View of /trunk/webwork2/lib/Apache/WeBWorK.pm

    1 # Apache::WeBWorK - The WeBWorK dispatcher module
    2 # Place something like the following in your Apache configuration to load the
    3 # WeBWorK module and install it as a handler for the WeBWorK system
    4 
    5 # PerlRequire /path/to/webwork/conf/init.pl
    6 # PerlSetVar webwork_root /path/to/webwork
    7 # <Location /webwork>
    8 # SetHandler perl-script
    9 # PerlHandler Apache::WeBWorK
   10 # </Location>
   11 
   12 # In addition, you will have to edit init.pl in what should be obvious ways.
   13 
   14 package Apache::WeBWorK;
   15 
   16 use strict;
   17 use Apache::Constants qw(:common REDIRECT);
   18 use Apache::Request;
   19 use WeBWorK::CourseEnvironment;
   20 use WeBWorK::Authen;
   21 use WeBWorK::Authz;
   22 use WeBWorK::ContentGenerator::Test;
   23 use WeBWorK::ContentGenerator::Login;
   24 use WeBWorK::ContentGenerator::ProblemSets;
   25 use WeBWorK::ContentGenerator::ProblemSet;
   26 #use WeBWorK::ContentGenerator::Problem;
   27 
   28 # Sets up the common environment needed for every subsystem and then dispatches
   29 # the page request to the appropriate content generator.
   30 
   31 # This function has MANY MANY points of exit (return statements)!  woo!
   32 # call it a quirk of my coding style.  I think it makes it easier to read in this case.
   33 
   34 sub handler() {
   35   my $r = Apache::Request->new(shift); # have to deal with unpredictable GET or POST data, and sift through it for the key.  So use Apache::Request
   36 
   37   # This stuff is pretty much copied out of the O'Reilly mod_perl book.
   38   # It's for figuring out the basepath.  I may change this up if I
   39   # find a better way to do it.
   40   my $path_info = $r->path_info;
   41   my $path_translated = $r->lookup_uri($path_info)->filename;
   42   my $current_uri = $r->uri;
   43   my $args = $r->args;
   44 
   45   # If it's a valid WeBWorK URI, it ends in a /.  This is assumed
   46   # alllll over the place.
   47   unless (substr($current_uri,-1) eq '/') {
   48     $r->header_out(Location => "$current_uri/" . ($args ? "?$args" : ""));
   49     return REDIRECT;
   50   }
   51 
   52   # Create the @components array, which contains the path specified in the URL
   53   my($junk, @components) = split "/", $path_info;
   54   my $webwork_root = $r->dir_config('webwork_root'); # From a PerlSetVar in httpd.conf
   55   my $course = shift @components;
   56 
   57   # Try to get the course environment.
   58   my $course_env = eval {WeBWorK::CourseEnvironment->new($webwork_root, $course);};
   59   if ($@) { # If there was an error getting the requested course
   60     # TODO: display an error page.  For now, 404 it.
   61     warn $@;
   62     return DECLINED;
   63   }
   64 
   65   # Freak out if the requested course doesn't exist.  For now, this is just a
   66   # check to see if the course directory exists.
   67   if (!-e $course_env->{webworkDirs}->{courses} . "/$course") {
   68     return DECLINED;
   69   }
   70 
   71   ### Begin dispatching ###
   72 
   73   # WeBWorK::Authen::verify erases the passwd field and sets the key field
   74   # if login is successful.
   75   if (!WeBWorK::Authen->new($r, $course_env)->verify) {
   76     return WeBWorK::ContentGenerator::Login->new($r, $course_env)->go;
   77   } else {
   78     # After we are authenticated, there are some things that need to be
   79     # sorted out, Authorization-wize, before we start dispatching to individual
   80     # content generators.
   81     my $effectiveUser = $r->param("effectiveUser");
   82     my $user = $r->param("user");
   83     my $su_authorized = WeBWorK::Authz->new($r, $course_env)->hasPermissions($user, "become_student", $effectiveUser);
   84     # This hoary statement has the effect of forcing effectiveUser to equal user unless
   85     # the user is otherwise authorized.
   86     if (!($user ne $effectiveUser && $su_authorized) || !defined $effectiveUser) {
   87       $r->param("effectiveUser",$user);
   88     }
   89 
   90     my $arg = shift @components;
   91     if (!defined $arg) { # We want the list of problem sets
   92       return WeBWorK::ContentGenerator::ProblemSets->new($r, $course_env)->go;
   93     } elsif ($arg eq "prof") {
   94       ###
   95     } elsif ($arg eq "prefs") {
   96       ###
   97     } elsif ($arg eq "test") {
   98       return WeBWorK::ContentGenerator::Test->new($r, $course_env)->go;
   99     } else { # We've got the name of a problem set.
  100       my $problem_set = $arg;
  101       my $ps_arg = shift @components;
  102 
  103       if (!defined $ps_arg) {
  104         # list the problems in the problem set
  105         return WeBWorK::ContentGenerator::ProblemSet->new($r, $course_env)->go($problem_set);
  106       } elsif ($ps_arg eq "hardcopy") {
  107         ###
  108       }
  109       else {
  110         # We've got the name of a problem
  111         my $problem = $ps_arg;
  112 #       return WeBWorK::ContentGenerator::Problem->new($r, $course_env)->go($problem_set, $problem);
  113       }
  114     }
  115 
  116   }
  117 
  118   # If the dispatcher doesn't know any modules that want to handle
  119   # the current path, it'll claim that the path does not exist by
  120   # declining the request.
  121   return DECLINED;
  122 }
  123 
  124 1;