--- loncom/interface/statistics/lonstathelpers.pm	2004/03/08 19:12:18	1.6
+++ loncom/interface/statistics/lonstathelpers.pm	2005/03/10 16:58:52	1.43
@@ -1,6 +1,6 @@
 # The LearningOnline Network with CAPA
 #
-# $Id: lonstathelpers.pm,v 1.6 2004/03/08 19:12:18 matthew Exp $
+# $Id: lonstathelpers.pm,v 1.43 2005/03/10 16:58:52 matthew Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -40,7 +40,6 @@ routines that are needed across multiple
 
 =head1 OVERVIEW
 
-
 =over 4
 
 =cut
@@ -59,6 +58,8 @@ use Apache::lonlocal;
 use HTML::Entities();
 use Time::Local();
 use Spreadsheet::WriteExcel();
+use GDBM_File;
+use Storable qw(freeze thaw);
 
 ####################################################
 ####################################################
@@ -67,8 +68,7 @@ use Spreadsheet::WriteExcel();
 
 =item &render_resource($resource)
 
-Input: a resource generated from 
-&Apache::loncoursedata::get_sequence_assessment_data().
+Input: a navmaps resource
 
 Retunrs: a scalar containing html for a rendering of the problem
 within a table.
@@ -81,11 +81,10 @@ sub render_resource {
     my ($resource) = @_;
     ##
     ## Render the problem
-    my $base;
-    ($base,undef) = ($resource->{'src'} =~ m|(.*/)[^/]*$|);
-    $base = "http://".$ENV{'SERVER_NAME'}.$base;
-    my $rendered_problem = 
-        &Apache::lonnet::ssi_body($resource->{'src'});
+    my ($base) = ($resource->src =~ m|^(.*/)[^/]*$|);
+    $base="http://".$ENV{'SERVER_NAME'}.$base;
+    my ($src,$symb)=($resource->src,&Apache::lonnet::escape($resource->symb));
+    my $rendered_problem = &Apache::lonnet::ssi_body($src.'?symb='.$symb);
     $rendered_problem =~ s/<\s*form\s*/<nop /g;
     $rendered_problem =~ s|(<\s*/form\s*>)|<\/nop>|g;
     return '<table bgcolor="ffffff"><tr><td>'.
@@ -99,7 +98,26 @@ sub render_resource {
 
 =pod
 
-=item &ProblemSelector($AcceptedResponseTypes)
+=item &get_resources
+
+=cut
+
+####################################################
+####################################################
+sub get_resources {
+    my ($navmap,$sequence) = @_;
+    my @resources = $navmap->retrieveResources($sequence,
+                                               sub { shift->is_problem(); },
+                                               0,0,0);
+    return @resources;
+}
+
+####################################################
+####################################################
+
+=pod
+
+=item &problem_selector($AcceptedResponseTypes)
 
 Input: scalar containing regular expression which matches response
 types to show.  '.' will yield all, '(option|radiobutton)' will match
@@ -107,27 +125,31 @@ all option response and radiobutton prob
 
 Returns: A string containing html for a table which lists the sequences
 and their contents.  A radiobutton is provided for each problem.
+Skips 'survey' problems.
 
 =cut
 
 ####################################################
 ####################################################
-sub ProblemSelector {
+sub problem_selector {
     my ($AcceptedResponseTypes) = @_;
     my $Str;
     $Str = "\n<table>\n";
-    foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
-        next if ($seq->{'num_assess'}<1);
+    my $rb_count =0;
+    my ($navmap,@sequences) = 
+        &Apache::lonstatistics::selected_sequences_with_assessments('all');
+    return $navmap if (! ref($navmap)); # error
+    foreach my $seq (@sequences) {
         my $seq_str = '';
-        foreach my $res (@{$seq->{'contents'}}) {
-            next if ($res->{'type'} ne 'assessment');
-            foreach my $part (@{$res->{'parts'}}) {
-                my $partdata = $res->{'partdata'}->{$part};
-                for (my $i=0;$i<scalar(@{$partdata->{'ResponseTypes'}});$i++){
-                    my $respid = $partdata->{'ResponseIds'}->[$i];
-                    my $resptype = $partdata->{'ResponseTypes'}->[$i];
+        foreach my $res (&get_resources($navmap,$seq)) {
+            foreach my $part (@{$res->parts}) {
+                my @response_ids   = $res->responseIds($part);
+                my @response_types = $res->responseType($part);
+                for (my $i=0;$i<scalar(@response_types);$i++){
+                    my $respid = $response_ids[$i];
+                    my $resptype = $response_types[$i];
                     if ($resptype =~ m/$AcceptedResponseTypes/) {
-                        my $value = &make_target_id({symb=>$res->{'symb'},
+                        my $value = &make_target_id({symb=>$res->symb,
                                                      part=>$part,
                                                      respid=>$respid,
                                                      resptype=>$resptype});
@@ -135,26 +157,29 @@ sub ProblemSelector {
                         if ($ENV{'form.problemchoice'} eq $value) {
                             $checked = 'checked ';
                         }
-                        my $title = $res->{'title'};
+                        my $title = $res->compTitle;
                         if (! defined($title) || $title eq '') {
-                            ($title) = ($res->{'src'} =~ m:/([^/]*)$:);
+                            ($title) = ($res->src =~ m:/([^/]*)$:);
                         }
-                        $seq_str .= '<tr><td>'.
-  '<input type="radio" name="problemchoice" value="'.$value.'" '.$checked.'/>'.
-  '</td><td>'.          
-  $resptype.'</td><td>'.
-  '<a href="'.$res->{'src'}.'">'.$title.'</a> ';
-#  '<a href="'.$res->{'src'}.'">'.$resptype.' '.$res->{'title'}.'</a> ';
-                        if (scalar(@{$partdata->{'ResponseIds'}}) > 1) {
+                        $seq_str .= '<tr>'.
+                            qq{<td><input type="radio" id="$rb_count" name="problemchoice" value="$value" $checked /></td>}.
+                            '<td><label for="'.$rb_count.'">'.$resptype.'</label></td>'.
+                            '<td><label for="'.$rb_count.'">'.$title.'</label>';
+                        if (scalar(@response_ids) > 1) {
                             $seq_str .= &mt('response').' '.$respid;
                         }
+                        my $link = $res->src.'?symb='.
+                            &Apache::lonnet::escape($res->symb);
+                        $seq_str .= ('&nbsp;'x2).
+                            qq{<a target="preview" href="$link">view</a>};
                         $seq_str .= "</td></tr>\n";
+                        $rb_count++;
                     }
                 }
             }
         }
         if ($seq_str ne '') {
-            $Str .= '<tr><td>&nbsp</td><td colspan="2"><b>'.$seq->{'title'}.'</b></td>'.
+            $Str .= '<tr><td>&nbsp</td><td colspan="2"><b>'.$seq->compTitle.'</b></td>'.
                 "</tr>\n".$seq_str;
         }
     }
@@ -167,6 +192,168 @@ sub ProblemSelector {
 
