NAME

Mojolicious::Plugin::Parallol - Because parallel requests should be as fun as parallololololol!

SYNOPSIS

  # Mojolicious
  $self->plugin('Parallol');

  # Mojolicious::Lite
  plugin 'Parallol';

DESCRIPTION

Mojolicious::Plugin::Parallol provides a simple helper for managing several parallel requests in the controller.

HELPERS

Mojolicious::Plugin::Parallol implements the following helpers.

parallol

Parallol optimizes for the common case: You want to call several parallel requests and render the view when they're done.

  get '/' => sub {
    my $self = shift;

    $self->ua->get('http://bbc.co.uk/', $self->parallol(sub {
      $self->stash(bbc => pop->res->dom->at('title')->text);
    }));

    $self->ua->get('http://mojolicio.us/', $self->parallol(sub {
      $self->stash(mojo => pop->res->dom->at('title')->text);
    }));
  };

By wrapping a callback in $self->parallol you mark the current response as asynchronous (see "render_later" in Mojolicious::Controller) and Parallol will render the view when all callbacks are called.

Automatic stashing

By passing a string to $self->parallol it will stash the last argument of the result instead. If we rewrite the previous example to use a helper, we can simplify our controller quite a lot.

  get '/' => sub {
    my $self = shift;

    $self->title('http://bbc.co.uk/',    $self->parallol('bbc'));
    $self->title('http://mojolicio.us/', $self->parallol('mojo'));
  };

  helper title => sub {
    my ($self, $url, $cb) = @_;
    $self->ua->get($url, sub {
      $cb->(pop->res->dom->at('title')->text);
    });
  };

It's recommended that you move as much logic to helpers and other classes/methods so you can take advantage of automatic stashing.

Overriding "done" behavior

When you need to do more than just rendering the view you can override the "done" callback:

  get '/' => sub {
    my $self = shift;
    $self->on_parallol(sub {
      shift->render(template => 'something_else');
    });
  };

PSGI support

If the Mojo IO loop is not running, Parallol will automatically start it for your request, and stop it again when all callbacks have been called. This means that asynchronous requests just works when you use Parallol in servers that don't use Mojo's IO loop (PSGI).

$self weakening

In order to prevent memory leaks, Parallol will automatically weaken $self. This means that if you don't refer to $self in your callback objects will magically disappear.

  # This controller will behave very strangely:
  get '/' => sub {
    my $self = shift;
    my $res = {};
    $self->ua->get('http://bbc.co.uk/', $self->parallol(sub {
      # There's no reference to $self in this block
      $res->{bbc} = pop->res->dom->at('title')->text;
    }));
  };

In these cases you can disabled weakening by passing in weaken => 0.

  # This controller is fine:
  get '/' => sub {
    my $self = shift;
    my $res = {};
    $self->ua->get('http://bbc.co.uk/', $self->parallol(weaken => 0, sub {
      # There's no reference to $self in this block
      $res->{bbc} = pop->res->dom->at('title')->text;
    }));
  };

METHODS

Mojolicious::Plugin::Parrallol inherits all methods from Mojolicious::Plugin and implements the following new ones.

register

  $plugin->register;

Register helpers in Mojolicious application.

SEE ALSO

Mojolicious, Parallol

AUTHOR

Magnus Holm mailto:magnus@nordaaker.com

LICENSE

This software is licensed under the same terms as Perl itself.

cpanm Parallol

perl -MCPAN -e shell
install Parallol