Constructor Detail

• TypePathExtractor

  public TypePathExtractor(Class<T> focusClass,
                   String typePath)

  calls this(type, typePath, false, false, true, jCas)

• TypePathExtractor

  public TypePathExtractor(Class<T> focusClass,
                   String typePath,
                   boolean traverseAllPaths,
                   boolean returnAllValues,
                   boolean uniqueValues)

  This extractor creates features from attributes of an annotation. For example, if you had a type called Token with an attribute called 'pos' you could use this extractor to extract a pos attribute for tokens. This would be done by calling the constructor with the values "pos", "pos", false, and false. The value you want may be nested within the type structure of the annotation that is being examined. For example, if you might have a type called 'NamedEntity' that has an attribute of type 'ResourceEntry' that has an attribute of type 'DbRecord' that has a String attribute called 'identifier'. You may want to extract the value of the identifier as a feature of the NamedEntity annotation. This could be done by calling the constructor with the values "identifier", "resourceEntry/dbRecord/identifier", false, and false (or something similar). The value you want for your featured may be multi-valued

  Parameters:

  focusClass - the type of annotation that you are doing feature extraction on.

  typePath - a string representation of the path that should be traversed to extract a feature value (e.g. "resourceEntry/dbRecord/identifier" or "pos" from the examples above.)

  traverseAllPaths - The path you traverse to the value you are trying to retrieve may include attributes that have multiple-values. If true, then all paths are examined and features for each traversal are added if possible. If false, then the first path that results in a non-null value will be examined.

  returnAllValues - The last node of the path may be multi-valued. If true, then all values found in the last node will be returned as features. If false, then only the first value of the last node is returned. If traverseAllPaths and returnAllValues are both false, then a list of size 0 or 1 will be returned. The other three combinations are each valid and may return a list of size 0 or greater.

  uniqueValues - if true, then the returned values of the extract method will be unique.

Method Detail

• createName

  public static String createName(String namePrefix,
                  String typePath)

  WARNING: this method is public for TypePathFeature backwards compatibility, but should not be used by anyone else!

• extract

  public List<Feature> extract(JCas view,
                      Annotation focusAnnotation)
                        throws CleartkExtractorException

  Description copied from interface: FeatureExtractor1
  Some feature extractors will require some specific number of annotations that is greater than one. Such extractors should not implement this interface.

  Specified by:

  extract in interface FeatureExtractor1<T extends Annotation>

  Parameters:

  view - the current view of the document.

  focusAnnotation - the annotation for which to collect features.

  Returns:

  a list of features generated by the extractor for the focus annotation.

  Throws:

  CleartkExtractorException

• getFeatureName

  public String getFeatureName()

  Description copied from interface: NamedFeatureExtractor1
  Gets the name that will be used for all features created by this feature extractor.

  Specified by:

  getFeatureName in interface NamedFeatureExtractor1<T extends Annotation>

  Returns:

  The feature name

• getFocusClass

  public Class<? extends Annotation> getFocusClass()

• getPath

  public String getPath()

• isAllPaths

  public boolean isAllPaths()

• isAllValues

  public boolean isAllValues()

• isUniqueValues

  public boolean isUniqueValues()

• isValidPath

  public static boolean isValidPath(Type type,
                    String path,
                    JCas view)

• isValidType

  public static boolean isValidType(Type type,
                    TypeSystem typeSystem)