[LON-CAPA-cvs] cvs: loncom /lonnet/perl lonnet.pm

[albertel]

albertel		Thu Feb 23 13:15:18 2006 EDT

  Modified files:              
    /loncom/lonnet/perl	lonnet.pm 
  Log:
  - changing the way conditions are stored, no longer are they a complete
    definiton of all of the individual expresssions but now allow the use
    of _<num>.<num> which point to another condition
  - directcondval now understands the existance of these condition pointers,
    looks them up and recurses into docondval to evaluate them
  
  
  
Index: loncom/lonnet/perl/lonnet.pm
diff -u loncom/lonnet/perl/lonnet.pm:1.712 loncom/lonnet/perl/lonnet.pm:1.713
--- loncom/lonnet/perl/lonnet.pm:1.712	Tue Feb 21 17:39:28 2006
+++ loncom/lonnet/perl/lonnet.pm	Thu Feb 23 13:15:16 2006
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.712 2006/02/21 22:39:28 albertel Exp $
+# $Id: lonnet.pm,v 1.713 2006/02/23 18:15:16 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -4699,11 +4699,30 @@
 
 # -------------------------------------------------------- Value of a Condition
 
+# gets the value of a specific preevaluated condition
+#    stored in the string  $env{user.state.<cid>}
+# or looks up a condition reference in the bighash and if if hasn't
+# already been evaluated recurses into docondval to get the value of
+# the condition, then memoizing it to 
+#   $env{user.state.<cid>.<condition>}
 sub directcondval {
     my $number=shift;
     if (!defined($env{'user.state.'.$env{'request.course.id'}})) {
 	&Apache::lonuserstate::evalstate();
     }
+    if (exists($env{'user.state.'.$env{'request.course.id'}.".$number"})) {
+	return $env{'user.state.'.$env{'request.course.id'}.".$number"};
+    } elsif ($number =~ /^_/) {
+	my $sub_condition;
+	if (tie(my %bighash,'GDBM_File',$env{'request.course.fn'}.'.db',
+		&GDBM_READER(),0640)) {
+	    $sub_condition=$bighash{'conditions'.$number};
+	    untie(%bighash);
+	}
+	my $value = &docondval($sub_condition);
+	&appenv('user.state.'.$env{'request.course.id'}.".$number" => $value);
+	return $value;
+    }
     if ($env{'user.state.'.$env{'request.course.id'}}) {
        return substr($env{'user.state.'.$env{'request.course.id'}},$number,1);
     } else {
@@ -4711,43 +4730,49 @@
     }
 }
 
+# get the collection of conditions for this resource
 sub condval {
     my $condidx=shift;
-    my $result=0;
     my $allpathcond='';
-    foreach (split(/\|/,$condidx)) {
-       if (defined($env{'acc.cond.'.$env{'request.course.id'}.'.'.$_})) {
-	   $allpathcond.=
-               '('.$env{'acc.cond.'.$env{'request.course.id'}.'.'.$_}.')|';
-       }
+    foreach my $cond (split(/\|/,$condidx)) {
+	if (defined($env{'acc.cond.'.$env{'request.course.id'}.'.'.$cond})) {
+	    $allpathcond.=
+		'('.$env{'acc.cond.'.$env{'request.course.id'}.'.'.$cond}.')|';
+	}
     }
     $allpathcond=~s/\|$//;
-    if ($env{'request.course.id'}) {
-       if ($allpathcond) {
-          my $operand='|';
-	  my @stack;
-           foreach ($allpathcond=~/(\d+|\(|\)|\&|\|)/g) {
-              if ($_ eq '(') {
-                 push @stack,($operand,$result)
-              } elsif ($_ eq ')') {
-                  my $before=pop @stack;
-		  if (pop @stack eq '&') {
-		      $result=$result>$before?$before:$result;
-                  } else {
-                      $result=$result>$before?$result:$before;
-                  }
-              } elsif (($_ eq '&') || ($_ eq '|')) {
-                  $operand=$_;
-              } else {
-                  my $new=directcondval($_);
-                  if ($operand eq '&') {
-                     $result=$result>$new?$new:$result;
-                  } else {
-                     $result=$result>$new?$result:$new;
-                  }
-              }
-          }
-       }
+    return &docondval($allpathcond);
+}
+
+#evaluates an expression of conditions
+sub docondval {
+    my ($allpathcond) = @_;
+    my $result=0;
+    if ($env{'request.course.id'}
+	&& defined($allpathcond)) {
+	my $operand='|';
+	my @stack;
+	foreach my $chunk ($allpathcond=~/(\d+|_\d+\.\d+|\(|\)|\&|\|)/g) {
+	    if ($chunk eq '(') {
+		push @stack,($operand,$result);
+	    } elsif ($chunk eq ')') {
+		my $before=pop @stack;
+		if (pop @stack eq '&') {
+		    $result=$result>$before?$before:$result;
+		} else {
+		    $result=$result>$before?$result:$before;
+		}
+	    } elsif (($chunk eq '&') || ($chunk eq '|')) {
+		$operand=$chunk;
+	    } else {
+		my $new=directcondval($chunk);
+		if ($operand eq '&') {
+		    $result=$result>$new?$new:$result;
+		} else {
+		    $result=$result>$new?$result:$new;
+		}
+	    }
+	}
     }
     return $result;
 }