When you go to download a file from the web you see a download dialog with a progress bar. Would you prefer that when you want to download ,say, a 50 MB zip file (which will take more than a second or two) off the internet that it follow the workflow you describe?
The fact that the Excel spreadsheet is generated dynamically is an internal detail. Again, we're talking about a download that takes a few minutes and not hours. Why should the end user go about a different workflow to download a file? On 1/12/07, Donahue, Michael <[EMAIL PROTECTED]> wrote:
Sanjiv - Strictly speaking as a web developer, this is a very bad approach to dealing with a task that may take more than a second or two complete. Typically, a web application should never make the user wait for more than a few seconds to completely load the next page. I don't think I would want to take your approach for a think client either. In the situation you described, it would be better to tell the user that their request has been accepted and as soon as it is complete they will be notified through some other mechanism that they can download or view the results. This could be through a screen/window pop. There still might be a few good places that it might make sense to have a streaming API, I'd prefer to see effort spent on tasks that have a broader utilization curve like the recently added comments support. Lastly; "THANK YOU!!" to all of the POI Project developers for all of their efforts to make POI better. -----Original Message----- From: Sanjiv Jivan [mailto:[EMAIL PROTECTED] Sent: Friday, January 12, 2007 12:41 PM To: POI Users List; [EMAIL PROTECTED] Subject: Re: HSSF - Generating large spreadsheets in streaming manner? I think that having a streaming API would be very useful and its not because of trying to generate a massive non human readable spreadsheet. You have to factor in the time it takes to build that data to be used for the spreadsheet too. Consider a use case where a user is trying to download a spreadsheet with 500 - 1000 rows but the logic involved in getting the data for the spreadsheet takes around a minute. Without a streaming API, when a user tries to download such a file they click on the link and basically the browser waits for 1 minute and only then pops up a save dialog since the contents of the spreadsheet could only be written out to the response stream after the entire spreadsheet was generated. Had there been a streaming API, the contents could have been written to the response stream on the fly and a nice download dialog with progress bar would have displayed by the browser. On 3/10/06, Andrew C. Oliver <[EMAIL PROTECTED]> wrote: > > not yet. Demand for the cocoon serializer hasn't been very high so it > is mostly deprecated (unless there is some massive uptake of support for > it). > > Okay its time for my yearly rant on this subject (not aimed at you...you > just reminded me I hadn't done it this year): > > I'm always a little curious about this. XLS is a HORRIBLE format (which > is why I started POI, I wanted to do something difficult). It is a > HORRIBLY inefficient format and WAS NOT DESIGNED to stream. Yet people > generate massive sheets in it. My pensiveness is that no human is > likely to read such a large sheet or be able to do anything patricularly > useful with it. So who are these sheets for? Often it turns out they > are some kind of data transfer, which is frankly BAFFLING. Why? > Because I could do the same transfer with like 1/10th of the storage, > bandwidth, CPU, etc in a more well-thought out (or at least lightweight) > format. Yet I saw a spreadsheet today that was 100mb. The power of > Excel is that it can style the data and use some formulas. This is good > for what is to me a summary report and not RAW 100m or gigs of data.. > Of course this comes from someone who knows how to hack the underlying > binary structures but barely knows how to run the Excel GUI. :-) > > We now return you to your previously scheduled mail list activity. > > -Andy > > PS. I wish the open office GUI wasn't so crappy, sluggish and > well...cruddy looking and printed nicely. Their file formats make so > much more sense (and with compression they're reasonably efficient) and > the brilliance of text is that it works nicely with revision control and > revision control tags. > > PPS. I also wish the open office developers would either learn C++, > convert all of their code to C and/or port open office to a language > they know how to write better structured code in. > > Brule, Jon wrote: > > Is it possible to generate a very large spreadsheet (e.g. several > > thousand rows) in a low-memory, streaming manner? I am looking for a > > corollary to the event model used to parse large spreadsheets. > > > > If not, I assume that the Cocoon serializer, which I understand uses > > HSSF, would not operate in a streaming manner either... > > > > Thank you. > > > > Regards, > > Jon > > _________________ > > Jon R. Brule > > Paramount Computing Associates > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > Mailing List: http://jakarta.apache.org/site/mail2.html#poi > > The Apache Jakarta Poi Project: http://jakarta.apache.org/poi/ > > > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > Mailing List: http://jakarta.apache.org/site/mail2.html#poi > The Apache Jakarta Poi Project: http://jakarta.apache.org/poi/ > > **************************************************************************** This email may contain confidential material. If you were not an intended recipient, Please notify the sender and delete all copies. 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