EOEditingContext.MessageHandler

(informal interface)

Package:
com.webobjects.eocontrol

Interface Description

The EOEditingContext.MessageHandler interface declares methods used for error reporting and determining fetch limits. See the EOEditingContext, EODatabaseContext (EOAccess), and EODisplayGroup (EOInterface) class specifications for more information.

Message handlers are primarily used to implement exception handling in the interface layer's EODisplayGroup, and wouldn't ordinarily be used in a command line tool or WebObjects application.

Message handlers are not required to provide implementations for all of the methods in the interface. When you write a handler, you don't have to use the implements keyword to specify that the object implements the EOEditingContext.MessageHandler interface. Instead, simply use the EOEditingContext method setMessageHandler method to assign your object as the EOEditingContext's handler and then declare and implement any subset of the methods declared in the EOEditingContext.MessageHandler interface. An EOEditingContext can determine if the handler doesn't implement a method and only attempts to invoke the methods the handler actually implements.

Instance Methods

editingContextPresentErrorMessage

public abstract void editingContextPresentErrorMessage( EOEditingContext anEditingContext, String message)

Invoked by anEditingContext, this method should present message to the user in whatever way is appropriate (whether by opening an attention panel or printing the message in a terminal window, for example). This message is sent only if the method is implemented.

editingContextShouldContinueFetching

public abstract boolean editingContextShouldContinueFetching( EOEditingContext anEditingContext, int count, int limit, EOObjectStore objectStore)

Invoked by an objectStore (such as an access layer EODatabaseContext) to allow the message handler for anEditingContext (often an interface layer EODisplayGroup) to prompt the user about whether or not to continue fetching the current result set. The count argument is the number of objects fetched so far. limit is the original limit specified an EOFetchSpecification. This message is sent only if the method is implemented.