Define computed index fields for a specific index

Question

I'm using Sitecore 10.2.

I want to define a custom computed field but I need it to be added to a specific index only.

I was able to add the computed field globally as below, but I need to specify it for one index only in SOLR, is there a way to do so?

<defaultSolrIndexConfiguration type="Sitecore.ContentSearch.SolrProvider.SolrIndexConfiguration, Sitecore.ContentSearch.SolrProvider" >
      <documentOptions type="Sitecore.ContentSearch.SolrProvider.SolrDocumentBuilderOptions, Sitecore.ContentSearch.SolrProvider">
        <fields hint="raw:AddComputedIndexField">
          <field fieldName="mycustomfield" returnType="textCollection">Project.Web.Search.ComputedFields.MyCustomField, Project.Web</field>
        </fields>
      </documentOptions>
    </defaultSolrIndexConfiguration>

Answer 1

The defaultSolrIndexConfiguration node is located under: .\App_Config\Sitecore\ContentSearch\Sitecore.ContentSearch.Solr.DefaultIndexConfiguration.config

You could create a custom index configuration node that is referenced by your custom index.

Warning: Don't do this for any of the out-of-the-box indexes since Sitecore relies on those index configurations to run properly.

Example

If I were to create a custom index for blog articles named sitecore_blog_master_index, my index configuration would look something like this (pay attention to the configuration/sitecore/contentSearch/configuration/indexes/index/configuration node):

<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 role:require="Standalone or ContentManagement" search:require="solr">
    <contentSearch>
      <configuration type="Sitecore.ContentSearch.ContentSearchConfiguration, Sitecore.ContentSearch">
        <indexes hint="list:AddIndex">
          <index id="sitecore_blog_master_index" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
            <param desc="name">$(id)</param>
            <param desc="core">$(id)</param>
            <param desc="propertyStore" ref="contentSearch/indexConfigurations/databasePropertyStore" param1="$(id)" />
            <configuration ref="contentSearch/indexConfigurations/blogSolrIndexConfiguration">
              <enableReadAccessIndexing>true</enableReadAccessIndexing>
            </configuration>
            <strategies hint="list:AddStrategy">
              <strategy ref="contentSearch/indexConfigurations/indexUpdateStrategies/manual" role:require="ContentManagement and !Indexing" />
              <strategy ref="contentSearch/indexConfigurations/indexUpdateStrategies/intervalAsyncMaster" role:require="Standalone or (ContentManagement and Indexing)" />
            </strategies>
            <locations hint="list:AddCrawler">
              <crawler type="Sitecore.ContentSearch.SitecoreItemCrawler, Sitecore.ContentSearch">
                <Database>master</Database>
                <Root>/sitecore</Root>
              </crawler>
            </locations>
            <enableItemLanguageFallback>false</enableItemLanguageFallback>
            <enableFieldLanguageFallback>false</enableFieldLanguageFallback>
          </index>
        </indexes>
      </configuration>
    </contentSearch>
  </sitecore>
</configuration>

You'd need to make sure to define your blogSolrIndexConfiguration element. You've got two options for this.

Option 1

The easiest thing to do is copy the defaultSolrIndexConfiguration element that I referenced above into your custom index config file, changing the element name to blogSolrIndexConfiguration. This results in a lot of duplicated configuration that makes your index harder to support in the future.

Option 2

Another solution would be to use the ref attribute to reference the subelements from the defaultSolrIndexConfiguration in your blogSolrIndexConfiguration. It would look something like this:

<sc.variable name="defaultSolrIndexConfiguration" 
             value="contentSearch/indexConfigurations/defaultSolrIndexConfiguration/" />

