Passing Custom Parameters to Computed Fields

Sometimes, you may want to pass custom parameters to a computed field. For example, following the Creating a Computed Date Field tutorial, you may want to control when the archivedate field is created on items. For this purpose, the current tutorial shows you how to configure the number of days before an item is archived.



  1. Using Visual Studio, open the ComputedDateField class.
  2. Add a constructor to accept additional XML configuration.

     private readonly XmlNode m_Configuration;
     public ArchiveDateField(XmlNode p_Configuration)
         m_Configuration = p_Configuration;
  3. Add a method to parse the configuration XML attributes and return their value.

     protected string GetConfigurationValue(string p_ConfigurationKey)
         string configurationValue = null;
         if (m_Configuration != null && m_Configuration.Attributes != null) {
             XmlAttribute configurationAttribute = m_Configuration.Attributes[p_ConfigurationKey];
             if (configurationAttribute != null) {
                 configurationValue = configurationAttribute.Value;
         return configurationValue;
  4. Add a property to retrieve the configuration value formatted as an integer.

     protected int DaysBeforeArchiving
         get {
             int daysCount;
             if (!Int32.TryParse(GetConfigurationValue("daysBeforeArchiving"), out daysCount)) {
                 daysCount = 365; // One year by default
             return daysCount;
  5. Change the ComputeFieldValue method to use the DaysBeforeArchiving property.

     /// <inheritdoc />
     public object ComputeFieldValue(IIndexable p_Indexable)
         SitecoreIndexableItem indexableItem = p_Indexable as SitecoreIndexableItem;
         if (indexableItem != null) {
             IIndexableDataField dateField = indexableItem.GetFieldByName(SITECORE_CREATED_FIELD);
             if (dateField != null) {
                 DateTime itemCreationDate = DateUtil.ParseDateTime(dateField.Value.ToString(), DateTime.MaxValue);
                 return itemCreationDate.AddDays(DaysBeforeArchiving).ToString(COVEO_INDEX_DATE_FORMAT);
         return null;
  6. Compile your project.

  7. Copy the resulting assembly (Coveo.Custom.dll) to the bin folder of your Sitecore instance.

  8. Open your Coveo.SearchProvider.Custom.config file and add the daysBeforeArchiving parameter as an XML attribute.

     <field fieldName="archiveDate" daysBeforeArchiving="30">Coveo.Custom.ArchiveDateField, Coveo.Custom</field>
  9. Rebuild your indexes using the Indexing Manager (Sitecore Desktop > Start Menu > Control Panel > Indexing > Indexing Manager).
  10. Validate that your computed field now uses the DaysBeforeArchiving parameter by following the validation steps described in step 3 of Creating a Computed Date Field. There should be a difference of 30 days between both dates.