On Thursday, 10 November 2016 at 22:30:34 UTC, Karabuta wrote:
Hello community, does anyone have on something for PDF
generation in D? I may need a PDF generation library in a
vibe.d project I'm working on. :)
Hi,
I did read all the replies posted up to now. Posting a few
alternative methods I thought of, some of which involve calling C
libraries from D - not sure how suitable they will be for your
specific needs, some checking will be required:
- check out libharu - it is an open source C library for PDF
generation. If you can call it from D, it may work for your needs.
http://libharu.org/ . Libharu needs a new maintainer now, but the
site says it still works.
- check out PDFlib(.com). PDFlib is a paid product, and the core
is a C library. However it has an open source version IIRC, and
may be free for personal use (not sure if you want this for
personal or commercial use). Again, would need to call it's (C)
functions from D. PDFlib is a mature product which has been
around for many years. It also has binding to some other
languages.
(I've tried both the above libs at least a bit, and they do work.)
- this one is an obvious, though roundabout method: if the D- and
C-based ones are not suitable for whatever reason, there are
generic methods applicable to calling (a program that uses) a
PDF-generation library (or any library for that matter) in any
other language, such as via XML-RPC (if D has a client library
for that, or if D can call a C client XML-RPC library), REST or
sockets.
- an even simpler method than above (though, of course, less
efficient for multiple calls) may be to shell out to some
executable [1] written in another language which has a PDF
generation library, pass the necessary inputs on the command line
(as command-line options, an input file name, and an output PDF
filename.
[1] By executable here, I don't only mean a compiled user
executable such as a C or C++ or Java app. It could also be a
call to a language interpreter (the executable) taking a script
in that language, as an argument to run, and the script name
could be followed by arguments for the script itself (e.g. python
pdf_gen_prog.py arg1 arg2 ...) . Using this approach, for
example, one could shell out to Python, run a Python script that
uses ReportLab, and use that to do the job, since ReportLab is
fairly powerful for PDF generation, though a bit low-level.
However, it does have things like Paragraphs, Stories, Styles,
and Platypus which are a bit higher-level. And if your PDF output
involves only text (i.e. no images, charts, varying fonts, etc.),
then you can even consider shelling out to a Python program you
write, that uses xtopdf - which is my PDF generation toolkit
written in Python, which uses ReportLab internally, and provides
a somewhat higher abstraction for a subset of ReportLab's
functionality, namely generation of text-only line-oriented PDF
output, with automatic headers, footers, page numbering and
pagination). xtopdf is quite easy to use: With low-level
Reportlab features, you have to write your PDF generation logic
in terms of operations on a Canvas object, not lines of text, so
you have to say things like writeString(x, y, string), and
calculate each x and y, reset the font to the same value after
each new page (a limitation), but with xtopdf you get the higher
level abstraction of something like a text file (a PDFWriter
object), and you just write lines of text to the PDFWriter object
using its writeLine(string) method, until you are done. Just have
to set the header and footer and font once, first (3 lines for
that). Total for a simple file is under 10 or so lines of Python
code, to generate a PDF from text input, using xtopdf - with some
amount of simple customized formatting of the text possible, in
terms of left-or-right-justifying, centering, etc., using
Python's easy string handling, with a few more lines of code.
ReportLab main site: http://reportlab.com
ReportLab open source version: http://reportlab.com/ftp
Good high-level overview of xtopdf:
http://slides.com/vasudevram/xtopdf (including uses, users,
supported input formats, supported platforms, example programs,
etc.)
xtopdf on Bitbucket: https://bitbucket.org/vasudevram/xtopdf
xtopdf examples on my blog:
http://jugad2.blogspot.com/search/label/xtopdf
Guide to installing and using xtopdf:
http://jugad2.blogspot.in/2012/07/guide-to-installing-and-using-xtopdf.html
HTH,
Vasudev
jugad2.blogspot.com
vasudevram.github.io
