CombinedDateAndTimeComputedFieldExample.cs

using System;
using Sitecore.ContentSearch;
using Sitecore.ContentSearch.ComputedFields;
using Sitecore.ContentSearch.Utilities;
using Sitecore.Data;
using Sitecore.Data.Items;

namespace Examples.ComputedIndexFields
{
  public class CombinedDateTime : IComputedIndexField
  {
    public object ComputeFieldValue(IIndexable indexable)
    {
      if (indexable == null)
        return null;

      var indexableItem = indexable as SitecoreIndexableItem;

      if (indexableItem == null)
        return null;

      ID templateId = new ID("TemplateId");

      // The IsDerived extension method can be found over at:
      // https://laubplusco.net/sitecore-extensions-does-a-sitecore-item-derive-from-a-template/
      if (indexableItem.Item.IsDerived(templateId))
      {
        DateTime? dateWithTime = GetCombinedDateAndTime(indexableItem.Item);
        return dateWithTime;
      }
      return null;
    }

    private DateTime? GetCombinedDateAndTime(Item item)
    {
      DateTime? selectedDate = GetSelectedDate(item);
      TimeSpan? selectedTime = GetSelectedTime(item);
      
      if (selectedDate.HasValue && selectedTime.HasValue)
      {
        DateTime dateWithTime = selectedDate.Value.Add(parsedTime);
        return dateWithTime;
      }
      return null;
    }
    
    private DateTime? GetSelectedDate(Item item)
    {
      DateField dateField = new DateField(item.Fields[new ID("DateFieldId")]);
        
      if (string.IsNullOrEmpty(dateField.InnerField.GetValue(true, true)))
        return null;
      
      return dateField.DateTime;
    }
    
    private TimeSpan? GetSelectedTime(Item item)
    {
      string selectedTime = item.Fields[new ID("TimeFieldId")].Value;

      if (string.IsNullOrEmpty(selectedTime))
        return null;

      TimeSpan parsedTime;
      if (TimeSpan.TryParse(theTime, out parsedTime))
        return parsedTime;
        
      return null;
    }

    public string FieldName { get; set; }
    public string ReturnType { get; set; }
  }
}