Class GeneratorFactory

Namespace: NOpenNLP.Tools.Util.Featuregen

Assembly: NOpenNLP.Tools.dll

Creates a set of feature generators based on a provided XML descriptor.

Example of an XML descriptor:

<featureGenerators name="namefind">
    <generator class="opennlp.tools.util.featuregen.CachedFeatureGeneratorFactory">
        <generator class="opennlp.tools.util.featuregen.WindowFeatureGeneratorFactory">
          <int name="prevLength">2</int>
          <int name="nextLength">2</int>
          <generator class="opennlp.tools.util.featuregen.TokenClassFeatureGeneratorFactory"/>
        </generator>
        <generator class="opennlp.tools.util.featuregen.WindowFeatureGeneratorFactory">
          <int name="prevLength">2</int>
          <int name="nextLength">2</int>
          <generator class="opennlp.tools.util.featuregen.TokenFeatureGeneratorFactory"/>
        </generator>
        <generator class="opennlp.tools.util.featuregen.DefinitionFeatureGeneratorFactory"/>
        <generator class="opennlp.tools.util.featuregen.PreviousMapFeatureGeneratorFactory"/>
        <generator class="opennlp.tools.util.featuregen.BigramNameFeatureGeneratorFactory"/>
        <generator class="opennlp.tools.util.featuregen.SentenceFeatureGeneratorFactory">
          <bool name="begin">true</bool>
          <bool name="end">false</bool>
        </generator>
    </generator>
</featureGenerators>

Each XML element is mapped to a GeneratorFactory.IXmlFeatureGeneratorFactory which is responsible to process the element and create the specified IAdaptiveFeatureGenerator. Elements can contain other elements in this case it is the responsibility of the mapped factory to process the child elements correctly. In some factories this leads to recursive calls the GeneratorFactory.IXmlFeatureGeneratorFactory.Create method.

In the example above the generators element is mapped to the AggregatedFeatureGeneratorFactory which then creates all the aggregated IAdaptiveFeatureGenerators to accomplish this it evaluates the mapping with the same mechanism and gives the child element to the corresponding factories. All created generators are added to a new instance of the AggregatedFeatureGenerator which is then returned.

public static class GeneratorFactory

Inheritance: object

GeneratorFactory

Inherited Members: object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Methods

Create(Stream, FeatureGeneratorResourceProvider)

Creates an IAdaptiveFeatureGenerator from an provided XML descriptor.

Usually this XML descriptor contains a set of nested feature generators which are then used to generate the features by one of the opennlp components.

public static IAdaptiveFeatureGenerator? Create(Stream xmlDescriptorIn, FeatureGeneratorResourceProvider resourceManager)

Parameters

xmlDescriptorIn Stream: the Stream from which the descriptor is read, the stream remains open and must be closed by the caller.
resourceManager FeatureGeneratorResourceProvider: the resource manager which is used to resolve resources referenced by a key in the descriptor

Returns

IAdaptiveFeatureGenerator: created feature generators

Exceptions

IOException: if an error occurs during reading from the descriptor Stream

ExtractArtifactSerializerMappings(Stream)

public static Dictionary<string, IArtifactSerializer> ExtractArtifactSerializerMappings(Stream xmlDescriptorIn)

Parameters

xmlDescriptorIn Stream

Returns

Dictionary<string, IArtifactSerializer>

GetDescriptorElements(Stream)

Provides a list with all the elements in the xml feature descriptor.

public static IList<XmlElement> GetDescriptorElements(Stream xmlDescriptorIn)

Parameters

xmlDescriptorIn Stream: the xml feature descriptor

Returns

IList<XmlElement>: a list containing all elements

Exceptions

IOException: if inputstream cannot be open
InvalidFormatException: if xml is not well-formed