Apple WebObjects 3.5 - Manual (Page 137)

Controlling Component State
137
responsibility for maintaining any needed component state. For this reason,
it’s rarely advisable to turn off page caching.
Using awake and sleep
Another way to control the amount of component state that’s maintained
between cycles is to make use of WOComponent’s
awake and sleep methods.
Unlike WOComponent’s init method that’s invoked just once in the life of
the component, a component’s awake and sleep methods are invoked at the
beginning and end of any request-response loop that involves the
component.
By moving a component’s variable initialization routines from its init method
to its awake method and implementing a sleep method to release those
variables, you can reduce the space requirements for storing a component.
For example, the code for DodgeLite’s Main component could be changed
to:
// rewritten DodgeLite Main.wos
id models, model, selectedModels;
id prices, price, selectedPrices;
id types, type, selectedTypes;
- awake {
anApplication = [WOApplication application];
models = [[anApplication modelsDict] allValues];
types = [[anApplication typesDict] allValues];
prices = [anApplication prices];
}
- sleep {
models = nil;
types = nil;
prices = nil;
}
Note that in WebScript you set a variable to nil to mark it for release. In
Objective-C you send the object a release message:
- sleep {
[models release];
[types release];
[prices release];
}
Of course, what you save in storage by moving variable initialization to the
awake method is lost in performance, since these variables will be
reinitialized on each cycle of the request-response loop.