Mark,
I believe that what you really need is a default WindowManager
implementation in Trinidad. When a WindowManager is present, Trinidad
will store the view state under the windows and the view state can be
cleaned up when the window is closed.
-- Blake Sullivan
On 7/27/10 9:24 PM, Mark Badorrek wrote:
Developers,
I have a Trinidad application that has a few independant frames that operate in
a non-modal fashion (The client needs tha app to work this way). All frames
extensively use 'PageFlowScope'.
Now PageFlowScope works well if you have a single frame, but gives no end of
grief if you have multipe frames. This can be explained:
Every time a user clicks on a page, Trinidad creates another viewstate object
and shoves it onto the pageflowscope map. The map is stored in the HTTP session
and is not limitless. You set the size of the map in web.xml. Once you start
adding viewstates to an already-full map, the map starts discarding the oldest
viewstates. Ususally this is not a problem (how many times could a user be
expected to click the 'Back' button?) But if you have multiple frames, the user
could spend 30minutes clicking in frame 'B', whilst the current viewstate of
frame 'A' becomes older and older and eventually gets pushed out of the
viewstate map. The the user clicks on frame 'A', the viewstate is not found and
everything falls in a smoking mess.
You can get around this by specifying a huge map-size in web.xml but this
results in spectacular memory wastage for no really good reason.
An alternative is to implement a new pageFlowScopeProvider that keeps separate
maps for each frame. Trinidad does not have one of these out-of-the-box, but I
have written one for my client. The problem is that it would be better to
imlement this as a general solution in Trinidad so that others may benefit (and
also that my client doesn't have to maintain it).
I've not been involved in the project for a while but I'd like to get a
solution in place for my client. Is there a preferred method to avoid the above
problem? Or should the custome PageFlowScopeProvider be pursued?
If the reccomendation is to pursue a custom pageFlowScopeProvider, my client (a
government client) is happy to enter into a commercial arangement with a
committer here. i.e. they will pay for a solution. Either to yourself of the
Apache foundation etc. My code is available if it helps.
Cheers,
MarkB
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