functionality questions

[Colin Chalmers <co...@xs4all.nl>]

Hi all,

I'm evaluating  different frameworks to enhance our use of Myfaces and 
address the following questions.

After reading through the Shale docs it's still unclear to me if/how 
shale tackles these problems, I'd appreciate some input from those
more familiar with shale/faces with respect to the following:

1. The browser Back-button
   when the user clicks on the browser back-button he should be taken 
back a page without loss of data .
   I've seen comments about client/side state saving in connection with 
cache expiry settings
   I've also seen solutions based on seam & shale when in a particular 
flow, how is this tackled in shale?

2. Bookmarking pages
   I've seen workarounds with servlet-filters. Does Shale solve this and 
if so how?

3. Google findable
   Is Shale able to help in getting the pages Google findable?

thx in advance

Colin

Re: functionality questions

[Craig McClanahan <cr...@apache.org>]

Intermixed.

On 2/25/07, Colin Chalmers <co...@xs4all.nl> wrote:
> Hi all,
>
> I'm evaluating  different frameworks to enhance our use of Myfaces and
> address the following questions.
>
> After reading through the Shale docs it's still unclear to me if/how
> shale tackles these problems, I'd appreciate some input from those
> more familiar with shale/faces with respect to the following:
>
> 1. The browser Back-button
>    when the user clicks on the browser back-button he should be taken
> back a page without loss of data .
>    I've seen comments about client/side state saving in connection with
> cache expiry settings
>    I've also seen solutions based on seam & shale when in a particular
> flow, how is this tackled in shale?
>

For non-dialog pages, Shale offers a mechanism to detect that a
duplicate form submit, via use of the "token" component that will
create a validation error in such cases.  This can be used to avoid
things like double charging to a credit card if the user tries to
check out with a shopping cart twice.

If you are using the "basic" dialog manager feature, you have a couple
of choices that can be configured at runtime with a context init
parameter:

* "none" -- ignore the fact that the user might be using the back arrow
  instead of your "previous page" button.  This is perfectly reasonable in
  use cases like a wizard dialog when you're just collecting a bunch of
  data on multiple pages, and it does not matter if values get re-entered.

* "top" -- ask the dialog manager to save and restore state information
  so that, if the user presses the back arrow, anything previously entered
  on that page is undone.  This does *not* support crossing into subdialogs
  because it only saves state for the topmost subdialog (if there is
more than one).

* "stack" -- like "top", but allows you to cross subdialog boundaries as well.
  The tradeoff is it takes more space/time to save and restore the
state information,
  because the entire stack is processed.

The SCXML version of the dialog manager operates in a manner similar
to the "stack" option by default, since it does not have the same
concept of subdialogs as the "basic" implementation.

> 2. Bookmarking pages
>    I've seen workarounds with servlet-filters. Does Shale solve this and
> if so how?

The most reasonable approach to this (for all Java based web
frameworks, not just JSF or Shale) is to do the following:

* Use the "redirect after post" pattern, so that when you navigate to
a different page,
  this is done with an HTTP redirect instead of a
RequestDispatcher.forward().  This
  causes the browser's URL to show the new page as expected, but costs you the
  extra network round trip.

* Make your application support both GET and POST requests.  With Shale, this
  is particularly easy because you can grab request parameters in the
init() method
  (if you are using the Shale view controller facility) in order to
react differently.


>
> 3. Google findable
>    Is Shale able to help in getting the pages Google findable?

What features or capabilities do you believe are necessary to make
pages "Google findable"?  For the most part, using techniques that
create bookmarkable URLs will deal with most such issues (although
expecting a search engine to index a dynamic application doesn't seem
very likely to yield useful results), but it sounds like you have
something else in mind as well.

>
> thx in advance
>
> Colin
>
>

Craig