Provided by: libdbix-class-schema-loader-perl_0.07045-1_all 
NAME
$class - Optional module dependency specifications (for module authors) EOC
#@@ #@@ SYNOPSIS HEADING #@@
push @chunks, <<"EOC"; =head1 SYNOPSIS
Somewhere in your build-file (e.g. ExtUtils::MakeMaker's Makefile.PL):
...
\$EUMM_ARGS{CONFIGURE_REQUIRES} = {
\%{ \$EUMM_ARGS{CONFIGURE_REQUIRES} || {} },
'DBIx::Class::Schema::Loader' => '$distver',
};
...
my %DBIC_CONFIG_AND_ORACLE_DEPS = %{ eval {
require $class;
$class->req_list_for([qw( dbicdump_config rdbms_oracle )]);
} || {} };
\$EUMM_ARGS{PREREQ_PM} = {
\%DBIC_CONFIG_AND_ORACLE_DEPS,
\%{ \$EUMM_ARGS{PREREQ_PM} || {} },
};
...
ExtUtils::MakeMaker::WriteMakefile(\%EUMM_ARGS);
Note: The "eval" protection within the example is due to support for requirements during
the "configure" build phase not being available on a sufficient portion of production
installations of Perl. Robust support for such dependency requirements is available in the
CPAN installer only since version "1.94_56" first made available for production with perl
version 5.12. It is the belief of the current maintainer that support for requirements
during the "configure" build phase will not be sufficiently ubiquitous until the year 2020
at the earliest, hence the extra care demonstrated above. It should also be noted that
some 3rd party installers (e.g. cpanminus) do the right thing with configure requirements
independent from the versions of perl and CPAN available. EOC
#@@ #@@ DESCRIPTION HEADING #@@
push @chunks, <<'EOC'; =head1 DESCRIPTION
Some of the less-frequently used features of DBIx::Class::Schema::Loader have external
module dependencies on their own. In order not to burden the average user with modules
they will never use, these optional dependencies are not included in the base Makefile.PL.
Instead an exception with a descriptive message is thrown when a specific feature can't
find one or several modules required for its operation. This module is the central holding
place for the current list of such dependencies, for DBIx::Class::Schema::Loader core
authors, and DBIx::Class::Schema::Loader extension authors alike.
Dependencies are organized in groups where each group can list one or more required
modules, with an optional minimum version (or 0 for any version). In addition groups
prefixed with "test_" can specify a set of environment variables, some (or all) of which
are marked as required for the group to be considered by "req_list_for"
Each group name (or a combination thereof) can be used in the public methods as described
below. EOC
#@@ #@@ REQUIREMENT GROUPLIST HEADING #@@
push @chunks, '=head1 CURRENT REQUIREMENT GROUPS';
my $standalone_info;
for my $group (sort keys %$dbic_reqs) {
my $info = $standalone_info->{$group} ||= $class->_groups_to_reqs($group);
next unless (
$info->{modreqs_fully_documented}
and
( $info->{augments} or $info->{modreqs} )
);
my $p = $dbic_reqs->{$group}{pod};
push @chunks, (
"=head2 $p->{title}",
"=head3 $group",
$p->{desc},
'=over',
);
if ( keys %{ $info->{modreqs}||{} } ) {
push @chunks, map
{ "=item * $_" . ($info->{modreqs}{$_} ? " >= $info->{modreqs}{$_}" : '') }
( sort keys %{ $info->{modreqs} } )
;
}
else {
push @chunks, '=item * No standalone requirements',
}
push @chunks, '=back';
for my $ag ( sort keys %{ $info->{augments} || {} } ) {
my $ag_info = $standalone_info->{$ag} ||= $class->_groups_to_reqs($ag);
my $newreqs = $class->modreq_list_for([ $group, $ag ]);
for (keys %$newreqs) {
delete $newreqs->{$_} if (
( defined $info->{modreqs}{$_} and $info->{modreqs}{$_} == $newreqs->{$_} )
or
( defined $ag_info->{modreqs}{$_} and $ag_info->{modreqs}{$_} == $newreqs->{$_} )
);
}
if (keys %$newreqs) {
push @chunks, (
"Combined with L</$ag> additionally requires:",
'=over',
( map
{ "=item * $_" . ($newreqs->{$_} ? " >= $newreqs->{$_}" : '') }
( sort keys %$newreqs )
),
'=back',
);
}
}
}
#@@ #@@ API DOCUMENTATION HEADING #@@
push @chunks, <<'EOC';
IMPORT-LIKE ACTIONS
Even though this module is not an Exporter, it recognizes several "actions" supplied to
its "import" method.
-skip_all_without
Arguments: @group_names
A convenience wrapper for use during testing: EOC
push @chunks, " use $class -skip_all_without => qw(admin test_rdbms_mysql);";
push @chunks, 'Roughly equivalent to the following code:';
push @chunks, sprintf <<'EOS', ($class) x 2;
BEGIN {
require %s;
if ( my $missing = %s->req_missing_for(\@group_names_) ) {
print "1..0 # SKIP requirements not satisfied: $missing\n";
exit 0;
}
}
EOS
push @chunks, <<'EOC';
It also takes into account the "RELEASE_TESTING" environment variable and behaves like
"-die_without" for any requirement groups marked as "release_testing_mandatory".
