File::ShareDir::ProjectDistDir - Simple set-and-forget using of a '/share' directory in your projects root
version 1.000010
STOP!. Before using this distribution, some warnings MUST be considered.
The primary use-case for this module is targeted at development projects that are NOT intended for CPAN
.
As such, using it for CPAN
is generally a bad idea, and better solutions generally involve the less fragile Test::File::ShareDir
, constraining any magical
behavior exclusively to where it is needed: Tests.
Why?
- Determining whether or not we are
dev
duringruntime
is a perilous heuristic that routinely fails with even slightly unusual file system layouts. - Auto-magical changing of behavior at
runtime
based on the above leads to many surprising and hard to debug problems.
For these reason, it is dangerous to rely on this distribution while striving to produce quality code.
If this documentation is not sufficient to dissuade you, I must strongly implore you to choose the "strict" mechanism,
because that substantially reduces the possibilities with regards to false-positive of potential dev
directories.
I have in mind to find a better mechanism to deliver the same objective, but no solutions are forthcoming at this time.
package An::Example::Package;
use File::ShareDir::ProjectDistDir;
# during development, $dir will be $projectroot/share
# but once installed, it will be wherever File::Sharedir thinks it is.
my $dir = dist_dir('An-Example')
Project layout requirements:
$project/
$project/lib/An/Example/Package.pm
$project/share/ # files for package 'An-Example' go here.
You can use a directory name other than 'share' ( Assuming you make sure when you install that, you specify the different directory there also ) as follows:
use File::ShareDir::ProjectDistDir ':all', defaults => {
projectdir => 'templates',
};
use File::ShareDir::ProjectDistDir (@args);
This uses Sub::Exporter
to do the heavy lifting, so most usage of this module can be maximized by
understanding that first.
-
:all
->import( ':all' , .... )
Import both
dist_dir
anddist_file
-
dist_dir
->import('dist_dir' , .... )
Import the dist_dir method
-
dist_file
->import('dist_file' , .... )
Import the dist_file method
-
projectdir
->import( .... , projectdir => 'share' )
Specify what the project directory is as a path relative to the base of your distributions source, and this directory will be used as a
ShareDir
simulation path for the exported methods During development.If not specified, the default value 'share' is used.
-
filename
->import( .... , filename => 'some/path/to/foo.pm' );
Generally you don't want to set this, as its worked out by caller() to work out the name of the file its being called from. This file's path is walked up to find the 'lib' element with a sibling of the name of your
projectdir
. -
distname
->import( .... , distname => 'somedistname' );
Specifying this argument changes the way the functions are emitted at installed
runtime
, so that instead of taking the standard arguments File::ShareDir does, the specification of thedistname
in those functions is eliminated.i.e:
# without this flag use File::ShareDir::ProjectDistDir qw( :all ); my $dir = dist_dir('example'); my $file = dist_file('example', 'path/to/file.pm' ); # with this flag use File::ShareDir::ProjectDistDir ( qw( :all ), distname => 'example' ); my $dir = dist_dir(); my $file = dist_file('path/to/file.pm' );
-
strict
->import( ... , strict => 1 );
This parameter specifies that all
dist
sharedirs
will occur within theprojectdir
directory using the following layout:<root>/<projectdir>/dist/<DISTNAME>/
As opposed to
<root>/<projectdir>
This means if Heuristics misfire and accidentally find another distributions
share
directory, it will not pick up on it unless thatshare
directory also has that layout, and will instead revert to theinstalldir
path in@INC
This parameter may become the default option in the future
Specifying this parameter also mandates you MUST declare the
DISTNAME
value in your file somewhere. Doing otherwise is considered insanity anyway. -
defaults
->import( ... , defaults => { filename => ...., projectdir => ...., });
This is mostly an alternative syntax for specifying
filename
andprojectdir
, which is mostly used internally, and their corresponding other values are packed into this one.
package Foo::Util;
sub import {
my ($caller_class, $caller_file, $caller_line ) = caller();
if ( grep { /share/ } @_ ) {
require File::ShareDir::ProjectDistDir;
File::ShareDir::ProjectDistDir->import(
filename => $caller_file,
dist_dir => { distname => 'myproject' , -as => 'share' },
dist_dir => { distname => 'otherproject' , -as => 'other_share' , projectdir => 'share2' },
-into => $caller_class,
);
}
}
....
