Manpages - Alien_Build_Manual_PluginAuthor.3pm
Table of Contents
NAME
Alien::Build::Manual::PluginAuthor - Alien::Build plugin author documentation
VERSION
version 2.44
SYNOPSIS
your plugin:
package Alien::Build::Plugin::Build::MyPlugin; use strict; use warnings; use Alien::Build::Plugin; has arg1 => default_for arg1; has arg2 => sub { [ default, for, arg2 ] }; sub init { my($self, $meta) = @_; … } 1;
and then from alienfile:
use alienfile; plugin Build::MyPlugin => ( arg1 => override for arg1, arg2 => [ something, else ], );
DESCRIPTION
This document explains how to write Alien::Build plugins using the
Alien::Build::Plugin base class. Plugins use Alien::Build::Plugin, which
sets the appropriate base class, and provides you with the has
property builder. has
takes two arguments, the name of the property
and the default value. (As with Moose and Moo, you should use a code
reference to specify default values for non-string defaults).
The only method that you need to implement is init
. From this method
you can add hooks to change the behavior of the alienfile recipe.
sub init { my($self, $meta) = @_; $meta->register_hook( probe => sub { my($build) = @_; if( … ) { return system; } else { return share; } }, ); }
Hooks get the Alien::Build instance as their first argument, and depending on the hook may get additional arguments.
You can also modify hooks using before_hook
, around_hook
and
after_hook
:
sub init { my($self, $meta) = @_; $meta->before_hook( build => sub { my($build) = @_; $build->log(this runs before the build); }, ); $meta->after_hook( build => sub { my($build) = @_; $build->log(this runs after the build); }, ); $meta->around_hook( build => sub { my $orig = shift; # around hooks are useful for setting environment variables local $ENV{CPPFLAGS} = -I/foo/include; $orig->(@_); }, ); }
You can and should write tests for your plugin. The best way to do this is using Test::Alien::Build, which allows you to write an inline alienfile in your test.
use Test::V0; use Test::Alien::Build; my $build = alienfile_ok q{ use alienfile; plugin Build::MyPlugin => ( arg1 => override for arg1, arg2 => [ something, else ], ); … }; # you can interrogate $build, it is an instance of L<Alien::Build>. my $alien = alien_build_ok; # you can interrogate $alien, it is an instance of L<Alien::Base>.
HOOKS
probe hook
$meta->register_hook( probe => sub { my($build) = @_; return system if …; # system install return share; # otherwise }); $meta->register_hook( probe => [ $command ] );
This hook should return the string system
if the operating system
provides the library or tool. It should return share
otherwise.
You can also use a command that returns true when the tool or library is
available. For example for use with pkg-config
:
$meta->register_hook( probe => [ %{pkgconf} –exists libfoo ] );
Or if you needed a minimum version:
$meta->register_hook( probe => [ %{pkgconf} –atleast-version=1.00 libfoo ] );
Note that this hook SHOULD NOT gather system properties, such as cflags,
libs, versions, etc, because the probe hook will be skipped in the event
the environment variable ALIEN_INSTALL_TYPE
is set. The detection of
these properties should instead be done by the gather_system
hook,
below.
gather_system hook
$meta->register_hook( gather_system => sub { my($build) = @_; $build->runtime_prop->{cflags} = …; $build->runtime_prop->{libs} = …; $build->runtime_prop->{version} = …; });
This hook is called for a system install to determine the properties
necessary for using the library or tool. These properties should be
stored in the runtime_prop
hash as shown above. Typical properties
that are needed for libraries are cflags and libs. If at all possible
you should also try to determine the version of the library or tool.
download hook
$meta->register_hook( download => sub { my($build) = @_; … });
This hook is used to download from the internet the source. Either as an archive (like tar, zip, etc), or as a directory of files (git clone, etc). When the hook is called, the current working directory will be a new empty directory, so you can save the download to the current directory. If you store a single file in the directory, Alien::Build will assume that it is an archive, which will be processed by the extract hook below. If you store multiple files, Alien::Build will assume the current directory is the source root. If no files are stored at all, an exception with an appropriate diagnostic will be thrown.
Note: If you register this hook, then the fetch, decode and prefer hooks will NOT be called.
fetch hook
package Alien::Build::Plugin::MyPlugin; use strict; use warnings; use Alien::Build::Plugin; use Carp (); has +url => sub { Carp::croak “url is required property” }; sub init { my($self, $meta) = @_; $meta->register_hook( fetch => sub { my($build, $url, %options) = @_; … } } 1;
Used to fetch a resource. The first time it will be called without an
argument (or with $url
set to undef
, so the configuration used to
find the resource should be specified by the plugin’s properties. On
subsequent calls the first argument will be a URL.
The %options
hash may contain these options:
- http_headers
- HTTP request headers, if an appropriate protocol is
being used. The headers are provided as an array reference of
key/value pairs, which allows for duplicate header keys with multiple
values. If a non-HTTP protocol is used, or if the plugin cannot
otherwise send HTTP request headers, the plugin SHOULD issue a warning
using the
$build->log
method, but because this option wasn’t part of the original spec, the plugin MAY no issue that warning while ignoring it.
Note that versions of Alien::Build prior to 2.39 did not pass the options hash into the fetch plugin.
