FWIW you can test for a property using "in" if (getChildren in obj)
________________________________ From: flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Mike Morearty Sent: Tuesday, April 03, 2007 5:44 PM To: flexcoders@yahoogroups.com Subject: [flexcoders] Re: getChildren Gordon's way does work -- and in fact it can be taken even further by not only checking that there is a property called "getChildren", but also that that property is a function: if (obj.hasOwnProperty("getChildren") && typeof obj["getChildren"] == "function") { children = obj.getChildren(); } However, I think Dordea's answer -- to test "obj is Container" -- is actually what you should be using. You are not really trying to check whether obj has a getChildren() function -- you are trying to check whether, semantically speaking, it is a container. To take the old object-oriented programming example, let's say there was a class called Artist, with a function draw(). If you just tested for the existence of function "draw" and then called it, that doesn't necessarily mean you are asking an Artist to draw -- that just means you have asked *something* to draw. Maybe Cowboy also has a draw() function, to draw his gun. Oops! So back to your example, I think probably what you're really trying to say is, "If the object that was passed in is a Container, then I want to get its children." So, "if (obj is Container)" is the way to go. - Mike Morearty, Flex Builder --- In flexcoders@yahoogroups.com <mailto:flexcoders%40yahoogroups.com> , "Gordon Smith" <[EMAIL PROTECTED]> wrote: > > I think this may be another way... > > if (obj.hasOwnProperty("getChildren")) > children = obj.getChildren(); > > - Gordon > > ________________________________ > > From: flexcoders@yahoogroups.com <mailto:flexcoders%40yahoogroups.com> [mailto:flexcoders@yahoogroups.com <mailto:flexcoders%40yahoogroups.com> ] On > Behalf Of dordea cosmin > Sent: Tuesday, April 03, 2007 12:13 PM > To: flexcoders@yahoogroups.com <mailto:flexcoders%40yahoogroups.com> > Subject: Re: [flexcoders] getChildren > > > > only objects that inherit the Container class have this functions. When > i have a situation like yours, I usually do something like : > if ( obj is Container) > { > //code here > } > > and it works fine. It is possible not to work if your object > was originally an Object , and you further created your > object using a class reference. > > > ----- Original Message ---- > From: Michael Schmalle <[EMAIL PROTECTED]> > To: flexcoders@yahoogroups.com <mailto:flexcoders%40yahoogroups.com> > Sent: Tuesday, April 3, 2007 11:51:48 AM > Subject: Re: [flexcoders] getChildren > > > > Hi, > > You could do this; > > try { > children = obj.getChildren( ); > } > catch (e:Error) > { > trace(e, "obj did not have getChildren( )"); > } > > > Peace, Mike > > > > > On 03 Apr 2007 11:41:25 -0700, blc187 <[EMAIL PROTECTED] com > <mailto:[EMAIL PROTECTED]> > wrote: > > is there a way to tell if an object has a getChildren method > before > calling it? > > I'm calling something that takes any type as the first argument > public function myFunc(obj:* ):void > > I need to tell if obj has a getChildren( ) method before I call > it and > get an error saying Error #1006: getChildren is not a function. > > > > > > > > > -- > Teoti Graphix > http://www.teotigra phix.com <http://www.teotigraphix.com <http://www.teotigraphix.com> > > > Blog - Flex2Components > http://www.flex2com ponents.com <http://www.flex2components.com <http://www.flex2components.com> > > > You can find more by solving the problem then by 'asking the question'. > > > ________________________________ > > Get your own web address. > <http://us.rd.yahoo.com/evt=49678/*http://smallbusiness.yahoo.com/domain <http://us.rd.yahoo.com/evt=49678/*http://smallbusiness.yahoo.com/domain > > s/?p=BESTDEAL> > Have a HUGE year through Yahoo! Small Business. > <http://us.rd.yahoo.com/evt=49678/*http://smallbusiness.yahoo.com/domain <http://us.rd.yahoo.com/evt=49678/*http://smallbusiness.yahoo.com/domain > > s/?p=BESTDEAL> >
