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Revision 562 - (download) (as text) (annotate)
Fri Sep 27 23:53:42 2002 UTC (10 years, 7 months ago) by sh002i
File size: 12578 byte(s)
- created macros/IO.pl, which is loaded with no opmask by PG.pm. It is a copy
  of WeBWorK::PG::IO.pm, with some changes to make it work as a macro package.
  The translator no longer shares IO.pm's functions with the safe compartment.
  This is a BAD THING, and should be reconsidered when the Translator is
  revised.
- Changed many (but not all) checks for HTML or HTML_tth modes to match /^HTML/
  in the macros.
- changed &header to &head in Problem.pm
- Added problem environment variables for gif2eps and png2eps and modified
  &dangerousMacros::alias to use them
- fixed MOST of the harmless warnings in the system. there's still the "Use
  of uninitialized value in null operation" warning in template(), tho.

Still to come:

- make images in PDFs work
- fix TTH mode character encodings on mac (maybe)
- have logout button invalidate key
- Pretty die messages (from outside of the translator)
- Feedback - need nice modular way of sending email
- Options - email address and password

    1 ################################################################################
    2 # WeBWorK mod_perl (c) 2000-2002 WeBWorK Project
    3 # $Id$
    4 ################################################################################
    5 
    6 package WeBWorK::ContentGenerator;
    7 
    8 =head1 NAME
    9 
   10 WeBWorK::ContentGenerator - base class for modules that generate page content.
   11 
   12 =cut
   13 
   14 use strict;
   15 use warnings;
   16 use Apache::Constants qw(:common);
   17 use CGI qw();
   18 use URI::Escape;
   19 use WeBWorK::DB::Auth;
   20 use WeBWorK::Utils qw(readFile);
   21 use Carp qw(cluck);
   22 
   23 ################################################################################
   24 # This is a very unruly file, so I'm going to use very large comments to divide
   25 # it into logical sections.
   26 ################################################################################
   27 
   28 # new(Apache::Request, WeBWorK::CourseEnvironment) -  create a new instance of a
   29 # content generator. Usually only called by the dispatcher, although one might
   30 # be able to use it for things like "sub-requests". Uh... uh... I have to think
   31 # about that one. The dispatcher uses this idiom:
   32 #
   33 #
   34 #   WeBWorK::ContentGenerator::WHATEVER->new($r, $ce)->go(@whatever);
   35 #
   36 # and throws away the result ;)
   37 #
   38 sub new($$$) {
   39   my $invocant = shift;
   40   my $class = ref($invocant) || $invocant;
   41   my $self = {};
   42   ($self->{r}, $self->{courseEnvironment}) = @_;
   43   bless $self, $class;
   44   return $self;
   45 }
   46 
   47 ################################################################################
   48 # Invocation and template processing
   49 ################################################################################
   50 
   51 # go(@otherArguments) - render a page, using methods from the particular
   52 # subclass of ContentGenerator. @otherArguments is passed to each method, so
   53 # that the dispatcher can pass CG-specific data. The order of calls looks like
   54 # this:
   55 #
   56 #   * &pre_header_initialize - give subclasses a chance to do initialization
   57 #     necessary for generating the HTTP header.
   58 #   * &header - this class provides a standard HTTP header with Content-Type
   59 #     text/html. Subclasses are welcome to overload this for things like
   60 #     an image-creation content generator or a PDF generator.
   61 #   * &initialize - let subclasses do post-header initialization.
   62 #   * any "template escapes" defined in the system template and supported by
   63 #     the subclass. Generic implementations of &title and &body are provided.
