I want to auto compute the remaining stock from inventory by typing in the input type named used. What I want to happen is after I type a number in 'Withdrawn' it should subtract to quantity then show the result to remaining stock. The values came from the database.
Here's what I did but I didn't work I don't know why can you please help me? I am still a beginner btw so correct my code if it looks wrong. Thank you
list.php:
<div class="modal fade" id="updatebtnmodal" role="dialog">
<div class="modal-dialog">
<!-- Modal content-->
<div class="modal-content">
<div class="modal-header">
<h4 class="modal-title">Update Used</h4>
<button type="button" class="close" data-dismiss="modal">×</button>
</div>
<div class="modal-body">
<form id="myForm" action="<?php echo base_url().'admin/inventory/updateused/'.$inv['i_id'];?>" method="POST"
class="form-container mx-auto shadow-container" style="width:80%" enctype="multipart/form-data">
<div class="form-group">
<input type="hidden" name="update_id" id="update_id">
<label for="cname">Category</label>
<input type="text" class="form-control my-2
<?php echo (form_error('name') != "") ? 'is-invalid' : '';?>" name="cname" id="cname"
placeholder="Enter Item name" value="<?php echo set_value('cname',$inv['cat_id']); ?>" readonly>
<?php echo form_error('cname'); ?>
<span></span>
</div>
<div class="row">
<div class="col-md-6">
<div class="form-group">
<input type="hidden" name="update_id" id="update_id">
<label for="name">Item Name</label>
<input type="text" class="form-control my-2
<?php echo (form_error('name') != "") ? 'is-invalid' : '';?>" name="name" id="name"
placeholder="Enter Item name" value="<?php echo set_value('name'); ?>" readonly>
<?php echo form_error('name'); ?>
<span></span>
</div>
<div class="form-group">
<label for="d_date">Delivered Date</label>
<input type="text" class="form-control my-2
<?php echo (form_error('d_date') != "") ? 'is-invalid' : '';?>" id="d_date" name="d_date"
placeholder="Delivered Date" value="<?php echo set_value('d_date'); ?>"readonly>
<?php echo form_error('d_date'); ?>
<span></span>
</div>
<div class="form-group">
<label for="used">Withdrawn</label>
<input type="number" class="form-control my-2
<?php echo (form_error('used') != "") ? 'is-invalid' : '';?>" id="used" name="used" class="used" onchange="calc()"
placeholder="Enter No. Withdrawn Items" value="<?php echo set_value('used'); ?>">
<?php echo form_error('used'); ?>
<span></span>
</div>
</div>
<div class="col-md-6">
<div class="form-group">
<label for="quantity">Quantity</label>
<input type="number" class="form-control my-2
<?php echo (form_error('quantity') != "") ? 'is-invalid' : '';?>" id="quantity" name="quantity" class="quantity"
placeholder="Enter Quantity" value="<?php echo set_value('quantity'); ?>">
<?php echo form_error('quantity'); ?>
<span></span>
</div>
<div class="form-group">
<label for="exp_date">Expiration Date</label>
<input type="text" class="form-control my-2
<?php echo (form_error('e_date') != "") ? 'is-invalid' : '';?>" id="e_date" name="e_date"
placeholder="Expiration Date" value="<?php echo set_value('e_date'); ?>"readonly>
<?php echo form_error('e_date'); ?>
<span></span>
</div>
<div class="form-group">
<label for="rem_qty">Remaining Stock</label>
<input type="number" class="form-control my-2
<?php echo (form_error('rem_qty') != "") ? 'is-invalid' : '';?>" id="rem_qty" name="rem_qty" class="rem_qty"
placeholder="Enter No. Remaining Stock" >
<?php echo form_error('rem_qty'); ?>
<span></span>
</div>
</div>
</div>
<button type="submit" name="updatedata" class="btn btn-primary ml-2">Make Changes</button>
<a href="<?php echo base_url().'admin/inventory/index'?>" class="btn btn-secondary">Back</a>
</div>
<div class="modal-footer">
<button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
</div>
</div>
</div>
</div>
Js:
function calc() {
var quantity = document.getElementById("quantity").innerHTML;
var used = document.getElementById("used").value;
var rem_qty = parseFloat(quantity) - used
if (!isNaN(rem_qty))
document.getElementById("rem_qty").innerHTML = rem_qty
}
Try this javascript code
function calc() {
var quantity = document.getElementById("quantity").value;
var used = document.getElementById("used").value;
var rem_qty = 0;
if(quantity >= used){
rem_qty = parseFloat(quantity) - used;
}
if(rem_qty != 0){
document.getElementById("rem_qty").value = rem_qty
}
}
I hope this code will help you out.