Jquery javascript dropdown in a loop and calculation

Question

I got a a dropdown list populating from a php while loop. There will be more than one select dropdown boxes. When i select any dropdown from the loop, the subsequent textbox should change the value.

<html>
   <head>
      <meta http-equiv="content-type" content="text/html; charset=UTF-8">
      <title></title>
      <script type='text/javascript' src='http://code.jquery.com/jquery-1.10.1.js'></script>
      <script type='text/javascript'>//<![CDATA[
         $(window).load(function(){
         $("#category").change(function () {
         var dept_number = $(this).val();
         var price = $(this).find(':selected').data('price');
         $('#dept-input').val(dept_number);
         $('#price-input').val(price);
         });
         });//]]> 


      </script>
   </head>
   <body>
      <select id="category[]">
         <option value="1" data-price="10">Item 1 second</option>
         <option value="2" data-price="20">Item 2 second</option>
         <option value="3" data-price="30">Item 3 second</option>
      </select>
      <br><br>
      <label>Dept. num:</label>
      <input type="text" id="dept-input[]"></input>
      <br><br>
      <label>Price:</label>
      <input type="text" id="price-input[]"></input>
   </body>
</html>

This script is working with out the loop. How will i change it to work with the loop.. Thank you in advance

<script type='text/javascript' src='http://code.jquery.com/jquery-1.10.1.js'></script>

<script type='text/javascript'>//<![CDATA[
$(window).load(function(){
$(document).ready(function(){
    $("select").on('change',function () {
        var dept_number = $(this).val();
        var price = $(this).find(':selected').data('price');
        $(this).siblings('.deptip').val(dept_number);
        $(this).siblings('.priceip').val(price);
        $(this).siblings('.total1').val(price * $(this).siblings('.total').data('value'));
    });
});
});//]]> 

</script>

<div class="base"> <!--Keep each group in base container-->
<table border="1"><tr>
    <td><select id="category0">
       <option value="1" data-price="10">Item 1 second</option>
       <option value="2" data-price="20">Item 2 second</option>
       <option value="3" data-price="30">Item 3 second</option>
    </select></td>
    <td><label>Dept. num:</label>
    <input type="text" class="deptip" id="dept-input"/><!--give them a class--></td>
    <td><label>Price:</label>
    <input type="text" class="priceip" id="price-input"/> <!--a class here too--></td>
    <td><label>Total:</label><input data-value="50" type="text" readonly class="total"/></td>
 <td><label>Total1:</label><input data-value="50" type="text" readonly class="total1"/></td>

</tr></table>
</div>

<div class="base"> <!--Keep each group in base container-->
<table border="1"><tr>
    <td><select id="category1">
       <option value="1" data-price="10">Item 1 second</option>
       <option value="2" data-price="20">Item 2 second</option>
       <option value="3" data-price="30">Item 3 second</option>
    </select></td>
    <td><label>Dept. num:</label>
    <input type="text" class="deptip" id="dept-input"/><!--give them a class--></td>
    <td><label>Price:</label>
    <input type="text" class="priceip" id="price-input"/> <!--a class here too--></td>
    <td><label>Total:</label><input data-value="50" type="text" readonly class="total"/></td>
 <td><label>Total1:</label><input data-value="50" type="text" readonly class="total1"/></td>

</tr></table>
</div>

<div class="base"> <!--Keep each group in base container-->
<table border="1"><tr>
    <td><select id="category2">
       <option value="1" data-price="10">Item 1 second</option>
       <option value="2" data-price="20">Item 2 second</option>
       <option value="3" data-price="30">Item 3 second</option>
    </select></td>
    <td><label>Dept. num:</label>
    <input type="text" class="deptip" id="dept-input"/><!--give them a class--></td>
    <td><label>Price:</label>
    <input type="text" class="priceip" id="price-input"/> <!--a class here too--></td>
    <td><label>Total:</label><input data-value="50" type="text" readonly class="total"/></td>
 <td><label>Total1:</label><input data-value="50" type="text" readonly class="total1"/></td>

</tr></table>
</div>

Guruprasad J Rao · Accepted Answer · 2015-08-11T08:13:05.747

4

DEMO

Categorize your multiple selects into some parent div container and assign class to input elements in each container

For ex:

<div class="base"> <!--Keep each group in base container-->
    <select id="category">
       <option value="1" data-price="10">Item 1 second</option>
       <option value="2" data-price="20">Item 2 second</option>
       <option value="3" data-price="30">Item 3 second</option>
    </select>
    <label>Dept. num:</label>
    <input type="text" class="deptip" id="dept-input"/><!--give them a class-->
    <label>Price:</label>
    <input type="text" class="priceip" id="price-input"/> <!--a class here too-->
</div>