   64 #
   65 sub go {
   66   my $self = shift;
   67   my $r = $self->{r};
   68   my $courseEnvironment = $self->{courseEnvironment};
   69 
   70   $self->pre_header_initialize(@_) if $self->can("pre_header_initialize");
   71   $self->header(@_);
   72   return OK if $r->header_only;
   73 
   74   $self->initialize(@_) if $self->can("initialize");
   75   $self->template($courseEnvironment->{templates}->{system}, @_);
   76 
   77   return OK;
   78 }
   79 
   80 # template(STRING, @otherArguments) - parse a template, looking for escapes of
   81 # the form <!--#NAME ARG1="FOO" ARG2="BAR"--> and calling a member function NAME
   82 # (if available) for each NAME. The escapes are called like:
   83 #
   84 #   $self->NAME(@otherArguments, \%escapeArguments)
   85 #
   86 # where @otherArguments originates in the dispatcher and %escapeArguments is
   87 # parsed out of the escape itself (i.e. ARG1 => FOO, ARG2 => BAR)
   88 #
   89 sub template {
   90   my ($self, $templateFile) = (shift, shift);
   91   my $r = $self->{r};
   92   my $courseEnvironment = $self->{courseEnvironment};
   93   my @ifstack = (1); # Start off in printing mode
   94     # say $ifstack[-1] to get the result of the last <#!--if-->
   95 
   96   # so even though the variable $/ APPEARS to contain a newline,
   97   # <TEMPLATE> is slurping the whole file into the first element of
   98   # @template ONLY AFTER THE TRANSLATOR RUNS. WTF!!!
   99   #
  100   #open(TEMPLATE, $templateFile) or die "Couldn't open template $templateFile";
  101   #my @template = <TEMPLATE>;
  102   #close TEMPLATE;
  103   #
  104   # Let's try something else instead:
  105   my @template = split /\n/, readFile($templateFile);
  106 
  107   foreach my $line (@template) {
  108     # This is incremental regex processing.
  109     # the /c is so that pos($line) doesn't die when the regex fails.
  110     while ($line =~ m/\G(.*?)<!--#(\w*)((?:\s+.*?)?)-->/gc) {
  111       my ($before, $function, $raw_args) = ($1, $2, $3);
  112       my @args = ($raw_args =~ /\S/) ? cook_args($raw_args) : ();
  113 
  114       if ($ifstack[-1]) {
  115         print $before;
  116       }
  117 
  118       if ($function eq "if") {
  119         push @ifstack, $self->$function(@_, [@args]);
  120       } elsif ($function eq "else" and @ifstack > 1) {
  121         $ifstack[-1] = not $ifstack[-1];
  122       } elsif ($function eq "endif" and @ifstack > 1) {
  123         pop @ifstack;
  124       } elsif ($ifstack[-1]) {
  125         if ($self->can($function)) {
  126           print $self->$function(@_, {@args});
  127         }
  128       }
  129     }
  130 
  131     if ($ifstack[-1]) {
  132       print substr($line, (defined pos $line) ? pos $line : 0), "\n";
  133     }
  134   }
  135 }
  136 
  137 # cook_args(STRING) - parses a string of the form ARG1="FOO" ARG2="BAR". Returns
  138 # a list which pairs into key/values and fits nicely in {}s.
  139 #
  140 sub cook_args($) {
  141   my ($raw_args) = @_;
  142   my @args = ();
  143 
  144   # Boy I love m//g in scalar context!  Go read the camel book, heathen.
  145   # First, get the whole token with the quotes on both ends...
  146   while ($raw_args =~ m/\G\s*(\w*)="((?:[^"\\]|\\.)*)"/g) {
  147     my ($key, $value) = ($1, $2);
  148     # ... then, rip out all the protecty backspaces
  149     $value =~ s/\\(.)/$1/g;
  150     push @args, $key => $value;
  151   }
  152 
  153   return @args;
  154 }
  155 
  156 # This is different.  It probably shouldn't print anything (except in debugging cases)
  157 # and it should return a boolean, not a string.  &if is called in a nonstandard way
  158 # by &template, with $args as an arrayref instead of a hashref.  this is a hack!  yay!
  159 
  160 # OK, this is a pluggin architecture.  it iterates through attributes of the "if" tag,
  161 # and for each predicate $p, it calls &if_$p in an object-oriented way, continuing the
  162 # grand templating theme of an object-oriented pluggable architecture using ->can($).
  163 sub if {
  164   my ($self, $args) = @_[0,-1];
  165   # A single if "or"s it's components.  Nesting produces "and".
  166 
  167   my @args = @$args; # Hahahahaha, get it?!
