--- loncom/homework/structuretags.pm	2014/05/18 02:13:45	1.519
+++ loncom/homework/structuretags.pm	2014/12/15 18:44:20	1.526
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA 
 # definition of tags that give a structure to a document
 #
-# $Id: structuretags.pm,v 1.519 2014/05/18 02:13:45 raeburn Exp $
+# $Id: structuretags.pm,v 1.526 2014/12/15 18:44:20 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -254,6 +254,55 @@ function image_response_click (which, e)
     input_element.value = click;
     img_element.src = '/adm/randomlabel.png?token='+token+'&clickdata='+click;
 }
+
+var submithandled = 0;
+var keypresshandled = 0;
+
+$(document).ready(function(){
+
+    $(document).keypress(function(event){
+        var keycode = (event.keyCode ? event.keyCode : event.which);
+        if ((keycode == '13') && (keypresshandled == 0)) {
+            if ( $( document.activeElement ).hasClass("LC_textline") ) {
+                keypresshandled = 1;
+                var idsArray = $( document.activeElement ).attr("id").split(/HWVAL_/);
+                if (idsArray.length) {
+                    event.preventDefault();
+                    var itemsArray = idsArray[1].split(/_/);
+                    var buttonId = idsArray[0]+'submit_'+itemsArray[0];
+                    $("#"+buttonId).trigger("click");
+                }
+            }
+        }
+    });
+
+    $(document).delegate('form :submit', 'click', function( event ) {
+        if ( $( this ).hasClass( "LC_hwk_submit" ) ) {
+            var buttonId = this.id;
+            if (submithandled == 0) {
+                submithandled = 1;
+                $( "#msg_"+buttonId ).css({"display": "inline","background-color": "#87cefa",
+                                           "color": "black","padding": "2px"}) ;
+                if (( $(this.form).id == "LC_page" ) && ($('input[name="all_submit"]').length )) {
+                    if (buttonId != "all_submit") {
+                        $( ".LC_status_"+buttonId ).hide();
+                        if (( "#"+buttonId+"_pressed" ).length) {
+                            $( "#"+buttonId+"_pressed" ).val( "1" );
+                        }
+                    }
+                } else {
+                    $( ".LC_status_"+buttonId ).hide();
+                }
+                $(this.form).submit();
+                $( ".LC_hwk_submit" ).prop( "disabled", true);
+                $( ".LC_textline" ).prop( "readonly", "readonly");
+                event.preventDefault();
+                return true;
+            }
+        }
+    });
+});
+
 // ]]>
 </script>
 JS
@@ -370,6 +419,9 @@ sub page_start {
 		"if (typeof swmenu != 'undefined') {swmenu.currentURL=null;}\n".
 		&Apache::loncommon::browser_and_searcher_javascript().
                 "\n</script>\n";
+            if ($target eq 'edit') {
+                $extra_head .= &Apache::edit::js_update_linknum();
+            }
 	}
     }
 
@@ -832,7 +884,7 @@ sub initialize_storage {
 	}
 	%Apache::lonhomework::history=
 	    &Apache::lonnet::tmprestore($namespace,'',$domain,$name);
-	my ($temp)=keys %Apache::lonhomework::history ;
+	my ($temp)=keys(%Apache::lonhomework::history) ;
 	&Apache::lonxml::debug("Return message of $temp");
     } else {
 	%Apache::lonhomework::history=
@@ -840,7 +892,7 @@ sub initialize_storage {
     }
 
     #ignore error conditions
-    my ($temp)=keys %Apache::lonhomework::history ;
+    my ($temp)=keys(%Apache::lonhomework::history);
     if ($temp =~ m/^error:.*/) { %Apache::lonhomework::history=(); }
 }
 
@@ -848,12 +900,37 @@ sub initialize_storage {
 
 =item finalize_storage()
 
-	Stores away the result has to a student's environment
-	checks form.grade_ for specific values, other wises stores
-	to the running users environment
-	Will increment totals for attempts, students, and corrects
-	if running user has student role.
-	
+	Stores away the result hash to a student's environment;
+	checks form.grade_ for specific values, otherwise stores
+	to the running user's environment.
+
+        &check_correctness_changes() is called in two circumstances
+        in which the results hash is to be stored permanently, for
+        grading triggered by a student's submission, where feedback on
+        correctness is to be provided to the student. 
+
+        1. Immediately prior to storing the results hash
+
+        To handle the case where a student's submission (and award) were 
+        stored after history was retrieved in &initialize_storage(), e.g.,
+        if a student submitted answers in quick succession (e.g., from 
+        multiple tabs).  &Apache::inputtags::hidealldata() is called for
+        any parts with out-of-order storage (i.e., correct then incorrect,
+        where awarded >= 1 when correct).
+
+        2. Immediately after storing the results hash
+
+        To handle the case where lond on the student's homeserver returns
+        delay:N -- where N is the number of transactions between the last
+        retrieved in &initialize_storage() and the last stored immediately
+        before permanent storage of the current transaction via 
+        lond::store_handler().  &Apache::grades::makehidden() is called  
+        for any parts with out-of-order storage (i.e., correct then incorrect,
+        where awarded >= 1 when correct).
+
+	Will call &store_aggregates() to increment totals for attempts, 
+        students, and corrects, if running user has student role.
+
 =cut
 
