On 4/3/2020 8:33 AM, Ulrike Fischer wrote:
Am Fri, 3 Apr 2020 02:08:25 +0200 schrieb Marcel Fabian Krüger:
Hi,
I recently tried to do something with the embedded pdfe library and
noticed that accessing strings comes with certain problems. PDF strings
are always returned in raw form without the surrounding <> or (), so any
script using them will need to know if it is a hex string or a "normal"
() delimited string in order to treat it correctly. So pdfe.getstring is
a bit weird: It gives a Lua string but no indication which type of
string is returned.
I just run into the same problem and used the detail field from
getfromdictionary/getfromarray to access the string type. But I
agree that it would be nice, if getstring would return this directly
\documentclass{article}
\begin{document}
\directlua{
doc= pdfe.open(kpse.find_file("example-image.pdf"))
trailerid = pdfe.getarray(pdfe.gettrailer (doc),"ID")
type,value,detail = pdfe.getfromarray(trailerid,1)
if detail then
print("HEXSTRING", value)
else
print("LITERALSTRING", value)
end
type,value,detail =
pdfe.getfromdictionary(pdfe.getinfo(doc),"Creator")
if detail then
print("HEXSTRING", value)
else
print("LITERALSTRING", value)
end
}
blub
\end{document}
the problem with return values for these basic types (string, number,
boolean) is that when they are used in arguments (and such) one then
need to encapsulate them in () to make sure that the first argument is
used (the string value) ... in the end these are strings (no matter if
they are hex encoded or not)
print("STRING", pdfe.getstring(trailerid,1))
adding an extra return value is no big deal but we can't predict
incompatibilities (and we're not assumed to introduce these)
Hans
-----------------------------------------------------------------
Hans Hagen | PRAGMA ADE
Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
-----------------------------------------------------------------
_______________________________________________
dev-luatex mailing list
dev-luatex@ntg.nl
https://mailman.ntg.nl/mailman/listinfo/dev-luatex
