UseMod Wiki: BananaSlicing

Tarquin's rough stab at turning UseMod into OO code...
#!/usr/bin/perl
###############################################################################
# UseMOO
# a sort of perl disaster by Tarquin
# based on UseModWiki by Clifford A. Adams
#
###############################################################################
#   OO code begins
###############################################################################
#
#   class Page
#
#   Base class for pages. 
#   should:
#     open an HTML scaffold file or build the UseModWiki 
#     default HTML page scaffold
#     determine what sort of page has been requested

{
  package Page;
  
  ###########################################################
  #  Static
  
  our @registered;
  sub propNested { @registered }

  ###########################################################
  #  Class conditions
  
  sub propConditions { }
  # just for inheritance
  
  ###########################################################
  #  Configuration
  
  our %configuration = (
    ConfigFile => 'config.pl',
    SiteName => 'Moo Wiki',
    HomePage => 'HomePage',
    RecentChanges => 'RecentChanges',
    );
    
  # at this point we should read in a configuration file if:
  #   a) this script's config asks for it
  #   b) it exists
  # this will change the values of the %configuration hash
  
  # we also need to read in user preferences. 
  # These will probably also go into %configuration to make retrieval simpler
 
  sub getConfiguration {
    # consider changing this to accept a list of keynames and 
    # return a list of values
    
    my $class = shift;  $class = (ref $class or $class);
    
    my $wantedkey = shift;
    
    return $configuration{$wantedkey};
  }
  
  
  ###########################################################
  #  Register
  
  sub register {

    my $class = shift;  $class = (ref $class or $class);
    
    push @registered, $class
      if $class->isa(Page)
      and not grep /^\Q$class\E$/, @registered;
      
    }
  
  ###########################################################
  #  New
  sub new {
  
    my $class = shift;  $class = (ref $class or $class);
    my %browseParameters = @_;

    my $self = {} ;
    my $text;
    
    my $childClass;
    
    # consider calling this $object instead; "self" is misleading
    
    # this is part of an earlier approach that involved 
    # storing HTML output in the created instance.
    $self->{outputText}   = {};
    
    # not sure what this is here for
    return if $class ne Page;
    
    # test child classes to see if they want to handle this page
    foreach my $childclass (@registered) {
      if( eval $childclass->propConditions ) { 
        return $childclass->new(%browseParameters);
      }
    }
    
    # return this class; if we get here then we've not properly handled the cases
    return bless $self, $class;
    
    # notes
    # the new sub should return an instance that actually holds some data
    # for example the page name
    
    # this might also allow recursive calling for preview, diffs, histories etc.
    # for these, I imagine faking a browseParameters entry called something like 'embed'
    # that would prevent the HTML wrapping etc
    
    # consider also using a sub name other than "new" for child classes
    # -- this would allow a default version of it here for inheritance.
    # what to call it though?
    

    }
    
  ###########################################################
  #  Browsing
  sub browsePage {
    my $self = shift;
    #$self->{outputText} .= "fish";
    # dont yet see any point in using a class variable to build output
    
    my $text;
    
    $text .= "Content-Type: text/html\n\n" ;
    $text .= $self->makePageHeader() ;
    $text .= $self->makePageContent();
    $text .= $self->makePageFooter();
    
    return $text;
  }

  sub makePageHeader {
    my $class = shift;  $class = (ref $class or $class);
    
    my $text ;
    $text .= "<!DOCTYPE HTML>\n" ;
    $text .= '<html><head><title>', $class->getConfiguration('SiteName'), "</title>\n" ;
      # Help! why didn't that work? How are the commas confusing the result of the sub call?
    $text .=  $class->getConfiguration('SiteName');
    $text .=  "</title>\n";
    $text .= "<body>\n" ;
    
    return $text;   
  }
  sub makePageContent {
    my $class = shift;  $class = (ref $class or $class);
    
    return "Default Page object\n";
  }
  sub makePageFooter {
    my $class = shift;  $class = (ref $class or $class);

    my $text ;
    $text .= "</body></html>\n" ;
    return $text;   
  }
  
}

###############################################################################
#
#   class WikiPage
#
#   Base class for wiki pages. 
#   should:
#     load and parse wiki text
#     determine if extra elements are needed: preview, diff, etc


{
  package WikiPage;
  
  our @ISA = Page;
  WikiPage->register();
  
  ###########################################################
  #  Class conditions
  #
  # wiki pages have wiki.cgi?pagename
  # this works out as {keywords}=pagename
  # if it's just wiki.cgi we want the home page.
  sub propConditions { q[$browseParameters{keywords} or %browseParameters == undef]  }

  our $pageName;
  
  sub new {
  
    my $class = shift;  $class = (ref $class or $class);
    my %browseParameters = @_;
    
    my $self = {};
    
    $pageName = $browseParameters{keywords}; 
    
    # putting data into the returned instance would make a lot more sense
    # we'd lose this hacky class variable $pageName
    
    return bless $self, $class;
    }
    
  sub makePageContent {
    
    my $class = shift;  $class = (ref $class or $class);
    
    my $text;
    if ($pageName eq '') {
      $pageName = $class->getConfiguration('HomePage');
    }
    
    
    $text .= "WikiPage class<BR>\n";
    $text .= "The name of this page is: '$pageName'<BR>";
    return $text;
    
  }
  
}

###############################################################################
#
#   class WikiVersion
#


{
  package WikiVersion;
  

  our @ISA = Page;
  WikiVersion->register();
  
  ###########################################################
  #  Class conditions
  sub propConditions { q[$browseParameters{action} eq 'version'] }
  
  
  ###########################################################
  #  New
  sub new {
  
    my $class = shift;  $class = (ref $class or $class);
    my $self = {};
    
    return bless $self, $class;
    }
    
  ###########################################################
  #  Content
  sub makePageContent {
    
    my $class = shift;  $class = (ref $class or $class);
    
    return "UseMOO version number\n";
    
  }
  
}

###############################################################################
{
  package UseMooWiki ;
  use strict;
  use CGI;
  use CGI::Carp qw(fatalsToBrowser);

  use vars qw( $q $MaxPost $ThisPage );

  $q = new CGI;
  
  our $log = '';

  {
    my %PageVariables = $q->Vars;

    # later handle Content-Length etc    
    print Page->new( %PageVariables )->browsePage();
    

  }
}