 =pod
 
+=item &MultipleProblemSelector($navmap,$selected,$inputname)
+
+Generate HTML with checkboxes for problem selection.
+
+Input: 
+
+$navmap: a navmap object.  If undef, navmaps will be called to create a
+new object.
+
+$selected: Scalar, Array, or hash reference of currently selected items.
+
+$inputname: The name of the form elements to use for the checkboxs.
+
+Returns: A string containing html for a table which lists the sequences
+and their contents.  A checkbox is provided for each problem.
+
+=cut
+
+####################################################
+####################################################
+sub MultipleProblemSelector {
+    my ($navmap,$inputname,$formname)=@_;
+    my $cid = $ENV{'request.course.id'};
+    my $Str;
+    # Massage the input as needed.
+    if (! defined($navmap)) {
+        $navmap = Apache::lonnavmaps::navmap->new();
+        if (! defined($navmap)) {
+            $Str .= 
+                '<h1>'.&mt('Error: cannot process course structure').'</h1>';
+            return $Str;
+        }
+    }
+    my $selected = {map { ($_,1) } (&get_selected_symbs($inputname))};
+    # Header
+    $Str .= <<"END";
+<script language="JavaScript" type="text/javascript">
+    function checkall(value,seqid) {
+        for (i=0; i<document.forms.$formname.elements.length; i++) {
+            ele = document.forms.$formname.elements[i];
+            if (ele.name == '$inputname') {
+                if (seqid != null) {
+                    itemid = document.forms.$formname.elements[i].id;
+                    thing = itemid.split(':');
+                    if (thing[0] == seqid) {
+                        document.forms.$formname.elements[i].checked=value;
+                    }
+                } else {
+                    document.forms.$formname.elements[i].checked=value;
+                }
+            }
+        }
+    }
+</script>
+END
+    $Str .= 
+        '<a href="javascript:checkall(true)">'.&mt('Select All').'</a>'.
+        ('&nbsp;'x4).
+        '<a href="javascript:checkall(false)">'.&mt('Unselect All').'</a>';
+    $Str .= $/.'<table>'.$/;
+    my $iterator = $navmap->getIterator(undef, undef, undef, 1);
+    my $sequence_string;
+    my $seq_id = 0;
+    my @Accumulator = (&new_accumulator($ENV{'course.'.$cid.'.description'},
+                                        '',
+                                        '',
+                                        $seq_id++,
+                                        $inputname));
+    my @Sequence_Data;
+    while (my $curRes = $iterator->next()) {
+        if ($curRes == $iterator->END_MAP) {
+            if (ref($Accumulator[-1]) eq 'CODE') {
+                my $old_accumulator = pop(@Accumulator);
+                push(@Sequence_Data,&{$old_accumulator}());
+            }
+        } elsif ($curRes == $iterator->BEGIN_MAP) {
+            # Not much to do here.
+        }
+        next if (! ref($curRes));
+        if ($curRes->is_map) {
+            push(@Accumulator,&new_accumulator($curRes->compTitle,
+                                               $curRes->src,
+                                               $curRes->symb,
+                                               $seq_id++,
+                                               $inputname));
+        } elsif ($curRes->is_problem) {
+            if (@Accumulator && $Accumulator[-1] ne '') {
+                &{$Accumulator[-1]}($curRes,
+                                    exists($selected->{$curRes->symb}));
+            }
+        }
+    }
+    my $course_seq = pop(@Sequence_Data);
+    foreach my $seq ($course_seq,@Sequence_Data) {
+        #my $seq = pop(@Sequence_Data);
+        next if (! defined($seq) || ref($seq) ne 'HASH');
+        $Str.= '<tr><td colspan="2">'.
+            '<b>'.$seq->{'title'}.'</b>'.('&nbsp;'x2).
+            '<a href="javascript:checkall(true,'.$seq->{'id'}.')">'.
+                                  &mt('Select').'</a>'.('&nbsp;'x2).
+            '<a href="javascript:checkall(false,'.$seq->{'id'}.')">'.
+                                  &mt('Unselect').'</a>'.('&nbsp;'x2).
+            '</td></tr>'.$/;
+        $Str.= $seq->{'html'};
+    }
+    $Str .= '</table>'.$/;
+    return $Str;
+}
+
+sub new_accumulator {
+    my ($title,$src,$symb,$seq_id,$inputname) = @_;
+    my $target;
+    my $item_id=0;
+    return 
+        sub {
+            if (@_) { 
+                my ($res,$checked) = @_;
+                $target.='<tr><td><label>'.
+                    '<input type="checkbox" name="'.$inputname.'" ';
+                if ($checked) {
+                    $target .= 'checked ';
+                }
+                $target .= 'id="'.$seq_id.':'.$item_id++.'" ';
+                $target.= 
+                    'value="'.&Apache::lonnet::escape($res->symb).'" />'.
+                    '&nbsp;'.$res->compTitle.'</label>'.
+                    ('&nbsp;'x2).'<a target="preview" '.
+                    'href="'.$res->src.'?symb='.
+                         &Apache::lonnet::escape($res->symb).'">view</a>'.
+                    '</td></tr>'.$/;
+            } else { 
+                if (defined($target)) {
+                    return { title => $title,
+                             symb  => $symb,
+                             src   => $src,
+                             id    => $seq_id,
+                             html  => $target, }; 
+                }
+                return undef;
+            }
+        };
+}
+
+sub get_selected_symbs {
+    my ($inputfield) = @_;
+    my $field = 'form.'.$inputfield;
+    my @Symbs;
+    if (exists($ENV{$field})) {
+        if (! ref($ENV{$field})) {
+            @Symbs = (&Apache::lonnet::unescape($ENV{$field}));
+        } else {
+            @Symbs = (map {&Apache::lonnet::unescape($_);} @{$ENV{$field}});
+        }
+    }
+    return @Symbs;
+}
+
+####################################################
+####################################################
+
+=pod
+
 =item &make_target_id($target)
 
