mod_rewrite for Plack
ap/Plack-Middleware-Rewrite
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Folders and files
Name | Name | Last commit message | Last commit date | |
---|---|---|---|---|
Repository files navigation
use 5.006; use strict; use warnings; package Plack::Middleware::Rewrite; our $VERSION = '2.102'; BEGIN { require Plack::Middleware; our @ISA = 'Plack::Middleware' } use Plack::Util::Accessor qw( request response rules ); use Plack::Request (); use Plack::Util (); use overload (); sub call { my $self = shift; my ( $env ) = @_; my ( $app, $res, $legacy ); my ( $rules, $modify_cb ) = ( $self->request, $self->response ); unless ( $rules or $modify_cb ) { $rules = $self->rules; $legacy = 1; } # call rules with $_ aliased to PATH_INFO ( $res ) = map { scalar $rules->( $env ) } $env->{'PATH_INFO'} if $rules; if ( $legacy ) { if ( 'CODE' eq ref $res ) { ( $modify_cb, $res ) = $res } elsif ( 'ARRAY' eq ref $res ) { undef $res if not @$res } elsif ( ref $res ) { undef $res } else { # upgrade scalar to response if it looks like an HTTP status $res = ( defined $res and $res =~ /\A[1-5][0-9][0-9]\z/ ) ? [ $res, [], [] ] : undef; } } else { if ( 'CODE' eq ref $res ) { ( $app, $res ) = $res } elsif ( 'ARRAY' eq ref $res ) { @$res = ( 303, [], [] ) if not @$res } elsif ( ref $res ) { die 'Unhandled reference type in request rewrite: ', overload::StrVal( $res ), "\n" } else { undef $res } } if ( $res ) { # external redirect, or explicit response push @$res, map { [] } @$res .. 2; if ( $res->[0] =~ /\A3(?:0[0-35-9]|[1-9][0-9])\z/ ) { my $dest = Plack::Util::header_get( $res->[1], 'Location' ); if ( not $dest ) { $dest = Plack::Request->new( $env )->uri; Plack::Util::header_set( $res->[1], Location => $dest ); } unless ( Plack::Util::content_length( $res->[2] ) or Plack::Util::header_exists( $res->[1], 'Content-Length' ) ) { my $href = Plack::Util::encode_html( $dest ); Plack::Util::header_set( $res->[1], qw( Content-Type text/html ) ); $res->[2] = [ qq'<!DOCTYPE html><title>Moved</title>This resource has moved to <a href="$href">a new address</a>.' ]; } } } else { # internal redirect $app ||= $self->app; $res = $app->( $env ); } return $res if not $modify_cb; Plack::Util::response_cb( $res, sub { my $response = $_[0]; my $hdrs = Plack::Util::headers( $response->[1] ); $hdrs->{'status'} = sub { @_ ? $response->[0] = $_[0] : $response->[0] }; my ( $result ) = map $modify_cb->( $env ), $hdrs; return 'CODE' eq ref $result ? $result : (); } ); } 1; __END__ =pod =encoding UTF-8 =head1 NAME Plack::Middleware::Rewrite - mod_rewrite for Plack =head1 SYNOPSIS # in app.psgi use Plack::Builder; builder { enable 'Rewrite', request => sub { s{^/here(?=/|$)}{/there}; return [303] if s{^/foo/?$}{/bar/} or s{^/baz/?$}{/quux/}; return [301, [ Location => 'http://example.org/' ], []] if m{^/example/?$}; return [201] if $_ eq '/favicon.ico'; return [503] if -e '/path/to/app/maintenance.lock'; return [200, [qw(Content-Type text/plain)], ['You found it!']] if $_ eq '/easter-egg'; }, response => sub { $_->status( 303 ) if $_->status eq 201 and $_->get( 'Location' ); $_->set( 'Content-Type', 'application/xhtml+xml' ) if ( $_[0]{'HTTP_ACCEPT'} || '' ) =~ m{application/xhtml\+xml(?!\s*;\s*q=0)}; }; $app; }; =head1 DESCRIPTION This middleware provides a convenient way to modify requests in flight in Plack apps. Rewrite rules are simply written in Perl, which means everything that can be done with mod_rewrite can be done with this middleware much more intuitively (if in syntactically wordier ways). Its primary purpose is rewriting paths, but almost anything is possible very easily. =head1 CONFIGURATION OPTIONS =head2 C<request> Takes a reference to a function that will be called in scalar context for each request. On call, C<$_> will be aliased to C<PATH_INFO>, so that you can easily use regexp matches and subtitutions to examine and modify it. The L<PSGI> environment will be passed to the function as its first and only argument. The function may return three kinds of valid value: =over 4 =item A plain scalar Ignored. The value will be thrown away and any path rewriting (or any other modifications of the PSGI environment) will take