perl舞者：将数据库信息传递给模板

Question

Following Dancer tutorial here:

http://search.cpan.org/dist/Dancer/lib/Dancer/Tutorial.pod

I'm using my own sqlite3 database with this schema

CREATE TABLE if not exists location (location_code TEXT PRIMARY KEY, name TEXT, stations INTEGER);
CREATE TABLE if not exists session (id INTEGER PRIMARY KEY, date TEXT, sessions INTEGER, location_code TEXT, FOREIGN KEY(location_code) REFERENCES location(location_code));

My dancer code ( helloWorld.pm ) for the database:

package helloWorld;
use Dancer;
use DBI;
use File::Spec;
use File::Slurp;
use Template;

our $VERSION = '0.1';

set 'template' => 'template_toolkit';
set 'logger'   => 'console';

my $base_dir = qq(/home/automation/scripts/Area51/perl/dancer);

# database crap
sub connect_db {
 my $db = qw(/home/automation/scripts/Area51/perl/dancer/sessions.sqlite);
 my $dbh = DBI->connect("dbi:SQLite:dbname=$db", "", "",
   { RaiseError => 1, AutoCommit => 1 });
 return $dbh;
}

    sub init_db {
 my $db = connect_db();
 my $file = qq($base_dir/schema.sql);
 my $schema = read_file($file);
 $db->do($schema) or die $db->errstr;
    }

get '/' => sub {
 my $branch_code = qq(BPT);
 my $dbh = connect_db();
 my $sql = q(SELECT * FROM session);
 my $sth = $dbh->prepare($sql) or die $dbh->errstr;
 $sth->execute or die $dbh->errstr;
 my $key_field = q(id);
 template 'show_entries.tt', {
  'branch' => $branch_code,
  'data' => $sth->fetchall_hashref($key_field),
 };
};

init_db();
true;

Tried the example template on the site, doesn't work.

<% FOREACH id IN data.keys.nsort %>
  <li>Date is: <% data.$id.sessions %> </li>
<% END %>

Produces page but with no data. How do I troubleshoot this as no clues come up in the console/cli?

* UPDATE * If I change the database code to this:

get '/' => sub {
    my $branch_code = qq(BPT);
    my $dbh = connect_db();
    my $sql = 'SELECT * FROM session';
    #my $sth = $dbh->prepare($sql) or die $dbh->errstr;
    #$sth->execute or die $dbh->errstr;
    #my $key_field = q(id);
    my $entries = $dbh->selectall_arrayref($sql,{});
    template 'show_entries.tt', {


'branch' => $branch_code,
        #'data' => $sth->fetchall_hashref('id'),
        'data' => @$entries,
    };
};

I get one result from the table in the template. So the info is being passed, but the syntax for the template does not work as described. This does fit with Template Toolkit syntax.

Thanks

Bubnoff

EDIT/RESOLUTION **

David reminded me of Data::Dumper which confirmed that the problem was indeed with the Template configuration. I commented out the template directive in the config file thinking that it would be redundant since it was in the code itself. WRONG!!! It must be configured in the YAML. Deleting an octothorpe in the config set everything to rights. Now I'm just embarrassed about not trying Data::Dumper in the first place. Thanks David!

Answer 1

First of all, make sure you're passing what you think you're passing to the template.

Assign the result of $sth->fetchall_hashref($key_field) to a temporary scalar, then dump it with Data::Dump or Data::Dumper (or see Dancer::Plugin::DebugDump for a way to make it dead easy).