Indexing Block's Content to make it searchable

By default, the content of a block (that is added to ContentArea on a page) is not indexed and therefore you can’t search for the content of that block instance in your site.

So, the content of a page (including block's content) is indexed as normal text under "SearchText$$string". To check if the content from Block is being indexed or not. Go to Episerver CMS, Find -> Overview -> Explore, look for the page you want to confirm. Expand to see all its indexed properties. You can see here that, by default the content of the block is not being indexed.

Let's talk about how to enable it. Here we go....

There are several ways to do that, use any of them as per your requirement.

1. To allow content of all the instances of a block type to be indexed. Just add an attribute [IndexInContentArea] on your block.

   [IndexInContentAreas]
   public class CopyBlock : SectionBlock

   Tip: If you still not see the content is being indexed. Perform some changes to your page and you will see it worked. It's only to reindex the page.

2. To exclude content of certain instances of the block, add a bool type property with exact name IndexInContentAreas on your block type.

   public virtual bool IndexInContentAreas { get; set; }

   And set its value to True, so that content of all instances will be indexed by default. To exclude content of any instance, uncheck the checkbox for property IndexInContentAreas (for that instance only).

3. Using search convention, changing the default behaviour of IContentIndexerConventions.ShouldIndexInContentAreaConvention.

   To index a particular block type, create a class and inherit it with interface IShouldIndexInContentAreaConvention

   public class ShouldIndexInContentAreaConvention : IShouldIndexInContentAreaConvention
   {
          public bool? ShouldIndexInContentArea(IContent content)
          {
          	return content is CopyBlock;
          }
   }
   

    Now create an Initializable module

   [InitializableModule]
   [ModuleDependency(typeof(EPiServer.Find.Cms.Module.IndexingModule))]
   public class SearchConventionInitializationModule : IInitializableModule
   {
           public void Initialize(InitializationEngine context)
           {
               ContentIndexer.Instance.Conventions.ShouldIndexInContentAreaConvention = new ShouldIndexInContentAreaConvention();
           }
   
           public void Uninitialize(InitializationEngine context)
           {
           }
   }
   

   In addition, to control the depth of ContentArea to be indexed, can be controlled by MaxDepthContentAreaConverter (by default all nested ContentArea are indexed)

   public class SearchConventionInitializationModule : IInitializableModule
   {
           private const int MaxDepth = 4;
   
           public void Initialize(InitializationEngine context)
           {
               ContentIndexer.Instance.Conventions.ShouldIndexInContentAreaConvention = new ShouldIndexInContentAreaConvention();
               SearchClient.Instance.Conventions.ForInstancesOf<ContentArea>().ModifyContract(x => x.Converter = new MaxDepthContentAreaConverter(MaxDepth));
           }
   
           public void Uninitialize(InitializationEngine context)
           {
           }
   }

Document reference: https://world.episerver.com/documentation/developer-guides/find/Integration/episerver-cms-7-5-with-updates/Indexing-content-in-a-content-area/

Happy Coding :)