1Plack::Middleware::CondUisteironCaoln(t3r)ibuted Perl DoPcluamcekn:t:aMtiidodnleware::Conditional(3)
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NAME

6       Plack::Middleware::Conditional - Conditional wrapper for Plack
7       middleware
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SYNOPSIS

10         use Plack::Builder;
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12         builder {
13             enable_if { $_[0]->{REMOTE_ADDR} eq '127.0.0.1' } 'StackTrace', force => 1;
14             $app;
15         };
16
17         # or using the OO interface:
18         $app = Plack::Middleware::Conditional->wrap(
19             $app,
20             condition  => sub { $_[0]->{REMOTE_ADDR} eq '127.0.0.1' },
21             builder => sub { Plack::Middleware::StackTrace->wrap($_[0], force => 1) },
22         );
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DESCRIPTION

25       Plack::Middleware::Conditional is a piece of meta-middleware, to run a
26       specific middleware component under runtime conditions. The goal of
27       this middleware is to avoid baking runtime configuration options in
28       individual middleware components, and rather share them as another
29       middleware component.
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EXAMPLES

32       Note that some of the middleware component names are just made up for
33       the explanation and might not exist.
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35         # Minify JavaScript if the browser is Firefox
36         enable_if { $_[0]->{HTTP_USER_AGENT} =~ /Firefox/ } 'JavaScriptMinifier';
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38         # Enable Stacktrace when being accessed from the local network
39         enable_if { $_[0]->{REMOTE_ADDR} =~ /^10\.0\.1\.*/ } 'StackTrace';
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41         # Work with other conditional setter middleware:
42         # Transcode Jpeg on the fly for mobile clients
43         builder {
44             enable 'MobileDetector';
45             enable_if { $_[0]->{'plack.mobile_detected'} }
46               'TranscodeJpeg', max_size => 30_000;
47             $app;
48         };
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50       Note that in the last example MobileDetector should come first because
51       the conditional check runs in pre-run conditions, which is from outer
52       to inner: that is, from the top to the bottom in the Builder DSL code.
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AUTHOR

55       Tatsuhiko Miyagawa
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57       Steve Cook
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SEE ALSO

60       Plack::Builder
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64perl v5.28.1                      2018-02-10 Plack::Middleware::Conditional(3)
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