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NAMELWP::Protocol - Base class for LWP protocolsSYNOPSISpackage LWP::Protocol::foo; use parent qw(LWP::Protocol); DESCRIPTIONThis class is used as the base class for all protocol implementations supported by the LWP library.When creating an instance of this class using "LWP::Protocol::create($url)", and you get an initialized subclass appropriate for that access method. In other words, the "create" in LWP::Protocol function calls the constructor for one of its subclasses. All derived "LWP::Protocol" classes need to override the "request()" method which is used to service a request. The overridden method can make use of the "collect()" method to collect together chunks of data as it is received. METHODSThe following methods and functions are provided:newmy $prot = LWP::Protocol->new(); The LWP::Protocol constructor is inherited by subclasses. As this is a virtual base class this method should not be called directly. createmy $prot = LWP::Protocol::create($scheme) Create an object of the class implementing the protocol to handle the given scheme. This is a function, not a method. It is more an object factory than a constructor. This is the function user agents should use to access protocols. implementormy $class = LWP::Protocol::implementor($scheme, [$class]) Get and/or set implementor class for a scheme. Returns '' if the specified scheme is not supported. request$response = $protocol->request($request, $proxy, undef); $response = $protocol->request($request, $proxy, '/tmp/sss'); $response = $protocol->request($request, $proxy, \&callback, 1024); Dispatches a request over the protocol, and returns a response object. This method needs to be overridden in subclasses. Refer to LWP::UserAgent for description of the arguments. collectmy $res = $prot->collect(undef, $response, $collector); # stored in $response my $res = $prot->collect($filename, $response, $collector); my $res = $prot->collect(sub { ... }, $response, $collector); Collect the content of a request, and process it appropriately into a scalar, file, or by calling a callback. If the first parameter is undefined, then the content is stored within the $response. If it's a simple scalar, then it's interpreted as a file name and the content is written to this file. If it's a code reference, then content is passed to this routine. The collector is a routine that will be called and which is responsible for returning pieces (as ref to scalar) of the content to process. The $collector signals "EOF" by returning a reference to an empty string. The return value is the HTTP::Response object reference. Note: We will only use the callback or file argument if "$response->is_success()". This avoids sending content data for redirects and authentication responses to the callback which would be confusing. collect_once$prot->collect_once($arg, $response, $content) Can be called when the whole response content is available as content. This will invoke "collect" in LWP::Protocol with a collector callback that returns a reference to $content the first time and an empty string the next. SEE ALSOInspect the LWP/Protocol/file.pm and LWP/Protocol/http.pm files for examples of usage.COPYRIGHTCopyright 1995-2001 Gisle Aas.This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
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