NAME¶
Plack::Middleware::Conditional - Conditional wrapper for Plack middleware
SYNOPSIS¶
use Plack::Builder;
builder {
enable_if { $_[0]->{REMOTE_ADDR} eq '127.0.0.1' } 'StackTrace', force => 1;
$app;
};
# or using the OO interface:
$app = Plack::Middleware::Conditional->wrap(
$app,
condition => sub { $_[0]->{REMOTE_ADDR} eq '127.0.0.1' },
builder => sub { Plack::Middleware::StackTrace->wrap($_[0], force => 1) },
);
DESCRIPTION¶
Plack::Middleware::Conditional is a piece of meta-middleware, to run a specific
middleware component under runtime conditions. The goal of this middleware is
to avoid baking runtime configuration options in individual middleware
components, and rather share them as another middleware component.
EXAMPLES¶
Note that some of the middleware component names are just made up for the
explanation and might not exist.
# Minify JavaScript if the browser is Firefox
enable_if { $_[0]->{HTTP_USER_AGENT} =~ /Firefox/ } 'JavaScriptMinifier';
# Enable Stacktrace when being accessed from the local network
enable_if { $_[0]->{REMOTE_ADDR} =~ /^10\.0\.1\.*/ } 'StackTrace';
# Work with other conditional setter middleware:
# Transcode Jpeg on the fly for mobile clients
builder {
enable 'MobileDetector';
enable_if { $_[0]->{'plack.mobile_detected'} }
'TranscodeJpeg', max_size => 30_000;
$app;
};
Note that in the last example
MobileDetector should come first because
the conditional check runs in
pre-run conditions, which is from outer
to inner: that is, from the top to the bottom in the Builder DSL code.
AUTHOR¶
Tatsuhiko Miyagawa
Steve Cook
SEE ALSO¶
Plack::Builder