Package elki.utilities.optionhandling.parameters

Class AbstractParameter<P extends AbstractParameter<P,T>,T>

java.lang.Object

elki.utilities.optionhandling.parameters.AbstractParameter<P,T>

Type Parameters:

P - type self-reference

T - the type of a possible value (i.e., the type of the option)

All Implemented Interfaces:

Parameter<T>

Direct Known Subclasses:

ClassParameter, EnumParameter, FileParameter, Flag, IntGeneratorParameter, ListParameter, NumberParameter, PatternParameter, RandomParameter, StringParameter

public abstract class AbstractParameter<P extends AbstractParameter<P,T>,T>
extends java.lang.Object
implements Parameter<T>

Abstract class for specifying a parameter.

A parameter is defined as an option having a specific value.

See the elki.utilities.optionhandling package for documentation!

Since:

0.1

Author:

Steffi Wanka, Erich Schubert

Field Summary

Fields

Modifier and Type	Field	Description
protected java.util.List<ParameterConstraint<? super T>>	constraints	Holds parameter constraints for this parameter.
protected T	defaultValue	The default value of the parameter (may be null).
private boolean	defaultValueTaken	Whether the default value of this parameter was used.
protected T	givenValue	The value last passed to this option.
protected boolean	optionalParameter	Specifies if this parameter is an optional parameter.
protected OptionID	optionid	The option name.
private T	value	The value of this option.

Constructor Summary

Constructors

Constructor	Description
AbstractParameter(OptionID optionID)	Constructs a parameter with the given optionID, and constraints.
AbstractParameter(OptionID optionID, T defaultValue)	Constructs a parameter with the given optionID, constraints, and default value.

Method Summary

Modifier and Type	Method	Description
P	addConstraint(ParameterConstraint<? super T> constraint)	Add an additional constraint.
java.lang.StringBuilder	describeValues(java.lang.StringBuilder description)	Describe the valid values.
java.util.List<ParameterConstraint<? super T>>	getConstraints()	Get the parameter constraints.
T	getDefaultValue()	Returns the default value of the parameter.
java.lang.String	getDefaultValueAsString()	Get the default value as string.
OptionID	getOptionID()	Return the OptionID of this option.
T	getValue()	Returns the value of the option.
boolean	hasDefaultValue()	Checks if this parameter has a default value.
boolean	isDefined()	Returns true if the value of the option is defined, false otherwise.
boolean	isOptional()	Checks if this parameter is an optional parameter.
boolean	isValid(java.lang.Object obj)	Checks if the given argument is valid for this option.
protected abstract T	parseValue(java.lang.Object obj)	Parse a given value into the destination type.
P	setDefaultValue(T defaultValue)	Sets the default value of this parameter.
P	setOptional(boolean opt)	Specifies if this parameter is an optional parameter.
void	setValue(java.lang.Object obj)	Sets the value of the option.
protected void	setValueInternal(T val)	Internal setter for the value.
boolean	tookDefaultValue()	Checks if the default value of this parameter was taken as the actual parameter value.
boolean	tryDefaultValue()	Handle default values for a parameter.
protected boolean	validate(T obj)	Validate a value after parsing (e.g., do constraint checks!)

Methods inherited from class java.lang.Object

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

Methods inherited from interface elki.utilities.optionhandling.parameters.Parameter

getSyntax, getValueAsString

Field Detail

optionid

protected final OptionID optionid

The option name.

defaultValue

protected T defaultValue

The default value of the parameter (may be null).

defaultValueTaken

private boolean defaultValueTaken

Whether the default value of this parameter was used.

optionalParameter

protected boolean optionalParameter

Specifies if this parameter is an optional parameter.

constraints

protected java.util.List<ParameterConstraint<? super T>> constraints

Holds parameter constraints for this parameter.

givenValue

protected T givenValue

The value last passed to this option.

value

private T value

The value of this option.

Constructor Detail

AbstractParameter

public AbstractParameter(OptionID optionID,
                         T defaultValue)

Constructs a parameter with the given optionID, constraints, and default value.

Parameters:

optionID - the unique id of this parameter

defaultValue - the default value of this parameter (may be null)

AbstractParameter

public AbstractParameter(OptionID optionID)

Constructs a parameter with the given optionID, and constraints.

Parameters:

optionID - the unique id of this parameter

Method Detail

setDefaultValue

public P setDefaultValue(T defaultValue)

Description copied from interface: Parameter

Sets the default value of this parameter.

Specified by:

setDefaultValue in interface Parameter<P extends AbstractParameter<P,T>>

Parameters:

defaultValue - default value of this parameter

Returns:

the parameter itself, for chaining

hasDefaultValue

public boolean hasDefaultValue()

Description copied from interface: Parameter

Checks if this parameter has a default value.

Specified by:

hasDefaultValue in interface Parameter<P extends AbstractParameter<P,T>>

Returns:

true, if this parameter has a default value, false otherwise

tryDefaultValue

public boolean tryDefaultValue()
                        throws UnspecifiedParameterException

Description copied from interface: Parameter

Handle default values for a parameter.

