Rolled tips and doc improvements from Web-page comments into docs/outputting_pdf.txt. Thanks to various contributors.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@2332 bcc190cf-cafb-0310-a4f2-bffc1f526a37
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Adrian Holovaty 2006-02-18 16:43:17 +00:00
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@ -79,6 +79,15 @@ mention:
whatever you want. It'll be used by browsers in the "Save as..." whatever you want. It'll be used by browsers in the "Save as..."
dialogue, etc. dialogue, etc.
* The ``Content-Disposition`` header starts with ``'attachment; '`` in this
example. This forces Web browsers to pop-up a dialog box
prompting/confirming how to handle the document even if a default is set
on the machine. If you leave off ``'attachment;'``, browsers will handle
the PDF using whatever program/plugin they've been configured to use for
PDFs. Here's what that code would look like::
response['Content-Disposition'] = 'filename=somefilename.pdf'
* Hooking into the ReportLab API is easy: Just pass ``response`` as the * Hooking into the ReportLab API is easy: Just pass ``response`` as the
first argument to ``canvas.Canvas``. The ``Canvas`` class expects a first argument to ``canvas.Canvas``. The ``Canvas`` class expects a
file-like object, and ``HttpResponse`` objects fit the bill. file-like object, and ``HttpResponse`` objects fit the bill.
@ -88,3 +97,56 @@ mention:
* Finally, it's important to call ``showPage()`` and ``save()`` on the PDF * Finally, it's important to call ``showPage()`` and ``save()`` on the PDF
file. file.
Complex PDFs
============
If you're creating a complex PDF document with ReportLab, consider using the
cStringIO_ library as a temporary holding place for your PDF file. The
cStringIO library provides a file-like object interface that is particularly
efficient. Here's the above "Hello World" example rewritten to use
``cStringIO``::
from cStringIO import StringIO
from reportlab.pdfgen import canvas
from django.utils.httpwrappers import HttpResponse
def some_view(request):
# Create the HttpResponse object with the appropriate PDF headers.
response = HttpResponse(mimetype='application/pdf')
response['Content-Disposition'] = 'attachment; filename=somefilename.pdf'
buffer = String()
# Create the PDF object, using the StringIO object as its "file."
p = canvas.Canvas(buffer)
# Draw things on the PDF. Here's where the PDF generation happens.
# See the ReportLab documentation for the full list of functionality.
p.drawString(100, 100, "Hello world.")
# Close the PDF object cleanly.
p.showPage()
p.save()
# Get the value of the StringIO buffer and write it to the response.
pdf = buffer.getvalue()
buffer.close()
response.write(pdf)
return response
.. cStringIO: http://www.python.org/doc/current/lib/module-cStringIO.html
Further resources
=================
* PDFlib_ is another PDF-generation library that has Python bindings. To
use it with Django, just use the same concepts explained in this article.
* HTMLdoc_ is a command-line script that can convert HTML to PDF. It
doesn't have a Python interface, but you can escape out to the shell
using ``system`` or ``popen`` and retrieve the output in Python.
* `forge_fdf in Python`_ is a library that fills in PDF forms.
.. _PDFlib: http://www.pdflib.org/
.. _HTMLdoc: http://www.htmldoc.org/
.. _forge_fdf in Python: http://www.accesspdf.com/article.php/20050421092951834