Apple WebObjects 3.5 - Manual (Page 51)

Request-Handling Methods
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As you implement request-handling methods, you must invoke the
superclass’s implementation of the same methods. But consider where you
invoke it because it can affect the request, response, and context
information available at any given point. In short, you want to perform
certain tasks before
super is invoked and other tasks after super is invoked.
Taking Input Values From a Request
The takeValuesFromRequest:inContext: method is invoked during the first phase of
the request-response loop, immediately after all of the objects involved in
the request have performed their
awake methods. When this phase
concludes, the request component has been initialized with the bindings
made in WebObjects Builder.
Override takeValuesFromRequest:inContext: when you want to do one of the
following:
• Access information from the request or context object.
• Perform postprocessing on user input.
In the first case, you can place your code before the message to super . In the
second case, you must place your code after the message to super . For
example, the following implementation of takeValuesFromRequest:inContext:
records the kinds of browsers—user agents—from which requests are
made:
// WebScript example
- takeValuesFromRequest:request inContext:context {
id userAgent = [request headerForKey:@"user-agent"];
[self recordUserAgent:userAgent];
[super takeValuesFromRequest:request inContext:context];
}
The following example performs postprocessing. It takes the values for the
street , city , state , and zipCode variables and stores them in the address variable
formatted as a standard mailing address.
// WebScript example
- takeValuesFromRequest:request inContext:context {
[super takeValuesFromRequest:request inContext:context];
address = [NSString stringWithFormat:@"%@\n%@, %@ %@",
street, city, state, zipCode];
}
// Java example
public void takeValuesFromRequest(Request request, Context context) {
super.takeValuesFromRequest(request, context);
address = street + city + state + zipCode;
}