package Foo;
use Foo::Util qw( share );
my $dir = share();
my $other_dir => other_share();
use File::ShareDir::ProjectDirDir ( : all );
# this calls
my $coderef = File::ShareDir::ProjectDistDir->build_dist_dir(
'dist_dir' => {},
{ defaults => { filename => 'path/to/yourcallingfile.pm', projectdir => 'share' } }
);
use File::ShareDir::ProjectDirDir ( qw( :all ), distname => 'example-dist' );
# this calls
my $coderef = File::ShareDir::ProjectDistDir->build_dist_dir(
'dist_dir' => {},
{ distname => 'example-dist', defaults => { filename => 'path/to/yourcallingfile.pm', projectdir => 'share' } }
);
use File::ShareDir::ProjectDirDir
dist_dir => { distname => 'example-dist', -as => 'mydistdir' },
dist_dir => { distname => 'other-dist', -as => 'otherdistdir' };
# This calls
my $coderef = File::ShareDir::ProjectDistDir->build_dist_dir(
'dist_dir',
{ distname => 'example-dist' },
{ defaults => { filename => 'path/to/yourcallingfile.pm', projectdir => 'share' } },
);
my $othercoderef = File::ShareDir::ProjectDistDir->build_dist_dir(
'dist_dir',
{ distname => 'other-dist' },
{ defaults => { filename => 'path/to/yourcallingfile.pm', projectdir => 'share' } },
);
# And leverages Sub::Exporter to create 2 subs in your package.
Generates the exported 'dist_dir' method. In development environments, the generated method will return a path to the
development directories 'share' directory. In non-development environments, this simply returns File::ShareDir::dist_dir
.
As a result of this, specifying the Distribution name is not required during development ( unless in strict
mode ), however,
it will start to matter once it is installed. This is a potential avenues for bugs if you happen to name it wrong.
In strict
mode, the distribution name is ALWAYS REQUIRED, either at least at import
or dist_dir()
time.
use File::ShareDir::ProjectDirDir ( : all );
# this calls
my $coderef = File::ShareDir::ProjectDistDir->build_dist_file(
'dist_file' => {},
{ defaults => { filename => 'path/to/yourcallingfile.pm', projectdir => 'share' } }
);
use File::ShareDir::ProjectDirDir ( qw( :all ), distname => 'example-dist' );
# this calls
my $coderef = File::ShareDir::ProjectDistDir->build_dist_file(
'dist_file' => {},
{ distname => 'example-dist', defaults => { filename => 'path/to/yourcallingfile.pm', projectdir => 'share' } }
);
use File::ShareDir::ProjectDirDir
dist_file => { distname => 'example-dist', -as => 'mydistfile' },
dist_file => { distname => 'other-dist', -as => 'otherdistfile' };
# This calls
my $coderef = File::ShareDir::ProjectDistDir->build_dist_file(
'dist_file',
{ distname => 'example-dist' },
{ defaults => { filename => 'path/to/yourcallingfile.pm', projectdir => 'share' } },
);
my $othercoderef = File::ShareDir::ProjectDistDir->build_dist_file(
'dist_file',
{ distname => 'other-dist' },
{ defaults => { filename => 'path/to/yourcallingfile.pm', projectdir => 'share' } },
);
# And leverages Sub::Exporter to create 2 subs in your package.
Generates the 'dist_file' method.
In development environments, the generated method will return
a path to the development directories 'share' directory. In non-development environments, this simply returns
File::ShareDir::dist_file
.
Caveats as a result of package-name as stated in "build_dist_dir" also apply to this method.
use File::ShareDir::ProjectDistDir ':all', strict => 1;
use File::ShareDir::ProjectDistDir 'dist_dir' => { strict => 1 };
Starting with 1.000000
, there is a parameter strict
that changes
how sharedir
resolution performs.
Without strict:
lib/...
share/...
With strict
lib/...
share/dist/Dist-Name-Here/...
This technique greatly builds resilience to the long standing problem with "develop" vs "install" heuristic ambiguity.