<div class="base">
    <select id="category1">
       <option value="1" data-price="10">Item 1 second</option>
       <option value="2" data-price="20">Item 2 second</option>
       <option value="3" data-price="30">Item 3 second</option>
    </select>
    <label>Dept. num:</label>
    <input type="text" class="deptip" id="dept-input"/><!--same goes here-->
    <label>Price:</label>
    <input type="text" class="priceip" id="price-input"/><!--and here too-->
</div>

<div class="base">
    <select id="category2">
       <option value="1" data-price="10">Item 1 second</option>
       <option value="2" data-price="20">Item 2 second</option>
       <option value="3" data-price="30">Item 3 second</option>
    </select>
    <label>Dept. num:</label>
    <input type="text" class="deptip" id="dept-input"/>
    <label>Price:</label>
    <input type="text" class="priceip" id="price-input"/>
</div>

Write a common jquery on change event to select element.

For Ex:

$(document).ready(function(){ //Write it in document.ready()
    $("select").on('change',function () {
        var dept_number = $(this).val();
        var price = $(this).find(':selected').data('price');
        $(this).siblings('.deptip').val(dept_number); //find its siblings with classname 
        $(this).siblings('.priceip').val(price);
    });
});

Update

DEMO

Hoping the html will be there for each group

<label>Total:</label><input data-value="50" type="text" readonly class="total"/><br/>
<!-- Added value fetched from php to data-value attribute of input-->

So your modified JS would be as below:

$(document).ready(function(){
    $("select").on('change',function () {
        var dept_number = $(this).val();
        var price = $(this).find(':selected').data('price');
        $(this).siblings('.deptip').val(dept_number);
        $(this).siblings('.priceip').val(price);
        $(this).siblings('.total').val(price * $(this).siblings('.total').data('value'));//Add this line
    });
});

UPDATE 2

DEMO

For your current structure you could change your script as below:

$(document).ready(function(){
    $("select").on('change',function () {
        var dept_number = $(this).val();
        var price = $(this).find(':selected').data('price');
        $(this).closest('table').find('.deptip').val(dept_number);
        $(this).closest('table').find('.priceip').val(price);
        $(this).closest('table').find('.total').val(price * $(this).closest('table').find('.total').data('value'));
    });
});

Basically here we are finding the parent table of the clicked select and then finding required elements within that parent

edited Aug 11 '15 at 08:13

answered Aug 11 '15 at 05:07

Guruprasad J Rao

29,410
14
101
200

It is working fantastic. Thank you. I have one more doubt. I have a field called Total in all the loop with the select. Its a readonly field with a value. Now when i select from a dropdown, it should calculate price*total and show it another field. Its actually a continuation for me. Can u pls help me Guru with this also? – Sujith Nair Aug 11 '15 at 05:35
Or do i need to post as a separate question? – Sujith Nair Aug 11 '15 at 05:43
Total for each `select` group? – Guruprasad J Rao Aug 11 '15 at 05:45
So `total` wil be `price*?` – Guruprasad J Rao Aug 11 '15 at 05:51
Yes. Exactly. i have a field called total and total1 in each row. Yes, if i select 'Item 1 second' it should take calculate value of data-price*total and display the total value in total1 field. – Sujith Nair Aug 11 '15 at 05:51
So what will be the value of `total` at first!! your said `data-price*total` – Guruprasad J Rao Aug 11 '15 at 05:52
My php script will be bringing the value of total from a query. – Sujith Nair Aug 11 '15 at 05:54
Am i confusing you? Iam really sorry for that. Do you want me to explain it oncemore? – Sujith Nair Aug 11 '15 at 05:55
No No.. I got it.. Updating answer!! – Guruprasad J Rao Aug 11 '15 at 05:56
@SujithNair Updated answer!! check and let me know!! – Guruprasad J Rao Aug 11 '15 at 05:58
Thanx a lot. This is what i was expecting. Thank you so much. – Sujith Nair Aug 11 '15 at 06:05
Anytime.. happy coding.. :) – Guruprasad J Rao Aug 11 '15 at 06:05
A small issue. When i put the fields inside a table, its not working? is there anything i have to takecare of? – Sujith Nair Aug 11 '15 at 07:59
You might need to post the proper structure to understand it!! Just post html structure or edit the fiddle once it is rendered in browser! – Guruprasad J Rao Aug 11 '15 at 08:00
i have added the html in the question itself. Kindly have a look. Thanx – Sujith Nair Aug 11 '15 at 08:09
Updated answer @SujithNair – Guruprasad J Rao Aug 11 '15 at 08:13
Thank you Guruprasad. It is working fine now. :) Thank you once again.:) – Sujith Nair Aug 11 '15 at 08:36
is it possible that i can give some if condition in the script. For example : if dropdown selected value == 'Item 1 second' { different calculation} and if dropdown selected value == 'Item 2 second' { different calculation} etc etc?? – Sujith Nair Aug 11 '15 at 08:45
yes you can!! but this should not go extended like this!! I mean this question has taken different path now!! Well in `on change` you can write `var selected=$(this).find('option:selected').text()` and then check `if(selected=="Item 2 second")` then do a different calculation store in in a `var` and assign it to `textbox` – Guruprasad J Rao Aug 11 '15 at 08:53
1

