[reportlab-users] Conditional Frame/Page Break

[b1205]

Hello,

(Please forgive me if this is a duplicate post as I am new to mailing lists.)

I am using the PLATYPUS framework to generate a 3 page document.  Each
page contains several frames.

Eventually I would like to use a database query to return a list with
each element populating a frame.  For the majority of elements I will be
able to control frame breaks from the database side by limiting the
character length.  For example, a date element from the database will
always be X characters and the frame behavior _should_ be controlled by
the frame dimensions.  Since I am still doing layout and have not tied
the database query in yet I am using test strings such as:

    story.append(Paragraph("John Doe", styleNormal))
    story.append(FrameBreak)

    story.append(Paragraph("PHB", styleNormal))
    story.append(FrameBreak)

    story.append(Paragraph("2004-11-16", styleNormal))
    story.append(FrameBreak)

where "John Doe" will eventually be replaced by:

    for value in result:
      story.append(Paragraph(value, styleNormal))
      story.append(FrameBreak)


I do have one variable which _may_ be long enough to break the
frame/page.

One page 2 the last frame is (self.pts is an instance of a point class):

    fr45 = Frame(self.pts[17].x + X_OFF, self.pts[17].y + Y_OFF,
                 532, 186, id='long_string')

One page 3 the first frame is:

    fr1 = Frame(self.pts[7].x + X_OFF, self.pts[7].y + Y_OFF,
                532, 336, id='long_string_1')

For example if long_variable is large enough to spill from fr45->fr1
this will work:

    for value in result:
      story.append(Paragraph(value, styleNormal))
      story.append(FrameBreak)	# This will break out of fr1
				# and the next element of fixed
				# length will populate fr2.

However if long_variable = "Not so long" then:

    for value in result:
      story.append(Paragraph(value, styleNormal))
      story.append(FrameBreak)	# This will break out of fr45,
				# however the next fixed element
				# will populate fr1 versus flowing to fr2 
				# where it should be.

I thought I could use the DocTemplate class afterFlowable:

    def afterFlowable(self, flowable):

      #psudeo code
      #check to see what flowable we just finished 	    
      if flowable.identity() == long_variable:  # This won't work as I
can't
						# seem to find a way
						# to uniquely identify the flowable
						# (i.e. The element of the result list)

        #If we finished the flowable on page 2
        if self.page.id == 2:

          #Break out of fr45 and flow to 3rd page, fr1
          self.handle_frameEnd()

          #The default frame break should force
          #the next flowable to page3 fr2
		
        #If we finished the flowable on page 3
        elif self.page.id == 3:

          #Do nothing as the default frame break should push us to fr2

I thought CondPageBreak may work but I don't think that this will work
either.

Maybe using handle_frameEnd() I could check to see what the current/next
flowable is?


In summary, I guess my question is how can I produce the behavior where:

If the long_variable does _not_ cause a page break -> the next frame
should be fr2 on Page3
If the long_variable does cause a page break continue normally onto the
next frame which is fr2


Thanks in advance,
Brian