Specified by:

tryDefaultValue in interface Parameter<P extends AbstractParameter<P,T>>

Returns:

Return code: true if it has a default value, false if it is optional without a default value. Exception if it is a required parameter!

Throws:

UnspecifiedParameterException - If the parameter requires a value

setOptional

public P setOptional(boolean opt)

Description copied from interface: Parameter

Specifies if this parameter is an optional parameter.

Specified by:

setOptional in interface Parameter<P extends AbstractParameter<P,T>>

Parameters:

opt - true if this parameter is optional, false otherwise

Returns:

the parameter itself, for chaining

isOptional

public boolean isOptional()

Description copied from interface: Parameter

Checks if this parameter is an optional parameter.

Specified by:

isOptional in interface Parameter<P extends AbstractParameter<P,T>>

Returns:

true if this parameter is optional, false otherwise

tookDefaultValue

public boolean tookDefaultValue()

Description copied from interface: Parameter

Checks if the default value of this parameter was taken as the actual parameter value.

Specified by:

tookDefaultValue in interface Parameter<P extends AbstractParameter<P,T>>

Returns:

true, if the default value was taken as actual parameter value, false otherwise

isDefined

public boolean isDefined()

Description copied from interface: Parameter

Returns true if the value of the option is defined, false otherwise.

Specified by:

isDefined in interface Parameter<P extends AbstractParameter<P,T>>

Returns:

true if the value of the option is defined, false otherwise.

getDefaultValue

public T getDefaultValue()

Description copied from interface: Parameter

Returns the default value of the parameter.

If the parameter has no default value, the method returns null.

Specified by:

getDefaultValue in interface Parameter<P extends AbstractParameter<P,T>>

Returns:

the default value of the parameter, null if the parameter has no default value.

describeValues

public java.lang.StringBuilder describeValues(java.lang.StringBuilder description)

Description copied from interface: Parameter

Describe the valid values.

Specified by:

describeValues in interface Parameter<P extends AbstractParameter<P,T>>

Parameters:

description - Buffer to append to

Returns:

Buffer

validate

protected boolean validate(T obj)
                    throws ParameterException

Validate a value after parsing (e.g., do constraint checks!)

Parameters:

obj - Object to validate

Returns:

true iff the object is valid for this parameter.

Throws:

ParameterException - when the object is not valid.

getOptionID

public OptionID getOptionID()

Description copied from interface: Parameter

Return the OptionID of this option.

Specified by:

getOptionID in interface Parameter<P extends AbstractParameter<P,T>>

Returns:

Option ID

setValue

public void setValue(java.lang.Object obj)
              throws ParameterException

Description copied from interface: Parameter

Sets the value of the option.

Specified by:

setValue in interface Parameter<P extends AbstractParameter<P,T>>

Parameters:

obj - the option's value to be set

Throws:

ParameterException - if the given value is not a valid value for this option.

setValueInternal

protected void setValueInternal(T val)

Internal setter for the value.

Parameters:

val - Value

getValue

public final T getValue()

Description copied from interface: Parameter

Returns the value of the option.

You should use either Parameterization.grab(elki.utilities.optionhandling.parameters.Parameter<?>) or Parameter.isDefined() to test if getValue() will return a well-defined value.

Specified by:

getValue in interface Parameter<P extends AbstractParameter<P,T>>

Returns:

the option's value.

isValid

public final boolean isValid(java.lang.Object obj)
                      throws ParameterException

Description copied from interface: Parameter

Checks if the given argument is valid for this option.

Specified by:

isValid in interface Parameter<P extends AbstractParameter<P,T>>

Parameters:

obj - option value to be checked

Returns:

true, if the given value is valid for this option

Throws:

ParameterException - if the given value is not a valid value for this option.

parseValue

protected abstract T parseValue(java.lang.Object obj)
                         throws ParameterException

Parse a given value into the destination type.

Parameters:

obj - Object to parse (may be a string representation!)

Returns:

Parsed object

Throws:

ParameterException - when the object cannot be parsed.

getDefaultValueAsString

public java.lang.String getDefaultValueAsString()

Description copied from interface: Parameter

Get the default value as string.

Specified by:

getDefaultValueAsString in interface Parameter<P extends AbstractParameter<P,T>>

Returns:

default value

addConstraint

public P addConstraint(ParameterConstraint<? super T> constraint)

Description copied from interface: Parameter

Add an additional constraint.

Specified by:

addConstraint in interface Parameter<P extends AbstractParameter<P,T>>

Parameters:

constraint - Constraint to add.

Returns:

the parameter itself, for chaining

getConstraints

public java.util.List<ParameterConstraint<? super T>> getConstraints()

Description copied from interface: Parameter

Get the parameter constraints.

Specified by:

getConstraints in interface Parameter<P extends AbstractParameter<P,T>>

Returns:

Parameter constraints