prog_guide -- programmer's guide for YATT


YATT consists of two layers. General purpose template engine "YATT::Lite", and sample Web Application Framework "WebMVC0".

Note: In this document, I choose simplicity of explanation over accuracy. Some methods/configs are described in subclass section as-if it is defined there (but actually not).

YATT::Lite -- General Purpose Template Engine

When requested, yatt converts a template into a set of perl functions and compile them. After successful compilation, yatt calls corresponding function. For example, assume we have a variable $template_1 which contains a template like following:

<!yatt:args x y>
<yatt:hello who=y />

<!yatt:widget hello who>
Hello &yatt:who;!

And our program is like following:

use YATT::Lite;
my $yatt = new YATT::Lite(vfs => [data => $template_1]);
print $yatt->render('', {x => "foo", y => "bar"});
# ..Or..
$yatt->render_into(\*STDOUT, "" => {x => "baz", y => "qux"});

Then, when $yatt->render is called, yatt generates following perl script (package) and invoke it as MyApp::EntNS->render_(...).

package MyApp::EntNS;
sub render_ {
  my ($this, $CON, $x, $y, $body) = @_;
  print $CON (q|<h2>|, YATT::Lite::Util::escape($x), q|</h2>|, "\n");
  $this->render_hello($CON, (undef, $y)[1, 0]); print $CON ("\n");}

sub render_hello {
  my ($this, $CON, $who, $body) = @_;
  print $CON (q|Hello |, YATT::Lite::Util::escape($who), q|!|, "\n");}

Note: if you specify template as a file, it is cached until the file is modified.