 Inputs: Hash ref with the following entries:
@@ -210,11 +397,23 @@ Returns: A hash reference, $target, cont
 ####################################################
 sub get_target_from_id {
     my ($id) = @_;
-    my ($symb,$part,$respid,$resptype) = split(':',$id);
-    return ({ symb    =>&Apache::lonnet::unescape($symb),
-             part     =>&Apache::lonnet::unescape($part),
-             respid   =>&Apache::lonnet::unescape($respid),
-             resptype =>&Apache::lonnet::unescape($resptype)});
+    if (! ref($id)) {
+        my ($symb,$part,$respid,$resptype) = split(':',$id);
+        return ({ symb     => &Apache::lonnet::unescape($symb),
+                  part     => &Apache::lonnet::unescape($part),
+                  respid   => &Apache::lonnet::unescape($respid),
+                  resptype => &Apache::lonnet::unescape($resptype)});
+    } elsif (ref($id) eq 'ARRAY') {
+        my @Return;
+        foreach my $selected (@$id) {
+            my ($symb,$part,$respid,$resptype) = split(':',$selected);
+            push(@Return,{ symb     => &Apache::lonnet::unescape($symb),
+                           part     => &Apache::lonnet::unescape($part),
+                           respid   => &Apache::lonnet::unescape($respid),
+                           resptype => &Apache::lonnet::unescape($resptype)});
+        }
+        return \@Return;
+    }
 }
 
 ####################################################
@@ -222,7 +421,7 @@ sub get_target_from_id {
 
 =pod
 
-=item &get_prev_curr_next($target)
+=item &get_prev_curr_next($target,$AcceptableResponseTypes,$granularity)
 
 Determine the problem parts or responses preceeding and following the
 current resource.
@@ -230,7 +429,7 @@ current resource.
 Inputs: $target (see &Apache::lonstathelpers::get_target_from_id())
   $AcceptableResponseTypes, regular expression matching acceptable
                             response types,
-  $granularity, either 'part' or 'response'
+  $granularity, either 'part', 'response', or 'part_survey'
 
