Add custom fields to a Solr schema

Version:

You can create a custom helper class to add custom fields to a Solr schema.

To add custom fields:

Create a class that inherits SchemaPopulateHelper, and use this class to define the fields and the field types you want to add to the Solr schema:

using System.Collections.Generic;
using System.Linq;
using System.Xml.Linq;
using Sitecore.ContentSearch.SolrProvider.Pipelines.PopulateSolrSchema;
using SolrNet.Schema;

namespace Documentation.Examples
{
    public class CustomPopulateHelper : SchemaPopulateHelper
    {
        public CustomPopulateHelper(SolrSchema schema) : base(schema)
        {

        }
        
        public override IEnumerable<XElement> GetAllFields()
        {
            return base.GetAllFields().Union(GetAddCustomFields());
        }

        public override IEnumerable<XElement> GetAllFieldTypes()
        {
            return base.GetAllFieldTypes().Union(GetAddCustomFieldTypes());
        }

        private IEnumerable<XElement> GetAddCustomFields()
        {            
            yield return CreateField("*_t_pl", 
                "text_general", 
                isDynamic: true, 
                required: false, 
                indexed: true, 
                stored: true, 
                multiValued: false, 
                omitNorms: false, 
                termOffsets: false, 
                termPositions: false, 
                termVectors: false);
       }

        private IEnumerable<XElement> GetAddCustomFieldTypes()
        {
            var fieldType = CreateFieldType("custom_text", "solr.TextField",
                new Dictionary<string, string>
                {
                    { "positionIncrementGap", "100" },
                    { "multiValued", "false" },
                });
           var indexAnalyzer = new XElement("indexAnalyzer");
           indexAnalyzer.Add(new XElement("tokenizer", new XElement("class", "solr.StandardTokenizerFactory")));
           indexAnalyzer.Add(new XElement("filters", new XElement("class", "solr.StopFilterFactory"), new XElement("ignoreCase", "true"), new XElement("words", "stopwords.txt")));
           indexAnalyzer.Add(new XElement("filters", new XElement("class", "solr.LowerCaseFilterFactory")));
           fieldType.Add(indexAnalyzer);

           var queryAnalyzer = new XElement("queryAnalyzer");
           queryAnalyzer.Add(new XElement("tokenizer", new XElement("class", "solr.StandardTokenizerFactory")));
           queryAnalyzer.Add(new XElement("filters", new XElement("class", "solr.StopFilterFactory"), new XElement("ignoreCase", "true"), new XElement("words", "stopwords.txt")));
           queryAnalyzer.Add(new XElement("filters", new XElement("class", "solr.SynonymFilterFactory"), new XElement("synonyms", "synonyms.txt"), new XElement("ignoreCase", "true"), new XElement("expand", "true")));
           queryAnalyzer.Add(new XElement("filters", new XElement("class", "solr.LowerCaseFilterFactory")));
           fieldType.Add(queryAnalyzer);

           yield return fieldType;
        }
    }
}

Override the GetAllFields method to add custom fields. It is important that you call the base method and combine the results with the results of the custom method.
Override the GetAllFieldTypes method to add custom field types. It is important that you call the base method and combine the results with the results of the custom method.

Use the CreateField method to add new field and attributes. The Solr documentation has descriptions of all parameters, except for these two:

Parameter	Type	Description	Default value
defaultName	string	Specify a default value for the field	null
isDynamic	bool	Specify whether the field is a dynamic field	false

Use the CreateFieldType method to add new field type and attributes. The Solr documementation has descriptions of all parameters.

Create a PopulateHelper factory class that inherits from IPopulateHelperFactory, implements the GetPopulateHelper method, and returns your custom class:

using Sitecore.ContentSearch.SolrProvider.Abstractions;
using Sitecore.ContentSearch.SolrProvider.Pipelines.PopulateSolrSchema;
using SolrNet.Schema;

namespace Documentation.Examples
{
    public class CustomPopulateHelperFactory : IPopulateHelperFactory
    {
        public ISchemaPopulateHelper GetPopulateHelper(SolrSchema solrSchema)
        {
            return new CustomPopulateHelper(solrSchema);
        }
    }
}

Create a configuration patch file that overrides the Sitecore class factory with the one you created:

<?xml version="1.0" encoding="utf-8" ?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <pipelines>
      <contentSearch.PopulateSolrSchema>
        <processor type="Sitecore.ContentSearch.SolrProvider.Pipelines.PopulateSolrSchema.PopulateFields, Sitecore.ContentSearch.SolrProvider">
       <param type="Documentation.Examples.CustomPopulateHelperFactory, Documentation.Examples" patch:instead="*[@type='Sitecore.ContentSearch.SolrProvider.Factories.DefaultPopulateHelperFactory']"/>
     </processor>
      </contentSearch.PopulateSolrSchema>
    </pipelines>
  </sitecore>
</configuration>

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