1 files changed, 66 insertions, 0 deletions
diff --git a/lib/Plack/Client/Backend.pm b/lib/Plack/Client/Backend.pm
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+++ b/lib/Plack/Client/Backend.pm
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+package Plack::Client::Backend;
+use strict;
+use warnings;
+# ABSTRACT: turns a Plack::Request into a PSGI app
+
+use Carp;
+use Scalar::Util qw(weaken);
+
+use overload '&{}' => sub { shift->as_code(@_) }, fallback => 1;
+
+=head1 SYNOPSIS
+
+  package My::Backend;
+  use base 'Plack::Client::Backend';
+
+  sub app_from_request {
+      my $self = shift;
+      my ($req) = @_;
+      return sub { ... }
+  }
+
+=head1 DESCRIPTION
+
+This is a base class for L<Plack::Client> backends. These backends are handlers
+for a particular URL scheme, and translate a L<Plack::Request> instance into a
+PSGI application coderef.
+
+=cut
+
+=method new
+
+Creates a new backend instance. Takes no parameters by default, but may be
+overridden in subclasses.
+
+=cut
+
+sub new {
+    my $class = shift;
+    bless {}, $class;
+}
+
+=method app_from_request
+
+This method is called with an argument of a L<Plack::Request> object, and
+should return a PSGI application coderef. The Plack::Request object it receives
+contains the actual env hash that will be passed to the application, so
+backends can modify that too, if they need to.
+
+=cut
+
+sub app_from_request {
+    croak "Backends must implement app_from_request";
+}
+
+=method as_code
+
+Returns a coderef which will call L</app_from_request> as a method.
+
+=cut
+
+sub as_code {
+    my $self = shift;
+    return sub { $self->app_from_request(@_) };
+}
+
+1;