How to prevent a form from clearing fields on submit in Elementor Pro?

I have a form created with Elementor Pro on my WordPress website. After clicking the button, I can process the results in some way using the WordPress backend, but at the same moment the form is reloaded and all fields have default values again. In some cases, this hinders greatly - for example, when you are trying to build a simple web application.

To be specific, let's build the form to add two numbers (this tutorial).

Frontend looks like this:

Adder Form

HTML code for "The result will appear here" element:

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script>
    jQuery( document ).ready(function( $ ){
        jQuery( document ).on('submit_success', function(event, response){
            document.getElementById("result").innerHTML = response.data['1'].result;
        });
    });
</script>
<p id='result'>The result will appear here.</p>

PHP code (in Code Snippets WordPress plugin):

function add_two_numbers($fields) {
    $a = $fields['a'];
    $b = $fields['b'];
    return $a + $b;
}

// A send custom WebHook
add_action( 'elementor_pro/forms/new_record', function( $record, $handler ) {
    // make sure its our form
    $form_name = $record->get_form_settings( 'form_name' );
    if ( 'AdderForm' !== $form_name ) {
        return;
    }
    
    $raw_fields = $record->get( 'fields' );
    $fields = [];
    foreach ( $raw_fields as $id => $field ) {
        $fields[ $id ] = $field['value'];
    }
    
    $output['result'] = add_two_numbers($fields);
    
    $handler->add_response_data( true, $output );
}, 10, 2 );

I've been trying to dig into the Elementor documentation, setting dynamic "default" values, exploring form setting and googling things like "Elementor don't reload form after submit", "Elementor save default values form", etc, but I didn't find anything. Apparently, official Elementor tools does not allow you to do this, which, in my opinion, is quite weird.

I found a solution that I want to share with others, but it doesn't seem intuitive to me. Feel free to comment if you know the better solution or if the new versions of Elementor allow you to do this.

Solution

The answer I found is to explicitly return the current values of the form fields and display them using jQuery.

To do this, change the PHP code as follows (CHANGE line):

function add_two_numbers($fields) {
    $a = $fields['a'];
    $b = $fields['b'];
    return $a + $b;
}

// A send custom WebHook
add_action( 'elementor_pro/forms/new_record', function( $record, $handler ) {
    // make sure its our form
    $form_name = $record->get_form_settings( 'form_name' );
    if ( 'AdderForm' !== $form_name ) {
        return;
    }
    
    $raw_fields = $record->get( 'fields' );
    $fields = [];
    foreach ( $raw_fields as $id => $field ) {
        $fields[ $id ] = $field['value'];
    }
    
    $output = $fields; // send input data back to the form to display <- CHANGE
    $output['result'] = add_two_numbers($fields);
    
    $handler->add_response_data( true, $output );
}, 10, 2 );

And jQuery script for the HTML element:

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script>
    jQuery( document ).ready(function( $ ){
        jQuery( document ).on('submit_success', function(event, response){
            document.getElementById("result").innerHTML = response.data['1'].result;
            
            // display the data of the previous request on the form
            $("#form-field-a").value(response.data['1'].a);
            $("#form-field-b").value(response.data['1'].b);
        });
    });
</script>
<p id='result'>The result will appear here.</p>