How can I manipulate the values on a form when the submit button is clicked

Question

Update 2 - Solved

On reflection with Update 1 I was close to solving my problem, this is my final solution.

<button type='submit' onclick="validate()" class='btn btn-default'>Submit</button>


validate = function() {
       document.getElementById('id_Price').value="2988.99"
}

Update 1

I have had a bit more success with this -

<button type='submit' onclick="validate()" class='btn btn-default'>Submit</button>


validate = function() {
  console.log("Anything happening? (2)")

  RoomBookingsForm['Price'].value()="2988.99"
  document.getElementById('id_Price').value()="2988.99"
}

Original Question

How can I manipaluate the values on a form when the submit button is clicked? I have tried -

<button type='submit' class='btn btn-default'>Submit</button>
function submit(){
  document.getElementById('id_Price').innerHTML()="2988.99"
  RoomBookingsForm['Price'].value()="2988.99"
  document.getElementById('id_Price').value()="2988.99"
}


<button type='submit' onsubmit='submitForm()' class='btn btn-default'>Submit</button>          
function submitForm(){
  document.getElementById('id_Price').innerHTML()="2988.99"
  RoomBookingsForm['Price'].value()="2988.99"
  document.getElementById('id_Price').value()="2988.99"
}

The purpose of this is to present the dates on the form based on the users language / timezone web browser settings. But ultimately save the date to the backend using the American format.

What sort of input is `id_Price` as you've attempted both `innerHTML` and `value` (both incorrectly, but it should be one or the other) ? — freedomn-m, Oct 26 '21 at 12:21
Check the browser console (F12, select console) to see any errors. Essentially, you can't do `function() = something` - it would either be `object.property = something` or `object.function(something)`. — freedomn-m, Oct 26 '21 at 12:22
not sure where you learned how to set a form value that way, but it is wrong. — epascarello, Oct 26 '21 at 12:41
https://stackoverflow.com/questions/7609130/set-the-value-of-an-input-field — epascarello, Oct 26 '21 at 12:43
epascarello my problem is setting a form value once the form has been submitted — Ross Symonds, Oct 26 '21 at 12:51
This was one of my reference points - https://stackoverflow.com/questions/44989121/run-javascript-function-on-form-submit — Ross Symonds, Oct 26 '21 at 12:51
I can't make heads or tails of this question because of all the Update headers. Please [edit] your question so that there is one cohesive question, as if you are asking the question from the start, knowing what you know from the updates. — Heretic Monkey, Oct 29 '21 at 11:52
Apologies. I have solved my problem and need no more help. I added Update 2 in case anyone else faces my issue in the future. — Ross Symonds, Oct 29 '21 at 12:07

score 1 · Accepted Answer · answered Oct 29 '21 at 12:10

In order to change the value when user hits submit you can (for example) change the type to button and then submit your data programaticaly via js.

Something like this:

validate = function() {
  // change value when click
  document.getElementById('id_Price').value="2988.99";
  // submit the form progrematically 
  document.getElementById('demo').submit();
}

<form id="demo">
  <input id="id_Price" value="100" />
  <button type='button' onclick="validate()" class='btn btn-default'>Submit</button>
</form>

How can I manipulate the values on a form when the submit button is clicked

1 Answers1