/// <summary>
/// A fuzzy based query that uses similarity based on Levenshtein (edit distance) algorithm.
/// Warning: this query is not very scalable with its default prefix length of 0 – in this case,
/// every term will be enumerated and cause an edit score calculation or max_expansions is not set.
/// </summary>
public QueryContainer Fuzzy(Action <FuzzyQueryDescriptor <T> > selector)
{
var query = new FuzzyQueryDescriptor <T>();
selector(query);
return(this.New(query, q => q.Fuzzy = query));
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
var j = JObject.Load(reader);
if (!j.HasValues)
{
return(null);
}
var firstProp = j.Properties().FirstOrDefault();
if (firstProp == null)
{
return(null);
}
var field = firstProp.Name;
var jo = firstProp.Value.Value <JObject>();
if (jo == null)
{
return(null);
}
JToken v = null;
if (!jo.TryGetValue("value", out v))
{
return(null);
}
IFuzzyQuery fq = null;
if (v.Type == JTokenType.Date)
{
fq = new FuzzyDateQueryDescriptor <object>();
}
else if (v.Type == JTokenType.String)
{
fq = new FuzzyQueryDescriptor <object>();
}
else if (v.Type == JTokenType.Integer || v.Type == JTokenType.Float)
{
fq = new FuzzyNumericQueryDescriptor <object>();
}
else
{
return(null);
}
fq.Field = field;
fq.Boost = GetPropValue <double?>(jo, "boost");
fq.Fuzziness = GetPropValue <string>(jo, "fuzziness");
fq.MaxExpansions = GetPropValue <int?>(jo, "max_expansions");
fq.UnicodeAware = GetPropValue <bool?>(jo, "unicode_aware");
fq.Transpositions = GetPropValue <bool?>(jo, "transpositions");
var rewriteString = GetPropValue <string>(jo, "rewrite");
if (!rewriteString.IsNullOrEmpty())
{
fq.Rewrite = Enum.Parse(typeof(RewriteMultiTerm), rewriteString) as RewriteMultiTerm?;
}
if (fq is IStringFuzzyQuery)
{
var fqs = fq as IStringFuzzyQuery;
fqs.PrefixLength = GetPropValue <int?>(jo, "prefix_length");
fqs.Value = GetPropValue <string>(jo, "value");
}
if (fq is IFuzzyDateQuery)
{
var fdq = fq as IFuzzyDateQuery;
fdq.Value = GetPropValue <DateTime?>(jo, "value");
}
if (fq is IFuzzyNumericQuery)
{
var fnq = fq as IFuzzyNumericQuery;
fnq.Value = GetPropValue <double?>(jo, "value");
}
return(fq);
}