Jenda Krynicky wrote:
From: Rob Dixon <[EMAIL PROTECTED]>
Hi Dermot
You get some fun stuff to do don't you!
To be honest I wouldn't go near XML::Simple because of exactly the
problems you're experiencing. It turns XML into a nested hash
structure where the hash values can be a hash reference, an array
reference or a simple string scalar.
Ever heard of ForceArray, ForceContent and SuppressEmpty?
If a tag may be repeated ... add it to ForceArray, if you have tags
that sometimes do and sometimes don't have attributes use
ForceContent.
To process the structure you have
to check what sort of thing each value is so that you know what to do
with it.
No, if you set the above options right you don't.
Sure, if you set all those options you get all hash values being anonymous
arrays (or text strings) and all array elements being anonymous hashes. But
accessing all this gets ugly IMO. Using the XML sample in my previous post I
have to write:
my $ref = XMLin($xml,
ForceArray => 1,
ForceContent => 1,
SuppressEmpty => '',
);
my @address = @{$ref->{order_number}[0]{address}[0]{line}};
foreach (@address) {
if (ref) {
print $_->{content};
}
print "\n";
}
And you still need to check whether the content is a hash reference as there's
also a problem with ForceContent and SuppressEmpty. If you enable both as above
then empty content is stored as just a null string '' instead of
{ 'content' => '' }.
Finally, because XML::Simple stores its data in hashes it can't preserve the
document order of elements, and all those with the same tag must be grouped
together. Consider:
<locations>
<name>Jenda</name>
<country>Czechoslovakia</country>
<name>Rob</name>
<town>Shrewsbury</town>
<country>England</country>
<postcode>SY1 1XB</postcode>
<name>Dermot</name>
<postcode>W9 3RB</postcode>
</locations>
which isn't a nice use of XML I agree but I have had to work with worse. Parsing
this with XML::Simple leaves us with
{
'country' => [
{ 'content' => 'Czechoslovakia' },
{ 'content' => 'England' }
],
'name' => [
{ 'content' => 'Jenda' },
{ 'content' => 'Rob' },
{ 'content' => 'Dermot' }
],
'town' => [
{ 'content' => 'Shrewsbury' }
],
'postcode' => [
{ 'content' => 'SY1 1XB' },
{ 'content' => 'W9 3RB' }
]
}
which is of little use.
All in all I prefer to avoid XML::Simple, but if it works for you then of course
that's fine.
Rob
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