Problem with passing hashes between modules

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

Hi all,
I need to pass an array of values, to be accessed by another module.
I use the following code,
This does not give me desired result(all values from 1st module).
I need to incorporate 2 such modules(like 1st) into 3rd.

module1
.....
..... <some code>
sub passMe{
my @data=();
push(@data,
            {
        %params,
        %extend_params,
        %basics,
        %annotations,
        %navigator,
        position    => 'annotations',    
        sid         => $sid,
        navigator_link      => '<a id="expand_nav" onclick="Element.hi
+de(\'expand_nav\');">[brief]</a>',
        annotations_detail_link => q|[<a id="sed" onclick="Element.hid
+e('sed'); Element.show('hed'); show_experiment_details();"> experimen
+t details</a>]|,
        template => $tmpl
    });
    
    return \@data, $ID;
}

module2

sub report {
my ($aa, $bb)= &passMe;
while ( my ($key, $val) = each( %{$aa}) ) {
      while ( my ($key1, $value) = each(%{$key}) ) {
        print "$key1 =>   $value\n";
        }
    }
}
[download]

Please help me to solve this.

Thanking all in advance.
Sailas

Comment on Problem with passing hashes between modules Download Code

Replies are listed 'Best First'.
Re: Problem with passing hashes between modules by hipowls (Curate) on Mar 05, 2008 at 10:50 UTC
You are returning a reference to an array whose content is a single hash reference. You then attempt to dereference the array as a hash. You probably mean something like this `sub passMe { my %data = ( # note not '{' ... ); return \%data, $ID; }` [download] If you aren't getting what you expect then using Data::Dumper or YAML to print out the data structure will often help you find where the problem lies.	[reply] [d/l]
Re: Problem with passing hashes between modules by Fletch (Bishop) on Mar 05, 2008 at 14:31 UTC
Also note that you're going to get the contents of the subsidiary hashes flattened out into a list of key value pairs when you do `{ %params, %extended_params, ... }` like that with whatever appears for any given key last winning (e.g. if `%params` and `%navigator` both had a key "foo" then the new hashref's value for "foo" would be what was in `$navigator{"foo"}`). (Which may be just what you want, but just calling attention to it.) The cake is a lie. The cake is a lie. The cake is a lie.	[reply] [d/l] [select]
Re: Problem with passing hashes between modules by hangmanto (Monk) on Mar 05, 2008 at 15:56 UTC
I modified you subroutine 'PassMe' so that only references to a hash are pushed into the array @data. (I named it 'other_hash', but you should definitely rename it!). This should ease the maintenance. `sub passMe { my @data = (); my %other_hash = ( position => 'annotations', sid => $sid, navigator_link => '<a id="expand_nav" onclick="Element.hide(\'expand_nav\');"> +[brief]</a>', annotations_detail_link => q\|[<a id="sed" onclick="Element.hide('sed'); Element.show('h +ed'); show_experiment_details();"> experiment details</a>]\|, template => $tmpl ); push( @data, { \%params, \%extend_params, \%basics, \%annotations, \%navigator, \%other_hash } ); return \@data, $ID; }` [download]	[reply] [d/l]
Re^2: Problem with passing hashes between modules by Fletch (Bishop) on Mar 05, 2008 at 16:21 UTC
Erm, so you've now given him a hashref which contains a reference to `%extend_params` keyed by the stringified reference to `%params`, a reference to `%annotations` keyed by the stringified ref to `%basics`, and likewise for the last two elements. Can you share what color the sky is on your planet where that's a useful data structure? The cake is a lie. The cake is a lie. The cake is a lie.	[reply] [d/l] [select]