in reply to XML::Simple--dealing with a variable element

Chew on this: 
@attrs = map { @{ $_->{attributes}{attribute} } }
             values %{ $data->{dataschemas}{dataschema} };

[download]

Update: actually, it doesn't look like your attribute nodes result in an array. Do you need the attribute names too, or just the values?

Maybe this will be clearer: 

foreach my $dataschema ( values %{ $data->{dataschemas}{dataschema} } 
+)
{
    while( my ($name, $value) = each %{ $dataschema->{attributes}{attr
+ibute} } )
    {
        # do something with the name and value
    }
}

[download]

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Re^2: XML::Simple--dealing with a variable element
by bw (Novice) on Jul 26, 2006 at 22:57 UTC
    I'll crack the book to decipher your code. I simply need the names.

    My end goal for all of this is to figure out existing attribute names being used, give a user the opportunity to select from that existing list or add new ones, write out a new <dataschema> stanza, and then update the config file where the <dataschemas> stanza came from.
[reply]
      Are you sure the names are unique for all the varying groups? If so, then 
      @attrs = map { keys %{ $_->{attributes}{attribute} } }
         values %{ $data->{dataschemas}{dataschema} };

      [download]
      should do the trick. I think. I usually get dizzy with data structures this deep ;)
[reply]
[d/l]
        Let's say for a given <dataschema> that one of the <attribute> stanza attributes is 'category'. Within that given <dataschema>, all 'category' names are unique. Some of those 'category' names, however, will appear in other <dataschema> stanza's 'category' names.

        Does that make sense? Does that change the code at all? Have I made you so dizzy that you can't get off the floor?
[reply]
Re^2: XML::Simple--dealing with a variable element
by bw (Novice) on Jul 27, 2006 at 17:13 UTC
    rhesa: the foreach option is almost working!

    The first element within <attribute> is:
      <attributes>
        <attribute category="" parser="CSVParser" />

    which produces the error:
    Argument "" isn't numeric in each at xmlparser.pl line 58.
      Bad index while coercing array into hash at xmlparser.pl line 58.

    when using the code:

    foreach my $dataschema ( values %{ $data->{dataschemas}{dataschema} } 
+)
{
  while( my ($name, $value) = each %{ $dataschema->{attributes}{attrib
+ute} } ){
    # do something with the name and value
    print "\$name is: $name\n\$value is: $value\n";
    }
}

    [download]
    When I used keys in place of each, I get the print line to work, but I'm stuck in an infinite loop in the process.

    This shows that I don't understand very well hashes and hash functions with respect to the while( my ($name, $value) = each %{ $dataschema->{attributes}{attribute} } ) line since this error doesn't make sense to me.

    I know that I'm getting hung up on the category="" item, but that's as far as I've gone in my debug process.
[reply]
[d/l]
      Your newer data shows that you usually have an array of "attribute" nodes, while I was assuming it would be a hash. I'm forcing XML::Simple to always make an array of the "attribute" nodes, and have changed the code to accomodate that. 
      use XML::Simple;

$data  = XMLin( \*DATA, KeepRoot => 1, ForceArray => [ qw/attribute/ ]
+ );

@attrs = map { $_->{category} }                        # We want the c
+ategory value 
         map { @{ $_->{attributes}{attribute} } }      # for each attr
+ibute
         values %{ $data->{dataschemas}{dataschema} }; # in all datasc
+hemas.

print "@attrs\n";

__DATA__
<dataschemas>
  <dataschema name="varyingName1">
   <attributes>
    <attribute category="one" fair="no" />
   </attributes>
  </dataschema>
  <dataschema name="varyingName2">
     <attributes>
        <attribute category="" parser="CSVParser" />
        <attribute category="APS" internalCategory="aps" />
        <attribute category="ASC" internalCategory="asc" />
        <attribute category="ASMT" internalCategory="asmt" />
        <attribute category="LE" internalCategory="l&amp;e" />
        <attribute category="NCO" internalCategory="nco" />
        <attribute category="NEED TITLE" internalCategory="need title"
+ />
        <attribute category="New Need ID" internalCategory="need id" /
+>
        <attribute category="SUMMARY OF DELIVERABLES" parser="TextPars
+er" extract="true" segmentation="hard" />
    </attributes>
  </dataschema>
</dataschemas>

      [download]
      A version based on the foreach / while idea: 
      foreach my $dataschema ( values %{ $data->{dataschemas}{dataschema} } 
+)
{
    foreach my $attr ( @{ $dataschema->{attributes}{attribute} } ){
        print "category is: ",
              $attr->{category},
              "\n";
    }
}

      [download]
[reply]
[d/l]
[select]


        I wrapped the XML snippet with <document> tags and the error went away. Now I can't get anything to print out from within the foreach loop ...

        I tried both versions of this -- foreach and 'map' ones -- and keep getting the following error:

        junk after document element at line 24, column 0, byte 825 at C:/Perl/site/lib/XML/Parser.pm line 168

        where line 24 occurs just above __DATA__. I couldn't figure out from Parser.pm what could be happening. Do you have any suggestions? Thanks much.
[reply]

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