  168 
  169   if (@args % 2 != 0) {
  170     # flip out and kill people, but do not commit seppuku
  171     print '<!--&if recieved an uneven number of arguments.  This shouldn\'t happen, but I\'ll let it slide.-->\n';
  172   }
  173 
  174   while (@args > 1) {
  175     my ($key, $value) = (shift @args, shift @args);
  176 
  177     # a non-existent &if_$key is the same as a false result, but we're ORing, so it's OK
  178     my $sub = "if_$key"; # perl doesn't like it when you try to construct a string right in a method invocation
  179     if ($self->can("if_$key") and $self->$sub("$value")) {
  180       return 1;
  181     }
  182   }
  183 
  184   return 0;
  185 }
  186 
  187 ################################################################################
  188 # Macros used by content generators to render common idioms
  189 ################################################################################
  190 
  191 # pathMacro(HASHREF, LIST) - helper macro for <!--#path--> escape: the hash
  192 # reference contains the "style", "image", and "text" arguments to the escape.
  193 # The LIST consists of ordered key-value pairs of the form:
  194 #
  195 #   "Page Name" => URL
  196 #
  197 # If the page should not have a link associated with it, the URL should be left
  198 # empty. Authentication data is added to the URL so you don't have to. A fully-
  199 # formed path line is returned, suitable for returning by a function
  200 # implementing the #path escape.
  201 #
  202 sub pathMacro {
  203   my $self = shift;
  204   my %args = %{ shift() };
  205   my @path = @_;
  206   my $sep;
  207   if ($args{style} eq "image") {
  208     $sep = CGI::img({-src=>$args{image}, -alt=>$args{text}});
  209   } else {
  210     $sep = $args{text};
  211   }
  212   my $auth = $self->url_authen_args;
  213   my @result;
  214   while (@path) {
  215     my $name = shift @path;
  216     my $url = shift @path;
  217     push @result, $url
  218       ? CGI::a({-href=>"$url?$auth"}, $name)
  219       : $name;
  220   }
  221   return join($sep, @result), "\n";
  222 }
  223 
  224 sub siblingsMacro {
  225   my $self = shift;
  226   my @siblings = @_;
  227   my $sep = CGI::br();
  228   my $auth = $self->url_authen_args;
  229   my @result;
  230   while (@siblings) {
  231     my $name = shift @siblings;
  232     my $url = shift @siblings;
  233     push @result, $url
  234       ? CGI::a({-href=>"$url?$auth"}, $name)
  235       : $name;
  236   }
  237   return join($sep, @result), "\n";
  238 }
  239 
  240 sub navMacro {
  241   my $self = shift;
  242   my %args = %{ shift() };
  243   my @links = @_;
  244   my $auth = $self->url_authen_args;
  245   my @result;
  246   while (@links) {
  247     my $name = shift @links;
  248     my $url = shift @links;
  249     push @result, $url
  250       ? CGI::a({-href=>"$url?$auth"}, $name)
  251       : $name;
  252   }
  253   return join($args{separator}, @result), "\n";
  254 }
  255 
  256 # hidden_fields(LIST) - return hidden <INPUT> tags for each field mentioned in
  257 # LIST (or all fields if list is empty), taking data from the current request.
  258 #
  259 sub hidden_fields($;@) {
  260   my $self = shift;
  261   my $r = $self->{r};
  262   my @fields = @_;
  263   @fields or @fields = $r->param;
  264   my $courseEnvironment = $self->{courseEnvironment};
  265   my $html = "";
  266 
  267   foreach my $param (@fields) {
  268     my $value = $r->param($param);
  269     $html .= CGI::input({-type=>"hidden",-name=>"$param",-value=>"$value"});
  270   }
  271   return $html;
  272 }
  273 
  274 # hidden_authen_fields() - use hidden_fields to return hidden <INPUT> tags for
  275 # request fields used in authentication.
  276 #
  277 sub hidden_authen_fields($) {
  278   my $self = shift;
  279   return $self->hidden_fields("user","effectiveUser","key");
  280 }
  281 
  282 # url_args(LIST) - return a URL query string (without the leading `?')
  283 # containing values for each field mentioned in LIST, or all fields if list is
  284 # empty. Data is taken from the current request.
  285 #
  286 sub url_args($;@) {
  287   my $self = shift;
  288   my $r = $self->{r};
  289   my @fields = @_;
  290   @fields or @fields = $r->param;
  291   my $courseEnvironment = $self->{courseEnvironment};
  292 
  293   my @pairs;
  294   foreach my $param (@fields) {
  295     my $value = $r->param($param) || "";
  296     push @pairs, uri_escape($param) . "=" . uri_escape($value);
  297   }
  298 
  299   return join("&", @pairs);
  300 }
  301 
  302 # url_authen_args() - use url_args to return a URL query string for request
  303 # fields used in authentication.