effect during the current request cycle, invisibly to the client user agent. =item An array reference A L<PSGI> array response to return immediately without invoking the wrapped PSGI application. The array may have fewer than 3 elements, in which case it will be filled to 3E<nbsp>elements by pushing the default values: an empty body array, empty headers array, and a 303E<nbsp>statusE<nbsp>code. If the C<Location> header is missing from a redirect response (i.e. one with 3xxE<nbsp>statusE<nbsp>code), it will be filled in automatically from the value left in C<PATH_INFO> by your callback. (Note that this only allows you to redirect to URLs with the same hostname. To redirect the client to a different host, you will have to supply a C<Location> header manually.) =item A code reference A PSGI application which will be called to process the request. This prevents the wrapped application from being called. =item Any other kind of reference Error. An exception will be thrown. =back =head2 C<response> Takes a reference to a function that will be called I<after> the request has been processed and the response is ready to be returned. On call, C<$_> will be aliased to a specially extended a L<C<Plack::Util::headers>|Plack::Util/headers> object for the response, for convenient alteration of headers. The extension is a C<status> method, which allows you to inspect and modify the response status code. Just as in L</C<request>>, the L<PSGI> environment is passed as first and only argument. Any return value from this function will be ignored unless it is a code reference. In that case it will be used to filter the response body, as documented in L<Plack::Middleware/RESPONSE CALLBACK>: =over 4 return sub { my $chunk = shift; return unless defined $chunk; $chunk =~ s/Foo/Bar/g; return $chunk; }; The callback takes one argument C<$chunk> and your callback is expected to return the updated chunk. If the given C<$chunk> is undef, it means the stream has reached the end, so your callback should also return undef, or return the final chunk and return undef when called next time. =back =head1 LEGACY INTERFACE The old interface uses a single attribute, C<rules>, instead of the C<request> and C<response> pair, with a more complex set of return values, containing an ambiguity. It is also less expressive than the new interface. The old interface is documented here for the purposes of maintaining old code; its use in new code is L<discouraged|perlpolicy/Terminology>. In the far future it may get removed entirely, and in the meantime it will not gain new features. The return value of the C<rules> callback is interpreted as follows: =over 4 =item An array reference (with at least one element) A regular L<PSGI> response, except that you may omit either or both the headers and body elements. You I<may not> omit the status. =item A scalar value that looks like an HTTP status Like returning a reference to a one-element. Beware: every subroutine in Perl has a return value, even if you do not return anything explicitly. To avoid ambiguities you must return one-element arrays instead of plain values and use an explicit C<return> at the end of your rules: return [201] if $_ eq '/favicon.ico'; s{^/here(?=/|$)}{/there}; return; =item A code reference Equivalent to the L</C<response>> callback in the new interface, with the same arguments and return values. =item Any other kind of value Internal rewrite. =back =head2 Porting from the old to the new interface There are two major incompatibilities between the interfaces: =over 4 =item 1. You can no longer return status codes as plain scalars, as in C<return 301>. You B<must> now C<return [301]> (which you could before, but didn't have to). =item 2. Rewriting the response is no longer done by returning a C<sub>. Instead you must use the C<response> attribute. This may be inconvient if the function was closing over variables from the C<rules> callback; in that case you now have to explicitly pass that state from one callback to the other through the environment hash. However, such code is rare, and in all other cases your code will be more readable under the new interface. =back =cut
About
mod_rewrite for Plack