Package uk.ac.starlink.task

Class 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 Detail

      • ChoiceParameter

        public ChoiceParameter​(java.lang.String name,
                       java.lang.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​(java.lang.String name,
                       java.lang.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​(java.lang.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 Detail

      • stringToObject

        public T stringToObject​(Environment env,
                        java.lang.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 java.lang.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

      • setUsage

        public void setUsage​(java.lang.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