com.webobjects.foundation
Interface NSKeyValueCoding.ErrorHandling

All Known Subinterfaces:

EOEnterpriseObject, EOKeyValueCoding, EOKeyValueCodingAdditions

All Known Implementing Classes:

WODirectAction, WOComponent, WOHTTPConnection, WODisplayGroup, WOCookie, WOApplication, WOStatisticsStore, WOContext, WOMessage, WOSession, EOController

Enclosing class:

NSKeyValueCoding

public static interface NSKeyValueCoding.ErrorHandling

The NSKeyValueCoding.ErrorHandling interface declares an API for handling errors that occur during key-value coding. If implemented, these methods allow customized handling error in the default implementation of key value coding.

See Also:

NSKeyValueCoding

Method Summary

Object	handleQueryWithUnboundKey(String key) Invoked from valueForKey when it finds no property binding for key.
void	handleTakeValueForUnboundKey(Object value, String key) Invoked from takeValueForKey when it finds no property binding for key.
void	unableToSetNullForKey(String key) Invoked from takeValueForKey when it is given a null value for a scalar property (such as an int or a float).

Method Detail

handleQueryWithUnboundKey

public Object handleQueryWithUnboundKey(String key)

Invoked from valueForKey when it finds no property binding for key. The default implementation throws an NSKeyValueCoding.UnknownKeyException, with the target object(TargetObjectUserInfoKey) and key(UnknownUserInfokey) in the user info. An NSKeyValueCoding.ErrorHandling class can override this method to handle the query in some other way. The method can return a value, in which case that value is returned by the corresponding valueForKey invocation.

Parameters:

key - the property name which generated this error

Returns:

any Object or null that the custom implementation desires. The default implementation throws an exception instead.

Throws:

NSKeyValueCoding.UnknownKeyException - when it finds no property binding for key

See Also:

NSKeyValueCoding.valueForKey(java.lang.String), NSKeyValueCoding.UnknownKeyException, NSKeyValueCoding.DefaultImplementation

handleTakeValueForUnboundKey

public void handleTakeValueForUnboundKey(Object value,
                                         String key)

Invoked from takeValueForKey when it finds no property binding for key. The default implementation throws an NSKeyValueCoding.UnknownKeyException, with the target object(TargetObjectUserInfoKey) and key(UnknownUserInfoKey) in the user info dictionary of the exception. An NSKeyValueCoding.ErrorHandling class can override this method to handle the error in some other way.

Parameters:

value - the new value which could not be set

key - the name of the property which generated this error

Throws:

NSKeyValueCoding.UnknownKeyException - when it finds no property binding for key

See Also:

NSKeyValueCoding.takeValueForKey(java.lang.Object, java.lang.String), NSKeyValueCoding.UnknownKeyException, NSKeyValueCoding.DefaultImplementation

unableToSetNullForKey

public void unableToSetNullForKey(String key)

Invoked from takeValueForKey when it is given a null value for a scalar property (such as an int or a float). The default implementation throws an IllegalArgumentException. You might want to implement the method (or override the inherited implementation) to handle the request in some other way, such as by substituting new Integer(0) or a sentinel value and invoking takeValueForKey again.

Parameters:

key - the name of the property which generated this error

Throws:

IllegalArgumentException - when it is given a null value for a scalar property

See Also:

NSKeyValueCoding.takeValueForKey(Object value, String key), NSKeyValueCoding.DefaultImplementation