Enabling/Disabling inputs based on checkbox activity

Question

Please note, I have referred to this answer and my solution is currently using that approach.

Here is my HTML:

<head>
<script>

document.getElementById('average_price').onchange = function() {
    document.getElementById('average_price_symbol').disabled = !this.checked;

};

</script>
</head>

<center>
<form action="/custom" method="POST">
    <h2>Generate Custom Report</h2>
        <br>

        <input type="checkbox" id="average_price" name="average_price"> <b>Average Price</b>
        <br>
        <input type="text" id="average_price_symbol" name="average_price_symbol" placeholder="symbol" disabled>
        <br>

        <input type="submit" value="RUN">
</form>

</center>

When the form loads, the text field is disabled, however, the checkbox does not change the state of the field. I'm not exactly sure what's going wrong.

score 0 · Accepted Answer · answered May 29 '18 at 16:10

0

Your script executes before your HTML loads, so this doesn't find anything:

document.getElementById('average_price')

Move the script to the bottom of the page, traditionally just inside the </body> tag.

answered May 29 '18 at 16:10

David

208,112
36
198
279

Thanks for this! – Harrison May 29 '18 at 16:22

score 0 · Answer 2 · answered May 29 '18 at 16:15

Disable your input programatically

Reminder: ALWAYS put your scripts before the closing body tag

HTML

<h2>Generate Custom Report</h2>
  <br>
  <input type="checkbox" id="average_price" name="average_price"> <b>Average Price</b>
  <br>
  <input type="text" id="average_price_symbol" name="average_price_symbol" placeholder="symbol" >
  <br>
  <input type="submit" value="RUN">

JS

var checkbox = document.getElementById('average_price');
var input = document.getElementById('average_price_symbol');

input.disabled = true;
checkbox.addEventListener('change', function (e) {
  console.log('CHECKED', this.checked);
  input.disabled = !this.checked;
  (!input.disabled && input.focus());
});

score 0 · Answer 3 · answered May 29 '18 at 16:17

0

Adding the code to a document ready function will help.

$('document').ready(function(){ document.getElementById('average_price') });

answered May 29 '18 at 16:17

jkort13

11
2

Enabling/Disabling inputs based on checkbox activity

3 Answers3