--- loncom/interface/statistics/lonstathelpers.pm 2004/01/19 21:29:46 1.1
+++ loncom/interface/statistics/lonstathelpers.pm 2004/08/03 19:53:12 1.18
@@ -1,6 +1,6 @@
# The LearningOnline Network with CAPA
#
-# $Id: lonstathelpers.pm,v 1.1 2004/01/19 21:29:46 matthew Exp $
+# $Id: lonstathelpers.pm,v 1.18 2004/08/03 19:53:12 matthew Exp $
#
# Copyright Michigan State University Board of Trustees
#
@@ -59,6 +59,8 @@ use Apache::lonlocal;
use HTML::Entities();
use Time::Local();
use Spreadsheet::WriteExcel();
+use GDBM_File;
+use Storable qw(freeze thaw);
####################################################
####################################################
@@ -94,6 +96,1036 @@ sub render_resource {
'';
}
+####################################################
+####################################################
+
+=pod
+
+=item &ProblemSelector($AcceptedResponseTypes)
+
+Input: scalar containing regular expression which matches response
+types to show. '.' will yield all, '(option|radiobutton)' will match
+all option response and radiobutton problems.
+
+Returns: A string containing html for a table which lists the sequences
+and their contents. A radiobutton is provided for each problem.
+Skips 'survey' problems.
+
+=cut
+
+####################################################
+####################################################
+sub ProblemSelector {
+ my ($AcceptedResponseTypes) = @_;
+ my $Str;
+ $Str = "\n
\n";
+ foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess('all')) {
+ next if ($seq->{'num_assess'}<1);
+ my $seq_str = '';
+ foreach my $res (@{$seq->{'contents'}}) {
+ next if ($res->{'type'} ne 'assessment');
+ foreach my $part (@{$res->{'parts'}}) {
+ my $partdata = $res->{'partdata'}->{$part};
+ next if ($partdata->{'Survey'});
+ for (my $i=0;$i{'ResponseTypes'}});$i++){
+ my $respid = $partdata->{'ResponseIds'}->[$i];
+ my $resptype = $partdata->{'ResponseTypes'}->[$i];
+ if ($resptype =~ m/$AcceptedResponseTypes/) {
+ my $value = &make_target_id({symb=>$res->{'symb'},
+ part=>$part,
+ respid=>$respid,
+ resptype=>$resptype});
+ my $checked = '';
+ if ($ENV{'form.problemchoice'} eq $value) {
+ $checked = 'checked ';
+ }
+ my $title = $res->{'title'};
+ if (! defined($title) || $title eq '') {
+ ($title) = ($res->{'src'} =~ m:/([^/]*)$:);
+ }
+ $seq_str .= '
\n";
+ }
+ }
+ }
+ }
+ if ($seq_str ne '') {
+ $Str .= '
'.$seq->{'title'}.'
'.
+ "
\n".$seq_str;
+ }
+ }
+ $Str .= "
\n";
+ return $Str;
+}
+
+####################################################
+####################################################
+
+=pod
+
+=item &make_target_id($target)
+
+Inputs: Hash ref with the following entries:
+ $target->{'symb'}, $target->{'part'}, $target->{'respid'},
+ $target->{'resptype'}.
+
+Returns: A string, suitable for a form parameter, which uniquely identifies
+the problem, part, and response to do statistical analysis on.
+
+Used by Apache::lonstathelpers::ProblemSelector().
+
+=cut
+
+####################################################
+####################################################
+sub make_target_id {
+ my ($target) = @_;
+ my $id = &Apache::lonnet::escape($target->{'symb'}).':'.
+ &Apache::lonnet::escape($target->{'part'}).':'.
+ &Apache::lonnet::escape($target->{'respid'}).':'.
+ &Apache::lonnet::escape($target->{'resptype'});
+ return $id;
+}
+
+####################################################
+####################################################
+
+=pod
+
+=item &get_target_from_id($id)
+
+Inputs: $id, a scalar string from Apache::lonstathelpers::make_target_id().
