Re: [Plplot-devel] Will disappear until next Thursday

[Rafael L. <lab...@ps...>]

* Alan W. Irwin <ir...@be...> [2003-03-09 16:32]:

> You are probably right; we need to learn more about this aspect, and my
> educated guesses may be leading us astray. The critical question then is
> how does the perl parser know the location of those xml/sgml files you
> mentioned where the required entities are defined?

I dug a little bit deeper and found the following: the Perl module
XML::DOM::Parser extends the module XML::Parser, which uses the expat
library (package libexpat1 in Debian).  The error that Joao gets:

    undefined entity at line 2915, column 62, byte 85921 at
    /usr/lib/perl5/site_perl/5.8.0/i586-linux-thread-multi/XML/Parser.pm 
    line 185

comes for the expat library (I am 100% sure about this).  What is intriguing
is that the expat library have different behaviors in Joao's system than in
Debian.  However, I could replicate the bug above when I changed the first
line of src/plplotdoc.xml.in to:

    <?xml version="1.0" standalone="yes"?>

The standalone declaration tells the parser that the document has no
external definitions.  It seems that Joao system's expat library is assuming
this.  

I did a commit recently that may fix this problem.  I added an explicit
declaration standalone="yes" to the temporary file that is parsed by
api2txt.pl, which is a "concatenation" of plplotdoc.xml.in (yes, Alan,
*.in!) and api.xml.  I also added "text" definition for the entities usually
found in api.xml.  The nice side-effect of this change is that, contrary to
what happened before, the output in the *.txt is correct, with entities like
"&deg;", "&gt;", and "&ndash;" being translated into " degrees", ">", and
"--", respectively.

Test this, please.

When I will have some time, I will commit the change in bindings/octave/
Makefile.am to include the files in plplot_octave_txt into the tarball
through make dist, such that regular users won't need XML Perl modules in
order to build the Octave bindings.

-- 
Rafael