--- loncom/interface/lonprintout.pm	2005/09/01 18:39:47	1.381.2.1
+++ loncom/interface/lonprintout.pm	2005/08/15 22:39:43	1.383
@@ -1,7 +1,7 @@
 #  The LearningOnline Network
 # Printout
 #
-# $Id: lonprintout.pm,v 1.381.2.1 2005/09/01 18:39:47 albertel Exp $
+# $Id: lonprintout.pm,v 1.383 2005/08/15 22:39:43 foxr Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -44,6 +44,100 @@ use Apache::lonlocal;
 
 my $resources_printed = '';
 
+#  Determine if a code is a valid numeric code.  Valid
+#  numeric codes must be comprised entirely of digits and
+#  have a maximum number of allowable digits.
+#
+#  Parameters:
+#     value      - proposed code value.
+#     max_digits - Maximum digits allowed.
+#
+sub is_valid_numeric_code {
+    my ($value, $max_digits) = @_;
+    #   Remove leading/trailing whitespace;
+    $value =~ s/^\s*//;
+    $value =~ s/\s*$//;
+    
+    #  All digits?
+
+    if ($value =~ /^[0-9]+$/) {
+	if (length($value) <= $max_digits) {
+	    return undef;
+	} else {
+	    return "Numeric code $value  has too many digits (max = $max_digits)";
+	}
+    } else {
+	return "Numeric code $value has invalid characters - must only be digits";
+    }
+}
+#   Determines if a code is a valid alhpa code.  Alpha codes
+#   are ciphers that map  [A-J,a-j] -> 0..9 0..9.
+#   They also have a maximum digit count.
+# Parameters:
+#     value          - Proposed code value.
+#     max_letters    - Maximum number of letters.
+# Note:
+#    leading and trailing whitespace are ignored.
+#
+sub is_valid_alpha_code {
+    my ($value, $max_letters) = @_;
+    
+     # strip leading and trailing spaces.
+
+    $value =~ s/^\s*//g;
+    $value =~ s/\s*$//g;
+
+    #  All alphas in the right range?
+
+    if ($value =~ /^[A-J,a-j]+$/) {
+	if (length($value) <= $max_letters) {
+	    return undef;
+	} else {
+	    return "Letter code $value has too many letters (max = $max_letters)";
+	}
+    } else {
+	return "Invalid letter code $value must only contain A-J";
+    }
+}
+
+#   Determine if a code entered by the user in a helper is valid.
+#   valid depends on the code type and the type of code selected.
+#   The type of code selected can either be numeric or 
+#   Alphabetic.  If alphabetic, the code, in fact is a simple
+#   substitution cipher for the actual numeric code: 0->A, 1->B ...
+#   We'll be nice and be case insensitive for alpha codes.
+# Parameters:
+#    code_value    - the value of the code the user typed in.
+#    code_option   - The code type selected from the set in the scantron format
+#                    table.
+# Returns:
+#    undef         - The code is valid.
+#    other         - An error message indicating what's wrong.
+#
+sub is_code_valid {
+    my ($code_value, $code_option) = @_;
+    my ($code_type, $code_length) = ('letter', 6);	# defaults.
+    open(FG, $Apache::lonnet::perlvar{'lonTabDir'}.'/scantronformat.tab');
+    foreach my $line (<FG>) {
+	my ($name, $type, $length) = (split(/:/, $line))[0,2,4];
+	if($name eq $code_option) {
+	    $code_length = $length;
+	    if($type eq 'number') {
+		$code_type = 'number';
+	    }
+	}
+    }
+    my $valid;
+    if ($code_type eq 'number') {
+	$valid = &is_valid_numeric_code($code_value, $code_length);
+    } else {
+	$valid = &is_valid_alpha_code($code_value, $code_length);
+    }
+  
+
+    return "Entering a single code is not supported (yet): $code_type $code_length $valid";
+}
+
 #   Compare two students by name.  The students are in the form
 #   returned by the helper:
 #      user:domain:section:last,   first:status
@@ -390,7 +484,6 @@ sub character_chart {
     $result =~ s/&(prod|\#8719);/\\ensuremath\{\\prod\}/g;
     $result =~ s/&(sum|\#8721);/\\ensuremath\{\\sum\}/g;
     $result =~ s/&(minus|\#8722);/\\ensuremath\{-\}/g;
-    $result =~ s/–/\\ensuremath\{-\}/g;
     $result =~ s/&(lowast|\#8727);/\\ensuremath\{*\}/g;
     $result =~ s/&(radic|\#8730);/\\ensuremath\{\\surd\}/g;
     $result =~ s/&(prop|\#8733);/\\ensuremath\{\\propto\}/g;
@@ -1990,13 +2083,29 @@ CHOOSE_STUDENTS
     <string variable="NUMBER_TO_PRINT_TOTAL" maxlength="5" size="5">
        <validator>
 	if (((\$helper->{'VARS'}{'NUMBER_TO_PRINT_TOTAL'}+0) < 1) &&
-	    !\$helper->{'VARS'}{'REUSE_OLD_CODES'}) {
+	    !\$helper->{'VARS'}{'REUSE_OLD_CODES'}                &&
+            !\$helper->{'VARS'}{'SINGLE_CODE'}) {
 	    return "You need to specify the number of assignments to print";
 	}
 	return undef;
        </validator>
     </string>
     <message></td></tr><tr><td></message>
+    <message><b>Value of CODE to print?</b></td><td></message>
+    <string variable="SINGLE_CODE" size="10" defaultvalue="zzzz">
+        <validator>
+           # Not sure of exact call context so...
+	   use Apache::lonprintout;
+	   if(!\$helper->{'VARS'}{'NUMBER_TO_PRINT_TOTAL'}           &&
+	      !\$helper->{'VARS'}{'REUSE_OLD_CODES'}) {
+	      return &Apache::lonprintout::is_code_valid(\$helper->{'VARS'}{'SINGLE_CODE'},
+						      \$helper->{'VARS'}{'CODE_OPTION'});
+	   } else {
+	       return undef;	# Other forces control us.
+	   }
+        </validator>
+    </string>
+    <message></td></tr><tr><td></message>
     <message><b>Names to store the CODEs under for later:</b></message>
     <message></td><td></message>
     <string variable="ANON_CODE_STORAGE_NAME" maxlength="50" size="20" />