+
+Returns: A hash reference, $target, containing the following keys:
+ $target->{'symb'}, $target->{'part'}, $target->{'respid'},
+ $target->{'resptype'}.
+
+=cut
+
+####################################################
+####################################################
+sub get_target_from_id {
+ my ($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($resptype)});
+}
+
+####################################################
+####################################################
+
+=pod
+
+=item &get_prev_curr_next($target,$AcceptableResponseTypes,$granularity)
+
+Determine the problem parts or responses preceeding and following the
+current resource.
+
+Inputs: $target (see &Apache::lonstathelpers::get_target_from_id())
+ $AcceptableResponseTypes, regular expression matching acceptable
+ response types,
+ $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
+on the value of $granularity. Values of undef indicate there is no
+previous or next part/response. A value of undef for all three indicates
+there was no match found to the current part/resource.
+
+The hash references contain the following keys:
+ symb, part, resource
+
+If $granularity eq 'response', the following ADDITIONAL keys will be present:
+ respid, resptype
+
+=cut
+
+####################################################
+####################################################
+sub get_prev_curr_next {
+ my ($target,$AcceptableResponseTypes,$granularity) = @_;
+ #
+ # Build an array with the data we need to search through
+ my @Resource;
+ foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess('all')) {
+ foreach my $res (@{$seq->{'contents'}}) {
+ next if ($res->{'type'} ne 'assessment');
+ foreach my $part (@{$res->{'parts'}}) {
+ my $partdata = $res->{'partdata'}->{$part};
+ if ($partdata->{'Survey'}) {
+ if ($granularity eq 'part_survey'){
+ push (@Resource,
+ { symb => $res->{symb},
+ part => $part,
+ resource => $res,
+ } );
+ }
+ } elsif ($granularity eq 'part') {
+ push (@Resource,
+ { symb => $res->{symb},
+ part => $part,
+ resource => $res,
+ } );
+ } elsif ($granularity eq 'response') {
+ for (my $i=0;
+ $i{'ResponseTypes'}});
+ $i++){
+ my $respid = $partdata->{'ResponseIds'}->[$i];
+ my $resptype = $partdata->{'ResponseTypes'}->[$i];
+ next if ($resptype !~ m/$AcceptableResponseTypes/);
+ push (@Resource,
+ { symb => $res->{symb},
+ part => $part,
+ respid => $partdata->{'ResponseIds'}->[$i],
+ resource => $res,
+ resptype => $resptype
+ } );
+ }
+ }
+ }
+ }
+ }
+ #
+ # Get the index of the current situation
+ my $curr_idx;
+ for ($curr_idx=0;$curr_idx<$#Resource;$curr_idx++) {
+ my $curr_item = $Resource[$curr_idx];
+ if ($granularity eq 'part' || $granularity eq 'part_survey') {
+ if ($curr_item->{'symb'} eq $target->{'symb'} &&
+ $curr_item->{'part'} eq $target->{'part'}) {
+ last;
+ }
+ } elsif ($granularity eq 'response') {
+ if ($curr_item->{'symb'} eq $target->{'symb'} &&
+ $curr_item->{'part'} eq $target->{'part'} &&
+ $curr_item->{'respid'} eq $target->{'respid'} &&
+ $curr_item->{'resptype'} eq $target->{'resptype'}) {
+ last;
+ }
+ }
+ }
+ my $curr_item = $Resource[$curr_idx];
+ if ($granularity eq 'part' || $granularity eq 'part_survey') {
+ if ($curr_item->{'symb'} ne $target->{'symb'} ||
+ $curr_item->{'part'} ne $target->{'part'}) {
+ # bogus symb - return nothing
+ return (undef,undef,undef);
+ }
+ } elsif ($granularity eq 'response') {
+ if ($curr_item->{'symb'} ne $target->{'symb'} ||
