Creating handles for a menu

[IanC74]

Hi, Im trying to create a menu for a small group of screens which is controlled by a menu definitions table. So basically i create a menu structure from the labels/exec/direcoties defined in that table.

It works fine for a single level, i.e. using hmenu, hsubmenu and hsubmenuitem handles to control the top level menu, submenu off that menu and items for the menus.

However, if i want to create another level of submenus and submenuitems (so i can have another submenu on a submenu) i would need to define another 2 handles for that submenu and its submenuitems.

Thats ok, but if i wanted to be dynamic and have further submenus later without changing code i dont want to have to create numbers of handles in the code, but create them at run time.

Is this possible, i.e. craete a variable and assign the handle name to the variable and create the handle name from value(handvariable)?

Hope this makes sense!

TIA

Ian

 

[GregTomkins]

As usual I am not 100% sure I understand (it's me, not you), but:

You cannot dynamically create variables per se. Greg Higgins suggested this at a conference once and I thought, "wow what a great idea!", but AFAIK nothing ever came of it.

However, you could create a dynamic temp-table and then create handle fields inside that. You can do all sorts of crazy stuff such as a DTT containing handles to other DTT's, so I am pretty sure this would work for menus too.

 

[IanC74]

Thanks Greg, hmm thats interesting about the dynamic temp table. Do you know of any examples of DTT with handles? Sorry for being a pain, im almost ready to pull my hair out (whats left of it!).

Ian

As usual I am not 100% sure I understand (it's me, not you), but:

You cannot dynamically create variables per se. Greg Higgins suggested this at a conference once and I thought, "wow what a great idea!", but AFAIK nothing ever came of it.

However, you could create a dynamic temp-table and then create handle fields inside that. You can do all sorts of crazy stuff such as a DTT containing handles to other DTT's, so I am pretty sure this would work for menus too.

 

[GregTomkins]

Actually I looked into our code that does menus and maybe the DTT suggestion was silly. Our menu system is 100% table driven and it definitely supports nested menus though I'm not sure if they can be arbitrarily deep. Here is an edited version of the code we use:

RUN get_menu_items ON SERVER(OUTPUT tmp_user_menu_item):

FOR EACH tmp_user_menu_item NO-LOCK
CREATE SUB-MENU h_cascading_menu_item_hdl
ASSIGN PARENT = h_submenu_item_hdl
LABEL = tmp_user_menu_item.menu_label
PRIVATE-DATA = tmp_user_menu_item.proc_name.

FOR EACH bf_tmp_user_menu_item NO-LOCK
WHERE bf_tmp_user_menu_item.sub_menu_key = tmp_user_menu_item.cascading_key:

CREATE MENU-ITEM h_menu_item_hdl
ASSIGN PARENT = h_cascading_menu_item_hdl
LABEL = bf_tmp_user_menu_item.menu_label.

/*store the procedure name in the private data to be run when the user selects the menu item,
along with the toggle state*/
h_menu_item_hdlRIVATE-DATA = bf_tmp_user_menu_item.proc_name.

The reason my DTT suggestion might have been silly is, I don't think we actually care about the menu handles once they have been created. We stuff an identifier into PRIVATE-DATA, set them all to run a common handler, and then use PRIVATE-DATA to figure out what to do.

I do not claim this to be perfect or the only way, and I didn't write this!!, but it seems to work OK for us...

 

[IanC74]

Hi Greg, thanks for all your help. I think I was on the right track with my menus after looking at your code, i think i see where I was going wrong.

Really appreciate your help.

Thank you
Ian