 Returns: three hash references, $prev, $curr, $next, which refer to the
 preceeding, current, or following problem parts or responses, depending
@@ -253,30 +452,40 @@ sub get_prev_curr_next {
     #
     # Build an array with the data we need to search through
     my @Resource;
-    foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
-        foreach my $res (@{$seq->{'contents'}}) {
-            next if ($res->{'type'} ne 'assessment');
-            foreach my $part (@{$res->{'parts'}}) {
-                my $partdata = $res->{'partdata'}->{$part};
-                if ($granularity eq 'part') {
+    my ($navmap,@sequences) = 
+        &Apache::lonstatistics::selected_sequences_with_assessments('all');
+    return $navmap if (! ref($navmap));
+    foreach my $seq (@sequences) {
+        my @resources = &get_resources($navmap,$seq);
+        foreach my $res (@resources) {
+            foreach my $part (@{$res->parts}) {
+                if ($res->is_survey($part) && ($granularity eq 'part_survey')){
+                    push (@Resource,
+                          { symb     => $res->symb,
+                            part     => $part,
+                            resource => $res,
+                        } );
+                } elsif ($granularity eq 'part') {
                     push (@Resource,
-                          { symb     => $res->{symb},
+                          { symb     => $res->symb,
                             part     => $part,
                             resource => $res,
                         } );
                 } elsif ($granularity eq 'response') {
+                    my @response_ids   = $res->responseIds($part);
+                    my @response_types = $res->responseType($part);
                     for (my $i=0;
-                         $i<scalar(@{$partdata->{'ResponseTypes'}});
+                         $i<scalar(@response_ids);
                          $i++){
-                        my $respid = $partdata->{'ResponseIds'}->[$i];
-                        my $resptype = $partdata->{'ResponseTypes'}->[$i];
+                        my $respid   = $response_ids[$i];
+                        my $resptype = $response_types[$i];
                         next if ($resptype !~ m/$AcceptableResponseTypes/);
                         push (@Resource,
-                              { symb     => $res->{symb},
+                              { symb     => $res->symb,
                                 part     => $part,
-                                respid   => $partdata->{'ResponseIds'}->[$i],
+                                respid   => $respid,
+                                resptype => $resptype,
                                 resource => $res,
-                                resptype => $resptype
                                 } );
                     }
                 }
@@ -288,7 +497,7 @@ sub get_prev_curr_next {
     my $curr_idx;
     for ($curr_idx=0;$curr_idx<$#Resource;$curr_idx++) {
         my $curr_item = $Resource[$curr_idx];
-        if ($granularity eq 'part') {
+        if ($granularity eq 'part' || $granularity eq 'part_survey') {
             if ($curr_item->{'symb'} eq $target->{'symb'} &&
                 $curr_item->{'part'} eq $target->{'part'}) {
                 last;
@@ -303,7 +512,7 @@ sub get_prev_curr_next {
         }
     }
     my $curr_item = $Resource[$curr_idx];
-    if ($granularity eq 'part') {
+    if ($granularity eq 'part' || $granularity eq 'part_survey') {
         if ($curr_item->{'symb'}     ne $target->{'symb'} ||
             $curr_item->{'part'}     ne $target->{'part'}) {
             # bogus symb - return nothing
@@ -334,7 +543,7 @@ sub get_prev_curr_next {
         $curr = $Resource[$curr_idx  ];
         $next = $Resource[$curr_idx+1];
     }
-    return ($prev,$curr,$next);
+    return ($navmap,$prev,$curr,$next);
 }
 
 
@@ -343,15 +552,126 @@ sub get_prev_curr_next {
 
 =pod
 
+=item GetStudentAnswers($r,$problem,$Students)
+
+Determines the correct answer for a set of students on a given problem.
+The students answers are stored in the student hashes pointed to by the
+array @$Students under the key 'answer'.
+
+Inputs: $r
+$problem: hash reference containing the keys 'resource', 'part', and 'respid'.
+$Students: reference to array containing student hashes (need 'username', 
+    'domain').  
+
+Returns: nothing 
+
+=cut
+
+#####################################################
+#####################################################
+sub GetStudentAnswers {
+    my ($r,$problem,$Students,$formname,$inputname) = @_;
+    my %answers;
+    my $status_type;
+    if (defined($formname)) {
+        $status_type = 'inline';
+    } else {
+        $status_type = 'popup';
+    }    
+    my $c = $r->connection();
+    my %Answers;
+    my ($resource,$partid,$respid) = ($problem->{'resource'},
+                                      $problem->{'part'},
+                                      $problem->{'respid'});
+    # Read in the cache (if it exists) before we start timing things.
+    &Apache::lonstathelpers::ensure_proper_cache($resource->{'symb'});
+    # Open progress window
+    my %prog_state=&Apache::lonhtmlcommon::Create_PrgWin
+        ($r,'Student Answer Compilation Status',
+         'Student Answer Compilation Progress', scalar(@$Students),
+         $status_type,undef,$formname,$inputname);
+    $r->rflush();
+    foreach my $student (@$Students) {
+        last if ($c->aborted());
+        my $sname = $student->{'username'};
+        my $sdom = $student->{'domain'};
+        my $answer = &Apache::lonstathelpers::get_student_answer
+            ($resource,$sname,$sdom,$partid,$respid);
+        &Apache::lonhtmlcommon::Increment_PrgWin($r,\%prog_state,
+                                                 &mt('last student'));
+        $answers{$answer}++;
+        $student->{'answer'} = $answer;
+    }
+    &Apache::lonstathelpers::write_analysis_cache();
+    return if ($c->aborted());
+    $r->rflush();
+    # close progress window
+    &Apache::lonhtmlcommon::Close_PrgWin($r,\%prog_state);
+    return \%answers;
+}
+
+#####################################################
+#####################################################
+
+=pod
+
 =item analyze_problem_as_student
 