+ $curr_item->{'part'} ne $target->{'part'} ||
+ $curr_item->{'respid'} ne $target->{'respid'} ||
+ $curr_item->{'resptype'} ne $target->{'resptype'}){
+ # bogus symb - return nothing
+ return (undef,undef,undef);
+ }
+ }
+ #
+ # Now just pick up the data we need
+ my ($prev,$curr,$next);
+ if ($curr_idx == 0) {
+ $prev = undef;
+ $curr = $Resource[$curr_idx ];
+ $next = $Resource[$curr_idx+1];
+ } elsif ($curr_idx == $#Resource) {
+ $prev = $Resource[$curr_idx-1];
+ $curr = $Resource[$curr_idx ];
+ $next = undef;
+ } else {
+ $prev = $Resource[$curr_idx-1];
+ $curr = $Resource[$curr_idx ];
+ $next = $Resource[$curr_idx+1];
+ }
+ return ($prev,$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 $status_type;
+ if (defined($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 $answer = &Apache::lonstathelpers::analyze_problem_as_student
+ ($resource,$sname,$sdom,$partid,$respid);
+ &Apache::lonhtmlcommon::Increment_PrgWin($r,\%prog_state,
+ &mt('last student'));
+ $student->{'answer'} = $answer;
+ }
+ &Apache::lonstathelpers::write_answer_cache();
+ return if ($c->aborted());
+ $r->rflush();
+ # close progress window
+ &Apache::lonhtmlcommon::Close_PrgWin($r,\%prog_state);
+ return;
+}
+
+#####################################################
+#####################################################
+
+=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.
+
+Inputs: $resource: a resource object
+ $sname, $sdom, $partid, $respid
+
+Returns: $answer
+
+If $partid and $respid are specified, $answer is simply a scalar containing
+the correct answer for the response.
+
+If $partid or $respid are undefined, $answer will be a hash reference with
+keys $partid.'.'.$respid.'.answer'.
+
+=cut
+
+#####################################################
+#####################################################
+sub analyze_problem_as_student {
+ my ($resource,$sname,$sdom,$partid,$respid) = @_;
+ my $returnvalue;
+ my $url = $resource->{'src'};
+ my $symb = $resource->{'symb'};
+ my $answer = &get_from_answer_cache($sname,$sdom,$symb,$partid,$respid);
+ if (defined($answer)) {
+ return($answer);
+ }
+ 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);
+ #
+ undef($answer);
+ foreach my $partid (@{$resource->{'parts'}}) {
+ my $partdata = $resource->{'partdata'}->{$partid};
+ foreach my $respid (@{$partdata->{'ResponseIds'}}) {
+ my $prefix = $partid.'.'.$respid;
+ my $key = $prefix.'.answer';
+ $answer->{$partid}->{$respid} = &get_answer($prefix,$key,%Answer);
+ }
+ }
+ &store_answer($sname,$sdom,$symb,undef,undef,$answer);
+ if (! defined($partid)) {
+ $returnvalue = $answer;
+ } elsif (! defined($respid)) {
+ $returnvalue = $answer->{$partid};
+ } else {
+ $returnvalue = $answer->{$partid}->{$respid};
+ }
+ return $returnvalue;
+}
+
+sub get_answer {
+ my ($prefix,$key,%Answer) = @_;
+ my $returnvalue;
+ if (exists($Answer{$key})) {
+ my $student_answer = $Answer{$key}->[0];
+ if (! defined($student_answer)) {
+ $student_answer = $Answer{$key}->[1];
+ }
+ $returnvalue = $student_answer;
+ } else {
+ if (exists($Answer{$prefix.'.shown'})) {
+ # The response has foils
+ my %values;
+ while (my ($k,$v) = each(%Answer)) {
+ next if ($k !~ /^$prefix\.foil\.(value|area)\.(.*)$/);
+ my $foilname = $2;
+ $values{$foilname}=$v;
+ }
+ foreach my $foil (@{$Answer{$prefix.'.shown'}}) {
+ if (ref($values{$foil}) eq 'ARRAY') {
+ $returnvalue.=&HTML::Entities::encode($foil,'<>&"').'='.
