Validation to prevent duplicate selection in dropdown fields.

Question

I have 4 dropdown fields that are using dynamic options. It is possible that 2 or more of the dropdowns may contain the same values as a selection option. I would like to setup validation so there is no duplication of a value amongst the four fields when the form is submitted..

Max_admin · Accepted Answer

For this you will need to use Custom Validation function:

https://www.chronoengine.com/faqs/chronoforms/chronoforms8/how-to-use-custom-javascript-or-php-validation-in-your-form

You may get the values of other fields in PHP using

$this->data("field_name")

and in JavaScript function using

document.querySelector("[name='field_name']").value