1. [Win32Lib] Best way to get data from input controls
Hi,
Suppose I have a window with several checkboxes, radio buttons, and
text fields. There is an OK button that uses the options specified by
these controls to perform a task (as in any Windows app). A Euphoria
variable is set up for each control to hold its value in case the value
happens to be used more than once while the task is performed. What is
the most efficient way to get data from these controls when the OK
button is pressed? From my perspective, there are two possibilities:
1. On every Change event, assign the new value of the control to that
control's variable. When the OK button is pressed, all the values are
already stored and immediately available for execution of the task.
2. Don't do anything until the OK button is pressed. When it is
pressed, successively get each control's value and store it in that
control's variable. Then proceed with the execution of the task.
Between these two options, which is the most efficient? Which is used
more often? Is there another method? (Is this such a beginner's
question that the answer should be obvious?)
Andrew Hall
2. Re: [Win32Lib] Best way to get data from input controls
Andrew,
I'm no expert, but I would think your second method, (get all option info on
press OK), is probably preferable, since you're not going to *use* the info
until the OK button is pressed, and it probably won't take but a 1/10 second
or less to get all the data, and you will only have to write one event
handler.
Dan Moyer
----- Original Message -----
From: "A. Hall" <cheetah_heels at myrealbox.com>
To: <EUforum at topica.com>
Sent: Friday, November 21, 2003 10:56 PM
Subject: [Win32Lib] Best way to get data from input controls
>
>
> Hi,
>
> Suppose I have a window with several checkboxes, radio buttons, and
> text fields. There is an OK button that uses the options specified by
> these controls to perform a task (as in any Windows app). A Euphoria
> variable is set up for each control to hold its value in case the value
> happens to be used more than once while the task is performed. What is
> the most efficient way to get data from these controls when the OK
> button is pressed? From my perspective, there are two possibilities:
>
> 1. On every Change event, assign the new value of the control to that
> control's variable. When the OK button is pressed, all the values are
> already stored and immediately available for execution of the task.
>
> 2. Don't do anything until the OK button is pressed. When it is
> pressed, successively get each control's value and store it in that
> control's variable. Then proceed with the execution of the task.
>
> Between these two options, which is the most efficient? Which is used
> more often? Is there another method? (Is this such a beginner's
> question that the answer should be obvious?)
>
> Andrew Hall
>
>
>
> TOPICA - Start your own email discussion group. FREE!
>
3. Re: [Win32Lib] Best way to get data from input controls
----- Original Message -----
From: "A. Hall" <cheetah_heels at myrealbox.com>
To: <EUforum at topica.com>
Subject: RE: [Win32Lib] Best way to get data from input controls
>
>
> Dan,
>
> Good point - it's definitely easier to code. For this reason, I would guess
> that this is the method most people use.
>
> Win32Lib users: Is this how everyone normally gets input data?
>
> Andrew Hall
>
> -----Original Message-----
> From: Dan Moyer [mailto:DANIELMOYER at prodigy.net]
> Sent: Friday, November 21, 2003 11:27 PM
> To: EUforum at topica.com
> Subject: Re: [Win32Lib] Best way to get data from input controls
>
>
> Andrew,
>
> I'm no expert, but I would think your second method, (get all option info on
> press OK), is probably preferable, since you're not going to *use* the info
> until the OK button is pressed, and it probably won't take but a 1/10 second
> or less to get all the data, and you will only have to write one event
> handler.
>
> Dan Moyer
>
> ----- Original Message -----
> From: "A. Hall" <cheetah_heels at myrealbox.com>
> To: <EUforum at topica.com>
> Sent: Friday, November 21, 2003 10:56 PM
> Subject: [Win32Lib] Best way to get data from input controls
>
>
> > Hi,
> >
> > Suppose I have a window with several checkboxes, radio buttons, and
> > text fields. There is an OK button that uses the options specified by
> > these controls to perform a task (as in any Windows app). A Euphoria
> > variable is set up for each control to hold its value in case the value
> > happens to be used more than once while the task is performed. What is
> > the most efficient way to get data from these controls when the OK
> > button is pressed? From my perspective, there are two possibilities:
> >
> > 1. On every Change event, assign the new value of the control to that
> > control's variable. When the OK button is pressed, all the values are
> > already stored and immediately available for execution of the task.
> >
> > 2. Don't do anything until the OK button is pressed. When it is
> > pressed, successively get each control's value and store it in that
> > control's variable. Then proceed with the execution of the task.
> >
> > Between these two options, which is the most efficient? Which is used
> > more often? Is there another method? (Is this such a beginner's
> > question that the answer should be obvious?)
> >
Andrew,
this issue is not a win32lib-only issue. It applies to any GUI application.
In broad terms, the only reasons to fetch data on a Change event is when the
current content effects other controls/variables in real time, and when it is
absolutely essential that the control's data is valid BEFORE the user leaves the
control (changes focus). The first reason is fairly common but the second is
fairly rare.
The usual situation is that the data in controls is only needed (to be validated
and/or used) at specific events - such as the user pressing OK or Cancel or the
like.
It is nearly ALWAYS better to validate the control's data after the user has
pressed OK than on a field-by-field basis as this gives the user control over the
program rather the other way round. For example, it lets the user enter data in
an order that makes sense to them, and it allows the user to make corrections
prior to the program examining the data and showing that it knows more than the
user! Self-esteem is important to users of your programs.
So I would advise that you fetch the control data after the user has pressed OK.
Validate it if necessary, and show a list of all detected errors. Then let the
user correct them in their own order and manner. Of course, if there are no
errors, then just proceed to the next stage. It is better to chose input methods
that make it hard for the user to enter bad data in the first place.
--
Derek
