[reportlab-users] Variant nextPageTemplate's: "chapter" pages with subsequent pages

[Robin Becker]

On 24/01/2013 16:09, wandering free wrote:

> I am in the process of converting the database from pfaf.org (plant for a

> future) into a pdf book. I have hit a bit of a stumbling block regarding

...........

> The code (as you can probably tell) works fine for single page plants. It

> also works (semi) as expected for multi page plants.

>

> However, as you can also probably see, a two (or four,etc) page plant will

> break the template arrangement, because the above code assumes page

> position based upon plant number, rather than page number.

>

> I can't see a solution for this in the location of the code above (i.e

> during the Story.append cycle) - as at that point I can not tell whether

> the plant has used more than one page, and thus what page I am currently

> on, as such.

>

we do have code in the toolkit to allow dynamic behaviours in the story see the 
module reportlab/platypus/flowables.py for

DocAssign, DocExec, DocAssert, DocPara, DocIf & DocWhile

these flowables represent really primitive computational constructs which are 
evaluated at layout time.

sample from the latest tests folder



> from reportlab.lib.styles import ParagraphStyle

> from reportlab.platypus import SimpleDocTemplate, Paragraph

> from reportlab.platypus.flowables import DocAssign, DocExec, DocPara, DocIf, DocWhile

> normal = ParagraphStyle(name='Normal', fontName='Helvetica', fontSize=8.5, leading=11)

> header = ParagraphStyle(name='Heading1', parent=normal, fontSize=14, leading=19,

> 			spaceAfter=6, keepWithNext=1)

> story = [

> 		DocAssign('currentFrame','doc.frame.id'),

> 		DocAssign('currentPageTemplate','doc.pageTemplate.id'),

> 		DocAssign('aW','availableWidth'),

> 		DocAssign('aH','availableHeight'),

> 		DocAssign('aWH','availableWidth,availableHeight'),

> 		DocAssign('i',3),

> 		DocIf('i>3',Paragraph('The value of i is larger than 3',normal),Paragraph('The value of i is not larger than 3',normal)),

> 		DocIf('i==3',Paragraph('The value of i is equal to 3',normal),Paragraph('The value of i is not equal to 3',normal)),

> 		DocIf('i<3',Paragraph('The value of i is less than 3',normal),Paragraph('The value of i is not less than 3',normal)),

> 		DocWhile('i',[DocPara('i',format='The value of i is %(__expr__)d',style=normal),DocExec('i-=1')]),

> 		DocPara('repr(doc._nameSpace)',escape=True),

> 		DocPara('doc.canv.getPageNumber()','The current page number is %(__expr__)d',style=normal)

> 		]

> doc = SimpleDocTemplate(outputfile('test_doc_programming.pdf'))

> doc.build(story)


you can access the document doc and lots of its properties etc etc. That should 
allow you to check the page number and then select a suitable template using 
appropriate logic.



> I hoped that I could perhaps tweak the nextPageTemplate structure from my

> custom docTemplate, but I can't figure out if this is possible.

>

> Is it? Or is there another solution? Would really appreciate any help. Have

> been reading all over, but the best examples I can find don't quite cover

> this scenario.

>

> Any questions, please ask. Thank you



-- 
Robin Becker