+ join(',',map {&HTML::Entities::encode($_,'<>&"')} @{$values{$foil}}).'&';
+ } else {
+ $returnvalue.=&HTML::Entities::encode($foil,'<>&"').'='.
+ &HTML::Entities::encode($values{$foil},'<>&"').'&';
+ }
+ }
+ $returnvalue =~ s/ /\%20/g;
+ chop ($returnvalue);
+ }
+ }
+ return $returnvalue;
+}
+
+
+#####################################################
+#####################################################
+
+=pod
+
+=item Caching routines
+
+=over 4
+
+=item &load_answer_cache($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 $current_symb = undef;
+ my %cache;
+
+sub load_answer_cache {
+ my ($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_answer_cache($sname,$sdom,$symb,$partid,$respid)
+
+Returns the appropriate data from the cache, or undef if no data exists.
+If $respid is undefined, a hash ref containing the answers for the given
+$partid is returned. If $partid is undefined, a hash ref containing answers
+for all of the parts is returned.
+
+=cut
+
+#####################################################
+#####################################################
+sub get_from_answer_cache {
+ my ($sname,$sdom,$symb,$partid,$respid) = @_;
+ &ensure_proper_cache($symb);
+ my $returnvalue;
+ if (exists($cache{$sname.':'.$sdom}) &&
+ ref($cache{$sname.':'.$sdom}) eq 'HASH') {
+ if (defined($partid) &&
+ exists($cache{$sname.':'.$sdom}->{$partid})) {
+ if (defined($respid) &&
+ exists($cache{$sname.':'.$sdom}->{$partid}->{$respid})) {
+ $returnvalue = $cache{$sname.':'.$sdom}->{$partid}->{$respid};
+ } else {
+ $returnvalue = $cache{$sname.':'.$sdom}->{$partid};
+ }
+ } else {
+ $returnvalue = $cache{$sname.':'.$sdom};
+ }
+ } else {
+ $returnvalue = undef;
+ }
+ return $returnvalue;
+}
+
+#####################################################
+#####################################################
+
+=pod
+
+=item &write_answer_cache($symb)
+
+Writes the in memory cache to disk so that it can be read in with
+&load_answer_cache($symb).
+
+=cut
+
+#####################################################
+#####################################################
+sub write_answer_cache {
+ return if (! defined($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($symb)
+
+Called to make sure we have the proper cache set up. This is called
+prior to every answer lookup.
+
+=cut
+
+#####################################################
+#####################################################
+sub ensure_proper_cache {
+ my ($symb) = @_;
+ my $cid = $ENV{'request.course.id'};
+ my $new_filename = '/home/httpd/perl/tmp/'.
+ 'problemanalysis_'.$cid.'_answer_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 $symb until after the cache is
+ # loaded. This is what tells &load_answer_cache to load in a new
+ # symb cache.
+ &load_answer_cache($symb);
+ $current_symb = $symb;
+ }
+}
+
+#####################################################
+#####################################################
+
+=pod
+
+=item &store_answer($sname,$sdom,$symb,$partid,$respid,$dataset)
+
+Stores the answer data in the in memory cache.
+
+=cut
+
+#####################################################
+#####################################################
+sub store_answer {
+ my ($sname,$sdom,$symb,$partid,$respid,$dataset) = @_;
+ return if ($symb ne $current_symb);
+ if (defined($partid)) {
+ if (defined($respid)) {
+ $cache{$sname.':'.$sdom}->{$partid}->{$respid} = $dataset;
+ } else {
+ $cache{$sname.':'.$sdom}->{$partid} = $dataset;
+ }
+ } else {
+ $cache{$sname.':'.$sdom}=$dataset;
+ }
+ return;
+}
+
+}
+#####################################################
+#####################################################
+
+=pod
+
+=back
+
+=cut
+
+#####################################################
+#####################################################
+
+##
+## The following is copied from datecalc1.pl, part of the
+## Spreadsheet::WriteExcel CPAN module.
