Package uk.ac.starlink.task

Class ChoiceParameter<T>

java.lang.Object
uk.ac.starlink.task.Parameter<T>
uk.ac.starlink.task.AbstractChoiceParameter<T,T>
uk.ac.starlink.task.ChoiceParameter<T>
public class ChoiceParameter<T> extends AbstractChoiceParameter<T,T>
Parameter whose legal value must be one of a disjunction of given values. Matching is case-insensitive against the stringified value of the option.
Since:
15 Aug 2005
Author:
Mark Taylor

  • Constructor Details

    • ChoiceParameter

      public ChoiceParameter(String name, Class<T> clazz, T[] options)
      Constructor.
      Parameters:
      name - parameter name
      clazz - type for values of this parameter
      options - initial array of legal values of this parameter

    • ChoiceParameter

      public ChoiceParameter(String name, Class<T> clazz)
      Constructs a choice parameter with no initially set options.
      Parameters:
      name - parameter name
      clazz - type for values of this parameter

    • ChoiceParameter

      public ChoiceParameter(String name, T[] options)
      Constructs a choice parameter with an initial option set. The data type is taken from the supplied array type.
      Parameters:
      name - parameter name
      options - initial array of legal values of this parameter

  • Method Details

    • stringToObject

      public T stringToObject(Environment env, String sval) throws TaskException
      Description copied from class: Parameter
      Takes a non-blank string, as supplied by the execution environment, and turns it into a typed value for this parameter. This method also performs validation, so if the string value is unacceptable in any way, a ParameterValueException should be thrown.

      It is an error to supply a null or empty string value.

      If this method fails (throws a ParameterValueException) and if allowClassnameValue is set, then a subsequent attempt will be made to interpret the stringVal as the classname of a suitable class with a no-arg constructor.

      Specified by:
      stringToObject in class Parameter<T>
      Parameters:
      env - execution environment; in most cases this is not required but for some purposes environment-specific characteristics may influence the result
      sval - non-null, non-empty string value
      Returns:
      typed value
      Throws:
      TaskException

    • objectToString

      public String objectToString(Environment env, T objVal)
      Description copied from class: Parameter
      Takes a typed value of this parameter and formats it as a string which may be used for presentation to the user. Ideally, round-tripping between this method and stringToObject should be possible, but that is not in general required/guaranteed.

      The default implementation uses the value's toString method, but subclasses can override this for smarter behaviour.

      Overrides:
      objectToString in class Parameter<T>
      Parameters:
      env - execution environment
      objVal - typed parameter value
      Returns:
      string value for presentation

    • getUsage

      public String getUsage()
      Returns a usage message. Unless it has been overriden by an earlier call to setUsage(java.lang.String), this will return a usage message based on the list of known options.
      Overrides:
      getUsage in class Parameter<T>
      Returns:
      usage message
      See Also:

    • setUsage

      public void setUsage(String usage)
      Description copied from class: Parameter
      Sets a usage string for this parameter. This should be terse (in particular no newline characters) and conform to the following rules:
      • the parameter name is not included in the message
      • placeholders are enclosed in angle brackets (<>)
      • literals are not enclosed in angle brackets
      • a disjunction is represented using the "|" character
      The Parameter class uses the string "<value>" as the default usage string.
      Overrides:
      setUsage in class Parameter<T>
      Parameters:
      usage - usage string

    • setDefaultOption

      public void setDefaultOption(T option)
      Sets the default value for this parameter to one of the previously added options.
      Parameters:
      option - default option