Interface IIndexableField

Represents a single field for indexing. IndexWriter consumes IEnumerable<IndexableField> as a document.

Note

This API is experimental and might change in incompatible ways in the next release.

Namespace: Lucene.Net.Index

Assembly: Lucene.Net.dll

Syntax

public interface IIndexableField

Properties

Boost

Returns the field's index-time boost.

Only fields can have an index-time boost, if you want to simulate a "document boost", then you must pre-multiply it across all the relevant fields yourself.

The boost is used to compute the norm factor for the field. By default, in the ComputeNorm(FieldInvertState) method, the boost value is multiplied by the length normalization factor and then rounded by EncodeNormValue(Single) before it is stored in the index. One should attempt to ensure that this product does not overflow the range of that encoding.

It is illegal to return a boost other than 1.0f for a field that is not indexed (IsIndexed is false) or omits normalization values (OmitNorms returns true).

Declaration

float Boost { get; }

Property Value

Type	Description
System.Single

See Also

ComputeNorm(FieldInvertState)

EncodeNormValue(Single)

IndexableFieldType

IIndexableFieldType describing the properties of this field.

Declaration

IIndexableFieldType IndexableFieldType { get; }

Property Value

Type	Description
IIndexableFieldType

Name

Field name

Declaration

string Name { get; }

Property Value

Type	Description
System.String

NumericType

Gets the NumericFieldType of the underlying value, or NONE if the value is not set or non-numeric.

Expert: The difference between this property and NumericType is this is represents the current state of the field (whether being written or read) and the FieldType property represents instructions on how the field will be written, but does not re-populate when reading back from an index (it is write-only).

In Java, the numeric type was determined by checking the type of
GetNumericValue(). However, since there are no reference number types in .NET, using GetNumericValue() so will cause boxing/unboxing. It is therefore recommended to use this property to check the underlying type and the corresponding Get*Value() method to retrieve the value.

NOTE: Since Lucene codecs do not support BYTE or INT16, fields created with these types will always be INT32 when read back from the index.

Declaration

NumericFieldType NumericType { get; }

Property Value

Type	Description
NumericFieldType

Methods

GetBinaryValue()

Non-null if this field has a binary value.

Declaration

BytesRef GetBinaryValue()

Returns

Type	Description
BytesRef

GetByteValue()

Returns the field value as System.Byte or null if the type is non-numeric.

Declaration

byte? GetByteValue()

Returns

Type	Description
System.Nullable<System.Byte>	The field value or null if the type is non-numeric.

GetDoubleValue()

Returns the field value as System.Double or null if the type is non-numeric.

Declaration

double? GetDoubleValue()

Returns

Type	Description
System.Nullable<System.Double>	The field value or null if the type is non-numeric.

GetInt16Value()

Returns the field value as System.Int16 or null if the type is non-numeric.

Declaration

short? GetInt16Value()

Returns

Type	Description
System.Nullable<System.Int16>	The field value or null if the type is non-numeric.

GetInt32Value()

Returns the field value as System.Int32 or null if the type is non-numeric.

Declaration

int? GetInt32Value()

Returns

Type	Description
System.Nullable<System.Int32>	The field value or null if the type is non-numeric.

GetInt64Value()

Returns the field value as System.Int64 or null if the type is non-numeric.

Declaration

long? GetInt64Value()

Returns

Type	Description
System.Nullable<System.Int64>	The field value or null if the type is non-numeric.

GetNumericValue()

Non-null if this field has a numeric value.

Declaration

[Obsolete("In .NET, use of this method will cause boxing/unboxing. Instead, use the NumericType property to check the underlying type and call the appropriate GetXXXValue() method to retrieve the value.")]
object GetNumericValue()

Returns

Type	Description
System.Object

GetReaderValue()

Non-null if this field has a System.IO.TextReader value

Declaration

TextReader GetReaderValue()

Returns

Type	Description
System.IO.TextReader

GetSingleValue()

Returns the field value as System.Single or null if the type is non-numeric.

Declaration

float? GetSingleValue()

Returns

Type	Description
System.Nullable<System.Single>	The field value or null if the type is non-numeric.

GetStringValue()

Non-null if this field has a string value.

Declaration

string GetStringValue()

Returns

Type	Description
System.String	The string representation of the value if it is either a System.String or numeric type.

GetStringValue(IFormatProvider)

The value of the field as a System.String, or null. If null, the System.IO.TextReader value or binary value is used. Exactly one of GetStringValue(), GetReaderValue(), and GetBinaryValue() must be set.

Declaration

string GetStringValue(IFormatProvider provider)

Parameters

Type	Name	Description
System.IFormatProvider	provider	An object that supplies culture-specific formatting information. This parameter has no effect if this field is non-numeric.

Returns

Type	Description
System.String	The string representation of the value if it is either a System.String or numeric type.

GetStringValue(String)

The value of the field as a System.String, or null. If null, the System.IO.TextReader value or binary value is used. Exactly one of GetStringValue(), GetReaderValue(), and GetBinaryValue() must be set.

Declaration

string GetStringValue(string format)

Parameters

Type	Name	Description
System.String	format	A standard or custom numeric format string. This parameter has no effect if this field is non-numeric.

Returns

Type	Description
System.String	The string representation of the value if it is either a System.String or numeric type.

GetStringValue(String, IFormatProvider)

The value of the field as a System.String, or null. If null, the System.IO.TextReader value or binary value is used. Exactly one of GetStringValue(), GetReaderValue(), and GetBinaryValue() must be set.

Declaration

string GetStringValue(string format, IFormatProvider provider)

Parameters

Type	Name	Description
System.String	format	A standard or custom numeric format string. This parameter has no effect if this field is non-numeric.
System.IFormatProvider	provider	An object that supplies culture-specific formatting information. This parameter has no effect if this field is non-numeric.

Returns

Type	Description
System.String	The string representation of the value if it is either a System.String or numeric type.

GetTokenStream(Analyzer)

Creates the TokenStream used for indexing this field. If appropriate, implementations should use the given Analyzer to create the TokenStreams.

Declaration

TokenStream GetTokenStream(Analyzer analyzer)

Parameters

Type	Name	Description
Analyzer	analyzer	Analyzer that should be used to create the TokenStreams from

Returns

Type	Description
TokenStream	TokenStream value for indexing the document. Should always return a non-null value if the field is to be indexed

Exceptions

Type	Condition
System.IO.IOException	Can be thrown while creating the TokenStream

Extension Methods

IndexableFieldExtensions.GetByteValueOrDefault(IIndexableField)

IndexableFieldExtensions.GetInt16ValueOrDefault(IIndexableField)

IndexableFieldExtensions.GetInt32ValueOrDefault(IIndexableField)

IndexableFieldExtensions.GetInt64ValueOrDefault(IIndexableField)

IndexableFieldExtensions.GetSingleValueOrDefault(IIndexableField)

IndexableFieldExtensions.GetDoubleValueOrDefault(IIndexableField)