+##
+##
+######################################################################
+#
+# Demonstration of writing date/time cells to Excel spreadsheets,
+# using UNIX/Perl time as source of date/time.
+#
+# Copyright 2000, Andrew Benham, adsb@bigfoot.com
+#
+######################################################################
+#
+# UNIX/Perl time is the time since the Epoch (00:00:00 GMT, 1 Jan 1970)
+# measured in seconds.
+#
+# An Excel file can use exactly one of two different date/time systems.
+# In these systems, a floating point number represents the number of days
+# (and fractional parts of the day) since a start point. The floating point
+# number is referred to as a 'serial'.
+# The two systems ('1900' and '1904') use different starting points:
+# '1900'; '1.00' is 1 Jan 1900 BUT 1900 is erroneously regarded as
+# a leap year - see:
+# http://support.microsoft.com/support/kb/articles/Q181/3/70.asp
+# for the excuse^H^H^H^H^H^Hreason.
+# '1904'; '1.00' is 2 Jan 1904.
+#
+# The '1904' system is the default for Apple Macs. Windows versions of
+# Excel have the option to use the '1904' system.
+#
+# Note that Visual Basic's "DateSerial" function does NOT erroneously
+# regard 1900 as a leap year, and thus its serials do not agree with
+# the 1900 serials of Excel for dates before 1 Mar 1900.
+#
+# Note that StarOffice (at least at version 5.2) does NOT erroneously
+# regard 1900 as a leap year, and thus its serials do not agree with
+# the 1900 serials of Excel for dates before 1 Mar 1900.
+#
+######################################################################
+#
+# Calculation description
+# =======================
+#
+# 1900 system
+# -----------
+# Unix time is '0' at 00:00:00 GMT 1 Jan 1970, i.e. 70 years after 1 Jan 1900.
+# Of those 70 years, 17 (1904,08,12,16,20,24,28,32,36,40,44,48,52,56,60,64,68)
+# were leap years with an extra day.
+# Thus there were 17 + 70*365 days = 25567 days between 1 Jan 1900 and
+# 1 Jan 1970.
+# In the 1900 system, '1' is 1 Jan 1900, but as 1900 was not a leap year
+# 1 Jan 1900 should really be '2', so 1 Jan 1970 is '25569'.
+#
+# 1904 system
+# -----------
+# Unix time is '0' at 00:00:00 GMT 1 Jan 1970, i.e. 66 years after 1 Jan 1904.
+# Of those 66 years, 17 (1904,08,12,16,20,24,28,32,36,40,44,48,52,56,60,64,68)
+# were leap years with an extra day.
+# Thus there were 17 + 66*365 days = 24107 days between 1 Jan 1904 and
+# 1 Jan 1970.
+# In the 1904 system, 2 Jan 1904 being '1', 1 Jan 1970 is '24107'.
+#
+######################################################################
+#
+# Copyright (c) 2000, Andrew Benham.
+# This program is free software. It may be used, redistributed and/or
+# modified under the same terms as Perl itself.
+#
+# Andrew Benham, adsb@bigfoot.com
+# London, United Kingdom
+# 11 Nov 2000
+#
+######################################################################
+#-----------------------------------------------------------
+# calc_serial()
+#
+# Called with (up to) 2 parameters.
+# 1. Unix timestamp. If omitted, uses current time.
+# 2. GMT flag. Set to '1' to return serial in GMT.
+# If omitted, returns serial in appropriate timezone.
+#
+# Returns date/time serial according to $DATE_SYSTEM selected
+#-----------------------------------------------------------
+sub calc_serial {
+ # Use 1900 date system on all platforms other than Apple Mac (for which
+ # use 1904 date system).
+ my $DATE_SYSTEM = ($^O eq 'MacOS') ? 1 : 0;
+ my $time = (defined $_[0]) ? $_[0] : time();
+ my $gmtflag = (defined $_[1]) ? $_[1] : 0;
+ #
+ # Divide timestamp by number of seconds in a day.
