation(){
if(isset($_POST['btn'])){
if(empty($_POST['id'])){
$this->addResto();
}
else{
$this->updatingResto();
}
}
}
public function updateResto($id){
$this->load->model('AdminModel');
$restaurantinfo['restaurantinfo']=$this->AdminModel->getResto($id);
$this->load->view('admin/UpdateRestoPage',$restaurantinfo);
}
public function updatePage(){
$this->load->view('admin/UpdateRestoPage');
}
public function updatingResto(){
$id = $_POST['id'];
$this->load->model('AdminModel');
$this->AdminModel->update($id);
}

Answer 1

You should also check if there is a checkbox that is checked
public function operation(){
if(isset($_POST['btn'])){
if(empty($_POST['category'])){
$this->load->view('YOUR_VIEW_FILE',array('error'=>'category'));
}else if(empty($_POST['id'])){
$this->addResto();
}
else{
$this->updatingResto();
}
}
}
your view file add a condition
<?php
if(!empty($error) && $error=="category"){
?>
<script>alert("You have to select at least one.");</script>
<?php
}
?>

Answer 2

Add validation in your called php
<?php
$checked = false;
foreach($_POST["category"] as $key) {
if(!empty($key)) {
$checked = true;
}
}
if(!$checked) {
echo "<script>";
echo "alert('You have to select at least one.');";
echo "history.back();";
echo "</script>";
exit();
}
?>

Answer 3

in your controllers operation function use
if (isset($_POST['mycheckbox'])) {
echo "checked!";
} esle {
//send again with error message
}

Answer 4

Using this validation in javascript:
$("input:checkbox[name='a']:checked").length == 0
Example:
HTML code:
<from name='frm1' method='' action='POST'>
<label>Favorites:</label>
<span>sports</span><input type="checkbox" name="fav" value="1"/>
<span>music</span> <input type="checkbox" name="fav" value="2"/>
<span>reading</span> <input type="checkbox" name="fav" value="3"/>
<input type="button" value="validate">
</form>
Javascript code:
function validate() {
//replace with your own code here
if ($('input:checkbox[name="fav"]:checked').length == 0) {
alert("You have to select at least one.");
}
}
$("input[type='button']").click(validate)
It's just a simple example to demonstrate the use of :check selector(JQuery), you need to
change and embed it in your project!

Answer 5

try to add this in your html code:
<script type="text/javascript">
function check () {
var inputs = document.querySelectorAll("input[type='checkbox']");
for(var i = 0; i < inputs.length; i++) {
if (inputs[i].checked) {
return true;
}
}
alert("You have to select at least one.");
return false;
}
</script>
This one will show the error before the page refreshes. And add something like this in your html :
<input type = "button" onclick = "check();">
UPDATE : try to replace your code with this.
<div>
<div><span class="font-2">Categories:</span></div>
</div>
<script type="text/javascript">
function check () {
var inputs = document.querySelectorAll("input[type='checkbox']");
for(var i = 0; i < inputs.length; i++) {
if (inputs[i].checked) {
return true;
}
}
alert("You have to select at least one.");
return false;
}
</script>
<div class = "addinfo">
<?php $categories = array('Breakfast', 'Lunch', 'Dinner', 'Snack', 'Grill', 'Buffet', 'Fast Food');
$values = explode(',' , $row['categories']);
?>
<?php foreach($categories as $category) {
$cat='';
foreach($values as $value){
if($value == $category){
$cat ="checked";
}
?>
<input <?php echo $cat ?> type="checkbox" name="category[]" value="<?php echo $category?>"><?php echo $category?><br>
<?php }
}?>
<input type = "button" onclick = "check();">
</div>