uk.ac.starlink.ttools.task

Class FilterParameter

java.lang.Object

uk.ac.starlink.task.Parameter<ProcessingStep[]>

uk.ac.starlink.ttools.task.FilterParameter

All Implemented Interfaces:

MultiParameter, ExtraParameter

public class FilterParameter
extends Parameter<ProcessingStep[]>
implements ExtraParameter, MultiParameter

Parameter which contains a value representing one or more ProcessingSteps.

Since:

17 Aug 2005

Author:

Mark Taylor

Field Summary

Fields inherited from class uk.ac.starlink.task.Parameter

BY_NAME

Constructor Summary

Constructors

Constructor and Description
FilterParameter(String name)

Method Summary

Modifier and Type	Method and Description
String	getExtraUsage(TableEnvironment env) Returns an extended usage message.
static String	getFiltersUsage(TableEnvironment env) Returns a formatted string listing available filter commands with their usage.
char	getValueSeparator() Returns a character which is to be used as the separator between values found in adjacent occurrences of the parameter in the execution environment.
void	setTableDescription(String shortDescrip, AbstractInputTableParameter<?> tableParam, Boolean isBefore) Sets the wording used to refer to the target table for the filters this parameter acquires.
ProcessingStep[]	stepsValue(Environment env) Returns the value of this parameter as an array of processing steps.
ProcessingStep[]	stringToObject(Environment env, String sval) Takes a non-blank string, as supplied by the execution environment, and turns it into a typed value for this parameter.

Methods inherited from class uk.ac.starlink.task.Parameter

clearValue, getDescription, getName, getPosition, getPreferExplicit, getPrompt, getStringDefault, getUsage, getValueClass, isNullPermitted, objectToString, objectValue, setDescription, setDescription, setName, setNullPermitted, setPosition, setPreferExplicit, setPrompt, setStringDefault, setUsage, setValue, setValueFromObject, setValueFromString, stringValue, toArray, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

FilterParameter

public FilterParameter(String name)

Method Detail

setTableDescription

public final void setTableDescription(String shortDescrip,
                                      AbstractInputTableParameter<?> tableParam,
                                      Boolean isBefore)

Sets the wording used to refer to the target table for the filters this parameter acquires. The description and prompt are set. If not set, the wording "the table" is used to describe the table.

Parameters:

shortDescrip - text to replace "the table"

tableParam - if supplied, gives the table parameter on behalf of which this format parameter is operating; may be null

isBefore - TRUE means filter is applied before any other processing, FALSE means after, null don't know

getValueSeparator

public char getValueSeparator()

Description copied from interface: MultiParameter

Returns a character which is to be used as the separator between values found in adjacent occurrences of the parameter in the execution environment.

Specified by:

getValueSeparator in interface MultiParameter

stringToObject

public ProcessingStep[] 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<ProcessingStep[]>

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

stepsValue

public ProcessingStep[] stepsValue(Environment env)
                            throws TaskException

Returns the value of this parameter as an array of processing steps.

Parameters:

env - execution environment

Returns:

array of zero or more processing steps

Throws:

TaskException

getExtraUsage

public String getExtraUsage(TableEnvironment env)

Description copied from interface: ExtraParameter

Returns an extended usage message. This should not repeat the content of the normal usage message. It should be preformatted, that is it should contain newlines to keep the line length down to less than 80 characters.

Specified by:

getExtraUsage in interface ExtraParameter

Parameters:

env - execution envrionment

Returns:

extended usage message

getFiltersUsage

public static String getFiltersUsage(TableEnvironment env)

Returns a formatted string listing available filter commands with their usage.

Parameters:

env - execution environment

Returns:

usge string