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HTTP::Proxy::BodyFilter::simple(3pm) User Contributed Perl Documentation HTTP::Proxy::BodyFilter::simple(3pm)


HTTP::Proxy::BodyFilter::simple - A class for creating simple filters


    use HTTP::Proxy::BodyFilter::simple;
    # a simple s/// filter
    my $filter = HTTP::Proxy::BodyFilter::simple->new(
        sub { ${ $_[1] } =~ s/foo/bar/g; }
    $proxy->push_filter( response => $filter );


HTTP::Proxy::BodyFilter::simple can create BodyFilter without going through the hassle of creating a full-fledged class. Simply pass a code reference to the "filter()" method of your filter to the constructor, and you'll get the adequate filter.

Constructor calling convention

The constructor can be called in several ways, which are shown in the synopsis:

The code reference must conform to the standard filter() signature:

    sub filter {
        my ( $self, $dataref, $message, $protocol, $buffer ) = @_;

It is assumed to be the code for the "filter()" method. See HTTP::Proxy::BodyFilter for more details about the "filter()" method.

The name is the name of the method ("filter", "begin", "end") and the coderef is the method itself.

See HTTP::Proxy::BodyFilter for the methods signatures.


This filter "factory" defines the standard HTTP::Proxy::BodyFilter methods, but those are only, erm, "proxies" to the actual CODE references passed to the constructor. These "proxy" methods are:

Two other methods are actually HTTP::Proxy::BodyFilter::simple methods, and are called automatically:

Initialise the filter instance with the code references passed to the constructor.
Return the actual code reference that will be run, and not the "proxy" methods. If called with any other name than "begin", "end" and "filter", calls "UNIVERSAL::can()" instead.

There is also a method that returns a boolean value:

The "will_modify()" method returns a scalar value (boolean) indicating if the filter may modify the body data. The default method returns a true value, so you only need to set this value when you are absolutely certain that the filter will not modify data (or at least not modify its final length).

Here's a simple example:

    $filter = HTTP::Proxy::BodyFilter::simple->new(
        filter => sub { ${ $_[1] } =~ s/foo/bar/g; },
        will_modify => 0,    # "foo" is the same length as "bar"


HTTP::Proxy, HTTP::Proxy::BodyFilter.


Philippe "BooK" Bruhat, <>.


Copyright 2003-2015, Philippe Bruhat.


This module is free software; you can redistribute it or modify it under the same terms as Perl itself.

2019-03-01 perl v5.28.1