Computed Twig not working on multiple wizard pages

Using cascading computed twig elements with Ajax can cause significant performance problems and racing conditions.

A good solution is to use a custom Twig function to centralize all the business logic.

You could also use JavaScript to visually calculate the sub-totals but still use Twig to calculate the final total securely.

If you can post an example webform, I can probably help you track down the issues but the above recommendations will probably still apply.

Please isolate the problem to an English example that is not specific to your project.

I need to be able to replicate this issue locally.

Can you please export the Webform as YAML and attach it here?

@see https://www.youtube.com/watch?v=4xI-T1OuHn4

The YAML in #8 should be enough to replicate and debug this issue.

I see the problem now, you are running into an error where twig is trying to do a calculation on an empty string. A single page form would not have as many empty values as a multistep form.

You need to make sure the expected data exists before doing any twig calculations. I usually wrap my computation in an if statement. (i.e. {% if data.select_a|length and data.select_b|length %})

Here is an example from the attached webform.

   subtotal_one:
      '#type': webform_computed_twig
      '#title': 'Subtotal One'
      '#display_on': view
      '#template': '{% if data.select_a|length and data.select_b|length %}{{ (data.select_a + data.select_b) }}{% endif %}'
      '#store': true

Does this solve your problem?

This ticket was completed using Open Collective funds. Please consider joining the Webform module's Open Collective to help ensure that the Webform module is maintained.

Many thanks again for your help! Is there a way to send you some coffee?

Donating to the Webform module's Open Collective is the best way to pay it (and me) forward.

Thx for your contribution to the Webform module's Open Collective.