View of /trunk/pg/lib/PGanswergroup.pm

    1 ################################################################################
    2 # WeBWorK Online Homework Delivery System
    3 # Copyright © 2000-2007 The WeBWorK Project, http://openwebwork.sf.net/
    4 # $CVSHeader: pg/lib/PGanswergroup.pm,v 1.1 2010/05/14 11:39:02 gage Exp $
    5 #
    6 # This program is free software; you can redistribute it and/or modify it under
    7 # the terms of either: (a) the GNU General Public License as published by the
    8 # Free Software Foundation; either version 2, or (at your option) any later
    9 # version, or (b) the "Artistic License" which comes with this package.
   10 #
   11 # This program is distributed in the hope that it will be useful, but WITHOUT
   12 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
   13 # FOR A PARTICULAR PURPOSE.  See either the GNU General Public License or the
   14 # Artistic License for more details.
   15 ################################################################################
   16 package PGanswergroup;
   17 use Exporter;
   18 use PGcore qw(not_null);
   19 use PGresponsegroup;
   20 
   21 our @ISA=qw(PGcore);
   22 
   23 #############################################
   24 # An object which contains an answer label and
   25 # an answer evaluator
   26 # and the links to and contents of all associated answer blanks
   27 # (i.e the student responses)
   28 #############################################
   29 # Notes
   30 # Answergroup -- input to a single answerEvaluator, may have several answer blanks
   31 #    for example an array or a radio button group or several checkboxes
   32 # 1. create a answerEvaluator label name
   33 # 2. provide space for an answerEvaluator
   34 # 3. indicate that an answer blank or blanks has been published to receive the responses
   35 # for example store the number of response strings associated with this answerEvaluator label name
   36 # 4. space for the contents of the responses is provided in the PGresponse group
   37 # 5. provide a method for applying the evaluator to the responses
   38 #
   39 # use Tie: IxHash??? to create ordered hash? (see Perl Cookbook)
   40 
   41 sub new {
   42   my $class = shift;
   43   my $label = shift;
   44   my $self = {
   45       ans_label => $label,
   46     ans_eval  => undef,                         # usually an AnswerEvaluator, sometimes a CODE
   47     response  => new PGresponsegroup($label),    # A PGresponse object which holds the responses
   48                                                 # which make up the answer
   49     active    => 1,                             # whether this answer group is currently active (for multistate problems)
   50 
   51     @_,
   52   };
   53   bless $self, $class;
   54   return $self;
   55 
   56 }
   57 
   58 sub evaluate {     # applies the answer evaluator to the student response and returns an answer hash
   59 
   60 
   61 
   62 }
   63 
   64 sub complete {    # test to see if answer evaluator and appropriate response blanks are all present
   65 
   66 
   67 
   68 }
   69 sub ans_eval {
   70   my $self = shift;
   71   my $ans_eval = shift;
   72   $self->{ans_eval}= $ans_eval if ref($ans_eval);
   73   $self->{ans_eval};
   74 }
   75 sub append_responses { #add or modify a response to the PGresponsegroup object
   76   my $self = shift;
   77   my @response_list = @_;  # ordered list of label/ value pairs
   78     $self->{response}->append_responses(@response_list);
   79 }
   80 
   81 sub insert_responses    {        # add a group of responses ( label/value pairs)
   82   my $self = shift;
   83   my @response_list = @_;
   84   $self->{response}->clear();
   85   $self->{response}->append_responses(@response_list);
   86 }
   87 
   88 sub insert_response_value { # add a response value(with  label defined by answer group label)
   89   my $self = shift;
   90   my $value = shift;
   91   $self->{response}->append_reponse($self->{ans_label}, $value);
   92 }
   93 sub replace_response { # add a response value(with  label defined by answer group label)
   94   my $self = shift;
   95   my $response_label = shift;
   96   my $value = shift;
   97   $self->{response}->replace_response($response_label, $value);
   98 }
   99 sub insert {         # add new values to PGanswergroup keys preserve existing values
  100   my $self = shift;
  101   my @in = @_;
  102   my %hash = ();
  103   if ( ref($in[0]=~/HASH/) ) {
  104     %hash = %{$in[0]};
  105   } else {
  106     %hash = @in;
  107   }
  108   foreach my $key (keys %hash) {
  109       next if not_null( $self->{$key} );
  110     $self->{$key} = $hash{$key};
  111   }
  112   $self;
  113 }
  114 
  115 
  116 sub replace {     # add new values ot PGanswergroup, overwriting existing values when duplicated
  117   my $self = shift;
  118   my @in = @_;
  119   my %hash = ();
  120   if ( ref($in[0]=~/HASH/) ) {
  121     %hash = %{$in[0]};
  122   } else {
  123     %hash = @in;
  124   }
  125   foreach my $key (keys %hash) {
  126     $self->{$key} = $hash{$key};
  127   }
  128   $self;
  129 }
  130 
  131 
  132 
  133 
  134 sub delete_from_hash {   # don't want to redefine delete
  135   my $self = shift;
  136   my @in = @_;
  137   my %hash = ();
  138   if ( ref($in[0]=~/HASH/) ) {
  139     %hash = %{$in[0]};
  140   } else {
  141     %hash = @in;
  142   }
  143   foreach my $key (keys %hash) {
  144     $self->{$key} = undef;
  145   }
  146   $self;
  147 }
  148 
  149 
  150 1;