General design question

As I read thru info on developing a web app, one general design question comes
to mind.

In my plus app, the user selects a primary category in a combobox.  Their
selection determines what options will be displayed in a listbox on the same
form.  They can then choose multiple items in the listbox.  

If they change their mind on the primary category, the onchange for the primary
category causes a change in the options available in the listbox, and they can
start over.

At this beginning stage, it appears without an onchange event on web controls, I
will need to place the primary category on one page with a submit button, then
bring up the next page on submit with the listbox of options.  The second page
would have a back button to let them go back to page one and change their
primary selection.

Is there a way this kind of behavior can be done more similar to my plus app,
i.e., having both on the same page?

Thanks for some direction on this,
Mark

Mark wrote:
> 
> Is there a way this kind of behavior can be done more similar to my plus
app, i.e., having both on the same page?

Assuming the page does not have data from a table so that when the category 
changes that app does not need to fetch data from a database: Then an
alternative 
design is to use JavaScript in you HTML page. JavaScript can make your web pages

more dynamic--more like your dBASE desktop app. The downside is that you will
need 
to learn JavaScript.

For what it's worth, I have some web apps that work similar what you describe.
I'm 
a bit too old to become proficient with JavaScript. But there are some users who

frequent this group and are quite good with it.

Michael,

When they change the value of the primary category, there is a need to either
set a filter for the listbox, or use sql to select the items corresponding to
their primary selection, so I believe a fetch of data would be needed.

If I could find a web page that already has used javascript to do this I could
probably follow it, but finding time to learn javascript would be hard for me as
well.

I could create page 2 with the same info as page 1, but only showing the value
they selected, with a listbox to pick their subcategory.  Then if they click on
the value displayed from page 1 when they are in page 2, maybe I could submit a
call to open page 1 and let them pick a different value.  When they submit the
different value in page 1, it would again open page 2 with the new listing. 
From the user's perspective, that behavior would look as tho everything was
happening in one page.  

I know it is not possible to "click" a displayed value, so possibly I
could place a Change button next to the value they selected when it is displayed
on page 2, and that would actually initiate a call to open page 1 to start
over.

Does that sound feasible to you?

Thanks again,
Mark


Michael Nuwer Wrote:

> Mark wrote:
> > 
> > Is there a way this kind of behavior can be done more similar to my
plus app, i.e., having both on the same page?
> 
> Assuming the page does not have data from a table so that when the category

> changes that app does not need to fetch data from a database: Then an
alternative 
> design is to use JavaScript in you HTML page. JavaScript can make your web
pages 
> more dynamic--more like your dBASE desktop app. The downside is that you
will need 
> to learn JavaScript.
> 
> For what it's worth, I have some web apps that work similar what you
describe. I'm 
> a bit too old to become proficient with JavaScript. But there are some
users who 
> frequent this group and are quite good with it.
> 
> 
> 

Mark wrote:
> Michael,
> 
> When they change the value of the primary category, there is a need to
either set a filter for the listbox, or use sql to select the items
corresponding to their primary selection, so I believe a fetch of data would be
needed.

In this case, then, JavaScript will not help.

> 
> If I could find a web page that already has used javascript to do this I
could probably follow it, but finding time to learn javascript would be hard for
me as well.
> 
> I could create page 2 with the same info as page 1, but only showing the
value they selected, with a listbox to pick their subcategory.  Then if they
click on the value displayed from page 1 when they are in page 2, maybe I could
submit a call to open page 1 and let them pick a different value.  When they
submit the different value in page 1, it would again open page 2 with the new
listing.  From the user's perspective, that behavior would look as tho
everything was happening in one page.  

Maybe (you know your system best). Another option to consider is that page 1 and

page 2 could be in HTML frames. Both pages will be visible at the same time, but

there will be a degree of independence between them.

An HTML action executed in the page 1 frame should include the
"target" attribute. 
That target should be the frame-name of the page 2 frame.

A similar approach is to use small pop-up (browser) windows. Unfortunately 
spammers have made working with pop-ups difficulty. I've stopped using pop-ups 
altogether.

> 
> I know it is not possible to "click" a displayed value, 

Use an anchor tag for this: <A href="command.exe">displayed
value<a>

> so possibly I could place a Change button next to the value they selected
when it is displayed on page 2, and that would actually initiate a call to open
page 1 to start over.
> 
> Does that sound feasible to you?

I suggest a scaled-down prototype. With such a test you can see whether the
design 
meets you needs. Then you can add the bells and such. Remember, one test is
worth 
   1,000 expert opinions.

Michael,

HTML frames...that will be something I will need to learn more about.  The
anchor tag is also something I will check out.

Thanks for a copule things I can keep an eye out for as I continue the learning
process.

Thanks,
MArk

Michael Nuwer Wrote:

> Mark wrote:
> > Michael,
> > 
> > When they change the value of the primary category, there is a need to
either set a filter for the listbox, or use sql to select the items
corresponding to their primary selection, so I believe a fetch of data would be
needed.
> 
> In this case, then, JavaScript will not help.
> 
> > 
> > If I could find a web page that already has used javascript to do this
I could probably follow it, but finding time to learn javascript would be hard
for me as well.
> > 
> > I could create page 2 with the same info as page 1, but only showing
the value they selected, with a listbox to pick their subcategory.  Then if they
click on the value displayed from page 1 when they are in page 2, maybe I could
submit a call to open page 1 and let them pick a different value.  When they
submit the different value in page 1, it would again open page 2 with the new
listing.  From the user's perspective, that behavior would look as tho
everything was happening in one page.  
> 
> Maybe (you know your system best). Another option to consider is that page
1 and 
> page 2 could be in HTML frames. Both pages will be visible at the same
time, but 
> there will be a degree of independence between them.
> 
> An HTML action executed in the page 1 frame should include the
"target" attribute. 
> That target should be the frame-name of the page 2 frame.
> 
> A similar approach is to use small pop-up (browser) windows. Unfortunately

> spammers have made working with pop-ups difficulty. I've stopped using
pop-ups 
> altogether.
> 
> > 
> > I know it is not possible to "click" a displayed value, 
> 
> Use an anchor tag for this: <A href="command.exe">displayed
value<a>
> 
> > so possibly I could place a Change button next to the value they
selected when it is displayed on page 2, and that would actually initiate a call
to open page 1 to start over.
> > 
> > Does that sound feasible to you?
> 
> I suggest a scaled-down prototype. With such a test you can see whether the
design 
> meets you needs. Then you can add the bells and such. Remember, one test is
worth 
>    1,000 expert opinions.
>