NAME LWP::UserAgent::Plugin - LWP::UserAgent with plugins VERSION This document describes version 0.004 of LWP::UserAgent::Plugin (from Perl distribution LWP-UserAgent-Plugin), released on 2020-08-13. SYNOPSIS # set plugins to use, globally use LWP::UserAgent::Plugin Retry=>{retries=>3, retry_delay=>2}, 'Cache'; my $ua = LWP::UserAgent::Plugin->new; my $res; $res = $ua->get("http://www.example.com/"); # will retry a few times if failed $res = $ua->get("http://www.example.com/"); # will get cached response # to set plugins locally { my @old_plugins = LWP::UserAgent::Plugin->set_plugins(Retry=>{max_attempts=>3, delay=>2}, 'Cache'); # do stuffs LWP::UserAgent::Plugin->set_plugins(@old_plugins); } DESCRIPTION EARLY RELEASE, THINGS MIGHT STILL CHANGE A LOT. Like HTTP::Tiny::Plugin, LWP::UserAgent::Plugin allows you to extend functionalities of LWP::UserAgent using plugins instead of subclassing. This makes it easy to combine several functionalities together. (Ironically, LWP::UserAgent::Plugin itself is a subclass of LWP::UserAgent, but the plugins need not be.) Plugins A plugin should be module named under "LWP::UserAgent::Plugin::", e.g. LWP::UserAgent::Plugin::Cache, LWP::UserAgent::Plugin::Some::Other::Name, etc. Plugins are used either via import arguments to LWP::UserAgent::Plugin: use LWP::UserAgent::Plugin Retry=>{retries=>3, retry_delay=>2}, 'Cache'; or via calling "set_plugins". Hooks Plugin can define zero or more hooks (as methods with the same name as the hook) that will be executed during various stages. Hook arguments Hooks will be called with argument $r, a hash that contains various information. Keys that are common for all hooks: * method The related LWP::UserAgent method. For example, in "before_request" and "after_request" hook, the value is "request". * config Hash. * ua Object. The LWP::UserAgent object. * hook The current hook name. * hook The hook name. * argv Array. Arguments passed to hook-related method. For example, for "before_request" and "after_request" hooks, "argv" will contain arguments (@_) passed to "request()". * response Object. The HTTP::Response object. Hooks can modify this. Hook return value Hooks can return an integer, which can be used to signal declination/success/failure as well as flow control. The following values are possible: * -1 Declare decline (i.e. try next hook). * Declare failure status (for the stage). For a stage that only wants a single plugin to respond, this will stop hook execution for that stage and the next plugin in line will not be called. For a stage that wants to execute all plugins, this will still continue to the next plugin. The status of the stage is from the status of the plugin called last. * 1 Declare success/OK status (for the stage). For a stage that only wants a single plugin to respond, this will stop hook execution for that stage and the next plugin in line will not be called. For a stage that wants to execute all plugins, this will still continue to the next plugin. The status of the stage is from the status of the plugin called last. * 99 Skip execution of hook-related method. For example, if we return 99 in "before_request" then "request()" will be skipped. Will also immediately stop hook execution for that stage. * 98 Repeat execution of hook-related method. For example, if we return 98 in "after_request" then "request()" will be repeated. Will also immediately stop hook execution for that stage. List of available hooks Below is the list of hooks in order of execution during a request: * before_request Will be called before "request()". All plugins will be called. Stage will interpret 99 (skip calling "request()"). * after_request Will be called before "request()". All plugins will be called. Stage will interpret 98 (repeat calling "request()"). * before_mirror Will be called before "mirror()". All plugins will be called. Stage will interpret 99 (skip calling "mirror()"). * after_mirror Will be called before "request()". All plugins will be called. Stage will interpret 98 (repeat calling "mirror()"). METHODS set_plugins Usage: LWP::UserAgent::Plugin->set_plugins('Plugin1', 'Plugin2'=>{arg=>val, ...}, ...); Class method. Set plugins to use (and replace the previous set of plugins used). Will return a list containing previous set of plugins. Argument is a list of plugin names, with/without the "LWP::UserAgent::Plugin::" prefix. After each plugin name, an optional hashref can be specified to configure the plugin. ENVIRONMENT LWP_USERAGENT_PLUGIN_TRACE Bool. If set to true, will produce more trace log statements. LWP_USERAGENT_PLUGINS A JSON-encoded array. If set, will call "set_plugins" with the decoded value. HOMEPAGE Please visit the project's homepage at . SOURCE Source repository is at . BUGS Please report any bugs or feature requests on the bugtracker website When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature. SEE ALSO LWP::UserAgent HTTP::Tiny::Plugin LWP::UserAgent::Patch::Plugin AUTHOR perlancar COPYRIGHT AND LICENSE This software is copyright (c) 2020, 2019 by perlancar@cpan.org. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.