Normally the first fetch will be to either a file or a directory listing. If it is a file then the content should be returned as a hash reference with the following keys:
$filename, content => $content, version => $version, # optional, if known }; # content of file stored in the filesystem return { type => file, filename => $filename, path => $path, # full file system path to file version => $version, # optional, if known tmp => $tmp, # optional };
$tmp
if set will indicate if the file is temporary or not, and can be
used by Alien::Build to save a copy in some cases. The default is true,
so Alien::Build assumes the file or directory is temporary if you don’t
tell it otherwise.
If the URL points to a directory listing you should return it as either a hash reference containing a list of files:
return { type => list, list => [ # filename: each filename should be just the # filename portion, no path or url. # url: each url should be the complete url # needed to fetch the file. # version: OPTIONAL, may be provided by some fetch or prefer { filename => $filename1, url => $url1, version => $version1 }, { filename => $filename2, url => $url2, version => $version2 }, ] };
or if the listing is in HTML format as a hash reference containing the HTML information:
return { type => html, charset => $charset, # optional base => $base, # the base URL: used for computing relative URLs content => $content, # the HTML content };
or a directory listing (usually produced by ftp servers) as a hash reference:
return { type => dir_listing, base => $base, content => $content, };
decode hook
sub init { my($self, $meta) = @_; $meta->register_hook( decode => sub { my($build, $res) = @_; … } }
This hook takes a response hash reference from the fetch
hook above
with a type of html
or dir_listing
and converts it into a response
hash reference of type list
. In short it takes an HTML or FTP file
listing response from a fetch hook and converts it into a list of
filenames and links that can be used by the prefer hook to choose the
correct file to download. See fetch
for the specification of the input
and response hash references.
prefer hook
sub init { my($self, $meta) = @_; $meta->register_hook( prefer => sub { my($build, $res) = @_; return { type => list, list => [sort @{ $res->{list} }], }; } }
This hook sorts candidates from a listing generated from either the
fetch
or decode
hooks. It should return a new list hash reference
with the candidates sorted from best to worst. It may also remove
candidates that are totally unacceptable.
extract hook
$meta->register_hook( extract => sub { my($build, $archive) = @_; … });
patch hook
$meta->register_hook( patch => sub { my($build) = @_; … });
This hook is completely optional. If registered, it will be triggered after extraction and before build. It allows you to apply any patches or make any modifications to the source if they are necessary.
patch_ffi hook
$meta->register_hook( patch_ffi => sub { my($build) = @_; … });
This hook is exactly like the patch
hook, except it fires only on an
FFI build.
build hook
$meta->register_hook( build => sub { my($build) = @_; … });
This does the main build of the alienized project and installs it into
the staging area. The current directory is the build root. You need to
run whatever tools are necessary for the project, and install them into
%{.install.prefix}
.
build_ffi hook
$meta->register_hook( build_ffi => sub { my($build) = @_; … });
This is the same as build
, except it fires only on a FFI build.
gather_share hook
$meta->register_hook( gather_share => sub { my($build) = @_; … });
This is the same as gather_system
, except it fires after a share
install.
gather_ffi hook
$meta->register_hook( gather_ffi => sub { my($build) = @_; … });
This is the same as gather_share
, except it fires after a share
FFI
install.
override hook
$meta->register_hook( override => sub { my($build) = @_; });
This allows you to alter the override logic. It should return one of
share
, system
, default
or . The default implementation is just
this:
return $ENV{ALIEN_INSTALL_TYPE} || ;
clean_install
$meta->register_hook( clean_install => sub { my($build) = @_; });
This hook allows you to remove files from the final install location before the files are installed by the installer layer (examples: Alien::Build::MM, Alien::Build::MB or App::af). This hook is never called by default, and must be enabled via the interface to the installer layer.
This hook SHOULD NOT remove the _alien
directory or its content from
the install location.
The default implementation removes all the files EXCEPT the _alien
directory and its content.
AUTHOR
Author: Graham Ollis <plicease@cpan.org>
Contributors:
Diab Jerius (DJERIUS)
Roy Storey (KIWIROY)
Ilya Pavlov
David Mertens (run4flat)
Mark Nunberg (mordy, mnunberg)
Christian Walde (Mithaldu)
Brian Wightman (MidLifeXis)
Zaki Mughal (zmughal)
mohawk (mohawk2, ETJ)
Vikas N Kumar (vikasnkumar)
Flavio Poletti (polettix)
Salvador Fandiño (salva)
Gianni Ceccarelli (dakkar)
Pavel Shaydo (zwon, trinitum)
Kang-min Liu (劉康民, gugod)
Nicholas Shipp (nshp)
Juan Julián Merelo Guervós (JJ)
Joel Berger (JBERGER)
Petr Písař (ppisar)
Lance Wicks (LANCEW)
Ahmad Fatoum (a3f, ATHREEF)
José Joaquín Atria (JJATRIA)
Duke Leto (LETO)
Shoichi Kaji (SKAJI)
Shawn Laffan (SLAFFAN)
Paul Evans (leonerd, PEVANS)
Håkon Hægland (hakonhagland, HAKONH)
nick nauwelaerts (INPHOBIA)
COPYRIGHT AND LICENSE
This software is copyright (c) 2011-2020 by Graham Ollis.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.