com.webobjects.eointerface
Class EOActionAssociation

java.lang.Object
  |
  +--com.webobjects.eocontrol.EODelayedObserver
        |
        +--com.webobjects.eointerface.EOAssociation
              |
              +--com.webobjects.eointerface.EOWidgetAssociation
                    |
                    +--com.webobjects.eointerface.EOActionWidgetAssociation
                          |
                          +--com.webobjects.eointerface.EOActionAssociation

All Implemented Interfaces:

EOObserving, NSDisposable

public class EOActionAssociation

extends EOActionWidgetAssociation

An EOActionAssociation object allows you to set up an interface object, such as a button, to send a message to the Enterprise Objects selected in the association's display group when the interface object is acted on.

Usable with:
com.webobjects.eointerface.swing: Any object that implements the method addActionListener (javax.swing.JButton and javax.swing.JMenuItem, for example).
com.webobjects.eointerface.cocoa: NSControl, NSActionCell, and their subclasses.

Aspects:

action	Bound to a key that names the method to invoke on the selected objects. If the argument aspect isn't bound, the method must take no arguments. If the argument aspect is bound, then the method must take exactly one argument.
argument	An object attribute or relationship of the selected object, passed as an argument to the action method. (Usually bound to a different EODisplayGroup than the one bound to action.)
enabled	A boolean attribute of the selected object, which determines whether the display object is enabled.

Examples:

Suppose you have an application that manages member accounts, each of which has a restriction on the outstanding balance allowed. You want a user to be able to increase the restriction limit by selecting one or more members and then clicking a button. To do this, you define a boostRestrictions method in the Member class that increases the limit by 20%. In Interface Builder, control-drag a connection from the button to the Member display group. Select EOActionAssociation in the Connections inspector, and bind the association's action aspect to the "boostRestrictions" key.

In another scenario, one EODisplayGroup shows Members, while another shows video tapes available for rent. Here, you want a user to be able to select a member, select a video tape, and then click a Rent button that checks the selected tape out to the selected member. To do this, define a rentVideoTape method in the Member class that takes a VideoTape as an argument and handles the accounting involved in a video rental. Then, in Interface Builder, control-drag a connection from the button to the Members display group. Select EOActionAssociation in the Connections inspector, and bind the association's action aspect to Member's rentVideoTape action. Similarly, control-drag a connection from the button to the VideoTape display group. Select EOActionAssociation in the Connections inspector, and bind the association's argument aspect to the VideoTape display group. Now, when the user selects a Member, selects a VideoTape, and clicks the button, the selected Member is sent a rentVideoTape message with the selected VideoTape.

Nested Class Summary

Nested classes inherited from class com.webobjects.eointerface.EOActionWidgetAssociation

EOActionWidgetAssociation.ActionPlugin

Nested classes inherited from class com.webobjects.eointerface.EOWidgetAssociation

EOWidgetAssociation.WidgetPlugin

Field Summary

Fields inherited from class com.webobjects.eointerface.EOAssociation

ActionAspect, ArgumentAspect, AttributeAspectSignature, AttributeToManyAspectSignature, AttributeToOneAspectSignature, AttributeToOneToManyAspectSignature, BackgroundColorAspect, BoldAspect, ChildrenAspect, DestinationAspect, EnabledAspect, ExpandedIconAspect, IconAspect, IgnoreValue, IsLeafAspect, ItalicAspect, MatchKey1Aspect, MatchKey2Aspect, MatchKey3Aspect, NullAspectSignature, ParentAspect, RootAspect, SelectedIndexAspect, SelectedObjectAspect, SelectedTitleAspect, SetValue, SourceAspect, TextColorAspect, TitlesAspect, ToManyAspectSignature, ToOneAspectSignature, ToOneToManyAspectSignature, UnsetValue, URLAspect, ValueAspect

Fields inherited from class com.webobjects.eocontrol.EODelayedObserver

ObserverNumberOfPriorities, ObserverPriorityFifth, ObserverPriorityFirst, ObserverPriorityFourth, ObserverPriorityImmediate, ObserverPriorityLater, ObserverPrioritySecond, ObserverPrioritySixth, ObserverPriorityThird

Constructor Summary

EOActionAssociation(Object object)
Creates a new EOActionAssociation to monitor and update the value in aDisplayObject, typically a button or menu item.

Method Summary

protected boolean	displayGroupSelectionsAllowEnabled() Returns whether or not the set of selected items in the action display group allows for this association to perform its action.
void	invokeAction() Invoked by the receiver's plugin when its display object is acted upon.
String	primaryAspect() Returns the primary aspect this association gets bound to.

Methods inherited from class com.webobjects.eointerface.EOActionWidgetAssociation

isEnabled, isEnabledAtIndex, subjectChanged, widgetPluginClass

Methods inherited from class com.webobjects.eointerface.EOWidgetAssociation

canSupportValueFormatter, defaultPrefersContinuousChangeNotification, dispose, isUsableWithObject, objectKeysTaken, prefersContinuousChangeNotification, setDefaultPrefersContinuousChangeNotification, setObject, setPrefersContinuousChangeNotification, setValueFormatter, valueFormatter, widgetPlugin

Methods inherited from class com.webobjects.eointerface.EOAssociation

aspects, aspectSignatures, associationClassesForObject, bindAspect, breakConnection, copyMatchingBindingsFromAssociation, displayGroupForAspect, displayGroupKeyForAspect, endEditing, establishConnection, isConnected, isExplicitlyDisabled, object, priority, registerAssociationClass, setExplicitlyDisabled, setValueForAspect, setValueForAspectAtIndex, shouldEndEditing, shouldEndEditingAtIndex, valueForAspect, valueForAspectAtIndex

Methods inherited from class com.webobjects.eocontrol.EODelayedObserver

discardPendingNotification, objectWillChange, observerQueue

Methods inherited from class java.lang.Object

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

Constructor Detail

EOActionAssociation

public EOActionAssociation(Object object)

Creates a new EOActionAssociation to monitor and update the value in aDisplayObject, typically a button or menu item.

You normally set up associations in Interface Builder, in which case you don't need to create them programmatically. However, if you do create them up programmatically, setting them up is a multi-step process. After creating an association, you must bind its aspects and establish its connections.

See Also:

EOAssociation.bindAspect(java.lang.String, com.webobjects.eointerface.EODisplayGroup, java.lang.String), EOAssociation.establishConnection()

Method Detail

displayGroupSelectionsAllowEnabled

protected boolean displayGroupSelectionsAllowEnabled()

Returns whether or not the set of selected items in the action display group allows for this association to perform its action. If true, then the action can be invoked, otherwise nothing will happen when the invokeAction method is called on this association.

Overrides:

displayGroupSelectionsAllowEnabled in class EOActionWidgetAssociation

Returns:

true if the action display group selection is not empty and either the argument aspect is not bound or the argument display group selection is not empty; false otherwise

invokeAction

public void invokeAction()

Invoked by the receiver's plugin when its display object is acted upon. Sends the method identified by the receiver's action aspect (with an argument, if the argument aspect is bound) to the selected objects.

Specified by:

invokeAction in class EOActionWidgetAssociation

primaryAspect

public String primaryAspect()

Returns the primary aspect this association gets bound to.

Overrides:

primaryAspect in class EOAssociation

Returns:

EOAssociaion.ActionAspect