Set DefaultSelectedItems of Combobox on App OnStart – Custom Page -Power Apps (Dataverse)

Recently in one of our custom pages, we had to set the default value (DefaultSelectedItems) of the combo box based on one of the lookup fields on the record. We were opening the custom page from the ribbon button on the form.

Below is our function to pass the record’s GUID to the custom page from the button.


    openSearchCustomPage: function (primaryControl, firstPrimaryItemId) {
        var pageInputCustom = {
            pageType: 'custom',
            name: 'custom_searchproduct_570ed',
            entityName: 'lead',
            recordId: firstPrimaryItemId
        };

        var navigationOptions = {
            target: 2,
            position: 1,
            width: 1350
        };

        Xrm.Navigation.navigateTo(pageInputCustom, navigationOptions).then(
            function success(result) {
                console.log(result);
            },
            function error(error) {
                console.log(error);
            }
        );
    }

Next in App’s OnStart, we are setting the GUID of the record to a variable first, and than setting another variable to store the GUID of the Region lookup field on that record.

// text variable passed by the form / webresource/ ribbon
Set(varEnquiryIdWithoutCurlyBraces,GUID(Substitute(Substitute(Param("recordId"),"{",""),"}","")));

// get the Region Of Interest from the Lead / Enquiry ID
// If value present use it for prefiltering the Gallery Items
Set(varRegionOfInterest,LookUp(Enquiries,Lead=varEnquiryIdWithoutCurlyBraces, 'Region of Interest'));

And lastly, for the combo box (Items = Region (custom table)), we are setting the DefaultSelectedItems as follows