Chip 2000 May

home *** CD-ROM | disk | FTP | other *** search

/ Chip 2000 May / Chip_2000-05_cd1.bin / zkuste / Perl / ActivePerl-5.6.0.613.msi / 䆊䌷䈹䈙䏵-䞅䞆䞀㡆䞃䄦䠥 / _4c1ea67396ec8f4c25ca3ff3c9160db3 < prev next >

Wrap

Text File | 2000-03-23 | 5.7 KB | 144 lines

<HTML> <HEAD> <TITLE>LWP::Protocol - Base class for LWP protocols</TITLE> <LINK REL="stylesheet" HREF="../../../Active.css" TYPE="text/css"> <LINK REV="made" HREF="mailto:"> </HEAD> <BODY> <TABLE BORDER=0 CELLPADDING=0 CELLSPACING=0 WIDTH=100%> <TR><TD CLASS=block VALIGN=MIDDLE WIDTH=100% BGCOLOR="#cccccc"> LWP::Protocol - Base class for LWP protocols </TD></TR> </TABLE> <A NAME="__index__"></A>  <UL> <LI><A HREF="#name">NAME</A></LI><LI><A HREF="#supportedplatforms">SUPPORTED PLATFORMS</A></LI> <LI><A HREF="#synopsis">SYNOPSIS</A></LI> <LI><A HREF="#description">DESCRIPTION</A></LI> <LI><A HREF="#see also">SEE ALSO</A></LI> <LI><A HREF="#copyright">COPYRIGHT</A></LI> </UL>  <HR> <H1><A NAME="name">NAME</A></H1> LWP::Protocol - Base class for LWP protocols <HR> <H1><A NAME="supportedplatforms">SUPPORTED PLATFORMS</A></H1> <UL> <LI>Linux</LI> <LI>Solaris</LI> <LI>Windows</LI> </UL> <HR> <H1><A NAME="synopsis">SYNOPSIS</A></H1> <PRE> package LWP::Protocol::foo; require LWP::Protocol; @ISA=qw(LWP::Protocol);</PRE> <HR> <H1><A NAME="description">DESCRIPTION</A></H1> This class is used a the base class for all protocol implementations supported by the LWP library. When creating an instance of this class using <A HREF="#item_create"><CODE>LWP::Protocol::create($url)</CODE></A>, and you get an initialised subclass appropriate for that access method. In other words, the LWP::Protocol::create() function calls the constructor for one of its subclasses. All derived LWP::Protocol classes need to override the <A HREF="#item_request"><CODE>request()</CODE></A> method which is used to service a request. The overridden method can make use of the <A HREF="#item_collect"><CODE>collect()</CODE></A> function to collect together chunks of data as it is received. The following methods and functions are provided: <DL> <DT><A NAME="item_new">$prot = LWP::Protocol-><CODE>new()</CODE></A> <DD> The LWP::Protocol constructor is inherited by subclasses. As this is a virtual base class this method should not be called directly. <DT><A NAME="item_create">$prot = LWP::Protocol::create($url)</A> <DD> 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. <DT><A NAME="item_implementor">$class = LWP::Protocol::implementor($scheme, [$class])</A> <DD> Get and/or set implementor class for a scheme. Returns '' if the specified scheme is not supported. <DT><A NAME="item_request">$prot-><CODE>request(...)</CODE></A> <DD> <PRE> $response = $protocol->request($request, $proxy, undef); $response = $protocol->request($request, $proxy, '/tmp/sss'); $response = $protocol->request($request, $proxy, \&callback, 1024);</PRE> Dispactches a request over the protocol, and returns a response object. This method needs to be overridden in subclasses. Referer to <A HREF="../../../site/lib/LWP/UserAgent.html">the LWP::UserAgent manpage</A> for description of the arguments. <DT><A NAME="item_timeout">$prot-><CODE>timeout($seconds)</CODE></A> <DD> Get and set the timeout value in seconds <DT><A NAME="item_parse_head">$prot-><CODE>parse_head($yesno)</CODE></A> <DD> Should we initialize response headers from the <head> section of HTML documents. <DT><A NAME="item_collect">$prot->collect($arg, $response, $collector)</A> <DD> Called to collect the content of a request, and process it appropriately into a scalar, file, or by calling a callback. If $arg is undefined, then the content is stored within the $response. If $arg is a simple scalar, then $arg is interpreted as a file name and the content is written to this file. If $arg is a reference to a routine, then content is passed to this routine. The $collector is a routine that will be called and which is reponsible for returning pieces (as ref to scalar) of the content to process. The $collector signals EOF by returning a reference to an empty sting. The return value from <A HREF="#item_collect"><CODE>collect()</CODE></A> is the $response object reference. Note: We will only use the callback or file argument if $response->is_success(). This avoids sendig content data for redirects and authentization responses to the callback which would be confusing. <DT><A NAME="item_collect_once">$prot->collect_once($arg, $response, $content)</A> <DD> Can be called when the whole response content is available as $content. This will invoke <A HREF="#item_collect"><CODE>collect()</CODE></A> with a collector callback that returns a reference to $content the first time and an empty string the next. </DL> <HR> <H1><A NAME="see also">SEE ALSO</A></H1> Inspect the LWP/Protocol/file.pm and LWP/Protocol/http.pm files for examples of usage. <HR> <H1><A NAME="copyright">COPYRIGHT</A></H1> Copyright 1995-1997 Gisle Aas. This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. <TABLE BORDER=0 CELLPADDING=0 CELLSPACING=0 WIDTH=100%> <TR><TD CLASS=block VALIGN=MIDDLE WIDTH=100% BGCOLOR="#cccccc"> LWP::Protocol - Base class for LWP protocols </TD></TR> </TABLE> </BODY> </HTML>