com.vaadin.data.util
Class TransactionalPropertyWrapper<T>

java.lang.Object
  com.vaadin.data.util.AbstractProperty<T>
      com.vaadin.data.util.TransactionalPropertyWrapper<T>

Type Parameters:

T -

All Implemented Interfaces:

Property<T>, Property.ReadOnlyStatusChangeNotifier, Property.Transactional<T>, Property.ValueChangeNotifier, java.io.Serializable

public class TransactionalPropertyWrapper<T>
extends AbstractProperty<T>
implements Property.ValueChangeNotifier, Property.Transactional<T>

Wrapper class that helps implement two-phase commit for a non-transactional property. When accessing the property through the wrapper, getting and setting the property value take place immediately. However, the wrapper keeps track of the old value of the property so that it can be set for the property in case of a roll-back. This can result in the underlying property value changing multiple times (first based on modifications made by the application, then back upon roll-back). Value change events on the TransactionalPropertyWrapper are only fired at the end of a successful transaction, whereas listeners attached to the underlying property may receive multiple value change events.

Since:

7.0

Author:

Vaadin Ltd

See Also:

Property.Transactional, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.vaadin.data.util.AbstractProperty

AbstractProperty.ReadOnlyStatusChangeEvent

Nested classes/interfaces inherited from interface com.vaadin.data.Property

Property.Editor, Property.ReadOnlyException, Property.ReadOnlyStatusChangeEvent, Property.ReadOnlyStatusChangeListener, Property.ReadOnlyStatusChangeNotifier, Property.Transactional<T>, Property.ValueChangeEvent, Property.ValueChangeListener, Property.ValueChangeNotifier, Property.Viewer

Constructor Summary

TransactionalPropertyWrapper(Property<T> wrappedProperty)

Method Summary

void	commit() Commits and ends the transaction that is in progress.
protected void	endTransaction()
protected void	fireValueChange() Sends a value change event to all registered listeners.
java.lang.Class	getType() Returns the type of the Property.
T	getValue() Gets the value stored in the Property.
Property<T>	getWrappedProperty()
boolean	isReadOnly() Tests if the Property is in read-only mode.
void	rollback() Aborts and rolls back the transaction that is in progress.
void	setReadOnly(boolean newStatus) Sets the Property's read-only mode to the specified status.
void	setValue(T newValue) Sets the value of the Property.
void	startTransaction() Starts a transaction.

Methods inherited from class com.vaadin.data.util.AbstractProperty

addListener, addListener, addReadOnlyStatusChangeListener, addValueChangeListener, fireReadOnlyStatusChange, getListeners, removeListener, removeListener, removeReadOnlyStatusChangeListener, removeValueChangeListener, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.vaadin.data.Property.ValueChangeNotifier

addListener, addValueChangeListener, removeListener, removeValueChangeListener

Constructor Detail

TransactionalPropertyWrapper

public TransactionalPropertyWrapper(Property<T> wrappedProperty)

Method Detail

getType

public java.lang.Class getType()

Description copied from interface: Property

Returns the type of the Property. The methods getValue and setValue must be compatible with this type: one must be able to safely cast the value returned from getValue to the given type and pass any variable assignable to this type as an argument to setValue.

Specified by:

getType in interface Property<T>

Returns:

type of the Property

getValue

public T getValue()

Description copied from interface: Property

Gets the value stored in the Property. The returned object is compatible with the class returned by getType().

Specified by:

getValue in interface Property<T>

Returns:

the value stored in the Property

setValue

public void setValue(T newValue)
              throws Property.ReadOnlyException

Description copied from interface: Property

Sets the value of the Property.

Implementing this functionality is optional. If the functionality is missing, one should declare the Property to be in read-only mode and throw Property.ReadOnlyException in this function.

Note : Since Vaadin 7.0, setting the value of a non-String property as a String is no longer supported.

Specified by:

setValue in interface Property<T>

Parameters:

newValue - New value of the Property. This should be assignable to the type returned by getType

Throws:

Property.ReadOnlyException - if the object is in read-only mode

startTransaction

public void startTransaction()

Description copied from interface: Property.Transactional

Starts a transaction.

If the value is set during a transaction the value must not replace the original value until Property.Transactional.commit() is called. Still, Property.getValue() must return the current value set in the transaction. Calling Property.Transactional.rollback() while in a transaction must rollback the value to what it was before the transaction started.

Property.ValueChangeEvents must not be emitted for internal value changes during a transaction. If the value changes as a result of Property.Transactional.commit(), a Property.ValueChangeEvent should be emitted.

Specified by:

startTransaction in interface Property.Transactional<T>

commit

public void commit()

Description copied from interface: Property.Transactional

Commits and ends the transaction that is in progress.

If the value is changed as a result of this operation, a Property.ValueChangeEvent is emitted if such are supported.

This method has no effect if there is no transaction is in progress.

This method must never throw an exception.

Specified by:

commit in interface Property.Transactional<T>

rollback

public void rollback()

Description copied from interface: Property.Transactional

Aborts and rolls back the transaction that is in progress.

The value is reset to the value before the transaction started. No Property.ValueChangeEvent is emitted as a result of this.

This method has no effect if there is no transaction is in progress.

This method must never throw an exception.

Specified by:

rollback in interface Property.Transactional<T>

endTransaction

protected void endTransaction()

fireValueChange

protected void fireValueChange()

Description copied from class: AbstractProperty

Sends a value change event to all registered listeners.

Overrides:

fireValueChange in class AbstractProperty<T>

getWrappedProperty

public Property<T> getWrappedProperty()

isReadOnly

public boolean isReadOnly()

Description copied from class: AbstractProperty

Tests if the Property is in read-only mode. In read-only mode calls to the method setValue will throw ReadOnlyException and will not modify the value of the Property. Override for additional restrictions on what is considered a read-only property.

Specified by:

isReadOnly in interface Property<T>

Overrides:

isReadOnly in class AbstractProperty<T>

Returns:

true if the Property is in read-only mode, false if it's not

setReadOnly

public void setReadOnly(boolean newStatus)

Description copied from interface: Property

Sets the Property's read-only mode to the specified status. This functionality is optional, but all properties must implement the isReadOnly mode query correctly.

Specified by:

setReadOnly in interface Property<T>

Overrides:

setReadOnly in class AbstractProperty<T>

Parameters:

newStatus - new read-only status of the Property