XML::Reader

[Klaus]

Hi everybody,

I have released XML::Reader (ver 0.34)
http://search.cpan.org/~keichner/XML-Reader-0.34/lib/XML/Reader.pm

To explain the module, I have created a small demonstration program
that extracts XML-subtrees (for example any path that ends with '/.../
a') memory efficiently

An XML document can be very large (possibly many gigabytes), but is
composed of XML-subtrees, each of which is only a few kilobytes in
size. The demonstration program reads XML-subtrees one by one, only
the memory for one subtree is held at a time. Each subtree can then be
processed further at your convenience (for example by using regular
expressions, or, by using other XML-Modules, such as XML::Simple).

In principle, XML::Reader has no event driven callback functions, you
have to loop over the XML-document yourself and the resulting XML-
subtree is represented in text format.

Any question, suggestions, feedback are most welcome !

Here is my demonstration program:

use strict;
use warnings;
use XML::Reader 0.34;

use LWP::Simple;
use XML::Simple;
use Data::Dumper;

my $addr = 'http://www.w3.org/TR/xhtml1';

print "reading $addr...\n";
my $content = get $addr
or die "Error-0010: Can't get address '$addr'";

print "\n";

{
my $rdr = XML::Reader->newhd(\$content,
{ filter => 5 },
{ root => '/html/body/dl/dt', branch => '*' },
) or die "Error-0030: Can't X::R->new() because $!";

my $i;
while ($rdr->iterate) { $i++;
my $xml = $rdr->rval;

printf "<dt1> %3d. %s\n", $i, $xml;
}
print "\n";
}

{
my $rdr = XML::Reader->newhd(\$content,
{ filter => 5 },
{ root => '/html/body/dl/dt', branch => '*' },
) or die "Error-0020: Can't X::R->new() because $!";

my $i;
while ($rdr->iterate) { $i++;
my $xml = $rdr->rval;
my $ref = XMLin($xml);
my $dmp = Dumper($ref);

$dmp =~ s{\s}''xmsg;
$dmp =~ s{\$VAR1=}''xms;

printf "<dt2> %3d. %s\n", $i, $dmp;
}
print "\n";
}

{
my $rdr = XML::Reader->newhd(\$content,
{ filter => 5 },
{ root => '//a', branch => ['/', '/@href'] },
) or die "Error-0040: Can't X::R->new() because $!";

my $i;
while ($rdr->iterate) {
my ($text, $href) = $rdr->rval;
next unless defined $href;

my $stem = $rdr->rstem;

$i++;
for ($text, $href) {
$_ = '' unless defined $_;
}

printf "<a> %3d. %-35s: %-18.18s href=%s\n",
$i, $stem, $text, $href;
}
print "\n";
}

{
my $rdr = XML::Reader->newhd(\$content,
{ filter => 5 },
{ root => '//img',
branch => ['/@src', '/@height', '/@width'] },
) or die "Error-0040: Can't X::R->new() because $!";

my $i;
while ($rdr->iterate) {
my ($src, $height, $width) = $rdr->rval;

$i++;
for ($src, $height, $width) {
$_ = '' unless defined $_;
}

printf "<img> %3d. src=%-40s h=%-4s w=%s\n",
$i, $src, $height, $width;
}
print "\n";
}

And here is an extract from the output:

reading http://www.w3.org/TR/xhtml1...
[...]
<dt1> 20. <dt><code class='tag'>a</code></dt>
<dt1> 21. <dt><code class='tag'>pre</code></dt>
<dt1> 22. <dt><code class='tag'>button</code></dt>
<dt1> 23. <dt><code class='tag'>label</code></dt>
[...]
<dt2> 20. {'code'=>{'content'=>'a','class'=>'tag'}};
<dt2> 21. {'code'=>{'content'=>'pre','class'=>'tag'}};
<dt2> 22. {'code'=>{'content'=>'button','class'=>'tag'}};
<dt2> 23. {'code'=>{'content'=>'label','class'=>'tag'}};
[...]
<a> 43. /html/body/div/ul/li/a : Acknowledgements
href=#acks
<a> 44. /html/body/div/ul/li/a : References
href=#refs
<a> 45. /html/body/div/ul/li/a : What is XHTML?
href=#xhtml
<a> 46. /html/body/div/ul/li/ul/li/a : What is HTML 4?
href=#html4
<a> 47. /html/body/div/ul/li/ul/li/a : What is XML?
href=#xml
[...]
<img> 1. src=http://www.w3.org/Icons/w3c_home h=48 w=72
<img> 2. src=http://www.w3.org/WAI/wcag1AAA.png h=32 w=88

[Klaus]

On 27 avr, 16:18, Klaus <klau...@gmail.com> wrote:
> I have released XML::Reader (ver 0.34)
> http://search.cpan.org/~keichner/XML-Reader-0.34/lib/XML/Reader.pm

I have now released a new version of XML::Reader (ver 0.35) with some
bug fixes, warts removed, relicensing, etc...

http://search.cpan.org/~keichner/XML-Reader-0.35/lib/XML/Reader.pm

in my previous post (which was for XML::Reader ver 0.34) I wrote:

> my $rdr = XML::Reader->newhd(\$content, { filter => 5 },

With the new version 0.35 of XML::Reader, the same line would be
spelled:

my $rdr = XML::Reader->new(\*DATA, {mode => 'branches'});