Code breaks after update to Lucene.net 4.8.0-beta00001

Question

I have just started using Lucene.net for a project. I have based my code on the code provided here: https://github.com/synhershko/LuceneNetDemo by Itamar Syn-Hershko. After I updated to the newest NuGet, the code breaks in a couple of places. What do I need to change?

First problem:

searcherManager.ExecuteSearch(searcher =>
{
    var topDocs = searcher.Search(query, 10);
    _totalHits = topDocs.TotalHits;
    foreach (var result in topDocs.ScoreDocs)
    {
        var doc = searcher.Doc(result.Doc);
        l.Add(new SearchResult
        {
            Name = doc.GetField("name")?.StringValue,
            Description = doc.GetField("description")?.StringValue,
            Url = doc.GetField("url")?.StringValue,

            // Results are automatically sorted by relevance
            Score = result.Score,
        });
    }
}, exception => { Console.WriteLine(exception.ToString()); });

The errormessage:

'SearcherManager' does not contain a definition for 'ExecuteSearch' and no extension method 'ExecuteSearch' accepting a first argument of type 'SearcherManager' could be found (are you missing a using directive or an assembly reference?)

Second problem:

public class HtmlStripAnalyzerWrapper : Analyzer
{
    private readonly Analyzer _wrappedAnalyzer;

    public HtmlStripAnalyzerWrapper(Analyzer wrappedAnalyzer)
    {
        _wrappedAnalyzer = wrappedAnalyzer;
    }

    public override TokenStreamComponents CreateComponents(string fieldName, TextReader reader)
    {
        return _wrappedAnalyzer.CreateComponents(fieldName, new HTMLStripCharFilter(reader));
    }
}

The errormessage:

'HtmlStripAnalyzerWrapper.CreateComponents(string, TextReader)': cannot change access modifiers when overriding 'protected internal' inherited member 'Analyzer.CreateComponents(string, TextReader)'

And

Cannot access protected member 'Analyzer.CreateComponents(string, TextReader)' via a qualifier of type 'Analyzer'; the qualifier must be of type 'HtmlStripAnalyzerWrapper' (or derived from it)

Answer 1

There is an update to the demo at: https://github.com/NightOwl888/LuceneNetDemo

First Problem:

The API was inadvertently removed because it was not properly marked and does not exist in Lucene 4.8.0. However, it is only a supplemental API to SearcherManager.Acquire() and SearcherManager.Release(). You can see its usage in the SearcherManager documentation of Lucene 4.8.0.

var searcher = searcherManager.Acquire();
try
{
    var topDocs = searcher.Search(query, 10);
    _totalHits = topDocs.TotalHits;
    foreach (var result in topDocs.ScoreDocs)
    {
        var doc = searcher.Doc(result.Doc);
        l.Add(new SearchResult
        {
            Name = doc.GetField("name")?.GetStringValue(),
            Description = doc.GetField("description")?.GetStringValue(),
            Url = doc.GetField("url")?.GetStringValue(),

            // Results are automatically sorted by relevance
            Score = result.Score,
        });
    }
}
catch (Exception e)
{
    Console.WriteLine(e.ToString());
}
finally
{
    searcherManager.Release(searcher);
    searcher = null; // Never use searcher after this point!
}

We are considering whether to bring back the original ExecuteSearch() API, or create a new one that can be used with a using block for a more .NET-friendly experience. See an example of the second option in pull request 207. Feedback welcome.

Certainly, an API that swallows exceptions by default is less than ideal.

Second Problem:

Accessibility of API members was also corrected to match Lucene. CharFilters were not intended to be used in conjunction with pre-built Analyzers for performance reasons. Instead, you must build up an Analyzer from pre-built tokenizers and filters.

using Lucene.Net.Analysis;
using Lucene.Net.Analysis.CharFilters;
using Lucene.Net.Analysis.Core;
using Lucene.Net.Analysis.Standard;
using Lucene.Net.Util;
using System.IO;

namespace LuceneNetDemo.Analyzers
{
    class HtmlStripAnalyzer : Analyzer
    {
        private readonly LuceneVersion matchVersion;

        public HtmlStripAnalyzer(LuceneVersion matchVersion)
        {
            this.matchVersion = matchVersion;
        }

        protected override TokenStreamComponents CreateComponents(string fieldName, TextReader reader)
        {
            StandardTokenizer standardTokenizer = new StandardTokenizer(matchVersion, reader);
            TokenStream stream = new StandardFilter(matchVersion, standardTokenizer);
            stream = new LowerCaseFilter(matchVersion, stream);
            stream = new StopFilter(matchVersion, stream, StopAnalyzer.ENGLISH_STOP_WORDS_SET);
            return new TokenStreamComponents(standardTokenizer, stream);
        }

        protected override TextReader InitReader(string fieldName, TextReader reader)
        {
            return base.InitReader(fieldName, new HTMLStripCharFilter(reader));
        }
    }
}

Usage:

analyzer = new PerFieldAnalyzerWrapper(new HtmlStripAnalyzer(LuceneVersion.LUCENE_48),
new Dictionary<string, Analyzer>
{
    {"owner", new LowercaseKeywordAnalyzer()},
    {"name", new RepositoryNamesAnalyzer()},
});