-Analyzes a homework problem for a student and returns the correct answer
-for the student.  Attempts to put together an answer for problem types 
-that do not natively support it.
+Analyzes a homework problem for a student
 
 Inputs: $resource: a resource object
         $sname, $sdom, $partid, $respid
 
+Returns: the problem analysis hash
+
+=cut
+
+#####################################################
+#####################################################
+sub analyze_problem_as_student {
+    my ($resource,$sname,$sdom) = @_;
+    if (ref($resource) ne 'HASH') {
+        my $res = $resource;
+        $resource = { 'src' => $res->src,
+                      'symb' => $res->symb,
+                      'parts' => $res->parts };
+        foreach my $part (@{$resource->{'parts'}}) {
+            $resource->{'partdata'}->{$part}->{'ResponseIds'}=
+                [$res->responseIds($part)];
+        }
+    }
+    my $url = $resource->{'src'};
+    my $symb = $resource->{'symb'};
+    my $analysis = &get_from_analysis_cache($sname,$sdom,$symb);
+    if (! defined($analysis)) {
+        my $courseid = $ENV{'request.course.id'};
+        my $Answ=&Apache::lonnet::ssi($url,('grade_target' => 'analyze',
+                                            'grade_domain' => $sdom,
+                                            'grade_username' => $sname,
+                                            'grade_symb' => $symb,
+                                            'grade_courseid' => $courseid));
+        (my $garbage,$analysis)=split(/_HASH_REF__/,$Answ,2);
+        &store_analysis($sname,$sdom,$symb,$analysis);
+    }
+    my %Answer=&Apache::lonnet::str2hash($analysis);
+    #
+    return \%Answer;
+}
+
+#####################################################
+#####################################################
+
+=pod
+
+=item get_student_answer
+
+Analyzes a homework problem for a particular student and returns the correct 
+answer.  Attempts to put together an answer for problem types 
+that do not natively support it.
+
+Inputs: $resource: a resource object (from navmaps or hash from loncoursedata)
+        $sname, $sdom, $partid, $respid
+
 Returns: $answer
 
 If $partid and $respid are specified, $answer is simply a scalar containing
@@ -364,41 +684,39 @@ keys $partid.'.'.$respid.'.answer'.
 
 #####################################################
 #####################################################
-sub analyze_problem_as_student {
+sub get_student_answer {
     my ($resource,$sname,$sdom,$partid,$respid) = @_;
-    my $returnvalue;
-    my $url = $resource->{'src'};
-    my $symb = $resource->{'symb'};
-    my $courseid = $ENV{'request.course.id'};
-    my $Answ=&Apache::lonnet::ssi($url,('grade_target' => 'analyze',
-                                        'grade_domain' => $sdom,
-                                        'grade_username' => $sname,
-                                        'grade_symb' => $symb,
-                                        'grade_courseid' => $courseid));
-    (my $garbage,$Answ)=split(/_HASH_REF__/,$Answ,2);
-    my %Answer=&Apache::lonnet::str2hash($Answ);
     #
-    if (! defined($partid)) {
-        # If you do not specify a partid, you get them all.
-        foreach my $partid (@{$resource->{'parts'}}) {
-            my $partdata = $resource->{'partdata'}->{$partid};
-            foreach my $respid (@{$partdata->{'ResponseIds'}}) {
-                my $prefix = $partid.'.'.$respid;
-                my $key = $prefix.'.answer';
-                $returnvalue->{$key} = &get_answer($prefix,$key,%Answer);
-            }
+    if (ref($resource) ne 'HASH') {
+        my $res = $resource;
+        $resource = { 'src' => $res->src,
+                      'symb' => $res->symb,
+                      'parts' => $res->parts };
+        foreach my $part (@{$resource->{'parts'}}) {
+            $resource->{'partdata'}->{$part}->{'ResponseIds'}=
+                [$res->responseIds($part)];
         }
-    } elsif (! defined($respid)) {
+    }
+    #
+    my $analysis = 
+        &analyze_problem_as_student($resource,$sname,$sdom);
+    my $answer;
+    foreach my $partid (@{$resource->{'parts'}}) {
         my $partdata = $resource->{'partdata'}->{$partid};
         foreach my $respid (@{$partdata->{'ResponseIds'}}) {
             my $prefix = $partid.'.'.$respid;
             my $key = $prefix.'.answer';
-            $returnvalue->{$key} = &get_answer($prefix,$key,%Answer);
+            $answer->{$partid}->{$respid} = 
+                &get_answer($prefix,$key,%$analysis);
         }
+    }
+    my $returnvalue;
+    if (! defined($partid)) {
+        $returnvalue = $answer;
+    } elsif (! defined($respid)) {
+        $returnvalue = $answer->{$partid};
     } else {
-        my $prefix = $partid.'.'.$respid;
-        my $key = $prefix.'.answer';
-        $returnvalue = &get_answer($prefix,$key,%Answer);
+        $returnvalue = $answer->{$partid}->{$respid};
     }
     return $returnvalue;
 }
@@ -423,11 +741,11 @@ sub get_answer {
             }
             foreach my $foil (@{$Answer{$prefix.'.shown'}}) {
                 if (ref($values{$foil}) eq 'ARRAY') {
-                    $returnvalue.=&HTML::Entities::encode($foil).'='.
-                        join(',',map {&HTML::Entities::encode($_)} @{$values{$foil}}).'&';
+                    $returnvalue.=&HTML::Entities::encode($foil,'<>&"').'='.
+                        join(',',map {&HTML::Entities::encode($_,'<>&"')} @{$values{$foil}}).'&';
                 } else {
-                    $returnvalue.=&HTML::Entities::encode($foil).'='.
-                        &HTML::Entities::encode($values{$foil}).'&';
+                    $returnvalue.=&HTML::Entities::encode($foil,'<>&"').'='.
+                        &HTML::Entities::encode($values{$foil},'<>&"').'&';
                 }
             }
             $returnvalue =~ s/ /\%20/g;
@@ -437,6 +755,168 @@ sub get_answer {
     return $returnvalue;
 }
 
