How to sort the results from the search Results widget based on an external sorted list ?

This operation might be useful when having an external service that returns a list of ordered IDs and the goal is that the SearchResults shows the results ordered based on this list.

After customizing the SearchResults widget (following this link from the Sitefinity documentation: https://www.progress.com/documentation/sitefinity-cms/133/for-developers-customize-search-results-by-overriding-the-searchresults-class-webforms   ):
 

using System;
using System.Collections.Generic;
using System.Linq;
using Telerik.Sitefinity.Abstractions;
using Telerik.Sitefinity.Services.Search;
using Telerik.Sitefinity.Services.Search.Data;
using Telerik.Sitefinity.Services.Search.Web.UI.Public;

namespace SitefinityWebApp
{
public static class MySearchExtensionHelper 
{
public static IEnumerable<TResult> SortBy<TResult, TKey>(
this IEnumerable<TResult> itemsToSort,
IEnumerable<TKey> sortKeys,
Func<TResult, TKey> matchFunc)
{
return sortKeys.Join(itemsToSort,
key => key,
matchFunc,
(key, iitem) => iitem);
}


}

public class CustomSearchResults : SearchResults
{
protected override ISearchResultsBuilder GetSearcher()
{
return new MySearcher(this);
}




protected class MySearcher : ISearchResultsBuilder
{
public MySearcher(SearchResults control)
{
this.control = control;
}

public IEnumerable<IDocument> Search(string query, string catalogue, string[] searchFields, string[] highlightedFields, int skip, int take, out int hitCount)
{
var control = this.control;
var service = Telerik.Sitefinity.Services.ServiceBus.ResolveService<ISearchService>();
var queryBuilder = ObjectFactory.Resolve<IQueryBuilder>();

var searchQuery = queryBuilder.BuildQuery(query, control.SearchFields);
searchQuery.IndexName = catalogue;
searchQuery.Skip = skip;
searchQuery.Take = take;
searchQuery.OrderBy = null;
searchQuery.HighlightedFields = control.HighlightedFields;


IResultSet result = service.Search(searchQuery);


// Assuming this is an external already sorted List with ZIP codes ordered by distance
var listZIPsOnly = new List<string>() { "02139", "02451", "02472" };



hitCount = result.HitCount;


// changing the order of the search results based on the external list
var sortedList = result.SortBy(listZIPsOnly,c=>c.GetValue("Zip").ToString());

return sortedList.SetContentLinks();


}



protected readonly SearchResults control;
}
}


}

 

Please note that WebForms is deprecated since version 14.1. 

More details here: https://www.progress.com/documentation/sitefinity-cms/web-forms-deprecation-with-sitefinity-cms-14.1