Module io.github.mmm.property

Package io.github.mmm.property

Interface PropertyMetadata<V>

Type Parameters:

V - type of the property value.

All Known Implementing Classes:

AbstractPropertyMetadata

public interface PropertyMetadata<V>

Metadata of a Property. Implementations of PropertyMetadata are supposed to be immutable. It is discouraged and may have odd effects if the PropertyMetadata changes after it has been passed to the constructor of a property.

Since:

1.0.0

Method Summary

Modifier and Type	Method	Description
Map<String,Object>	asMap()
default <T> T	get(Class<T> type)	ATTENTION: This is a convenient method for get(String, Class) where Class.getName() is used as key.
Object	get(String key)
default <T> T	get(String key, Class<T> type)
Supplier<? extends V>	getExpression()
int	getKeyCount()
Iterable<String>	getKeys()
default AttributeReadOnly	getLock()
default io.github.mmm.marshall.Marshalling<V>	getMarshalling()
Validator<? super V>	getValidator()
Type	getValueType()
default boolean	hasKeys()
default boolean	isTransient()
static <V> PropertyMetadata<V>	of(AttributeReadOnly lock)
static <V> PropertyMetadata<V>	of(AttributeReadOnly lock, Validator<? super V> validator)
static <V> PropertyMetadata<V>	of(AttributeReadOnly lock, Validator<? super V> validator, Supplier<? extends V> expression)
static <V> PropertyMetadata<V>	of(AttributeReadOnly lock, Validator<? super V> validator, Supplier<? extends V> expression, Type valueType)
static <V> PropertyMetadata<V>	of(AttributeReadOnly lock, Validator<? super V> validator, Supplier<? extends V> expression, Type valueType, Map<String,Object> map)
static <V> PropertyMetadata<V>	ofExpression(Supplier<? extends V> expression)
PropertyMetadata<V>	withExpression(Supplier<? extends V> newExpression)
PropertyMetadata<V>	withLock(AttributeReadOnly newLock)
PropertyMetadata<V>	withValidator(Validator<? super V> newValidator)

Method Details

getValidator

Validator<? super V> getValidator()

Returns:

the Validator used to validate the property.

getExpression

Supplier<? extends V> getExpression()

Returns:

the optional Supplier that calculates the value dynamically. May be null for a regular property. If it is not null the property will automatically be read-only. You should not provide an explicit validator if you provide an expression.

get

Object get(String key)

Parameters:

key - the key of the requested metadata.

Returns:

the value of the metadata for the given key. Will be null if no metadata exists for the given key.

See Also:

• get(String, Class)

get

default <T> T get(String key,
 Class<T> type)

Type Parameters:

T - type of the metadata.

Parameters:

key - the key of the requested metadata.

type - Class reflecting the type of the requested metadata value.

Returns:

the value of the metadata for the given key. Will be null if no metadata exists for the given key.

get

default <T> T get(Class<T> type)

ATTENTION: This is a convenient method for get(String, Class) where Class.getName() is used as key. Be aware that this can only work for final classes, Annotations or if the producer of this PropertyMetadata provides the metadata under the type you are expecting as API. Also it is discouraged to use this method for generic types such as String or Long as values of such type can be anything and should have a semantic key.

Type Parameters:

T - type of the metadata.

Parameters:

type - Class reflecting the type of the requested metadata value.

Returns:

the value of the metadata for the given key. Will be null if no metadata exists for the given key.

See Also:

• get(String, Class)

getKeys

Iterable<String> getKeys()

Returns:

the Iterable of all metadata keys.

getKeyCount

int getKeyCount()

Returns:

the size of the key/ value pairs in this map.

hasKeys

default boolean hasKeys()

Returns:

true if this metadata has at least one key/value pair, false otherwise (if empty and key count is 0).

asMap

Map<String,Object> asMap()

Returns:

a new or immutable Map with this metadata key/value pairs.

getValueType

Type getValueType()

Returns:

the optional Type of the property value. May be null.

See Also:

• ReadableTypedValue.getValueClass()

getMarshalling

default io.github.mmm.marshall.Marshalling<V> getMarshalling()

Returns:

the optional custom Marshalling. If null the default marshalling of the Property is used. Overriding also allows to extend or replace the property value with more complex data from this metadata - e.g. to reuse a Bean to represent a query to find instances of that Bean.

isTransient

default boolean isTransient()

Returns:

true if transient (e.g. computed and therefore not to be marshalled), false otherwise.

See Also:

• ReadableProperty.isTransient()

withLock

PropertyMetadata<V> withLock(AttributeReadOnly newLock)

Parameters:

newLock - the new lock.

Returns:

a new instance of PropertyMetadata with the given AttributeReadOnly used for getLock().

withValidator

PropertyMetadata<V> withValidator(Validator<? super V> newValidator)

Parameters:

newValidator - the new Validator.

Returns:

a new instance of PropertyMetadata with the given Validator used for getValidator().

withExpression

PropertyMetadata<V> withExpression(Supplier<? extends V> newExpression)

Parameters:

newExpression - the new expression.

Returns:

a new instance of PropertyMetadata with the given Supplier used for getExpression().

getLock

default AttributeReadOnly getLock()

Returns:

the lock object that can make the owning Property read-only. Typically this is the owning bean.

of

static <V> PropertyMetadata<V> of(AttributeReadOnly lock,
 Validator<? super V> validator,
 Supplier<? extends V> expression,
 Type valueType,
 Map<String,Object> map)

Type Parameters:

V - type of the property value.

Parameters:

lock - the lock (owning bean).

validator - the validator.

expression - the expression.

valueType - the value type.

map - the metadata Map.

Returns:

the new PropertyMetadata.

of

static <V> PropertyMetadata<V> of(AttributeReadOnly lock)

Type Parameters:

V - type of the property value.

Parameters:

lock - the lock (owning bean).

Returns:

the new PropertyMetadata.

of

static <V> PropertyMetadata<V> of(AttributeReadOnly lock,
 Validator<? super V> validator)

Type Parameters:

V - type of the property value.

Parameters:

lock - the lock (owning bean).

validator - the validator.

Returns:

the new PropertyMetadata.

of

static <V> PropertyMetadata<V> of(AttributeReadOnly lock,
 Validator<? super V> validator,
 Supplier<? extends V> expression)

Type Parameters:

V - type of the property value.

Parameters:

lock - the lock (owning bean).

validator - the validator.

expression - the expression.

Returns:

the new PropertyMetadata.

of

static <V> PropertyMetadata<V> of(AttributeReadOnly lock,
 Validator<? super V> validator,
 Supplier<? extends V> expression,
 Type valueType)

Type Parameters:

V - type of the property value.

Parameters:

lock - the lock (owning bean).

validator - the validator.

expression - the expression.

valueType - the value type.

Returns:

the new PropertyMetadata.

ofExpression

static <V> PropertyMetadata<V> ofExpression(Supplier<? extends V> expression)

Type Parameters:

V - type of the property value.

Parameters:

lock - the lock (owning bean).

validator - the validator.

expression - the expression.

Returns:

the new PropertyMetadata.