[REBOL] Re: binding object content to layout items ...
From: gjones05:mail:orion at: 24-May-2001 6:19
From: "Petr Krenzelok"
> can anyone suggest me how to bind object (database) items to layout
> ones? I have following scenarion in mind:
>
> inet-init: context [
> name: ""
> IP: "172.25."
> ]
>
> Now I would like to create form, which should recognize init or edit
> state:
>
> 1) Init state
> ------------
>
> form items should be pre-initialised by inet-init object
>
> 2) Edit state
> ------------
>
> form items should be initialised by stored object which we want to
edit
> ...
>
> What are possible ways to do so?
The way I accomplished this a few months ago was to enclose the layout
within a function that contained a refinement. Called without the
refinement, the layout initialized to a standard default; with the
refinement, the layout initialized to that item. The code was too
lengthy to enclude here, but a very brief example would go something
like this:
default-item: [
field1: none
field2: "some default"
]
;versus the following set through database access
my-data: [
field1: "John Smith"
field2: "employee"
]
item-entry: func [/edit item-data] [
item-lo: layout [
across
txt "Field 1: "
f1: field [;validation, etc]
return
txt "Field 2: "
f2: field [;validation, etc]
do [
either edit [
f1/text: copy item-data/field1
f2/text: copy item-data/field2
][
f1/text: copy default-data/field1
f2/text: copy default-data/field2
]
show [f1 f2]
]
]
]
Then, from another portion of code, 'item-entry function can be called
alone to set up the layout with the dafault, or called with the
refinement to pass in data:
item-entry ;sets up form to default
view item-lo ;to show the form
;;;;;;versus
item-entry/edit my-data ;sets up form to a specific entry
view item-lo ;to show the form
It seems to work pretty well. As set up, most of the faces are
accessible directly from the global scope, which probably isn't such a
good idea, (as you well know better than I do!!). These could be made
local to the context to avoid namespace problems.
> There is also one other issue - there
> are items we would like to represent by different than "field" item on
> the screen - e.g. "rotary", but how to do it?
>
> inet-obj: context [
> name: ""
> IP: "172.25."
> email-type: ["POP3" "Lotus Notes"]
> ]
>
> view layout [rotary inet-obj/email-type .... will not work, as we
don't
> expect block here, but two separate valuues ...
Try:
view layout [rotary data inet-obj/email-type]
> Is there also any easy way of how to auto-layout object to window?
I am sorry, Petr, I am not sure what you mean by this. Can you explain
it in different words?
Hope this helps, and I will be glad to try again on the last question.
--Scott Jones