+#####################################################
+#####################################################
+
+=pod
+
+=item Caching routines
+
+=over 4
+
+=item &load_analysis_cache($symb)
+
+Loads the cache for the given symb into memory from disk.  
+Requires the cache filename be set.  
+Only should be called by &ensure_proper_cache.
+
+=cut
+
+#####################################################
+#####################################################
+{
+    my $cache_filename = undef;
+    my $current_symb = undef;
+    my %cache;
+
+sub load_analysis_cache {
+    my ($symb) = @_;
+    return if (! defined($cache_filename));
+    if (! defined($current_symb) || $current_symb ne $symb) {
+        undef(%cache);
+        my $storedstring;
+        my %cache_db;
+        if (tie(%cache_db,'GDBM_File',$cache_filename,&GDBM_READER(),0640)) {
+            $storedstring = $cache_db{&Apache::lonnet::escape($symb)};
+            untie(%cache_db);
+        }
+        if (defined($storedstring)) {
+            %cache = %{thaw($storedstring)};
+        }
+    }
+    return;
+}
+
+#####################################################
+#####################################################
+
+=pod
+
+=item &get_from_analysis_cache($sname,$sdom,$symb,$partid,$respid)
+
+Returns the appropriate data from the cache, or undef if no data exists.
+
+=cut
+
+#####################################################
+#####################################################
+sub get_from_analysis_cache {
+    my ($sname,$sdom,$symb) = @_;
+    &ensure_proper_cache($symb);
+    my $returnvalue;
+    if (exists($cache{$sname.':'.$sdom})) {
+        $returnvalue = $cache{$sname.':'.$sdom};
+    } else {
+        $returnvalue = undef;
+    }
+    return $returnvalue;
+}
+
+#####################################################
+#####################################################
+
+=pod
+
+=item &write_analysis_cache($symb)
+
+Writes the in memory cache to disk so that it can be read in with
+&load_analysis_cache($symb).
+
+=cut
+
+#####################################################
+#####################################################
+sub write_analysis_cache {
+    return if (! defined($current_symb) || ! defined($cache_filename));
+    my %cache_db;
+    my $key = &Apache::lonnet::escape($current_symb);
+    if (tie(%cache_db,'GDBM_File',$cache_filename,&GDBM_WRCREAT(),0640)) {
+        my $storestring = freeze(\%cache);
+        $cache_db{$key}=$storestring;
+        $cache_db{$key.'.time'}=time;
+        untie(%cache_db);
+    }
+    undef(%cache);
+    undef($current_symb);
+    undef($cache_filename);
+    return;
+}
+
+#####################################################
+#####################################################
+
+=pod
+
+=item &ensure_proper_cache($symb)
+
+Called to make sure we have the proper cache set up.  This is called
+prior to every analysis lookup.
+
+=cut
+
+#####################################################
+#####################################################
+sub ensure_proper_cache {
+    my ($symb) = @_;
+    my $cid = $ENV{'request.course.id'};
+    my $new_filename =  '/home/httpd/perl/tmp/'.
+        'problemanalysis_'.$cid.'_analysis_cache.db';
+    if (! defined($cache_filename) ||
+        $cache_filename ne $new_filename ||
+        ! defined($current_symb)   ||
+        $current_symb ne $symb) {
+        $cache_filename = $new_filename;
+        # Notice: $current_symb is not set to $symb until after the cache is
+        # loaded.  This is what tells &load_analysis_cache to load in a new
+        # symb cache.
+        &load_analysis_cache($symb);
+        $current_symb = $symb;
+    }
+}
+
+#####################################################
+#####################################################
+
+=pod
+
+=item &store_analysis($sname,$sdom,$symb,$partid,$respid,$dataset)
+
+Stores the analysis data in the in memory cache.
+
+=cut
+
+#####################################################
+#####################################################
+sub store_analysis {
+    my ($sname,$sdom,$symb,$dataset) = @_;
+    return if ($symb ne $current_symb);
+    $cache{$sname.':'.$sdom}=$dataset;
+    return;
+}
+
+}
+#####################################################
+#####################################################
+
+=pod
+
+=back
+
+=cut
+
+#####################################################
+#####################################################
+
 ##
 ## The following is copied from datecalc1.pl, part of the 
 ## Spreadsheet::WriteExcel CPAN module.
@@ -644,7 +1124,7 @@ sub get_problem_data {
         while (my($key,$value) = each(%Answer)) {
             #
             # Logging code:
-            if (1) {
+            if (0) {
                 &Apache::lonnet::logthis($part.' got key "'.$key.'"');
                 if (ref($value) eq 'ARRAY') {
                     &Apache::lonnet::logthis('    @'.join(',',@$value));
@@ -660,13 +1140,15 @@ sub get_problem_data {
                     $Partdata{$part}->{'_Options'}=$value;
                 } elsif ($key eq 'concepts') {
                     $Partdata{$part}->{'_Concepts'}=$value;
+                } elsif ($key eq 'items') {
+                    $Partdata{$part}->{'_Items'}=$value;
                 } elsif ($key =~ /^concept\.(.*)$/) {
                     my $concept = $1;
                     foreach my $foil (@$value) {
                         $Partdata{$part}->{'_Foils'}->{$foil}->{'_Concept'}=
                                                                       $concept;
                     }
-                } elsif ($key =~ /^(incorrect|answer|ans_low|ans_high)$/) {
+                } elsif ($key =~ /^(unit|incorrect|answer|ans_low|ans_high|str_type)$/) {
                     $Partdata{$part}->{$key}=$value;
                 }
             } else {
@@ -678,13 +1160,51 @@ sub get_problem_data {
                 } elsif ($key =~ /^foil\.value\.(.*)$/) {
                     my $foil = $1;
                     $Partdata{$part}->{'_Foils'}->{$foil}->{'value'}=$value;
+                } elsif ($key eq 'answercomputed') {
+                    $Partdata{$part}->{'answercomputed'} = $value;
                 }
             }
         }
     }
+    # Further debugging code
+    if (0) {
+        &Apache::lonnet::logthis('lonstathelpers::get_problem_data');
+        &log_hash_ref(\%Partdata);
+    }
     return %Partdata;
 }
 
