namespace::clean - phpMan

NAME
    namespace::clean - Keep imports and functions out of your namespace

SYNOPSIS
      package Foo;
      use warnings;
      use strict;

      use Carp qw(croak);   # 'croak' will be removed

      sub bar { 23 }        # 'bar' will be removed

      # remove all previously defined functions
      use namespace::clean;

      sub baz { bar() }     # 'baz' still defined, 'bar' still bound

      # begin to collection function names from here again
      no namespace::clean;

      sub quux { baz() }    # 'quux' will be removed

      # remove all functions defined after the 'no' unimport
      use namespace::clean;

      # Will print: 'No', 'No', 'Yes' and 'No'
      print +(__PACKAGE__->can('croak') ? 'Yes' : 'No'), "\n";
      print +(__PACKAGE__->can('bar')   ? 'Yes' : 'No'), "\n";
      print +(__PACKAGE__->can('baz')   ? 'Yes' : 'No'), "\n";
      print +(__PACKAGE__->can('quux')  ? 'Yes' : 'No'), "\n";

      1;

DESCRIPTION
  Keeping packages clean
    When you define a function, or import one, into a Perl package, it will
    naturally also be available as a method. This does not per se cause
    problems, but it can complicate subclassing and, for example, plugin
    classes that are included via multiple inheritance by loading them as
    base classes.

    The "namespace::clean" pragma will remove all previously declared or
    imported symbols at the end of the current package's compile cycle.
    Functions called in the package itself will still be bound by their
    name, but they won't show up as methods on your class or instances.

    By unimporting via "no" you can tell "namespace::clean" to start
    collecting functions for the next "use namespace::clean;" specification.

    You can use the "-except" flag to tell "namespace::clean" that you don't
    want it to remove a certain function or method. A common use would be a
    module exporting an "import" method along with some functions:

      use ModuleExportingImport;
      use namespace::clean -except => [qw( import )];

    If you just want to "-except" a single sub, you can pass it directly.
    For more than one value you have to use an array reference.

   Late binding caveat
    Note that the technique used by this module relies on perl having
    resolved all names to actual code references during the compilation of a
    scope. While this is almost always what the interpreter does, there are
    some exceptions, notably the sort SUBNAME style of the "sort" built-in
    invocation. The following example will not work, because "sort" does not
    try to resolve the function name to an actual code reference until
    runtime.

     use MyApp::Utils 'my_sorter';
     use namespace::clean;

     my @sorted = sort my_sorter @list;

    You need to work around this by forcing a compile-time resolution like
    so:

     use MyApp::Utils 'my_sorter';
     use namespace::clean;

     my $my_sorter_cref = \&my_sorter;

     my @sorted = sort $my_sorter_cref @list;

  Explicitly removing functions when your scope is compiled
    It is also possible to explicitly tell "namespace::clean" what packages
    to remove when the surrounding scope has finished compiling. Here is an
    example:

      package Foo;
      use strict;

      # blessed NOT available

      sub my_class {
          use Scalar::Util qw( blessed );
          use namespace::clean qw( blessed );

          # blessed available
          return blessed shift;
      }

      # blessed NOT available

  Moose
    When using "namespace::clean" together with Moose you want to keep the
    installed "meta" method. So your classes should look like:

      package Foo;
      use Moose;
      use namespace::clean -except => 'meta';
      ...

    Same goes for Moose::Role.

  Cleaning other packages
    You can tell "namespace::clean" that you want to clean up another
    package instead of the one importing. To do this you have to pass in the
    "-cleanee" option like this:

      package My::MooseX::namespace::clean;
      use strict;

      use namespace::clean (); # no cleanup, just load

      sub import {
          namespace::clean->import(
            -cleanee => scalar(caller),
            -except  => 'meta',
          );
      }

    If you don't care about "namespace::clean"s discover-and-"-except"
    logic, and just want to remove subroutines, try "clean_subroutines".

METHODS
  clean_subroutines
    This exposes the actual subroutine-removal logic.

      namespace::clean->clean_subroutines($cleanee, qw( subA subB ));

    will remove "subA" and "subB" from $cleanee. Note that this will remove
    the subroutines immediately and not wait for scope end. If you want to
    have this effect at a specific time (e.g. "namespace::clean" acts on
    scope compile end) it is your responsibility to make sure it runs at
    that time.

  import
    Makes a snapshot of the current defined functions and installs a
    B::Hooks::EndOfScope hook in the current scope to invoke the cleanups.

  unimport
    This method will be called when you do a

      no namespace::clean;

    It will start a new section of code that defines functions to clean up.

  get_class_store
    This returns a reference to a hash in a passed package containing
    information about function names included and excluded from removal.

  get_functions
    Takes a class as argument and returns all currently defined functions in
    it as a hash reference with the function name as key and a typeglob
    reference to the symbol as value.

IMPLEMENTATION DETAILS
    This module works through the effect that a

      delete $SomePackage::{foo};

    will remove the "foo" symbol from $SomePackage for run time lookups
    (e.g., method calls) but will leave the entry alive to be called by
    already resolved names in the package itself. "namespace::clean" will
    restore and therefor in effect keep all glob slots that aren't "CODE".

    A test file has been added to the perl core to ensure that this
    behaviour will be stable in future releases.

    Just for completeness sake, if you want to remove the symbol completely,
    use "undef" instead.

SEE ALSO
    B::Hooks::EndOfScope

THANKS
    Many thanks to Matt S Trout for the inspiration on the whole idea.

AUTHORS
    *   Robert 'phaylon' Sedlacek <rs AT 474.at>

    *   Florian Ragwitz <rafl AT debian.org>

    *   Jesse Luehrs <doy AT tozt.net>

    *   Peter Rabbitson <ribasushi AT cpan.org>

    *   Father Chrysostomos <sprout AT cpan.org>

COPYRIGHT AND LICENSE
    This software is copyright (c) 2011 by "AUTHORS"

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.