How to view the analyzed text when a custom analyzer was used?

Question

I can't figure out how to test my custom analyzer/view the analyzed data.

Normally I would add my custom analyzer to the "index settings" when creating the index. The problem I'm having in this case is that I'm not using an index or at least I think that I'm not and I don't know how to add my custom analyzer to the Elasticsearch client?

This is the method which I'm currently using for testing the "analysis" part:

public async Task AnalizeField(string analyzer, string textToAnalyze)
{
    var elasticClient = ElasticsearchHelper.DatabaseConnection();

    var analyzeResponse = await elasticClient.AnalyzeAsync(a => a
            .Analyzer(analyzer)
            .Text(textToAnalyze)
        );

    var result = "";

    if (analyzeResponse != null && analyzeResponse.Tokens.Count > 0)
    {
        foreach (var token in analyzeResponse.Tokens)
        {
            result += token.Token + " ";
        }

    }

    Console.WriteLine("Analyzing text \"" + textToAnalyze + "\" using the \"" + analyzer + "\" analyzer: " + result);
}

Answer 1

Found it: https://www.elastic.co/guide/en/elasticsearch/client/net-api/current/testing-analyzers.html#_testing_a_custom_analyzer_in_an_index

Testing a custom analyzer in an index

In this example, we’ll add a custom analyzer to an existing index. First, we need to close the index

client.CloseIndex("analysis-index");

Now, we can update the settings to add the analyzer

client.UpdateIndexSettings("analysis-index", i => i
    .IndexSettings(s => s
        .Analysis(a => a
            .CharFilters(cf => cf
                .Mapping("my_char_filter", m => m
                    .Mappings("F# => FSharp")
                )
            )
            .TokenFilters(tf => tf
                .Synonym("my_synonym", sf => sf
                    .Synonyms("superior, great")

                )
            )
            .Analyzers(an => an
                .Custom("my_analyzer", ca => ca
                    .Tokenizer("standard")
                    .CharFilters("my_char_filter")
                    .Filters("lowercase", "stop", "my_synonym")
                )
            )

        )
    )
);

And open the index again. Here, we also wait up to five seconds for the status of the index to become green

client.OpenIndex("analysis-index");
client.ClusterHealth(h => h
    .WaitForStatus(WaitForStatus.Green)
    .Index("analysis-index")
    .Timeout(TimeSpan.FromSeconds(5))
);

With the index open and ready, let’s test the analyzer

var analyzeResponse = client.Analyze(a => a
    .Index("analysis-index") 
    .Analyzer("my_analyzer")
    .Text("F# is THE SUPERIOR language :)")
);