[Templates-cvs] cvs commit: TT3/examples scanner.pl

[cvs@template-toolkit.org]

cvs         04/02/02 10:03:52

  Added:       examples scanner.pl
  Log:
  * added example showing use of the scanner and different tags
  
  Revision  Changes    Path
  1.1                  TT3/examples/scanner.pl
  
  Index: scanner.pl
  ===================================================================
  #!/usr/bin/perl -w                                            # -*- perl -*-
  #
  # Perl script written by Andy Wardley.  This is free software.
  #
  
  use strict;
  use warnings;
  use lib qw( ../lib ./lib );
  use Template::TT3::Handler;
  use Template::TT3::Scanner;
  use Template::TT3::Generator::Debug;
  use Template::TT3::Tag;
  
  # define scanner
  my $scanner = Template::TT3::Scanner->new({
      tags => [
          Template::TT3::Tag->new({   # TODO: should be able to pass hash refs
              start => '<$',          #       and have the scanner auto-vivify
              end   => '$>',          #       Tag objects for you
              parse => \&dollar_tag,
          }),
          Template::TT3::Tag->new({
              start => '<?',
              end   => '?>',
              parse => \&question_tag,
          }),
      ]
  });
  
  # subroutine for parsing <$ ... $> tags
  sub dollar_tag {
      my ($self, $textref, $handler, $match) = @_;
  
      # YOUR CODE HERE - we're just going to do some simple stuff
      # for debugging purposes, like fetching the current location
      # and collapsing whitespace
      $$textref =~ s/\s+/ /g;
      my $locn = $self->location();
  
      # notify the handler of some new content
      return $handler->directive( dollar => "at $locn: [$$textref]" )
          || $self->error($handler->error());
  }
  
  # subroutine for parsing <? ... ?> tags
  sub question_tag {
      my ($self, $textref, $handler, $match) = @_;
  
      # YOUR CODE HERE - we're just testing - see above
      $$textref =~ s/\s+/ /g;
      my $locn = $self->location();
  
      # first argument denotes the content type, any other args can follow
      return $handler->directive( question => "at $locn: [$$textref]" )
          || $self->error($handler->error());
  }
  
  # read input from __DATA__
  local $/ = undef;
  my $input = <DATA>;
  
  # define a handler to construct document content
  my $handler = Template::TT3::Handler->new();
  
  # scan document
  $handler->start();
  $scanner->scan($input, $handler) || die $scanner->error();
  my $result = $handler->end() || die $handler->error();
  
  # create a generator to display document
  my $generator = Template::TT3::Generator::Debug->new({});
  #    generators );
  
  my $output = $generator->generate($result)
      || die $generator->error();
  
  print "-- input --\n",
        $input, "\n",
        "-- output --\n",
        $output, "\n";
  
  __DATA__
  This is some text 
  before <? to be or not to be ?> after
  start <$ money, money, money $> end
  tags can <?
      span 
      multiple
      lines
      and ?> the scanner takes
  care of counting 
  <$
  
      line
      numbers
  
  $> for you