Here at least,
dist_dir('Dist-Name')
Will instead fall back to
@INC/auto/share/dist/Dist-Name
When
share/dist/Dist-Name
Does not exist.
This means if you have a layout like this:
<DEVROOT>/inc/<a local::lib path here>
<DEVROOT>/lib/<development files here>
Then when Foo-Bar-Baz
is installed as:
<DEVROOT>/inc/lib/Foo/Bar/Baz.pm
<DEVROOT>/inc/lib/auto/share/dist/Foo-Bar-Baz
Then Baz.pm
will not see the DEVROOT
and assume "Hey, this is development" and then proceed to try finding files in
DEVROOT/share
Instead, DEVROOT
must have DEVROOT/share/dist/Foo-Bar-Baz
too, otherwise it reverts
to DEVROOT/inc/lib/auto...
If you have any dependence on this function, now is the time to get yourself off it.
As the dependency has been dropped on Path::Class
, if you have CPAN
modules relying on Path::Class
interface, you should now at a very minimum
start declaring
{ requires => "Path::Class" }
This will keep your dist working, but will not be future proof against further changes.
Recommended approach if you want to stay using the Path::Class
interface:
use File::ShareDir::... etc
use Path::Class qw( dir file );
my $dir = dir( dist_dir('Dist-Name') );
This should future-proof you against anything File::ShareDir may do in the future.
This change is a superficial one, and should have no bearing on how significant you think this release is.
It is a significant release, but the primary reason for the version change is simply to avoid compatibility issues in versions themselves.
However, outside that, x.y.z
semantics are still intended to be semi-meaningful, just with less .
and more 0
☺
This was essentially a required change to make strict
mode plausible, because strict mode _requires_ the distname
to be
known, even in the development environment.
This should not have any user visible effects, but please, if you have any problems, file a bug.
dist_file('foo','bar')
Is now simply sugar syntax for
path(dist_dir('foo'))->child('bar')
This should have no side effects in your code, but please file any bugs you experience.
( return value is still undef
if the file does not exist, and still croak
's if the file is not a file, or unreadable, but
these may both be subject to change )
Starting with 0.5.0, instead of using our simple lib/../share
pattern heuristic, a more
advanced heuristic is used from the new Path::FindDev
and Path::IsDev
.
This relies on a more "concrete" marker somewhere at the top of your development tree, and more importantly, checks for the existence of specific files that are not likely to occur outside a project root.
lib
and share
based heuristics were a little fragile, for a few reasons:
-
lib
can, and does appear all over UNIX file systems, for purposes other than development project roots.For instance, have a look in
/usr/
/usr/bin /usr/lib /usr/share ## UHOH.
This would have the very bad side effect of anything installed in
/usr/lib
thinking its "in development".Fortunately, nobody seems to have hit this specific bug, which I suspect is due only to
/usr/lib
being a symbolic link on most x86_64 systems. -
lib
is also reasonably common withinCPAN
package names.For instance:
lib::abs
Which means you'll have a hierarchy like:
$PREFIX/lib/lib/abs
All you need for something to go horribly wrong would be for somebody to install a
CPAN
module named:share::mystuff
Or similar, and instantly, you have:
$PREFIX/lib/lib/ $PREFIX/lib/share/
Which would mean any module calling itself
lib::*
would be unable to use this module.
So instead, as of 0.5.0
, the heuristic revolves around certain specific files being in the dev
directory.
Which is hopefully a more fault resilient mechanism.
Starting with 0.5.0, the internals are now based on Path::Tiny
instead of Path::Class
,
and as a result, there may be a few glitches in transition.
Also, previously you could get a Path::Class::*
object back from dist_dir
and dist_file
by importing it as such:
use File::ShareDir::ProjectDistDir
qw( dist_dir dist_file ),
defaults => { pathclass => 1 };
Now you can also get Path::Tiny
objects back, by passing:
use File::ShareDir::ProjectDistDir
qw( dist_dir dist_file ),
defaults => { pathtiny => 1 };
For the time being, you can still get Path::Class objects back, it is deprecated since 1.000000
( In fact, I may even make 2 specific sub-classes of PDD
for people who want objects back, as it will make the API
and the
code much cleaner )
Kent Fredric kentnl@cpan.org
This software is copyright (c) 2017 by Kent Fredric kentnl@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.