+ # This gives a date serial with '0' on 1 Jan 1970.
+ my $serial = $time / 86400;
+ #
+ # Adjust the date serial by the offset appropriate to the
+ # currently selected system (1900/1904).
+ if ($DATE_SYSTEM == 0) { # use 1900 system
+ $serial += 25569;
+ } else { # use 1904 system
+ $serial += 24107;
+ }
+ #
+ unless ($gmtflag) {
+ # Now have a 'raw' serial with the right offset. But this
+ # gives a serial in GMT, which is false unless the timezone
+ # is GMT. We need to adjust the serial by the appropriate
+ # timezone offset.
+ # Calculate the appropriate timezone offset by seeing what
+ # the differences between localtime and gmtime for the given
+ # time are.
+ #
+ my @gmtime = gmtime($time);
+ my @ltime = localtime($time);
+ #
+ # For the first 7 elements of the two arrays, adjust the
+ # date serial where the elements differ.
+ for (0 .. 6) {
+ my $diff = $ltime[$_] - $gmtime[$_];
+ if ($diff) {
+ $serial += _adjustment($diff,$_);
+ }
+ }
+ }
+ #
+ # Perpetuate the error that 1900 was a leap year by decrementing
+ # the serial if we're using the 1900 system and the date is prior to
+ # 1 Mar 1900. This has the effect of making serial value '60'
+ # 29 Feb 1900.
+ #
+ # This fix only has any effect if UNIX/Perl time on the platform
+ # can represent 1900. Many can't.
+ #
+ unless ($DATE_SYSTEM) {
+ $serial-- if ($serial < 61); # '61' is 1 Mar 1900
+ }
+ return $serial;
+}
+
+sub _adjustment {
+ # Based on the difference in the localtime/gmtime array elements
+ # number, return the adjustment required to the serial.
+ #
+ # We only look at some elements of the localtime/gmtime arrays:
+ # seconds unlikely to be different as all known timezones
+ # have an offset of integral multiples of 15 minutes,
+ # but it's easy to do.
+ # minutes will be different for timezone offsets which are
+ # not an exact number of hours.
+ # hours very likely to be different.
+ # weekday will differ when localtime/gmtime difference
+ # straddles midnight.
+ #
+ # Assume that difference between localtime and gmtime is less than
+ # 5 days, then don't have to do maths for day of month, month number,
+ # year number, etc...
+ #
+ my ($delta,$element) = @_;
+ my $adjust = 0;
+ #
+ if ($element == 0) { # Seconds
+ $adjust = $delta/86400; # 60 * 60 * 24
+ } elsif ($element == 1) { # Minutes
+ $adjust = $delta/1440; # 60 * 24
+ } elsif ($element == 2) { # Hours
+ $adjust = $delta/24; # 24
+ } elsif ($element == 6) { # Day of week number
+ # Catch difference straddling Sat/Sun in either direction
+ $delta += 7 if ($delta < -4);
+ $delta -= 7 if ($delta > 4);
+ #
+ $adjust = $delta;
+ }
+ return $adjust;
+}
+
+###########################################################
+###########################################################
+
+=pod
+
+=item get_problem_data
+
+Returns a data structure describing the problem.
+
+Inputs: $url
+
+Returns: %Partdata
+
+=cut
+
+## note: we must force each foil and option to not begin or end with
+## spaces as they are stored without such data.
