[Templates] Templates and AJAX

[Larry Leszczynski]

On Sun, 19 Nov 2006, Buddy Burden wrote:

> We use OpenThought (http://www.openthought.net/) with TT2.
[snip]
> I understand that CGI::Application works well with TT2, but I don't know 
> how difficult it would be to convince the OT code to do that.

I have an app built with TT2 and CGI::Application, and found it _very_ 
easy to plug in AJAX functionality using OpenThought.

For example I have a login page where you can type in your username and 
request your password hint, something like this (stripped down):

    <!-- this is where hint gets pasted in -->
    <p id="password_hint">&nbsp;</p>

    <form method="POST" action="login">
       Username: <input type="text" name="username" /><br />
       <a href="#" onclick="showHint();return false">Show Hint</a>
    </form>

    <script>
       // Pass the current value of "username" form field
       // to the CGI::Application runmode "show_pw_hint":
       function showHint {
          OpenThought.CallUrl('[% self_url %]/show_pw_hint', 'username');
       }
    </script>

Then my CGI::Application runmode looks like this (error handling stripped 
out):

    sub show_pw_hint
    {
       my $self     = shift;
       my $username = $self->query->param('username');
       my $hint     = ... DB lookup of hint for $username ... ;

       # Replace content of "password_hint" HTML element,
       # and set focus to "username" form field:
       return $self->_do_OT({
          html        => {password_hint => "Your hint is: $hint"},
          focus       => 'username',
          error       => $any_error_msg,
          #fields     => {},
          #javascript => '',
       });
    }

    # Helper function to do OpenThought stuff:
    #
    sub _do_OT
    {
       my ($self, $args) = @_;
       my $error = delete $args->{error};

       my $OT = OpenThought2->new();

       if ($error) {
          my $url =  $self->param('self_url') .
                           '/error_runmode?msg=' . uri_escape($error);
          return $OT->parse_and_output({url => $url});
       }
       else {
          return $OT->parse_and_output($args);
       }
    }



Larry