To query the search index, one should create an instance of Composite.Search.SearchQuery and execute is via an instance of Composite.Search.ISearchProvider interface. An instance can be received either with Dependency Injection (in a startup handler, as an injected CMS function parameter) or by accessing Composite.Search.SearchFacade.SearchProvider property.

public interface ISearchProvider
{
	Task<SearchResult> SearchAsync(SearchQuery query);
}

public sealed class SearchQuery
{
	public SearchQuery(string query, CultureInfo cultureInfo);

	public void AddFieldFacet(string fieldName);
	
	public void AddFieldFacet(string fieldName, string[] values, string[] notValues);	
	
	public void FilterByAncestors(params EntityToken[] entityTokens)
	
	public void FilterByDataTypes(IEnumerable<Type> dataTypes);
	
	public void FilterByUser(string userName);

	public void ShowOnlyDocumentsWithUrls();

	public string Query { get; }

	public CultureInfo CultureInfo { get; }

	public int SearchResultOffset { get; set; }

	public int MaxDocumentsNumber { get; set; }
	
	public SearchQueryHighlightSettings HighlightSettings { get; set; }

	public ICollection<KeyValuePair<string, DocumentFieldFacet>> Facets { get; set; }

	public ICollection<SearchQuerySelection> Selection { get; set; }

	public IEnumerable<SearchQuerySortOption> SortOptions { get; set; }
}

AddFieldFacet(…) - allows returning facet values for a given field.

FilterByAncestors(…) - allows filtering results by ancestor elements in the console element tree. That enables limiting search results to f.e.  documents that are descendants of a certain website page or media library folder.

FilterByUser(…) - allows filtering results by the cms console permissions, so only the tree elements that’s visible for the given user will be shown in the results.

FilterByDataTypes(…) - allows limiting search document to specific data types.

ShowOnlyDocumentsWithUrls() - indicates that only documents that have a URL should be shown

Search result contains a list of found documents (along with matched text fragments) as well as facets information:

public sealed class SearchResult
{
	public IEnumerable<SearchResultItem> Items { get; set; }

	public int TotalHits { get; set; }

	public IDictionary<string, Facet[]> Facets { get; set; }
}

public sealed class SearchResultItem
{
	public SearchDocument Document { get; set; }

	public string LabelHtmlHighlight { get; set; }

	public string[] FullTextHtmlHighlights { get; set; }
}

public class Facet
{
	public string Value { get; set; }

	public int HitCount { get; set; }
}