Update to reportlab 4

[timobrembeck]

Short description

Update to reportlab 4

Proposed changes

• Remove version restriction
• Document installation of C extensions

Resolved issues

Fixes: #699

[timobrembeck]

@stefan6419846 do you think this will do?

[stefan6419846]

Apart from the fact that this will break reportlab 3 due to the requirements and enforce the (recommended, but not yet officially required) Cairo backend, it looks okay for me. To avoid this, we probably would have to utilize requirement extras groups, which I am not sure of how much additional maintenance effort this would introduce.

[timobrembeck]

Apart from the fact that this will break reportlab 3 due to the requirements and enforce the (recommended, but not yet officially required) Cairo backend, it looks okay for me. To avoid this, we probably would have to utilize requirement extras groups, which I am not sure of how much additional maintenance effort this would introduce.

Hmm yes, I agree that it's not ideal. But for now probably better than the previous restriction. At least people who rely on old versions of reportlab can just pin xhtml2pdf to an older version as well...
In the long term, we can evaluate the use of extra dependencies, probably after #692 has been merged...

[viniciusd]

I am still debugging it, so I am sharing in case someone else had the same issue with the new version, I have reportlab==4.0.7 and xhtml2pdf==0.2.12.

I am getting the exception:

    pdf = pisa.pisaDocument(BytesIO(html.encode("UTF-8")), dest=result, encoding='UTF-8')
  File xhtml2pdf/document.py, line 196, in pisaDocument
    doc.build(context.story)
  File reportlab/platypus/doctemplate.py, line 1082, in build
    self.handle_flowable(flowables)
  File reportlab/platypus/doctemplate.py, line 931, in handle_flowable
    if frame.add(f, canv, trySplit=self.allowSplitting):
  File reportlab/platypus/frames.py, line 169, in _add
    w, h = flowable.wrap(aW, h)
  File xhtml2pdf/xhtml2pdf_reportlab.py, line 832, in wrap
    remainingWidth -= colWidth
TypeError: unsupported operand type(s) for -=: 'float' and 'str'

remainingWidth is the float number, colWidth here is the string "12%".

I will do some digging before stating it is an issue/bug.

[viniciusd]

Yeah, it is a bug caused by a refactoring when the ruff linter was added:
a3211b8#diff-74f01775643512741726dc5b4de3062a970be3ce0a07bd148192173000fb872dL822

I will create a separate issue for that.

Edit
It was already described in #731