So my situation is this: I'm trying to parse an XML file using XML::Parser. The english explanation is rather bizarre and convoluted but here it is: What I'm trying to do is make a hash with the element name as a key, containing an array with one item for each element encountered, containing a hash with two keys - text and attributes, with the text value being the character data and the attributes value containing an unnamed hash that has the key and value pairs for the attribute in it.

To make that a little clearer, the data for an element that looks like this:
<requirement contactname="Joe Average">A power cord.</requirement>
would be like this: 

$tagstack{"requirements"}[0] = {
 "text" => "A Power Cord",
 "attributes" => ["contactname"=>"Joe Average"],
}

[download]


If you came across another <requirement> element like:
<requirement contactname="Jane Smith" contactnumber="555-1212">A node name</requirement>
it would get added to the structure like this: 

$tagstack{"requirements"}[1] = {
 "text" => "A node name",
 "attributes" => ["contactname"=>"Jane Smith", "contactnumber" => "555
+-1212"],
}

[download]

I'm thinking that what I should be doing is predefining my data structure but I'm not entirely sure how to do that without assigning values to the data structure when I start. I'd also prefer to be able to push/pop or shift/unshift the array instead of assigning it manually in a loop.

I've been searching through the Camel book (3rd Ed.) but haven't found what I'm looking for. Can anyone give me a page number or a quick tutorial? Help much appreciated. Thanks.

In reply to Predefining complex data structures? by Ionizor

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.