disable a submit button after clicking on it in codeigniter - php

Question

I'm new to php and codeigniter. I have this task that i'm working on right now which is a hostel management system. the student has the ability to choose the meal they want to eat by selecting on it, all im trying to do is to disable the select button after they click on it, in other words the student can choose a specific meal once.
here's my code:
<td><div><?php echo $row['type'];?></div></td <td><div><?php echo $row['content'];?></div></td>
<td><div><?php echo $row['date'];?></div></td>
<td align="center">
<?php $is_selected=$this->db->get_where('selected_meal', array( 'meal_id' => $row['meal_id'],'student_id'=>$this->session->userdata('student_id')))->row()->delivered;
<a data-toggle="modal" href="#modal-form" onclick="modal('order_meal',<?php echo $row['meal_id'];?>)" class="btn btn-gray btn-small">
<i class="icon-wrench"></i> <?php echo get_phrase('select');?>
</a>
<?php ?>
</td>

Answer 1

Here is sample form, button and javascript. You need to modify it to fit your needs.
<form name="myForm" id="myFormId" class="form-horizontal" method="post" action="<?=base_url('invoice/create_invoice');?>">
<input type="submit" id = "formSubmit" class="btn btn-primary" value="Submit">
</form>
<script type="text/javascript">
document.getElementById('myFormId').onsubmit = function() {
document.getElementById("formSubmit").disabled = true;
}
</script>

Answer 2

Give a class to element, which you want to select. Ex 'select-meal'.
$('.select-meal').click(function(){
$(this).attr('disabled', 'true');
})

Answer 3

It seems you are using bootstrap, you can add class "disabled" on click submit
Or, try this, add class dis-btn and write script on event click
$('.dis-btn').prop('disabled', true);