  304 #
  305 sub url_authen_args($) {
  306   my $self = shift;
  307   my $r = $self->{r};
  308   return $self->url_args("user","effectiveUser","key");
  309 }
  310 
  311 # print_form_data(BEGIN, MIDDLE, END, OMIT) - return a string containing request
  312 # fields not matched by OMIT, placing BEGIN before each field name, MIDDLE
  313 # between each field and its value, and END after each value. Values are taken
  314 # from the current request. OMIT is a quoted reguar expression.
  315 #
  316 sub print_form_data {
  317   my ($self, $begin, $middle, $end, $qr_omit) = @_;
  318   my $return_string = "";
  319   my $r=$self->{r};
  320   my @form_data = $r->param;
  321   foreach my $name (@form_data) {
  322     next if ($qr_omit and $name =~ /$qr_omit/);
  323     my @values = $r->param($name);
  324     foreach my $variable (qw(begin name middle value end)) {
  325       no strict 'refs';
  326       ${$variable} = "" unless defined ${$variable};
  327     }
  328     foreach my $value (@values) {
  329       $return_string .= "$begin$name$middle$value$end";
  330     }
  331   }
  332   return $return_string;
  333 }
  334 
  335 ################################################################################
  336 # Generic versions of template escapes
  337 ################################################################################
  338 
  339 # Reminder: here are the template functions currently defined:
  340 #
  341 # head
  342 # path
  343 #   style = text|image
  344 #   image = URL of image
  345 #   text  = text separator
  346 # links
  347 # siblings
  348 # nav
  349 #   style       = text|image
  350 #   imageprefix = prefix to image URL
  351 #   imagesuffix = suffix to image URL
  352 #   separator   = HTML to place in between links
  353 # title
  354 # body
  355 
  356 sub header {
  357   my $self = shift;
  358   my $r = $self->{r};
  359   $r->content_type('text/html');
  360   $r->send_http_header();
  361 }
  362 
  363 # drunk code. rewrite.
  364 sub links {
  365   my $self = shift;
  366   my $ce = $self->{courseEnvironment};
  367   my $userName = $self->{r}->param("user");
  368   my $courseName = $ce->{courseName};
  369   my $root = $ce->{webworkURLs}->{root};
  370   my $permLevel = WeBWorK::DB::Auth->new($ce)->getPermissions($userName);
  371   return "" unless defined $permLevel;
  372 
  373   my $probSets = "$root/$courseName/?" . $self->url_authen_args();
  374   my $prefs    = "$root/$courseName/prefs/?" . $self->url_authen_args();
  375   my $prof = "$root/$courseName/prof/?" . $self->url_authen_args();
  376   my $profLine;
  377   if ($permLevel > 0) {
  378     $profLine = CGI::a({-href=>$prof}, "Professor") . CGI::br(),
  379   }
  380   my $help     = $ce->{webworkURLs}->{docs} . "?" . $self->url_authen_args();
  381   my $logout   = "$root/$courseName/?user=$userName";
  382 
  383   return
  384     CGI::a({-href=>$probSets}, "Problem Sets"), CGI::br(),
  385     CGI::a({-href=>$prefs}, "User Options"), CGI::br(),
  386     $profLine,
  387     CGI::a({-href=>$help}, "Help"), CGI::br(),
  388     CGI::a({-href=>$logout}, "Log Out"), CGI::br(),
  389   ;
  390 }
  391 
  392 # &if_can will return 1 if the current object->can("do $_[1]")
  393 sub if_can ($$) {
  394   my ($self, $arg) = (@_);
  395 
  396   if ($self->can("$arg")) {
  397     return 1;
  398   } else {
  399     return 0;
  400   }
  401 }
  402 
  403 1;
  404 
  405 __END__
  406 
  407 =head1 AUTHOR
  408 
  409 Written by Dennis Lambe Jr., malsyned (at) math.rochester.edu
  410 and Sam Hathaway, sh002i (at) math.rochester.edu.
  411 
  412 =cut

aubreyja at gmail dot com
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