ch.jalu.configme.properties

Class OptionalProperty<T>

java.lang.Object

ch.jalu.configme.properties.OptionalProperty<T>

All Implemented Interfaces:

Property<Optional<T>>

public class OptionalProperty<T>
extends Object
implements Property<Optional<T>>

Property which may be empty.

Wraps another property with an Optional: if a property is not present in the property resource, Optional.empty() is returned.

Constructor Summary

Constructors

Constructor and Description
OptionalProperty(Property<T> baseProperty)
OptionalProperty(Property<T> baseProperty, T defaultValue)

Method Summary

Modifier and Type	Method and Description
PropertyValue<Optional<T>>	determineValue(PropertyReader reader) Returns the value, based on the given reader, which should be used for this property.
Optional<T>	getDefaultValue() Returns the default value of this property.
String	getPath()
boolean	isValidValue(Optional<T> value) Returns whether the value can be associated to the given property, i.e.
Object	toExportValue(Optional<T> value) Converts the given value to a representation that is suitable for exporting by a property resource.

Methods inherited from class java.lang.Object

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

Methods inherited from interface ch.jalu.configme.properties.Property

isValidInResource

Constructor Detail

OptionalProperty

public OptionalProperty(Property<T> baseProperty)

OptionalProperty

public OptionalProperty(Property<T> baseProperty,
                        T defaultValue)

Method Detail

getPath

public String getPath()

Specified by:

getPath in interface Property<Optional<T>>

Returns:

the path of the property

determineValue

public PropertyValue<Optional<T>> determineValue(PropertyReader reader)

Description copied from interface: Property

Returns the value, based on the given reader, which should be used for this property. By default this is the value as constructed from the reader, and otherwise the default value. Implementations of BaseProperty never return null. The return value must be in sync with Property.isValidValue(Object).

Specified by:

determineValue in interface Property<Optional<T>>

Parameters:

reader - the reader to construct the value from (if possible)

Returns:

the value to associate to this property

getDefaultValue

public Optional<T> getDefaultValue()

Description copied from interface: Property

Returns the default value of this property.

Specified by:

getDefaultValue in interface Property<Optional<T>>

Returns:

the default value

isValidValue

public boolean isValidValue(Optional<T> value)

Description copied from interface: Property

Returns whether the value can be associated to the given property, i.e. whether it fulfills all requirements which may be imposed by the property type.

This method is used in ConfigurationDataImpl.setValue(ch.jalu.configme.properties.Property<T>, T), which throws an exception if this method returns false. Therefore, this method is intended as a last catch for invalid values and to ensure that programmatically no invalid value can be set. Extended validation of values encountered in the property reader should be preferably handled in Property.determineValue(ch.jalu.configme.resource.PropertyReader), or in an extension of MigrationService.

Specified by:

isValidValue in interface Property<Optional<T>>

Parameters:

value - the value to check

Returns:

true if the value can be used for the property, false otherwise

toExportValue

public Object toExportValue(Optional<T> value)

Description copied from interface: Property

Converts the given value to a representation that is suitable for exporting by a property resource. The return value should contain the data in the given value represented with only basic types (String, Number, Boolean), as well as lists and maps thereof.

The values which are suitable for returning depend on the support of the used property resource. By default, the supported types include null, String, Integer, Double, Boolean; Collection of the aforementioned types; Map with String keys and values of any of the aforementioned types. Maps and collections can be nested at any arbitrary level. Null signifies that the property/value should be skipped in the export.

Specified by:

toExportValue in interface Property<Optional<T>>

Parameters:

value - the value to convert to an export value

Returns:

value to use for export, null to skip the property