Template Toolkit - passing hashes

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

Monday Monks,

Why isn't my hash passed to TT for processing? When I run this, I get one iteration of the template html and with no values inserted.

In the script (snippet):

use DBI;
use Template;

#get users list from database
$sql = "SELECT user_id, ufname, ulname FROM users";
$sth = $dbh->prepare($sql) or die("Could not prepare!" . $dbh->errstr)
+;
$sth->execute() or die("Could not execute!" . $dbh->errstr);

# build data structure
while (($user_id, $ufname, $ulname) = $sth->fetchrow_array()) {
     $data{$user_id} = {
          ufname => $ufname,
          ulname => $ulname
     }
}
$sth->finish;

#prep variables for TT
$vars = {
     data => %data,
     today => $today
};
$template_file = "./template/my_file.htm";

#process file
$template->process($template_file, $vars);
[download]

and in the template

Call list for [% today %]
<p>
[% FOREACH user IN data %]
     Be sure to call [% user.ulname %], [% user.ufname %]
[% END %]
[download]

I suspect there's something wrong with the way I'm passing the data hash?

Thanks.

updated for typo in code unrelated to question

Forget that fear of gravity,
Get a little savagery in your life.

Comment on Template Toolkit - passing hashes Select or Download Code

Replies are listed 'Best First'.
Re: Template Toolkit - passing hashes by imp (Priest) on Apr 02, 2007 at 13:17 UTC
Replace this: `$vars = { data => %data, today => $today };` [download] With: `$vars = { data => \%data, today => $today };` [download] Otherwise perl will expand the %data hash into a list. Another problem is that you are building a hash of hashes, but your template seems to expect a list of hashes. You should always use both strict and warnings by the way.	[reply] [d/l] [select]
Re^2: Template Toolkit - passing hashes by punch_card_don (Curate) on Apr 02, 2007 at 13:35 UTC
Thanks. Another problem is that you are building a hash of hashes, but your template seems to expect a list of hashes. But I thought: http://www.template-toolkit.org/docs/plain/Manual/Variables.html#Hash_Array_References `Members of hash arrays are accessed by specifying the hash reference a +nd key separated by the dot '.' operator. my $vars = { 'home' => 'http://www.myserver.com/homepage.html', 'page' => { 'this' => 'mypage.html', 'next' => 'nextpage.html', 'prev' => 'prevpage.html', }, }; template: <a href="[% home %]">Home</a> <a href="[% page.prev %]">Previous Page</a> <a href="[% page.next %]">Next Page</a>` [download] Forget that fear of gravity, Get a little savagery in your life.	[reply] [d/l]
Re^3: Template Toolkit - passing hashes by polettix (Vicar) on Apr 02, 2007 at 14:06 UTC
You're not reproducing the same setup. Instead of: `Call list for [% today %] <p> [% FOREACH user IN data %] Be sure to call [% user.ulname %], [% user.ufname %] [% END %]` [download] you should use the `values` virtual method: `Call list for [% today %] <p> [% FOREACH user IN data.values %] Be sure to call [% user.ulname %], [% user.ufname %] [% END %]` [download] which gives you back the list that `FOREACH` iterates on. As an alternative, you should modify your Perl code: `# build data structure my @data; while (($user_id, $ufname, $ulname) = $sth->fetchrow_array()) { push @data, { ufname => $ufname, ulname => $ulname } }` [download] and then pass `\@data` instead of `\%data`. Which way to go is up to you, but keep in mind that using the hash will destroy record order (which does not seem an issue in your case, you don't specify any `ORDER BY` clause in your SQL query) and using an array won't let you address every record by user_id. Just to name a few differences. Flavio perl -ple'$_=reverse' <<<ti.xittelop@oivalf Don't fool yourself.	[reply] [d/l] [select]
Re: Template Toolkit - passing hashes by Herkum (Parson) on Apr 02, 2007 at 13:33 UTC
If you are working with hashes in a template you need to use the keys and values methods to get the appropriate information. References to working with hashes in loops can be found here.	[reply]
Re^2: Template Toolkit - passing hashes by punch_card_don (Curate) on Apr 02, 2007 at 13:42 UTC
Yes, that did it. Thanks Forget that fear of gravity, Get a little savagery in your life.	[reply]
Re: Template Toolkit - passing hashes by punch_card_don (Curate) on Apr 02, 2007 at 13:44 UTC
Just to recap - it took both fixes: add the backslash to data => \%data use the keys method in the template Forget that fear of gravity, Get a little savagery in your life.	[reply]
Re^2: Template Toolkit - passing hashes by f00li5h (Chaplain) on Apr 03, 2007 at 01:51 UTC
(just to recap) If you already know the key, you can use it directly too with `[% thing.hashkey %]` like this: Read more... (1368 Bytes) `@_=qw; ask f00li5h to appear and remain for a moment of pretend better than a lifetime;;s;;@_[map hex,split'',B204316D8C2A4516DE];;y/05/os/&print;`	[reply] [d/l] [select]