Re: [Zope] Reportlab issue

28 Aug 2006


      ----- Original Message ----- 
From: "David H" <bluepaul@earthlink.net>
To: "zope user list" <zope@zope.org>
Sent: Sunday, August 27, 2006 9:48 PM
Subject: Re: [Zope] Reportlab issue
...
Jonathan wrote:
...
----- Original Message ----- From: "David H" <bluepaul@earthlink.net>
To: "Jonathan" <dev101@magma.ca>
Cc: "zope user list" <zope@zope.org>
Sent: Sunday, August 27, 2006 9:25 PM
Subject: Re: [Zope] Reportlab issue
...
Jonathan wrote:
...
----- Original Message ----- From: "David H" <bluepaul@earthlink.net>
To: "zope user list" <zope@zope.org>
Sent: Sunday, August 27, 2006 8:54 PM
Subject: [Zope] Reportlab issue
...
Hi Zope List,
I have an Zope application that uses ReportLab to generate acrobat 
viewable reports. (I already posted this to reportlab list - so far no 
solutions).
Heres the problem:
I display an acrobat report (using Firefox or IE 6) and say scroll 
down to page 10.  I then use the <browser> back button to re-enter my 
Zope application.
Now, even if I click various unrelated pages in the application 
(clearing the request,etc) and then return to the Report (which is 
always freshly generated) it will try to re-display at page 10 - 
instead of top of page.
This occurs even if the data being reported has changed, and this 
occurs even if a different report is generated!
Note: that I use
import tempfile and
tmpFile2 = tempfile.mktemp()
to keep pdfPath's unique ...
I've tried combinations of "Content-Disposition" params like changing 
filename=, etc.  Nothing is changing this behavior.
I've tried (a reportlab mailing list suggestion) varying to <forms 
action= like
<form name="printform" method="post" 
action="extensions/pyBudgetReports"
        tal:attributes="action python: 
'extensions/pyBudgetReports/?random=' + context.python.pyTime()">
No help either.
I have never used ReportLab, but is there a possibility that when you 
go back to the adobe document it is being served from a cache?  You 
could try using html meta tags or response.setHeader (better) to make 
sure the document is not being served from the cache.
Just a shot in the dark!
Jonathan
Hi Jonathan,
Yes, I did try that, e.g. (report lab + external file stuff)
  # -----------------------------------------------------------
  def writeReport(self, RESPONSE):
  # -----------------------------------------------------------
     """
       generates report output
     """
        self.save()
        theFile=open( self.pdfpath,'rb')
        result = theFile.read()
        theFile.close()
        os.remove(self.pdfpath)
        # the next 3 lines were snarked from google "zope no cache"  I 
think its a casey duncan recipe ...
        RESPONSE.setHeader('Pragma', 'no-cache')
        RESPONSE.setHeader('Cache-Control','no-cache')
        RESPONSE.setHeader('Expires', 'Sat, 1 Jan 2000 00:00:00 GMT')
        # the normal fair
        RESPONSE.setHeader('Content-Type','application/pdf')
RESPONSE.setHeader('Content-Disposition','inline;filename="reportNz.pdf"')
        RESPONSE.setHeader('Content-Length',len(result))
        RESPONSE.write(result) # result is
And it didn't help.
Another shot in the dark... could it be an adobe acrobat issue? By which 
i mean that adobe sees that you are looking at the same document 
(reportNz.pdf) and then tries to reopen the document at the last point 
you were looking.  Try randomizing the file name (add 2 or 3 random 
digits to the filename and see what happens).
Good luck!
Jonathan
Jonathan,
We think alike.  If you scan my original msg you'll see that I tested 
varying the Content-Dispostion ...  report= name as well.
Sorry, i missed that in your original post.  I'm all out of 
shots-in-the-dark!  Have you tried seeking help on the adobe acrobat 
developer lists?


Jonathan