Add controls to a form on-the-fly

[Sholom Hamada]

Is it possible to add controls on-the-fly onto a form between loading it and showing it?

I would like to add an unknown number of check-boxes to a form (within a frame). The reason I don't know the number of check-boxes I need beforehand, is because it will be dependent on the number of records in a file (to give the end-user the ability to add/delete choices).

Can I do this?

How do I give the coordinates of where I want the checkbox positioned inside a frame?

How do I set the other properties of the check-box?

Thanks

[Jim Chapman]

RE: Add controls to a form on-the-fly

Hello Sholom,

I am not aware of any functionality built into Alpha that would support this. The structure of a form is saved in the data dictionary in a binary format. One can read and write to the dictionary, so I believe that, given enough understanding of the format of this binary data, one could do almost anything. But my guess is that it would not be simple, and probably not worth trying.

It would make more sense to me to write your own User Object, or ActiveX object. This also would be no small task.

How about approaching it from a different angle. Put a browse to a child table within your frame. Make one of the columns of the browse a checkbox, dynamically populate the child table to display in the browse as you need. This would be well supported by built-in tools and techniques of Alpha Five v5.

Good luck,
Jim

[Keith Hubert]

RE: Add controls to a form on-the-fly

Sholom,

Following Jim's idea you can have conditional fields that would have the check boxes in depending on the conditions you set. For example on a form that people had to fill there personal details, the next form could have different check boxes if the person was male or femail, young or older, etc, etc.

Keith Hubert
London.

[CALocklin]

RE: Add controls to a form on-the-fly

Keith, is that the British spelling - femail? Or, is that just for those listed as mail order brides? (Sorry, I couldn't resist.)

Keith's suggestion for using conditional objects is a great one. You can even "embed" one conditional object inside another if you want. HOWEVER, don't even consider embedding one inside another if the conditional objects will also be placed on a tabbed sub-form. Just trust me on this one - your fields will effectively disappear at some point during development if you do.

It can be worked around with the proper procedure but if you forget just once, you start the form all over again from ground zero. So, if using a tabbed sub-form and conditional objects, never embed one conditional object inside another.

[Peter.Wayne]

RE: Add controls to a form on-the-fly

i actually did something like this for an application. what i did, though, was to create a predefined bunch of checkboxes. you can hide or unhide the checkboxes and change the text of the checkboxes so you can display, say, 6 or 8 or 12, as the case may be.
you can get an idea of how something similar is done by looking at http://www.learn alpha.com/Calendar/Calendar.htm

in that calendar example, there are 42 buttons, and they are given different properties as the month and year change.

[Peter.Wayne]

RE: Add controls to a form on-the-fly

you can also achieve your goal with xdialog. here's a sample:
[code]
' in a real application, "list" could be read from a table
list=""%lst%
widget
thingummy
gadget
flapdoodle
%lst%

code_list=*for_each(tag,"("+tag+") "+tag+";",list)

dim_list=*for_each(tag,"dim "+tag+" as l",list)
evaluate_template(dim_list)

dlg_code="Choose the items you want:;"+crlf()+code_list+crlf()+

[Blake]

RE: Add controls to a form on-the-fly

Also:

If there's a direct one-to-one link between your table records and the check-boxes, a simple checkbox list can do the trick.