Identifying form items
Elements defined in a form file can be identified with a name, to be used in programs.
Form fields are implicitly identified by the tabname.colname
specification after
the equal sign, while other (non-field) form items such as static labels and group boxes can get an
optional item name.
The form item name defined in the form file will be copied to the name
attribute
of the corresponding node in the .42f file. It can then be used by programs to
select a form element at runtime, to introspect or modify its attributes.
For example, specify the name for a
GROUP
container by writing an identifier
after the layout container type:GROUP group1 (TEXT="Customer")
Here the group name is '
group1
', and it can be used in a program to identify the
group
element:DEFINE w ui.Window
DEFINE g om.DomNode
LET w = ui.Window.getCurrent()
LET g = w.findNode("Group","group1")
CALL g.setAttribute("text","Another text")
Helper methods are provided for common tasks on form elements. For example, to hide a group with
the identifier
group1
, you can use the setElementHidden()
method
on a ui.Form
object:DEFINE f ui.Form
...
LET f = DIALOG.getForm()
...
CALL f.setElementHidden("group1", TRUE)
Consider defining unique names to identify form elements, and to simplify the search at runtime.
A good practice is the use of a prefix based on the type of form element (g_
for
groups, l_
for labels for example).
Static items (labels) in a
GRID
container cannot get a name, because these are
self-defined with the layout part of the item:GRID
{
Name: [f1 ]
...
}
END
In the above example, the label
"Name:"
cannot be identified. In order to give a
name to such a label, use an item tag and add a LABEL
item definition in the
ATTRIBUTES
section, to specify the name of the label after the
colon:GRID
{
[l1 ][f1 ]
...
}
END
...
ATTRIBUTES
LABEL l1: l_name, TEXT="Name:";
...