Apple WebObjects 3.5 Manual do Utilizador descarregar pdf (Página 179)

WebScript Language Elements

179

[self application]

WOComponent also deﬁnes a session method, so you can do this to retrieve

the current session:

[self session]

Sometimes, you actually do want to invoke the superclass’s method rather

than the current object’s method. For example, when you initialize an

object, you should always give the superclass a chance to perform its

initialization method before the current subclass. To do this, you send the

init message to super, which represents the superclass of the current object.

- init {

[super init];

// my initialization

return self;

}

The nil word represents an empty object. Any object before it is initialized

has the value

nil. nil is similar to a null pointer in C. For example, to test

whether an object has been allocated and initialized, you do this:

if (myArray == nil) //myArray hasn’t been initialized.

This next statement also tests to see if myArray is equal to nil:

if (!myArray) //myArray hasn’t been initialized.

“Modern” WebScript Syntax

WebScript supports two syntax styles. The style that you’ve been reading

about up until now is “classic” syntax, which is based on the syntax of

Objective-C. If you’re more familiar with languages such as Visual Basic or

Java, you may be more comfortable with the alternate syntax style, called

“modern” syntax.

The differences between classic and modern WebScript syntax are

summarized below:

• Method Deﬁnition

Classic:

- submit {

// <body>

}

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Apple WebObjects 3.5 Manual do Utilizador Página 179