Sitecore Lucene index datasource

Computed Index Field

namespace MyProject
{
    /// <summary>
    /// Index rendering/sublayout datasource
    /// </summary>
    public class IndexDataSource : IComputedIndexField
    {
        /// <inheritdoc />
        public string FieldName { get; set; }
        /// <inheritdoc />
        public string ReturnType { get; set; }

        /// <inheritdoc />
        public object ComputeFieldValue(IIndexable indexable)
        {
            Item item = indexable as SitecoreIndexableItem;

            if (item != null && !item.Paths.IsMediaItem) // Don't use this custom field on media items (PDFs)
            {
                var db = item.Database; // Can't use Sitecore.Context in searhc index
                var indexedContent = string.Empty;

                try
                {
                    var allRenderings = item.Visualization.GetRenderings(Sitecore.Context.Device, true);
                    var filteredRenderings = allRenderings.Where(x => x.RenderingItem.Name == "Rich Text" && !string.IsNullOrEmpty(x.Settings.DataSource)); // Filter the renderings

                    if (filteredRenderings.Any())
                    {
                        foreach (var rendering in filteredRenderings)
                        {
                            var datasource = db.GetItem(new Sitecore.Data.ID(rendering.Settings.DataSource)); // Get the datasource

                            if (datasource != null)
                            {
                                var indexField = datasource.Fields["Text"]; // Field to index

                                if (indexField.HasValue)
                                {
                                    indexedContent = indexedContent + Sitecore.StringUtil.RemoveTags(indexField.Value); // Concatenate content without HTML tags
                                }
                            }
                        }

                        return indexedContent;
                    }
                }
                catch (Exception)
                {
                    return null;
                }
            }
           
            return null; // Return null if nothing to index
        }
    }
}