You specify with an action declaration which scope you want your form bean to be placed in. There is a contract between actions/form beans that guarantees the form bean to be instantiated before the action is called (assuming you specified the form to be used in your config). So, you see, scope is highly relevant (we could elect to put all forms in request scope, rather than session [ which is the default]). Now, coupled with this, we have the idea that the user may want to specify their own key under which the form may be found. I'm not sure exactly why that's there, but let me take a stab at it (guys, feel free to correct me!).
Under most circumstances, you don't need to specify a value for "attribute" because Struts is going to use a given key automatically (I can't think of what it is right now) to place your bean into <whichever> scope and retrieve it from that same scope - it's got to have a name and it has to know under which scope that name is valid :-) Ok, so why not just use the default all the time? Well, what if you had a bean you wanted to be used as a form bean? OR - what if you wanted to do something with a session-stored form ... say you wanted to reference an attribute of it. Ok, because you have this nifty "attribute" property, you're able to give a succint name to the form. You can now have Struts use some custom bean to act like a form (better derive it from ActionForm though!) or reference a session-scoped form in subsequent pages to ... output a field, for example. Say it were a user registration form and it contained their name. You could reference the form to display their name. While I'm sure I'm not far off, I'm equally sure someone else can give better treatment to this :-) Hopefully that helps some. In any case, it sounds like you're rather new to Struts - I wouldn't bother trying any advanced features (of which I would say this is one) right off. Rather, sit down and build up a "teach myself Struts" app and build on it incrementally - adding (useful) "advanced features" as you go. While sitting down and learning all of the classes would certainly be a good exercise too, I think you would gain more (IMHO) from actually building something. Howard Miller wrote: >Thanks Eddie, > >That's interesting, *but* what does the attribute of an ActionMapping actually >*mean*, >why would I want to use it? > >I think I've completely failed to understand some important concept! I don't see how >a >mapping has a concept of scope when it belongs to an Action, not a FormBean or >similar. > >Howard Miller > -- Eddie Bush -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
