sequence. To output the next number in the sequence, all a user has to do
is write this on a wiki page:
- [[fib ]]
+ \[[!fib]]
-When the page is built, the inclusion will be replaced by the next number in the
-sequence.
+When the page is built, the [[ikiwiki/directive]] will be
+replaced by the next number in the sequence.
Most of ikiwiki's plugins are written in Perl, and it's currently easiest
to write them in Perl. So, open your favorite text editor and start
use warnings;
use strict;
- use IkiWiki 2.00;
+ use IkiWiki 3.00;
Ok, boilerplate is out of the way. Now to add the one function that ikiwiki
expects to find in any module: `import`. The import function is called when
}
This has hooked our plugin into the preprocess hook, which ikiwiki uses to
-expand [[PreprocessorDirectives|ikiwiki/preprocessordirective]]. Notice
+expand preprocessor [[directives|ikiwiki/directive]]. Notice
that "fib" has shown up again. It doesn't actually have to match the module
name this time, but it generally will. This "fib" is telling ikiwiki what
-kind of PreprocessorDirective to handle, namely one that looks like this:
+kind of preprocessor directive to handle, namely one that looks like this:
- [[fib ]]
+ [[!fib ]]
Notice the `\&preprocess`? This is how you pass a reference to a function,
and the `preprocess` function is the one that ikiwiki will call to expand
-the PreprocessorDirective. So, time to write that function:
+the preprocessor directive. So, time to write that function:
sub preprocess {
my %params=@_;
Feel free to try it out with a simple page like this:
- [[fib ]], [[fib ]], [[fib ]], [[fib ]], [[fib ]]
+ [[!fib ]], [[!fib ]], [[!fib ]], [[!fib ]], [[!fib ]]
Looks like it works ok, doesn't it? That creates a page that lists:
and the standalone page another. The numbers might even skip over part of
the sequence in some cases.
-Obviously, using a global `$last` veriable was a bad idea. It would
+Obviously, using a global `$last` variable was a bad idea. It would
work ok in a more regular cgi-based wiki, which only outputs one page per
run. But since ikiwiki is a wiki *compiler*, things are a bit more
complicated. It's not very hard to fix, though, if we do want the sequence
It would be nice to be able to jump directly to a given point in the
sequence:
- \[[fib seed=20]], [[fib ]], [[fib ]]
+ \[[!fib seed=20]], [[!fib ]], [[!fib ]]
Just insert these lines of code inside `preprocess`, in the appropriate
spot:
}
my $num=$last{$page}++;
if ($num > 25) {
- return "[[fib will only calculate the first 25 numbers in the sequence]]";
+ error "can only calculate the first 25 numbers in the sequence";
}
return fib($num);
}
either case, it will run forever. Here's one way to fix that:
if (int($num) != $num || $num < 1) {
- return "[[fib positive integers only, please]]";
+ error "positive integers only, please";
}
As these security problems have demonstrated, even a simple input from the