Module org.tquadrat.foundation.config

Package org.tquadrat.foundation.config.cli

Class CmdLineValueHandler<T>

java.lang.Object

org.tquadrat.foundation.config.cli.CmdLineValueHandler<T>

Type Parameters:

T - The target type.

Direct Known Subclasses:

BooleanValueHandler, DateValueHandler, DocumentValueHandler, EnumValueHandler, ImageValueHandler, SimpleCmdLineValueHandler, StringValueHandler, TimeValueHandler

@ClassVersion(sourceVersion="$Id: CmdLineValueHandler.java 1061 2023-09-25 16:32:43Z tquadrat $")
@API(status=STABLE,
     since="0.1.0")
public abstract class CmdLineValueHandler<T>
extends Object

The abstract base class for the value handler that takes a String value from the command line, translates it to the target type and sets the value to the property.

To circumvent possible problems with reflection in a modularised context, the handler uses an instance of BiConsumer to set the property; the BiConsumer.accept(Object, Object) method of that instance is called with two arguments:

1. the name of the property to set
2. the value for that property

Basically, the implementation of such a value setter function may be implemented in any way, but the annotation processor creates them as simple as possible. To set a value to the attribute m_Value, it would look like

(p,v) -> m_Value = v;

and to add a value to the list attribute m_List, it would be

(p,v) -> m_List.add( v );

That means that the name of the property is ignored.

But customer implementations may use other implementations as well.

Author:

Thomas Thrien (thomas.thrien@tquadrat.org)

Version:

$Id: CmdLineValueHandler.java 1061 2023-09-25 16:32:43Z tquadrat $

Since:

0.1.0

UML Diagram

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UML Diagram for "org.tquadrat.foundation.config.cli.CmdLineValueHandler"

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Field Summary

Fields

Modifier and Type	Field	Description
static final String	DEFAULT_PROPERTY_NAME	The default property name that is used if no context is given: "dummyProperty".
private CLIDefinition	m_CLIDefinition	The CLI definition that provides the context for this value handler.
private final BiConsumer<String,T>	m_ValueSetter	The value setter.
static final String	MSG_InvalidParameter	The error message for an invalid entry on the command line: "\'%1$s\' cannot be parsed as a valid command line parameter".
static final int	MSGKEY_InvalidParameter	The resource bundle key for the message about an invalid entry on the command line.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	CmdLineValueHandler(BiConsumer<String,T> valueSetter)	Creates a new CmdLineValueHandler instance.
protected	CmdLineValueHandler(CLIDefinition context, BiConsumer<String,T> valueSetter)	Creates a new CmdLineValueHandler instance.

Method Summary

Modifier and Type	Method	Description
protected final Optional<CLIDefinition>	getCLIDefinition()	Returns a reference to the context.
protected String	getPropertyName()	Returns the name of the property that is the target for the value.
protected final BiConsumer<String,T>	getValueSetter()	Returns a reference for the value setter.
int	parseCmdLine(Parameters params)	Parses the given command line snippet and stores the result to the property.
final void	setContext(CLIDefinition context)	Sets the CLI definition that provides the context for this value handler.
protected abstract Collection<T>	translate(Parameters params)	Translates the command line values that can be referenced via the params argument to the target type.

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_PROPERTY_NAME

public static final String DEFAULT_PROPERTY_NAME

The default property name that is used if no context is given: "dummyProperty".

See Also:

• Constant Field Values

MSG_InvalidParameter

public static final String MSG_InvalidParameter

The error message for an invalid entry on the command line: "\'%1$s\' cannot be parsed as a valid command line parameter".

See Also:

• Constant Field Values

MSGKEY_InvalidParameter

public static final int MSGKEY_InvalidParameter

The resource bundle key for the message about an invalid entry on the command line.

See Also:

• Constant Field Values

m_CLIDefinition

private CLIDefinition m_CLIDefinition

The CLI definition that provides the context for this value handler.

m_ValueSetter

private final BiConsumer<String,T> m_ValueSetter

The value setter.

The arguments of the lambda are:

1. the name of the property to set
2. the value for that property

In most usages, the first argument is ignored.

Constructor Details

CmdLineValueHandler

protected CmdLineValueHandler(BiConsumer<String,T> valueSetter)

Creates a new CmdLineValueHandler instance.

Parameters:

valueSetter - The Consumer that places the translated value to the property.

CmdLineValueHandler

protected CmdLineValueHandler(CLIDefinition context,
 BiConsumer<String,T> valueSetter)

Creates a new CmdLineValueHandler instance.

Parameters:

context - The CLI definition that provides the context for this value handler.

valueSetter - The Consumer that places the translated value to the property.

Method Details

getCLIDefinition

protected final Optional<CLIDefinition> getCLIDefinition()

Returns a reference to the context.

Returns:

An instance of Optional that holds the CLI definition.

getPropertyName

protected String getPropertyName()

Returns the name of the property that is the target for the value.

Returns:

The property name.

getValueSetter

protected final BiConsumer<String,T> getValueSetter()

Returns a reference for the value setter.

Returns:

The value setter.

parseCmdLine

@MountPoint
public int parseCmdLine(Parameters params)

Parses the given command line snippet and stores the result to the property.

Note:

• This method can be overridden, but in most cases, the implementation provided here should be sufficient.

Parameters:

params - The command line values to parse.

Returns:

The number of values that the method took from the command line.

Throws:

CmdLineException - An error occurred when parsing the parameters.

setContext

public final void setContext(CLIDefinition context)

Sets the CLI definition that provides the context for this value handler.

Parameters:

context - The CLI definition.

translate

protected abstract Collection<T> translate(Parameters params)
                                    throws CmdLineException

Translates the command line values that can be referenced via the params argument to the target type.

Parameters:

params - The command line values to translate.

Returns:

A collection with the result; each entry in the collection corresponds to one value from the command line.

Throws:

CmdLineException - The given parameters cannot be parsed to the target type.