Hi, Thanks for your reply. Yes that's what I wanted to say. The code will compile, I've tried it on www.flex.org online compiler and it did what expected without error. I think the compiler is not strict about type reference. But as has been said, it's better to type cast to the right ancestor or descendent an call the appropiate method. As coming from java land the java compiler won't tolerate this "error" if it is an error. When I get the target from the event it's not even a UIComponent, it's as been said an Object type. Anyway I'm still learning Flex. Java Swing id too slow, but I must say it wasn't a wast of time. It is a very elegant architecture but the problem is too slow. All the concept reading the Develp. Guide are familiar to me because they all implemented in Java Swing. Thanks Jairo --- Gordon Smith <[EMAIL PROTECTED]> wrote:
> The Developer's Guide is wrong... you won't get a > compilation error if > you don't cast. However, casting is best practice so > that the compiler > can help you catch coding mistakes. For example, > > e.currentTarget.setSytle(...) > > would compile despite the typo, but throw a runtime > error. However, > > Button(e.currentTarget).setSytle(...) > > would not compile. > > - Gordon > > ________________________________ > > From: [email protected] > [mailto:[EMAIL PROTECTED] On > Behalf Of Karl Johnson > Sent: Tuesday, February 27, 2007 10:27 AM > To: [email protected]; > [email protected] > Subject: RE: [flexcoders] Basic inheritance question > > > > In general you always want to cast something like > this - because > event.currentTarget is of type object and NOT > UIComponent or Button. But > since objects are loosely typed as type Object, then > you reference any > property or method you want at compile time. Often > at runtime though you > will hit errors unless it is properly casted. Your > sample application > was done in Flex 2 right? > > Definitely a best practice to be casting generic > objects like this to > the type of object you want to be working with to > avoid runtime errors > > Karl > Cynergy > > ________________________________ > > From: [email protected] on behalf of > jairokan > Sent: Tue 2/27/2007 11:53 AM > To: [email protected] > Subject: [flexcoders] Basic inheritance question > > > > Hi, > I'm reading the Developer's Guide and in the section > using Events, they > say on a paragraph that : > "If you try to call another method on the > currentTarget (for example, > the setStyle() method), Flex returns an error. The > setStyle() method is > defined on UIComponent, a subclass of DisplayObject. > Therefore, you must > cast currentTarget to UIComponent before calling the > setStyle() method" > for example: > <mx:Script> > <![CDATA[ > import mx.core.UIComponent; > > private function myEventHandler(e:Event):void { > > UIComponent(e.currentTarget).setStyle("color", > "red"); > } > ]]> > </mx:Script> > > and e.currentTarget is of type Button. But Button > extends UIComponent, > so we don't have to upcast the reference because > setStyle method is > public and is available to Button object reference0. > I tried the code > without upcasting and it works. > Is the writer wrong or Am I missing something on the > concept. > > Thanks > > Jairo > > > > > ____________________________________________________________________________________ Food fight? Enjoy some healthy debate in the Yahoo! Answers Food & Drink Q&A. http://answers.yahoo.com/dir/?link=list&sid=396545367
