ljr/ljcom/htdocs/dev/s2/2001-02-03.txt

# -*-perl-*-
#
#  Miscalleneous notes on S2, the 2nd major
#  version of the LiveJournal style system.
#
#  Brad Fitzpatrick <bradfitz@livejournal.com>
#  2001-02-03
#
###########
## goals
#
#   1. flexible/extensible:
#      - layers
#      - full programming language (*)
#        - allows for internationalization
#      - not specific to one view:
#        - describe how to format objects
#        - makes new views automatically supported,
#          at least mostly.
#   2. safe:
#      - (*) programming language has no unsafe
#            looping/branching.  only foreach
#            on finite lists, ifs, etc.
#   3. fast:
#     - precompiled
#   4. easy:
#     - wizards/tools to generate each layer
#       of S2 
#   
#
###########
##  layers
#
#
#   core (definitions, defaults)
#   style   - the "style"
#   colors  - tied to a style.
#   i18n    - not tied to a style
#   custom  - changing comment links, counters, 
#             page.insert_html shit.
#
#  layers are parsed and compiled before use.
#  compiled into native language of appserver
#  this is perl now, but easy to change later:
#     parser -> AST stays the same.
#     just change AST -> pretty printer.
#  S2 is not tied to perl, then.  can move to
#  something faster later... C, anybody?
#  S2 parser will be written in java, and
#  tools will be provided for users to run and
#  test styles on their own machines
#
###########
##  core layer
#
# only layer where classes can be declared.

set layertype  "core";
set author "webmaster";

class image {
  var string url,
  var int w,
  var int h,
  method void print (),   # allow trailing commas: so nice.
};

method image::print {
  """<img src="$url" width=$w height=$h border=0>""";
};

class comment_read {
  var string urlread,
  var int comment_count,
  method void print (),
};

method comment_read::print ()
{
   $noun = "Comments";
   if ($comment_count ==1 ) {
       $noun = "Comment";
   }
   """<a href="$urlread">Read $comment_count $noun</a>""";
};

class comment_post {
  var string urlpost,
  method void print (),    
};

method comment_post::print ()
{
    """<a href="$urlpost">Leave a comment!</a>""";
}

class comment_info {
  var bool can_comment,
  var comment_post post,
  var comment_read read,
  method void print (),
};

method comment_info::print () 
{
    if ($can_comment == false) {
	return;
    }
    if ($comment_count != 0) {
        call $read print;
	print " | ";
    } 
    call $post print;
}

# ack!  There's English in there! ^^^^^^^^^
#
# English will be default, everywhere, since it
# is anyway, right?  Later we can have our 
# master team of translators make new i18n layers
# that override these defaults.  still, users
# can then override those i18n layers later, with
# their own words.  users won't write in S2:
# we'll have stupid little wizards that ask them
# questions and generate/compile the S2 behind
# the scenes for them.  for them, the process will
# be like:
#
#   Pick Style:     [         \/ ]
#   Pick Language:  [         \/ ]
#
#                [ Continue--> ]
#
#   Pick Style color theme: [           \/]
#      or, enter your own:
#
#        [ Finish ] [ More Customization -->]   
# 
#   What do you want the comment links to say?
#   ____________________
#   How many items on a page at once? _______
#   More stupid questions:  _____________


class journal_entry {
  var string event,
  var string subject,
  var datetime eventtime,
  var string current_mood,
  var string mood_image,
  var string current_music,
  var bool opt_nocomments,
  var user userpost,
  var user userjournal,
  var image userpic,
  var comment_info comments,
  var string urlself,
  var string head,
  method void print,   
};

method journal_entry::print {
    print "<p><table><tr><td>\n";
    "<b>"; call $eventtime print_long; "</b><br>";
    print $event;
    if ($comments.can_comment) {
	"<p>";
	call $comments print;
    }
    "</td></tr></table>\n";
};

class page {
    var string view,
    var bool remote_logged_in,  # logged in user?
    var bool remote_is_owner,   # is it the journal owner?
    var journal_entry[] entries,  #    
    method void print,
};

method page::print
{
    local string title;
    if ($view == "lastn") {
	
    }
    """<html><head><title>$title</title>$head""";
    print "<body>\n";
    
       
    print "</body></html>";
}

########
###  style layer
##  

set layertype "style";
set layername "Generator";
set author "evan";

var string colitemborder = "#00f033";
var string colpageback = "#a0a0a0";


########
###  color layer
##  

set layertype "colors";
set overlays "Generator";  # only for style layers
set author "bradfitz";

var string colitemborder = "#ff0000";
var string colpageback = "#00cc00";

########
###  i18n layer
##  

set layertype "i18n";
set layerlang "de";
set author "mausal";

method comment_read::print ()
{
   $noun = "Kommentar";  # warning: probably wrong.
   if ($comment_count ==1 ) {
       $noun = "Kommentar";  # probably wrong.
   }
   """<a href="$urlread">Lesen $comment_count $noun</a>""";
};

method comment_post::print ()
{
    """<a href="$urlpost">Schrieben eine Kommentar!</a>""";
}

######
### custom layer
##
## - auto-generated from a wizard
##      ... or written by hand. (unlikely)

set layertype "custom";
set author "ibrad";

# ibrad-style popcorn links
method comment_read::print ()
{
   $noun = "Kernels";
   if ($comment_count ==1 ) {
       $noun = "Kernel";
   }
   """<a href="$urlread">$comment_count $noun.</a>""";
};

# ibrad-style popcorn links
method comment_post::print ()
{
    """<a href="$urlpost">Pop!</a>""";
}

########
### implementation 
#
#

request in: /users/bradfitz/

make_journal("bradfitz", "lastn");

my %methods;
foreach $layers ("core", @user_layers) {
   load_layer($layers, 
}

$pageob = new S2::ob::page;
$pageob->setup_all_datastructures($dbh, $user, $view);
$journal = $methods{'page'}->{'print'}->($pageob);