[WWcvs] pg: Added context flags to more finely control the allowed entry format (e.g., force the use of commas, force the use of decimal

[dpvc v. a. <we...@ma...>]

Log Message:
-----------
Added context flags to more finely control the allowed entry format
(e.g., force the use of commas, force the use of decimal places, and
so on.)  See the documentation at the top of the file for details.

Modified Files:
--------------
    pg/macros:
        contextCurrency.pl

Revision Data
-------------
Index: contextCurrency.pl
===================================================================
RCS file: /webwork/cvs/system/pg/macros/contextCurrency.pl,v
retrieving revision 1.4
retrieving revision 1.5
diff -Lmacros/contextCurrency.pl -Lmacros/contextCurrency.pl -u -r1.4 -r1.5
--- macros/contextCurrency.pl
+++ macros/contextCurrency.pl
@@ -99,6 +99,27 @@
  #
  #  would allow the student to enter just 150 rather than $150.
  #
+ #  By default, the students may omit the commas, but you can
+ #  force them to supply the commas using forceCommas=>1 in
+ #  your cmp() call.
+ #
+ #    ANS(Compute('$10,000.00')->cmp(forceCommas=>1));
+ #
+ #  By default, students need not enter decimal digits, so could use
+ #  $100 or $1,000. as valid entries.  You can require that the cents
+ #  be provided using the forceDecimals=>1 flag.
+ #
+ #    ANS(Compute('$10.95')->cmp(forceDecimals=>1));
+ #
+ #  By default, if the monitary value includes decimals digits, it
+ #  must have exactly two.  You can weaken this requirement to all
+ #  any number of decimals by using noExtraDecimals=>0.
+ #
+ #    ANS(Compute('$10.23372')->cmp(noExtraDecimals=>0);
+ #
+ #  If forceDecimals is set to 1 at the same time, then they must
+ #  have 2 or more decimals, otherwise any number is OK.
+ #
  ######################################################################
 
 =cut
@@ -180,7 +201,14 @@
     $symbol => {precedence => 10, associativity => $associativity, type => "unary", string => $symbol,
                 TeX => Currency::quoteTeX($symbol), class => 'Currency::UOP::currency'},
   );
-  $context->flags->set(tolerance => .005, tolType => "absolute", promoteReals => 1);
+  $context->flags->set(
+    tolerance => .005,
+    tolType => "absolute",
+    promoteReals => 1,
+    forceCommas => 0,
+    forceDecimals => 0,
+    noExtraDecimals => 1,
+  );
   $context->{_initialized} = 1;
   $context->update;
   $context->{error}{msg}{"Missing operand after '%s'"} = "There should be a number after '%s'";
@@ -316,7 +344,9 @@
 
 sub new {
   my $self = shift; my $equation = shift;
-  my $pattern = $equation->{context}{pattern};
+  my $context = $equation->{context};
+  my $pattern = $context->{pattern};
+  my $currency = $context->{currency};
   my $value = shift; my $value_string;
   if (ref($value) eq "") {
     $value_string = "$value";
@@ -348,16 +378,19 @@
 our @ISA = ('Parser::UOP');
 
 sub _check {
-  my $self = shift; my $decimal = $self->context->{pattern}{currencyDecimal};
-  my $op = $self->{op};
+  my $self = shift;
+  my $context = $self->context;
+  my $decimal = $context->{pattern}{currencyDecimal};
+  my $op = $self->{op}; my $value = $op->{value_string};
   $self->Error("'%s' can only be used with numeric constants",$self->{uop})
     unless $op->type eq 'Number' && $op->class eq 'Number';
-  ### FIXME: these checks should be controlled by context flags
-  ###   (e.g., force to have decimals, allow extra decimals, force commas, etc.)
   $self->{ref} = $op->{ref}; # highlight the number, not the operator
+  $self->Error("You should have a '%s' every 3 digits",$context->{currency}{comma})
+    if $context->flag("forceCommas") && $value =~ m/\d\d\d\d/;
   $self->Error("Monetary values must have exactly two decimal places")
-   if $op->{value_string} && $op->{value_string} =~ m/$decimal\d/ &&
-      $op->{value_string} !~ m/$decimal\d\d$/;
+   if $value && $value =~ m/$decimal\d/ && $value !~ m/$decimal\d\d$/ && $context->flag('noExtraDecimals');
+  $self->Error("Monitary values require two decimal places",shift)
+    if $context->flag("forceDecimals") && $value !~ m/$decimal\d\d$/;
   $self->{type} = {%{$op->typeRef}};
   $self->{isCurrency} = 1;
 }