+sub log_array_ref {
+    my ($arrayref,$prefix) = @_;
+    return if (ref($arrayref) ne 'ARRAY');
+    if (! defined($prefix)) { $prefix = ''; };
+    foreach my $v (@$arrayref) {
+        if (ref($v) eq 'ARRAY') {
+            &log_array_ref($v,$prefix.'  ');
+        } elsif (ref($v) eq 'HASH') {
+            &log_hash_ref($v,$prefix.'  ');
+        } else {
+            &Apache::lonnet::logthis($prefix.'"'.$v.'"');
+        }
+    }
+}
+
+sub log_hash_ref {
+    my ($hashref,$prefix) = @_;
+    return if (ref($hashref) ne 'HASH');
+    if (! defined($prefix)) { $prefix = ''; };
+    while (my ($k,$v) = each(%$hashref)) {
+        if (ref($v) eq 'ARRAY') {
+            &Apache::lonnet::logthis($prefix.'"'.$k.'" = array');
+            &log_array_ref($v,$prefix.'  ');
+        } elsif (ref($v) eq 'HASH') {
+            &Apache::lonnet::logthis($prefix.'"'.$k.'" = hash');
+            &log_hash_ref($v,$prefix.'  ');
+        } else {
+            &Apache::lonnet::logthis($prefix.'"'.$k.'" => "'.$v.'"');
+        }
+    }
+}
 ####################################################
 ####################################################
 
@@ -761,6 +1281,189 @@ sub get_time_limits {
     return ($starttime,$endtime);
 }
 
