Solr computed index field of type stringCollection not stored as expected

Question

I've made a computed index field in my solution. The class returns List<string> from the ComputeFieldValue method and the config patch includes the field within the fieldMap and documentOptions sections of the defaultSolrIndexConfiguration.

I'm following the answer provided here: Solr tokenization to split on semicolon character

My indexer class is as follows:

public class SemicolonDelimitedField : AbstractComputedIndexField
{
 public override object ComputeFieldValue(IIndexable indexable)
 {
  Item item = indexable as SitecoreIndexableItem;
  if (item == null)
  {
    return null;
  }

  if (item.TemplateID != Templates.Category.ID
      && item.TemplateID != Templates.CommerceProduct.ID)
  {
    return null;
  }

  var fieldValue = item[FieldName];
  var values = fieldValue?.Split(new[] {";"}, StringSplitOptions.RemoveEmptyEntries);
  if (values == null || values.Any() == false)
  {
    return null;
  }

  var returnValue = values.Select(v => v.Trim()).ToList();
  return returnValue;
 }
}

And the config patch is as follows

<?xml version="1.0" encoding="utf-8" ?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/"
               xmlns:role="http://www.sitecore.net/xmlconfig/role/"
               xmlns:search="http://www.sitecore.net/xmlconfig/search/">
  <sitecore search:require="solr">
    <contentSearch>
      <indexConfigurations>
        <defaultSolrIndexConfiguration type="Sitecore.ContentSearch.SolrProvider.SolrIndexConfiguration, Sitecore.ContentSearch.SolrProvider" >
          <fieldMap type="Sitecore.ContentSearch.SolrProvider.SolrFieldMap, Sitecore.ContentSearch.SolrProvider">
            <fieldNames hint="raw:AddFieldByFieldName">
              <field fieldName="myField" returnType="stringCollection" />
            </fieldNames>
          </fieldMap>

          <documentOptions type="Sitecore.ContentSearch.SolrProvider.SolrDocumentBuilderOptions, Sitecore.ContentSearch.SolrProvider">
            <fields hint="raw:AddComputedIndexField">
              <field fieldName="myField" storageType="NO" indexType="UNTOKENIZED">MyNamespace.SemicolonDelimitedField, MyAssembly</field>
            </fields>
          </documentOptions>
        </defaultSolrIndexConfiguration>
      </indexConfigurations>
    </contentSearch>
  </sitecore>
</configuration>

What I am seeing in my Solr index is that the computed field does not seem to be breaking up into separate entities in the array e.g.

"myField_sm":["Low level;High level"],

what I was expecting was

"myField_sm":["Low level", "High level"],

I attached the debugger to be 100% sure that a List<string> with two elements was really being returned. What part of the puzzle am I missing?

Answer 1

You wrote in your question that the value which is indexed is

"myField_sm":["Low level;High level"],

It doesn't look like indexing issue. I've never seen Sitecore or Solr adding ";" in document fields.

This looks rather like the field is indexed directly from item field value rather than from your custom code.

Try to use completely new name for your custom field in the config and see if that helps.