Advanced form validation

[MRown]

Hi Community,

Was wondering if its possible to validate a text field against a hidden lookup (dropdown) column field.

here is how the form looks now:

here's the code I have tried so far from this post Using JavaScript For Web Form Validation in Power Portal by @justinburch 

if (window.jQuery) {
  (function ($) {
     $(document).ready(function () {
        if (typeof (Page_Validators) == 'undefined') return;
        
        var newValidator = document.createElement('span');
        newValidator.style.display = "none";

        newValidator.id = "Customfieldvalidator";

        newValidator.controltovalidate = "exmp_text_field";

        newValidator.errormessage = "<a href='#exmp_text_field_label'>Example error message.</a>";

        newValidator.validationGroup = ""; 
        newValidator.initialvalue = "";

        newValidator.evaluationfunction = function () {
           var Textfield = $("#exmp_text_field").val();
           var Lookupfield = $("#exmp_lookup_field").val();
  if (Textfield !== Lookupfield)
            return false; 
  else 
            return true;         
        };
        
        Page_Validators.push(newValidator);
       
        $("a[href='#exmp_text_field_label']").on("click", function () { scrollToAndFocus('#exmp_text_field_label','#exmp_text_field'); });
     });
  }(window.jQuery));
}

 appreciate your help

[Fubar]

I am assuming that the validator is triggering and your issue is that you want to compare the Text field with the Name of the value in the Lookup (i.e. not the GUID in the lookup).

 var Lookupfield = $("#exmp_lookup_field_name").val();

[MRown]

🙈Yes, thank you! 

Is it possible to validate the text field against the value of a "hidden" column - as in:

a validation process that checks if the form input value in the text field matches an existing value in another column?

your help is appreciated!

kind regards,

Rowan 

[justinburch]

Hi @MRown, I haven't worked with Portals in a few years now outside of the help I provided on this forum before, so please keep in mind some of this may have changed.

You can compare against a hidden field in a couple of ways, but it isn't straight forward because "hiding" a field on a form in the editor would mean the field isn't available in the HTML on the portal side:

1. You can add a Web API Read setup (documentation here)
2. You can use the JS I showed in that same post you linked to hide the cell for the field you want to hide, but this will hide post-load
3. You can create a section on your portal form to put "hidden" fields, make the Logical Name something like hiddenSection, and then add CSS to your page/site to hide this section. I have a tutorial for this on my site, but it seems it's down right now 😣.

[Fubar]

How you do it may depend on exactly what you are trying to achieve.  e.g. if it was comparison of sensitive info like a password then you would not have the Lookup on the Portal form and do the comparison of the values Server-side.

If its not sensitive info, generally, on the DataVerse form would make the Lookup readonly (so the Portal user cannot hack the page and change the value in the Lookup and have it save back to Dataverse). personally I would add a Metadata item on the Portal Form's definition  for the attribute/column and add a CSS class to it (where the CSS class has display/visibility set to not show).  You can also hide via JavaScript/JQuery, but the CSS class on a metadata item loads in the browser before JavaScript runs on the page so is usually a better option.

[MRown]

Thanks all for your replies, 

This seems to throw the "if false" error message, not sure where the issue in the code is!

will check out the Web API approach also.

Appreciate all your help.

Rowan