 
@@ -874,8 +951,92 @@ sub finalize_storage {
 					      $namespace,'',$domain,$name);
 	    &Apache::lonxml::debug('Construct Store return message:'.$result);
 	} else {
+            my ($laststore,$checkedparts,@parts,%postcorrect);
+            if (($env{'user.name'} eq $name) && ($env{'user.domain'} eq $domain) &&
+                (!$Apache::lonhomework::scantronmode) && (!defined($env{'form.grade_symb'})) &&
+                (!defined($env{'form.grade_courseid'}))) {
+                if ($Apache::lonhomework::history{'version'}) {
+                    $laststore = $Apache::lonhomework::history{'version'}.'='.
+                                 $Apache::lonhomework::history{'timestamp'};
+                } else {
+                    $laststore = '0=0';
+                }
+                my %record = &Apache::lonnet::restore($symb,$courseid,$domain,$name);
+                if ($record{'version'}) {
+                    my ($newversion,$oldversion,$oldtimestamp);
+                    if ($Apache::lonhomework::history{'version'}) {
+                        $oldversion = $Apache::lonhomework::history{'version'};
+                        $oldtimestamp = $Apache::lonhomework::history{'timestamp'};
+                    } else {
+                        $oldversion = 0;
+                        $oldtimestamp = 0;
+                    }
+                    if ($record{'version'} > $oldversion) {
+                        if ($record{'timestamp'} >= $oldtimestamp) {
+                            $laststore = $record{'version'}.'='.$record{'timestamp'};
+                            $newversion = $record{'version'} + 1;
+                            $checkedparts = 1;
+                            foreach my $key (keys(%Apache::lonhomework::results)) {
+                                if ($key =~ /^resource\.([^\.]+)\.solved$/) {
+                                    my $part = $1;
+                                    if ($Apache::lonhomework::results{$key} eq 'incorrect_attempted') {
+                                        push(@parts,$part);
+                                    }
+                                }
+                            }
+                            if (@parts) {
+                                my @parts_to_hide = &check_correctness_changes($symb,$courseid,$domain,$name,
+                                                                               \%record,\@parts,$newversion,
+                                                                               $oldversion);
+                                if (@parts_to_hide) {
+                                    foreach my $part (@parts_to_hide) {
+                                        $postcorrect{$part} = 1;
+                                        &Apache::inputtags::hidealldata($part);
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
 	    $result=&Apache::lonnet::cstore(\%Apache::lonhomework::results,
-					    $symb,$courseid,$domain,$name);
+					    $symb,$courseid,$domain,$name,$laststore);
+            if ($result =~ /^delay\:(\d+)$/) {
+                my $numtrans = $1;
+                my ($oldversion) = split(/=/,$laststore);
+                if ($numtrans) {
+                    my $newversion = $oldversion + 1 + $numtrans;
+                    my @possparts;
+                    if ($checkedparts) {
+                        foreach my $part (@parts) {
+                            unless ($postcorrect{$part}) {
+                                push(@possparts,$part);
+                            }
+                        }
+                    } else {
+                        foreach my $key (keys(%Apache::lonhomework::results)) {
+                            if ($key =~ /^resource\.([^\.]+)\.solved$/) {
+                                my $part = $1;
+                                unless ($postcorrect{$part}) {
+                                    if ($Apache::lonhomework::results{$key} eq 'incorrect_attempted') {
+                                        push(@possparts,$part);
+                                    }
+                                }
+                            }
+                        }
+                    }
+                    if (@possparts) {
+                        my %newrecord = &Apache::lonnet::restore($symb,$courseid,$domain,$name);
+                        my @parts_to_hide = &check_correctness_changes($symb,$courseid,$domain,$name,
+                                                                       \%newrecord,\@possparts,$newversion,
+                                                                       $oldversion);
+                        if (@parts_to_hide) {
+                            my $partslist = join(',',@parts_to_hide);
+                            &Apache::grades::makehidden($newversion,$partslist,\%newrecord,$symb,$domain,$name,1);
+                        }
+                    }
+                }
+            }
 	    &Apache::lonxml::debug('Store return message:'.$result);
             &store_aggregates($symb,$courseid);
 	}
@@ -887,6 +1048,62 @@ sub finalize_storage {
 
