Creating a custom analyzer in ElasticSearch Nest client - elasticsearch

Question

Im very very new to elasticsearch using the nest client, I am creating an index with a custom analyzer, however when testing using analyze it does not seem to use the custom analyzer. Mainly no edgengram tokens appear. Is there anything I am missing that would make my custom analyser the default for the index? When I check my mappings using elastichq they show my custom analyzer.
ConnectionSettings settings = new ConnectionSettings(new Uri("http://localhost:9200"), defaultIndex: "forum-app");
IndexSettings indsettings = new IndexSettings();
var an = new CustomAnalyzer();
an.CharFilter = new List<string>();
an.CharFilter.Add("html_strip");
an.Tokenizer = "edgeNGram";
an.Filter = new List<string>();
an.Filter.Add("standard");
an.Filter.Add("lowercase");
an.Filter.Add("stop");
indsettings.Analysis.Tokenizers.Add("edgeNGram", new Nest.EdgeNGramTokenizer
{
MaxGram = 15,
MinGram = 3
});
indsettings.Analysis.Analyzers.Add("forumanalyzer", an);
ElasticClient client = new ElasticClient(settings);
client.CreateIndex("forum-app", c => c
.NumberOfReplicas(0)
.NumberOfShards(1)
.AddMapping<Forum>(e => e.MapFromAttributes())
.Analysis(analysis => analysis
.Analyzers(a => a
.Add("forumanalyzer", an)
)));
//To index I just do this
client.Index(aForum);

Answer 1

You've added your custom analyzer to your index, but now you need to apply it your fields. You can do this on a field mapping level:
client.CreateIndex("forum-app", c => c
.NumberOfReplicas(0)
.NumberOfShards(1)
.AddMapping<Forum>(e => e
.MapFromAttributes()
.Properties(p => p
.String(s => s.Name(f => f.SomeProperty).Analyzer("formanalyzer")))
)
.Analysis(analysis => analysis
.Analyzers(a => a
.Add("forumanalyzer", an)
)
)
);
Or you can apply it to all fields by default by setting it as the default analyzer of your index:
client.CreateIndex("forum-app", c => c
.NumberOfReplicas(0)
.NumberOfShards(1)
.AddMapping<Forum>(e => e.MapFromAttributes())
.Analysis(analysis => analysis
.Analyzers(a => a
.Add("default", an)
)
)
);
More info here in regards to analyzer defaults.

Answer 2

Add a custom analyzer:
var indexSettings = new IndexSettings
{
NumberOfReplicas = 0, // If this is set to 1 or more, then the index becomes yellow.
NumberOfShards = 5
};
indexSettings.Analysis = new Analysis();
indexSettings.Analysis.Analyzers = new Analyzers();
indexSettings.Analysis.TokenFilters = new TokenFilters();
var customAnalyzer = new CustomAnalyzer
{
//CharFilter = new List<string> { "mapping " },
Tokenizer = "standard",
Filter = new List<string> { "lowercase", "asciifolding" }
};
indexSettings.Analysis.Analyzers.Add("customAnalyzerLowercaseSynonymAsciifolding", customAnalyzer);
And then when creating the index, you specify the analyzer:
var indexConfig = new IndexState
{
Settings = indexSettings
};
var createIndexResponse = elasticClient.CreateIndex(indexName, c => c
.InitializeUsing(indexConfig)
.Mappings(m => m
.Map<ElasticsearchModel>(mm => mm
.Properties(
p => p
.Text(t => t.Name(elasticsearchModel => elasticsearchModel.StringTest).Analyzer("customAnalyzerLowercaseSynonymAsciifolding"))
)
)
)
);
elasticClient.Refresh(indexName);
And then you query it with something like:
var response = elasticClient.Search<ElasticsearchModel>(s => s
.Index(indexName)
.Query(q => q
.SimpleQueryString(qs => qs
.Fields(fs => fs
.Field(f => f.StringTest, 4.00)
)
.Query(query)
)
)
);
var results = new List<ElasticsearchModel>();
results = response.Hits.Select(hit => hit.Source).ToList();