XML::Twig and subchildren

jfroebe has asked for the wisdom of the Perl Monks concerning the following question:

Hi,

I know it is just something I'm missing... something simple.

<CONFIG_PARM NAME="default network packet size">
    <SETTING>512</SETTING>
    <TYPE>MIN</TYPE>
    <LINK_CONFIG NAME="max network packet size">
         <RELATIONSHIP>LESS OR EQUAL</RELATIONSHIP>
    </LINK_CONFIG>
</CONFIG_PARM>
[download]

The LINK_CONFIG is being retrieved with a hash reference $LINK_CONFIG_ref = $elt->first_child('LINK_CONFIG')->atts but am having trouble retrieving RELATIONSHIP. Is there a way to easily retrieve it without using a subtree?

Thanks

Jason

update (thanks mirod!): I was making it too difficult for myself.. here is the solution for this simple problem:

 
 $RELATIONSHIP = $elt->first_child('LINK_CONFIG')->text
    if ( defined($elt->first_child('LINK_CONFIG')) );
[download]

Produces:

  Linked to Config 'max online engines'
    EQUAL BUT POWER OF 2
[download]

No one has seen what you have seen, and until that happens, we're all going to think that you're nuts. - Jack O'Neil, Stargate SG-1

Comment on XML::Twig and subchildren Select or Download Code

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Re: XML::Twig and subchildren by mirod (Canon) on Aug 10, 2004 at 20:40 UTC
Did you try `$elt->first_child('LINK_CONFIG')->first_child( 'RELATIONSHIP')`? This would give you the element, you can get the content by applying `text` to it.	[reply] [d/l]
Re^2: XML::Twig and subchildren by jfroebe (Parson) on Aug 10, 2004 at 20:45 UTC
Unfortunately, $elt->first_child() doesn't return an element object... so `my $RELATIONSHIP = $elt->first_child('LINK_CONFIG')->first_child('RELATIONSHIP')->text;` will fail on compilation with "Can't call method "first_child" on an undefined value". Jason No one has seen what you have seen, and until that happens, we're all going to think that you're nuts. - Jack O'Neil, Stargate SG-1	[reply] [d/l]
Re^3: XML::Twig and subchildren by mirod (Canon) on Aug 10, 2004 at 20:54 UTC
`$elt->first_child('LINK_CONFIG')` returns an element, unless there is no `LINK_CONFIG` child. So if the code fails it will be at runtime, not compilation. If this is likely to happen then you have to process this case: `if( my $link_config= $elt->first_child('LINK_CONFIG')) { my $relationship= $link_config->first_child('RELATIONSHIP')->text; + # ... } else { warn "no LINK_CONFIG found\n"; # or any other processing necessary }` [download]	[reply] [d/l]
Re^4: XML::Twig and subchildren by jfroebe (Parson) on Aug 10, 2004 at 21:03 UTC
Re: XML::Twig and subchildren by GreyGlass (Sexton) on Aug 10, 2004 at 20:55 UTC
It sounds like you are looking for `$foo->text`, but it is not 100% clear from the question. If this is not enough, please try to give a code sample, describe specifically what you are trying to accomplish and specifically what kind of difficulties you are encountering.	[reply] [d/l]