+##
+###########################################################
+###########################################################
+sub get_problem_data {
+ my ($url) = @_;
+ my $Answ=&Apache::lonnet::ssi($url,('grade_target' => 'analyze'));
+ (my $garbage,$Answ)=split(/_HASH_REF__/,$Answ,2);
+ my %Answer;
+ %Answer=&Apache::lonnet::str2hash($Answ);
+ my %Partdata;
+ foreach my $part (@{$Answer{'parts'}}) {
+ while (my($key,$value) = each(%Answer)) {
+ #
+ # Logging code:
+ if (0) {
+ &Apache::lonnet::logthis($part.' got key "'.$key.'"');
+ if (ref($value) eq 'ARRAY') {
+ &Apache::lonnet::logthis(' @'.join(',',@$value));
+ } else {
+ &Apache::lonnet::logthis(' '.$value);
+ }
+ }
+ # End of logging code
+ next if ($key !~ /^$part/);
+ $key =~ s/^$part\.//;
+ if (ref($value) eq 'ARRAY') {
+ if ($key eq 'options') {
+ $Partdata{$part}->{'_Options'}=$value;
+ } elsif ($key eq 'concepts') {
+ $Partdata{$part}->{'_Concepts'}=$value;
+ } elsif ($key =~ /^concept\.(.*)$/) {
+ my $concept = $1;
+ foreach my $foil (@$value) {
+ $Partdata{$part}->{'_Foils'}->{$foil}->{'_Concept'}=
+ $concept;
+ }
+ } elsif ($key =~ /^(incorrect|answer|ans_low|ans_high)$/) {
+ $Partdata{$part}->{$key}=$value;
+ }
+ } else {
+ if ($key=~ /^foil\.text\.(.*)$/) {
+ my $foil = $1;
+ $Partdata{$part}->{'_Foils'}->{$foil}->{'name'}=$foil;
+ $value =~ s/(\s*$|^\s*)//g;
+ $Partdata{$part}->{'_Foils'}->{$foil}->{'text'}=$value;
+ } elsif ($key =~ /^foil\.value\.(.*)$/) {
+ my $foil = $1;
+ $Partdata{$part}->{'_Foils'}->{$foil}->{'value'}=$value;
+ }
+ }
+ }
+ }
+ return %Partdata;
+}
+
+####################################################
+####################################################
+
+=pod
+
+=item &limit_by_time()
+
+=cut
+
+####################################################
+####################################################
+sub limit_by_time_form {
+ my $Starttime_form = '';
+ my $starttime = &Apache::lonhtmlcommon::get_date_from_form
+ ('limitby_startdate');
+ my $endtime = &Apache::lonhtmlcommon::get_date_from_form
+ ('limitby_enddate');
+ if (! defined($endtime)) {
+ $endtime = time;
+ }
+ if (! defined($starttime)) {
+ $starttime = $endtime - 60*60*24*7;
+ }
+ my $state;
+ if (&limit_by_time()) {
+ $state = '';
+ } else {
+ $state = 'disabled';
+ }
+ my $startdateform = &Apache::lonhtmlcommon::date_setter
+ ('Statistics','limitby_startdate',$starttime,undef,undef,$state);
+ my $enddateform = &Apache::lonhtmlcommon::date_setter
+ ('Statistics','limitby_enddate',$endtime,undef,undef,$state);
+ my $Str;
+ $Str .= '';
+ $Str .= '';
+ return $Str;
+}
+
+sub limit_by_time {
+ if (exists($ENV{'form.limit_by_time'}) &&
+ $ENV{'form.limit_by_time'} ne '' ) {
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+sub get_time_limits {
+ my $starttime = &Apache::lonhtmlcommon::get_date_from_form
+ ('limitby_startdate');
+ my $endtime = &Apache::lonhtmlcommon::get_date_from_form
+ ('limitby_enddate');
+ return ($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) = @_;
+ &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 $statuskey)
+ ) {
+ &Apache::lonstatistics::Gather_Full_Student_Data($r,$formname,
+ $inputname);
+ }
+ #
+ my @Buttons =
+ ('',
+ ''.
+ &Apache::loncommon::help_open_topic('Statistics_Cache'),
+ '',
+ ''
+ );
+ #
+ if (! exists($ENV{'form.firstrun'})) {
+ $r->print('');
+ } else {
+ $r->print('');
+ }
+ #
+ return @Buttons;
+}
+
+
+
+
+####################################################
+####################################################
+
+=pod
+
+=back
+
+=cut
+
+####################################################
+####################################################
+
1;
__END__