added example for synchronizing multiple backend requests

mojolicious · Jan 31, 2012 · 386b690 · 386b690
1 parent e318e2f
commit 386b690
Show file tree

Hide file tree

Showing 2 changed files with 33 additions and 1 deletion.
diff --git a/Changes b/Changes
@@ -1,6 +1,6 @@
 This file documents the revision history for Perl extension Mojolicious.
 
-2.47    2012-01-31 00:00:00
+2.47    2012-02-01 00:00:00
         - Added EXPERIMENTAL drain event to Mojo::Content.
         - Added EXPERIMENTAL drain event to Mojo::Transaction::WebSocket.
         - Added EXPERIMENTAL support for RSV1-3 flags to

diff --git a/lib/Mojolicious/Guides/Cookbook.pod b/lib/Mojolicious/Guides/Cookbook.pod
@@ -282,6 +282,38 @@ latency backend web services.
     </body>
   </html>
 
+Multiple events such as parallel requests can be easily synchronized with a
+L<Mojo::IOLoop> delay.
+
+  use Mojolicious::Lite;
+
+  # Search Twitter for "perl" and "python"
+  get '/' => sub {
+    my $self = shift;
+
+    # Delay rendering
+    my $delay = Mojo::IOLoop->delay(sub {
+      my ($delay, @results) = @_;
+      $self->render(json => {results => \@results});
+    });
+
+    # First request
+    $delay->begin;
+    $self->ua->get('http://search.twitter.com/search.json?q=perl' => sub {
+      my ($ua, $tx) = @_;
+      $delay->end($tx->res->json->{results}->[0]->{text});
+    });
+
+    # Second request
+    $delay->begin;
+    $self->ua->get('http://search.twitter.com/search.json?q=python' => sub {
+      my ($ua, $tx) = @_;
+      $delay->end($tx->res->json->{results}->[0]->{text});
+    });
+  };
+
+  app->start;
+
 =head2 Timers
 
 Another primary feature of the L<Mojo::IOLoop> reactor are timers, which can