iam really sorry for this. If any more doubts, i will make a different question. Really appreciate the help. Thanx – Sujith Nair Aug 11 '15 at 09:27
Anytime.. hope it helped.. :) – Guruprasad J Rao Aug 11 '15 at 09:31
1

Yes it helped me a lot. Thank you so much. :) – Sujith Nair Aug 11 '15 at 09:47

Tahir Ahmed · Answer 2 · 2015-08-11T05:17:46.753

1

I think the only problem in your code is that the resulting HTML contains [] square brackets inside of the id attribute of some elements. Removing them should fix your problem: Example.

Otherwise, if you cannot modify HTML then, escape the characters when trying to access them in JavaScript: Example.

And for multiple select elements, you can do this.

Snippet:

var categories = $('select[id^=category]');
var deptNumbers = $('input[id^=dept-input]');
var priceNumbers = $('input[id^=price-input]');
categories.each(function(index) {
    $(this).change(function() {
        var dept_number = $(this).val();
        var price = $(this).find(':selected').data('price');
        deptNumbers.eq(index).val(dept_number);
        priceNumbers.eq(index).val(price);
    });
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.10.1/jquery.min.js"></script>
<select id="category[0]">
    <option value="1" data-price="10">Item 1 second</option>
    <option value="2" data-price="20">Item 2 second</option>
    <option value="3" data-price="30">Item 3 second</option>
</select>
<select id="category[1]">
    <option value="1" data-price="10">Item 1 second</option>
    <option value="2" data-price="20">Item 2 second</option>
    <option value="3" data-price="30">Item 3 second</option>
</select>
<br>
<br>
<label>Dept. num:</label>
<input type="text" id="dept-input[0]"></input>
<br>
<br>
<label>Price:</label>
<input type="text" id="price-input[0]"></input>
<br>
<br>
<label>Dept. num:</label>
<input type="text" id="dept-input[1]"></input>
<br>
<br>
<label>Price:</label>
<input type="text" id="price-input[1]"></input>

Hope this helps.

edited Aug 11 '15 at 05:17

answered Aug 11 '15 at 05:08

Tahir Ahmed

5,687
2
17
28

The script is working actually. Iam trying to change the script to work in a loop. Because the select boxes are coming inside a loop. There will be more than one select box and subsequent textboxes. – Sujith Nair Aug 11 '15 at 05:17
@SujithNair: modified the same snippet just now. I initially thought you would have multiple `select` elements but the same `dept-input` and `price-input` fields, but now I have modified to cater multiple fields as well. – Tahir Ahmed Aug 11 '15 at 05:23
Though I recommend getting rid of the `[]` square brackets in IDs: **[Link](http://stackoverflow.com/questions/1239095/find-dom-element-by-id-when-id-contains-square-brackets)** and **[Link](http://stackoverflow.com/questions/70579/what-are-valid-values-for-the-id-attribute-in-html)**. – Tahir Ahmed Aug 11 '15 at 05:27
Its working Tahir. Thankx a lot. It is working fantastic. Thank you. I have one more doubt. I have a field called Total in all the loop with the select. Its a readonly field with a value. Now when i select from a dropdown, it should calculate price*total and show it another field. Its actually a continuation for me. Can u pls help me with this also? – Sujith Nair Aug 11 '15 at 05:36
Or do i need to post as a separate question? – Sujith Nair Aug 11 '15 at 05:43
the _Total_ field is just one for the entire form or does it also loop in each _category_? – Tahir Ahmed Aug 11 '15 at 05:45

Jquery javascript dropdown in a loop and calculation

2 Answers2