desertrat has asked for the wisdom of the Perl Monks concerning the following question:

I'm trying to use Date::Manip::Recur to generate a list of dates for a room scheduling application, and I'm having trouble getting it to work correctly.

Per the docs, there's an OO way and a functional way of doing this.

The functional way works:

#!/usr/bin/perl
use Date::Manip;
@date = ParseRecur("0:0:1*1,3,5:0:0:0","May 25 2010","6/1/2010","8/30/
+2010");# every MWF between the two dates.
foreach $i (@date){
print "The date is $i\n";
}
exit;

[download]

results in:

The date is 2010060200:00:00
The date is 2010060400:00:00
The date is 2010060700:00:00
The date is 2010060900:00:00
The date is 2010061100:00:00
The date is 2010061400:00:00
The date is 2010061600:00:00
The date is 2010061800:00:00
The date is 2010062100:00:00

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and so on.

But

#!/usr/bin/perl

use Date::Manip;

print "Starting....\n";

$recur = new Date::Manip::Recur;

$start = $recur->new_date();
$end   = $recur->new_date();
$base = $recur->new_date();

$err=$start->parse("Jun 1 2010");
print "start err is $err \n";

$err=$end->parse("Aug 30 2010");
print "end err is $err \n";

$err=$base->parse("May 25 2010");
print "base err is $err \n";

$err=$recur->frequency("0:0:1*1,3,5:0:0:0");
print "freq err is $err \n";

@date = $recur->dates();
print "dates err is $err \n";

foreach $i (@date){
print "The date is $i\n";
}
exit;

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gives me:

Starting....
start err is 0 
end err is 0 
base err is 0 
freq err is 0 
dates err is 0

[download]

And nothing more.

I cannot even get the OO example given in the docs to work.

anyone here used this, and can point out my no doubt boneheaded mistake, before I bug the author?

Replies are listed 'Best First'.
Re: Date::Manip::Recur is not returning a list
by andreas1234567 (Vicar) on Jun 24, 2010 at 19:34 UTC
    It would always be a good idea to enable strict and warnings.

    From looking at the tests it looks like parse returns a true/false value depending on parse success/failure, and not the actual date(s). 

    $ perl -l
use strict;
use warnings;

use Date::Manip;

my $obj = new Date::Manip::Recur;
my $err = $obj->parse(
  qw(1:2:3:4*12:30:00
    2000010500:00:00
    2000010100:00:00
    2003010100:00:00
    )
);
die $obj->err() if $err;

my @dates = $obj->dates();
foreach my $date (@dates) {
  print $date->value;
}

__END__
200015123000
2001330123000
2002624123000
$

    [download]
    --
    No matter how great and destructive your problems may seem now, remember, you've probably only seen the tip of them. [1]
[reply]
[d/l]
[select]

      Yes, $recur->parse() only parses the recurrence string, it's $recur->dates() that returns the list of dates. What I don't understand is why it isn't in my case. Clearly it worked for you.

      When I try to replicate your code example, I get something new! I'm getting a list, but instead of a list of strings it's a list of hashes...

      #!/usr/bin/perl
use strict;
use warnings;
use Date::Manip;

print "Content-type: text/html \n\n";

print "Starting....<p>";

my $freq = "0:1:0*25:0:0:0";
my $mod = "DWD";
my $sday = "Jan 1 2010";
my $eday = "Dec 30 2010";
my $bday = "Jan 1 2010";

my $recur = new Date::Manip::Recur;

my $err =$recur->parse($freq,$bday,$sday,$eday);
print "parse err is $err <p>";

my @date = $recur->dates();

my $datenum = @date;

print "There are $datenum list members <p>";

foreach my $i (@date){
print "The date is $i->value<p>";
}
exit;

      [download]
      Starting....
parse err is 0

There are 12 list members

The date is Date::Manip::Date=HASH(0x8404c00)->value

The date is Date::Manip::Date=HASH(0x83ff830)->value

...

      [download]
      headdesk
[reply]
[d/l]
[select]
        print "The date is $i->value<p>";

        Method calls don't interpolate.  You're interpolating just the value of $i (which is an object/hashref), and the "->value" prints as is. Try 

        print "The date is ", $i->value, "<p>";

        [download]
[reply]
[d/l]
[select]

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