com.webobjects.appserver
Class WOVariableAssociation

java.lang.Object
  com.webobjects.appserver.WOAssociation
      com.webobjects.appserver.WOVariableAssociation

All Implemented Interfaces:

Cloneable

public class WOVariableAssociation
extends WOAssociation

Nested Class Summary

Nested classes/interfaces inherited from class com.webobjects.appserver.WOAssociation

WOAssociation.Event

Field Summary

Fields inherited from class com.webobjects.appserver.WOAssociation

TakeValueForKeyPathEvent, ValueForKeyPathEvent

Constructor Summary

WOVariableAssociation(String variable)

Method Summary

String	bindingInComponent(WOComponent aComponent) Returns the binding String as seen in WebObjects Builder.
boolean	isValueConstant() Used to check if an association value is constant at runtime.
boolean	isValueSettable() Used to check if an association can assign values at runtime.
String	keyPath() Overridden to return "".
void	setValue(Object aValue, WOComponent aComponent) Sets the value for this association in the component.
Object	valueInComponent(WOComponent aComponent) Returns the association's value for this component.

Methods inherited from class com.webobjects.appserver.WOAssociation

associationWithKeyPath, associationWithValue, booleanValueInComponent, isValueConstantInComponent, isValueSettableInComponent, setDebugEnabledForBinding, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

WOVariableAssociation

public WOVariableAssociation(String variable)

Method Detail

valueInComponent

public Object valueInComponent(WOComponent aComponent)

Description copied from class: WOAssociation

Returns the association's value for this component.

For example, invoking value on a WOAssociation created from this declaration,

   DOWNPAYMENT:WOString {value = downpayment};
 

returns the value of the current component's downpayment variable. Invoking value on a WOAssociation created from this declaration,

  DOWNPAYMENT:WOString {value = "$5000.00"};
 

returns the value "$5000.00" (independent of the current component).

This method raises an exception if it cannot resolve the WOAssociation's value with the current component.

This method is used to retrieve values throughout the WebObjects framework by all private subclasses of WODynamicElement.

Another way in which the WebObjects framework uses this method is to synchronize the values of nested components. When attributes in child and parent components are associated with one another and changes occur in one component, this method is invoked to migrate those changes to the other component.

Overrides:

valueInComponent in class WOAssociation

Parameters:

aComponent - component which should resolve the association

Returns:

a value based on receiver's association and the current component

See Also:

WOAssociation.setValue(Object aValue, WOComponent aComponent)

setValue

public void setValue(Object aValue,
                     WOComponent aComponent)

Description copied from class: WOAssociation

Sets the value for this association in the component. Using NSKeyValueCoding, this method finds the variable, or setter method in aComponent pointed to by the association binding name. It then sets the variable's value to aValue, or invokes the setter method with aValue as a parameter. This method throws an exception if the receiver's value is not settable. For example, invoking setValue on a WOAssociation created from this declaration,

   USER:WOTextField {value = userName};
 

sets the current component's userName variable to the value typed into the WOTextField.

This method is used to set values throughout the WebObjects framework by all private subclasses of WODynamicElement.

Another way in which the WebObjects framework uses this method is to synchronize the values of nested components. When attributes in child and parent components are associated with one another and changes occur in one component, this method is invoked to migrate those changes to the other component.

Overrides:

setValue in class WOAssociation

Parameters:

aValue - the input value

aComponent - component which should resolve the association

See Also:

WOAssociation.valueInComponent(WOComponent aComponent), WOAssociation.isValueSettable()

isValueSettable

public boolean isValueSettable()

Description copied from class: WOAssociation

Used to check if an association can assign values at runtime.

Overrides:

isValueSettable in class WOAssociation

Returns:

false if the association's value is constant, true otherwise

See Also:

WOAssociation.associationWithKeyPath(String aKeyPath), WOAssociation.isValueConstant(), WOAssociation.isValueSettableInComponent(WOComponent aComponent)

isValueConstant

public boolean isValueConstant()

Description copied from class: WOAssociation

Used to check if an association value is constant at runtime.

Overrides:

isValueConstant in class WOAssociation

Returns:

true if the WOAssociation's value is a constant, false otherwise

See Also:

WOAssociation.associationWithValue(Object aValue), WOAssociation.isValueSettable(), WOAssociation.isValueConstantInComponent(WOComponent aComponent)

bindingInComponent

public String bindingInComponent(WOComponent aComponent)

Description copied from class: WOAssociation

Returns the binding String as seen in WebObjects Builder. This abstract method is implemented by WOAssociation subclasses to return, as a String, the binding string from the declarations ('wod') file. It may be resolved by the component in which the association resides. This is used during DirectToWeb page generation.

Specified by:

bindingInComponent in class WOAssociation

Parameters:

aComponent -

Returns:

See Also:

WOAssociation.bindingInComponent(com.webobjects.appserver.WOComponent)

keyPath

public String keyPath()

Overridden to return "".

Specified by:

keyPath in class WOAssociation

Returns:

See Also:

WOAssociation.keyPath()