 =pod
 
+=item check_correctness_changes()
+
+        For all parts for which current results contain a solved status
+        of "incorrect_attempted", check if there was a transaction in which  
+        solved was set to "correct_by_student" in the time since the last 
+        transaction (retrieved when &initialize_storage() was called i.e., 
+        when &start_problem() was called), unless:
+        (a) questiontype parameter is set to survey or anonymous survey (+/- credit)
+        (b) problemstatus is set to no or no_feedback_ever
+        If such a transaction exists, and did not occur after "reset status" 
+        by a user with grading privileges, then the current transaction is an
+        example of an out-of-order transaction (i.e., incorrect occurring after
+        correct).  Accordingly, the current transaction should be hidden.
+
+=cut
+
+
+sub check_correctness_changes {
+    my ($symb,$courseid,$domain,$name,$record,$parts,$newversion,$oldversion) = @_;
+    my @parts_to_hide;
+    unless ((ref($record) eq 'HASH') && (ref($parts) eq 'ARRAY')) {
+        return @parts_to_hide;
+    }
+    if (@{$parts}) {
+        my $usec;
+        if (($env{'user.name'} eq $name) && ($env{'user.domain'} eq $domain) &&
+            ($env{'request.course.id'} eq $courseid)) {
+            $usec = $env{'request.course.sec'};
+        } else {
+            $usec = &Apache::lonnet::getsection($domain,$name,$courseid);
+        }
+        foreach my $id (@{$parts}) {
+            next if (($Apache::lonhomework::results{'resource.'.$id.'.type'} =~ /survey/) ||
+                     (&Apache::lonnet::EXT("resource.$id.problemstatus",$symb,
+                                           $domain,$name,$usec,undef,$courseid) =~ /^no/));
+            my $reset;
+            for (my $i=$newversion-1; $i>=$oldversion; $i--) {
+                if (($record->{$i.':resource.'.$id.'.regrader'}) &&
+                    ($record->{$i.':resource.'.$id.'.tries'} eq '') &&
+                    ($record->{$i.':resource.'.$id.'.award'} eq '')) {
+                    $reset = 1;
+                } elsif (($record->{$i.":resource.$id.solved"} eq 'correct_by_student') &&
+                         ($record->{$i.":resource.$id.awarded"} >= 1)) {
+                    unless ($reset) {
+                        push(@parts_to_hide,$id);
+                        last;
+                    }
+                }
+            }
+        }
+    }
+    return @parts_to_hide;
+}
+
+=pod
+
 item store_aggregates()
 
 	Sends hash of values to be incremented in nohist_resourcetracker.db
@@ -949,7 +1166,7 @@ sub store_aggregates {
             }
         }
     }
-    if (keys (%aggregate) > 0) {
+    if (keys(%aggregate) > 0) {
 	&Apache::lonnet::cinc('nohist_resourcetracker',\%aggregate,
                             $cdomain,$cname);
     }
@@ -1400,7 +1617,7 @@ sub end_problem {
 	my $id = $Apache::inputtags::part;
 	my $weight = &Apache::lonnet::EXT("resource.$id.weight");
 	my $packages=&Apache::lonnet::metadata($env{'request.uri'},'packages');
-	my @packages = split /,/,$packages;
+	my @packages = split(/,/,$packages);
 	my $allow_print_points = 0;
 	foreach my $partial_key (@packages) {
 	    if ($partial_key=~m/^part_0$/) {
@@ -2134,8 +2351,8 @@ sub start_randomlist {
                     }
                 }
             }
-	    for(0 .. $show) {
-		$bodytext .= "$randomlist[ $idx_arr[$_] ]";
+	    for my $i (0 .. $show) {
+		$bodytext .= "$randomlist[ $idx_arr[$i] ]";
 	    }
 	    &Apache::lonxml::newparser($parser,\$bodytext);
 	}
@@ -2299,7 +2516,7 @@ sub start_part {
 		    }
 		    my $weight = &Apache::lonnet::EXT("resource.$id.weight");
 		    my $allkeys=&Apache::lonnet::metadata($env{'request.uri'},'packages');
-		    my @allkeys = split /,/,$allkeys;
+		    my @allkeys = split(/,/,$allkeys);
 		    my $allow_print_points = 0;
 		    foreach my $partial_key (@allkeys) {
 			if ($partial_key=~m/^part_(.*)$/) {