1HTTP::Proxy::HeaderFiltUesre(r3)Contributed Perl DocumenHtTaTtPi:o:nProxy::HeaderFilter(3)
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NAME

6       HTTP::Proxy::HeaderFilter - A base class for HTTP message header fil‐
7       ters
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SYNOPSIS

10           package MyFilter;
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12           use base qw( HTTP::Proxy::HeaderFilter );
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14           # changes the User-Agent header in all requests
15           # this filter must be pushed on the request stack
16           sub filter {
17               my ( $self, $headers, $message ) = @_;
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19               $message->headers->header( User_Agent => 'MyFilter/1.0' );
20           }
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22           1;
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DESCRIPTION

25       The HTTP::Proxy::HeaderFilter class is used to create filters for HTTP
26       request/response headers.
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28       Creating a HeaderFilter
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30       A HeaderFilter is just a derived class that implements some methods
31       called by the proxy. Of all the methods presented below, only "fil‐
32       ter()" must be defined in the derived class.
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34       filter()
35           The signature of the filter() method is the following:
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37               sub filter { my ( $self, $headers, $message) = @_; ... }
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39           where $self is the filter object, $headers is a HTTP::Headers
40           object, and $message is either a HTTP::Request or a HTTP::Response
41           object.
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43           The $headers HTTP::Headers object is the one that will be sent to
44           the client (if the filter is on the response stack) or origin
45           server (if the filter is on the request stack). If $headers is mod‐
46           ified by the filter, the modified headers will be sent to the
47           client or server.
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49           The init() method (if it exists) is called by the new() construc‐
50           teur to perform all initisalisation tasks. It's called once in the
51           filter lifetime.
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53           A HTTP::Proxy::HeaderFilter object is a blessed hash, and the base
54           class reserves only hash keys that start with "_hphf".
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56       new()
57           The constructor is defined for all subclasses. Initialisation tasks
58           (if any) for subclasses should be done in the "init()" method (see
59           below).
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61       init()
62           This method is called by the "new()" constructeur to perform all
63           initisalisation tasks. It's called once in the filter lifetime.
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65           It receives all the parameters passed to "new()".
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67       Standard HeaderFilters
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69       Standard HTTP::Proxy::HeaderFilter classes are lowercase.
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71       The following HeaderFilters are included in the HTTP::Proxy distribu‐
72       tion:
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74       simple
75           This class lets you create a simple header filter from a code ref‐
76           erence.
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78       standard
79           This is the filter that provides standard headers handling for
80           HTTP::Proxy.  It is loaded automatically by HTTP::Proxy.
81
82       Please read each filter's documentation for more details about their
83       use.
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USEFUL METHODS FOR SUBCLASSES

86       Some methods are available to filters, so that they can eventually use
87       the little knowledge they might have of HTTP::Proxy's internals. They
88       mostly are accessors.
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90       proxy()
91           Gets a reference to the HTTP::Proxy objects that owns the filter.
92           This gives access to some of the proxy methods.
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AUTHOR

95       Philippe "BooK" Bruhat, <book@cpan.org>.
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SEE ALSO

98       HTTP::Proxy, HTTP::Proxy::BodyFilter.
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101       Copyright 2003-2005, Philippe Bruhat.
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LICENSE

104       This module is free software; you can redistribute it or modify it
105       under the same terms as Perl itself.
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109perl v5.8.8                       2006-09-04      HTTP::Proxy::HeaderFilter(3)
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