+
+
+####################################################
+####################################################
+
+=pod
+
+=item sections_description 
+
+Inputs: @Sections, an array of sections
+
+Returns: A text description of the sections selected.
+
+=cut
+
+####################################################
+####################################################
+sub sections_description {
+    my @Sections = @_;
+    my $sectionstring = '';
+    if (scalar(@Sections) > 1) {
+        if (scalar(@Sections) > 2) {
+            my $last = pop(@Sections);
+            $sectionstring = "Sections ".join(', ',@Sections).', and '.$last;
+        } else {
+            $sectionstring = "Sections ".join(' and ',@Sections);
+        }
+    } else {
+        if ($Sections[0] eq 'all') {
+            $sectionstring = "All sections";
+        } else {
+            $sectionstring = "Section ".$Sections[0];
+        }
+    }
+    return $sectionstring;
+}
+
+####################################################
+####################################################
+
+=pod
+
+=item &manage_caches
+
+Inputs: $r, apache request object
+
+Returns: An array of scalars containing html for buttons.
+
+=cut
+
+####################################################
+####################################################
+sub manage_caches {
+    my ($r,$formname,$inputname,$update_message) = @_;
+    &Apache::loncoursedata::clear_internal_caches();
+    my $sectionkey = 
+        join(',',
+             map {
+                     &Apache::lonnet::escape($_);
+                 } sort(@Apache::lonstatistics::SelectedSections)
+             );
+    my $statuskey = $Apache::lonstatistics::enrollment_status;
+    if (exists($ENV{'form.ClearCache'}) || 
+        exists($ENV{'form.updatecaches'}) || 
+        (exists($ENV{'form.firstrun'}) && $ENV{'form.firstrun'} ne 'no') ||
+        (exists($ENV{'form.prevsection'}) &&
+            $ENV{'form.prevsection'} ne $sectionkey) ||
+        (exists($ENV{'form.prevenrollstatus'}) &&
+            $ENV{'form.prevenrollstatus'} ne $statuskey)
+        ) {
+        if (defined($update_message)) {
+            $r->print($update_message);
+        }
+        if (0) {
+            &Apache::lonnet::logthis('Updating mysql student data caches');
+        }
+        &gather_full_student_data($r,$formname,$inputname);
+    }
+    #
+    my @Buttons = 
+        ('<input type="submit" name="ClearCache" '.
+             'value="'.&mt('Clear Caches').'" />',
+         '<input type="submit" name="updatecaches" '.
+             'value="'.&mt('Update Caches').'" />'.
+         &Apache::loncommon::help_open_topic('Statistics_Cache'),
+         '<input type="hidden" name="prevsection" value="'.$sectionkey.'" />',
+         '<input type="hidden" name="prevenrollstatus" value="'.$statuskey.'" />'
+         );
+    #
+    if (! exists($ENV{'form.firstrun'})) {
+        $r->print('<input type="hidden" name="firstrun" value="yes" />');
+    } else {
+        $r->print('<input type="hidden" name="firstrun" value="no" />');
+    }
+    #
+    return @Buttons;
+}
+
+sub gather_full_student_data {
+    my ($r,$formname,$inputname) = @_;
+    my $status_type;
+    if (defined($formname)) {
+        $status_type = 'inline';
+    } else {
+        $status_type = 'popup';
+    }
+    my $c = $r->connection();
+    #
+    &Apache::loncoursedata::clear_internal_caches();
+    #
+    my @Students = @Apache::lonstatistics::Students;
+    #
+    # Open the progress window
+    my %prog_state=&Apache::lonhtmlcommon::Create_PrgWin
+        ($r,&mt('Student Data Compilation Status'),
+         &mt('Student Data Compilation Progress'), scalar(@Students),
+         $status_type,undef,$formname,$inputname);
+    #
+    while (my $student = shift @Students) {
+        return if ($c->aborted());
+        my $status = &Apache::loncoursedata::ensure_current_full_data
+            ($student->{'username'},$student->{'domain'},
+             $ENV{'request.course.id'});
+        &Apache::lonhtmlcommon::Increment_PrgWin($r,\%prog_state,
+                                                 &mt('last student'));
+    }
+    &Apache::lonhtmlcommon::Close_PrgWin($r,\%prog_state);
+    $r->rflush();
+    return;
+}
+
+####################################################
+####################################################
+
+=pod
+
+=item &submission_report_form
+
+Input: The originating reportSelected value for the current stats page.
+
+Output: Scalar containing HTML with needed form elements and a link to 
+the student submission reports page.
+
+=cut
+
+####################################################
+####################################################
+sub submission_report_form {
+    my ($original_report) = @_;
+    # Note: In the link below we change the reportSelected value.  If
+    # the user hits the 'back' button on the browser after getting their
+    # student submissions report, this value may still be around.  So we
+    # output a script block to set it properly.  If the $original_report
+    # value is unset, you are just asking for trouble.
+    if (! defined($original_report)) {
+        &Apache::lonnet::logthis
+            ('someone called lonstathelpers::submission_report_form without '.
+             ' enough input.');
+    }
+    my $html = $/.
+        '<script type="Text/JavaScript">'.
+        "document.Statistics.reportSelected.value='$original_report';".
+        '</script>'.
+        '<input type="hidden" name="correctans" value="true" />'.
+        '<input type="hidden" name="prob_status" value="true" />'.
+        '<input type="hidden" name="all_sub" value="true" />';
+    my $output_selector = $/.'<select name="output">'.$/;
+    foreach ('HTML','Excel','CSV') {
+        $output_selector .= '    <option value="'.lc($_).'"';
+        if ($ENV{'form.output'} eq lc($_)) {
+            $output_selector .= ' selected ';
+        }
+        $output_selector .='>'.&mt($_).'</option>'.$/;
+    } 
+    $output_selector .= '</select>'.$/;
+    my $link = '<a href="javascript:'.
+       q{document.Statistics.reportSelected.value='student_submission_reports';}.
+       'document.Statistics.submit();">';
+    $html.= &mt('View data as [_1] [_2]go[_3]',$output_selector,
+                $link,'</a>').$/;
+    return $html
+}
+
 ####################################################
 ####################################################