<blogSolrIndexConfiguration type="Sitecore.ContentSearch.SolrProvider.SolrIndexConfiguration, Sitecore.ContentSearch.SolrProvider">
    <initializeOnAdd ref="$(defaultSolrIndexConfiguration)initializeOnAdd" />
    <fieldMap ref="$(defaultSolrIndexConfiguration)fieldMap"/>
    <mediaIndexing ref="$(defaultSolrIndexConfiguration)mediaIndexing"/>
    <virtualFields ref="$(defaultSolrIndexConfiguration)virtualFields"/>
    <fieldReaders ref="$(defaultSolrIndexConfiguration)fieldReaders"/>
    <indexFieldStorageValueFormatter ref="$(defaultSolrIndexConfiguration)indexFieldStorageValueFormatter"/>
    <indexDocumentPropertyMapper ref="$(defaultSolrIndexConfiguration)indexDocumentPropertyMapper"/>
    <documentBuilderType ref="$(defaultSolrIndexConfiguration)documentBuilderType"/>
    <defaultSearchSecurityOption ref="contentSearch/indexConfigurations/defaultSearchSecurityOption" />
    <enableReadAccessIndexing ref="contentSearch/indexConfigurations/enableReadAccessIndexing" />
    <searchOptions ref="$(defaultSolrIndexConfiguration)searchOptions"/>
    <highlightOptions ref="$(defaultSolrIndexConfiguration)highlightOptions"/>

    <documentOptions type="Sitecore.ContentSearch.SolrProvider.SolrDocumentBuilderOptions, Sitecore.ContentSearch.SolrProvider">
        {{Custom Configuration Goes Here}}
    </documentOptions>
</blogSolrIndexConfiguration>

This minimizes the duplication of configuration, allowing you to define specifically what's custom to your solution.

Answer 2

Use this simple configuration and extend as per your needs.

<indexes hint="list:AddIndex">
    <index id="your_index_name" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
        <param desc="name">$(id)</param>
        <param desc="folder">$(id)</param>
        <configuration ref="contentSearch/indexConfigurations/defaultSolrIndexConfiguration">
            <documentOptions ref="contentSearch/indexConfigurations/defaultSolrIndexConfiguration/documentOptions">
                <fields hint="raw:AddComputedIndexField">
                    <!-- Your Computed Index -->
                    <field fieldName="external_link" returnType="text">mydll.ComputedFields.ExternalLink, mydll</field>
                </fields>
            </documentOptions>
        </configuration>
      <enableItemLanguageFallback>false</enableItemLanguageFallback>
      <enableFieldLanguageFallback>false</enableFieldLanguageFallback>
    </index>
</indexes>

Hope this will help.

Answer 3

Assume you want to create a new separate index file for the Course then first need to develop a new index file, you can then make a replica of existing one: Sitecore.Foundation.CoursesMaster.Indexing.config

In the configuration section provide the new name:

<configuration type="Sitecore.ContentSearch.ContentSearchConfiguration, Sitecore.ContentSearch">
    <indexes hint="list:AddIndex">
      <!--index name-->
      <index id="course_custom_master_index" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
        <param desc="name">$(id)</param>
        <!--index name-->
        <param desc="core">course_custom_master_index</param>
        <!--other parameters-->
        ...
        <!--new custom configuration name-->
        <configuration ref="contentSearch/indexConfigurations/courseSolrIndexConfigurationMaster" />
        <strategies hint="list:AddStrategy">
          <strategy..../>
          <strategy .../>
        </strategies>
        <locations hint="list:AddCrawler">
          ....
        </locations>
      </index>
    </indexes>
  </configuration>

Here is your Id of the index 'course_custom_master_index' and instead of defaultSolrIndexConfiguration new indexConfigurations is courseSolrIndexConfigurationMaster.

Now your custom indexconfiguration will be:

<!--your custom index configuration-->
<courseSolrIndexConfigurationMaster type="Sitecore.ContentSearch.SolrProvider.SolrIndexConfiguration, Sitecore.ContentSearch.SolrProvider" >
  <documentOptions type="Sitecore.ContentSearch.SolrProvider.SolrDocumentBuilderOptions, Sitecore.ContentSearch.SolrProvider">
    <fields hint="raw:AddComputedIndexField">
      <!--custom field-->
      <field fieldName="courseCustomfield" returnType="textCollection">Project.Web.Search.ComputedFields.MyCustomField, Project.Web</field>
    </fields>
  </documentOptions>
</courseSolrIndexConfigurationMaster>

Rest, you can define your custom field and the implementation same. I hope it helps.