need to add custom contact and interaction facets into xConnect using ConvertToXConnectInteractionPipelineArgs

Question

I'm using sitecore 9.1.1.

I need to insert custom contact facet and custom interaction facet using below pipeline processor. I have already added custom values successfully in the same processor.

Personal() and WebVisit() are null hence getting error(object reference not set).

is there any other way around to get it done by injecting into args object.

public class ConvertInteractionFacet : ConvertToXConnectInteractionProcessorBase
{    
    public override void Process(ConvertToXConnectInteractionPipelineArgs args)
    {
        if (args != null)
        {
            //contact facet
            args.XConnectContact.Personal().FirstName = "myfirstnametest";
            args.XConnectContact.Personal().LastName = "mylastnametest";

            //interaction facet
            args.XConnectInteraction.WebVisit().SearchKeywords = "mytesting123";
        }
    }
}

Answer 1

Going off the comments that you might feel its the only place you can add this data is in session end. Here is the code to do it in session.

Search word: https://doc.sitecore.com/developers/93/sitecore-experience-platform/en/triggering-built-in-events.html

var searchEvent = Tracker.MarketingDefinitions.PageEvents[AnalyticsIds.SearchEvent.Guid];

Sitecore.Analytics.Tracker.Current.CurrentPage.Register(new PageEventData(searchEvent.Alias, searchEvent.Id)
{
    Data = "sitecore experience platform"
});

Updating personal info names. This is not complete code. You should have your own code for getting the xConnect client and contact. My getting code can be found in my answer here (Bind current visitor with Sitecore contact)

public void UpdateFacetInfo(ContactInfo contactInfo)
{
    var contactFacetsProvider = new ContactFacetsProvider();
    var contactReference = this.contactIdentificationRepository.GetContactReference();

    var facetsToGet = new List<string>
    {
        PhoneNumberList.DefaultFacetKey
    };

    using (var client = this.contactIdentificationRepository.CreateContext())
    {
        var contact = client.Get(contactReference, new ContactExpandOptions(facetsToGet.ToArray()));
        if (contact == null)
        {
            throw new ArgumentNullException(nameof(contact));
        }

        // set personal info
        var personalInformation = contact.GetFacet<PersonalInformation>(PersonalInformation.DefaultFacetKey) ?? new PersonalInformation();

        personalInformation.FirstName = contactInfo.FirstName;
        personalInformation.LastName = contactInfo.LastName;

        client.SetPersonal(contact, personalInformation);
        client.SetFacet(contact, PersonalInformation.DefaultFacetKey, personalInformation);

        client.Submit();
        contactFacetsProvider.UpdateTracker();
    }
}