On Thu, Nov 13, 2008 at 3:09 PM, Todd Rinaldo <[EMAIL PROTECTED]> wrote:
> On Thu, Nov 13, 2008 at 2:05 PM, Sean McAfee <[EMAIL PROTECTED]> wrote:
> > On Thu, Nov 13, 2008 at 10:58 AM, Todd Rinaldo <[EMAIL PROTECTED]> wrote:
> >>
> >> My question: Is there any easy way to make a recursive block that can
> >> test if an unpredictably deep hash is defined?
> >
> > Perhaps, but it would be easier to write a routine in Perl:
> >
> > sub nested {
> > my ($hash, @keys) = @_;
> > for my $key (@keys) {
> > return if ref $hash ne 'HASH' || !exists $hash->{$key};
> > $hash = $hash->{$key};
> > }
> > return 1;
> > }
> >
> > Provide the function to your template, and then you could say:
> >
> > [% NEXT IF !nested(hash, 'fi', 'fo', 'fum', 'bar') %]
> >
> > Alternately, you could make it a new hash vmethod.
> >
>
> Sean, a perl routine would be easier, but my restriction is my
> inability to turn off {TOLERANT => 0, EVAL_PERL => 0}.
>
The TOLERANT flag isn't really relevant to this situation, and the EVAL_PERL
flag only applies to Perl code that's encountered within the body of a
template. To see this, combine the following code with the nested()
function above:
my %hash = ( a => { b => { c => { d => 1 } } } );
my $template = Template->new({ TOLERANT => 0, EVAL_PERL => 0 });
$template->process(
\ '[% nested(hash, "a", "b", "c", "d") %]',
{ nested => \&nested, hash => \%hash }
) or die $template->error;
It prints "1".
It sounds like the vmethod is the way to go, but I'm not clear how to
> do that can you point me to where I could find an example?
>
See:
http://tt2.org/docs/manual/VMethods.html#section_Defining_Custom_Virtual_Methods
In short, you can say:
use Template::Stash;
$Template::Stash::HASH_OPS->{nested} = \&nested;
Then you can say
[% hash.nested("a", "b", "c", "d") %]
If you go this route, you no longer need to supply "nested" as a template
variable, as in my original example.
--Sean
_______________________________________________
templates mailing list
[email protected]
http://mail.template-toolkit.org/mailman/listinfo/templates
