Puppet variables, defaults, merging and a template

During the task of writing a module, I found out that I have a huge amount of configurable parts. To better organize the module (for the sake of read- and maintainability), I have chosen to split template files up. As those template parts/fragments already sum up groups of configurable variables, I thought it might come handy to use hashes that represent the contents of the template fragments

(hash) $db -> template( config.db.erb )(hash) $*** -> template( config.***.erb )

For some reason, I got something wrong with the Puppet/Ruby foo that I have set up, as only the thrown in hash values get used and the rest stays undef.

# Calling the moduleclass { 'wppuppet':  location => '/var/www/wp',  db       => {    prefix => 'foo',    user   => 'usr',    pass   => '^[:D',  },}

The actual init class inherits from the params defaults class

# init.ppclass wppuppet(  $location  = $wppuppet::params::location,  $db        = $wppuppet::params::db) inherits wppuppet::params {  validate_hash( $db )  validate_string( $db['name'] )  # ...  validate_bool( str2bool( $db['repair'] ) )  class { 'wppuppet::config':    db        => {      prefix  => $db['prefix'],      name    => $db['name'],      user    => $db['user'],      pass    => $db['pass'],      host    => $db['host'],      repair  => $db['repair'],    }  }# The params.pp defaults classclass wppuppet::params {  $db = {    prefix  => 'wp',    name    => 'wordpress',    user    => 'root',    pass    => 'root',    host    => 'localhost',    charset => 'utf8',    repair  => true,  }}

Then there's the config.pp file containing the wppuppet::config class that generates the file from the concatenated templates.

  # The actual config.php file  file { "${location}/config.php":    ensure  => file,    content => template('wppuppet/config.db.erb','wppuppet/config.debug.erb'      # ...    ),  }

And finally there's the config.database.erb file

define( 'DB_NAME',     '<%= @db['name'] %>' );define( 'DB_USER',     '<%= @db['user'] %>' );define( 'DB_PASSWORD', '<%= @db['pass'] %>' );define( 'DB_HOST',     '<%= @db['host'] %>' );

Edit Can someone explain me where I lost track and why I can't get the default values? When I place notice('params loaded') or simply dump the $db hash, I can see it being set in each class on the CLI, but not in the config.pp file / config class.