-die_without
Arguments: @group_names
A convenience wrapper around "die_unless_req_ok_for": EOC
push @chunks, " use $class -die_without => qw(deploy admin);";
push @chunks, <<'EOC';
-list_missing
Arguments: @group_names
A convenience wrapper around "modreq_missing_for":
perl -Ilib -MDBIx::Class::Schema::Loader::Optional::Dependencies=-list_missing,dbicdump_config,rdbms_oracle | cpanm
METHODS
req_group_list
Arguments: none
Return Value: \%list_of_requirement_groups
This method should be used by DBIx::Class::Schema::Loader packagers, to get a hashref of
all dependencies keyed by dependency group. Each key (group name), or a combination
thereof (as an arrayref) can be supplied to the methods below. The values of the returned
hash are currently a set of options without a well defined structure. If you have use for
any of the contents - contact the maintainers, instead of treating this as public (left
alone stable) API.
req_list_for
Arguments: $group_name | \@group_names
Return Value: \%set_of_module_version_pairs
This method should be used by DBIx::Class::Schema::Loader extension authors, to determine
the version of modules a specific set of features requires for this version of
DBIx::Class::Schema::Loader (regardless of their availability on the system). See the
"SYNOPSIS" for a real-world example.
When handling "test_*" groups this method behaves differently from "modreq_list_for" below
(and is the only such inconsistency among the "req_*" methods). If a particular group
declares as requirements some "environment variables" and these requirements are not
satisfied (the envvars are unset) - then the "module requirements" of this group are not
included in the returned list.
modreq_list_for
Arguments: $group_name | \@group_names
Return Value: \%set_of_module_version_pairs
Same as "req_list_for" but does not take into consideration any "environment variable
requirements" - returns just the list of required modules.
req_ok_for
Arguments: $group_name | \@group_names
Return Value: 1|0
Returns true or false depending on whether all modules/envvars required by the group(s)
are loadable/set on the system.
req_missing_for
Arguments: $group_name | \@group_names
Return Value: $error_message_string
Returns a single-line string suitable for inclusion in larger error messages. This method
would normally be used by DBIx::Class::Schema::Loader core features, to indicate to the
user that they need to install specific modules and/or set specific environment variables
before being able to use a specific feature set.
For example if some of the requirements for "deploy" are not available, the returned
string could look like: EOC
push @chunks, qq{ "Moose~$moosever" (see $class documentation for details)};
push @chunks, <<'EOC';
The author is expected to prepend the necessary text to this message before
returning the actual error seen by the user. See also L</modreq_missing_for>
modreq_missing_for
Arguments: $group_name | \@group_names
Return Value: $error_message_string
Same as "req_missing_for" except that the error string is guaranteed to be either empty,
or contain a set of module requirement specifications suitable for piping to e.g.
cpanminus. The method explicitly does not attempt to validate the state of required
environment variables (if any).
For instance if some of the requirements for "deploy" are not available, the returned
string could look like: EOC
push @chunks, qq{ "Moose~$moosever"};
push @chunks, <<'EOC';
See also "-list_missing".
skip_without
Arguments: $group_name | \@group_names
A convenience wrapper around skip. It does not take neither a reason (it is generated by
"req_missing_for") nor an amount of skipped tests (it is always 1, thus mandating
unconditional use of done_testing). Most useful in combination with ad hoc requirement
specifications: EOC
push @chunks, <<EOC;
SKIP: {
$class->skip_without([ deploy YAML>=0.90 ]);
...
}
EOC
push @chunks, <<'EOC';
die_unless_req_ok_for
Arguments: $group_name | \@group_names
Checks if "req_ok_for" passes for the supplied group(s), and in case of failure throws an
exception including the information from "req_missing_for". See also "-die_without".
modreq_errorlist_for
Arguments: $group_name | \@group_names
Return Value: \%set_of_loaderrors_per_module
Returns a hashref containing the actual errors that occurred while attempting to load each
module in the requirement group(s).
req_errorlist_for
Deprecated method name, equivalent (via proxy) to "modreq_errorlist_for".
EOC
#@@ #@@ FOOTER #@@
push @chunks, <<'EOC'; =head1 FURTHER QUESTIONS?
Check the list of additional DBIC resources.
COPYRIGHT AND LICENSE
This module is free software copyright by the DBIx::Class::Schema::Loader (DBICSL)
authors. You can redistribute it and/or modify it under the same terms as the
DBIx::Class::Schema::Loader library. EOC
eval {
open (my $fh, '>', $podfn) or die;
print $fh join ("\n\n", @chunks) or die;
print $fh "\n" or die;
close ($fh) or die;
} or croak( "Unable to write $podfn: " . ( $! || $@ || 'unknown error') );
}
1;
perl v5.22.1 DBIx::Class::Schema::Loader::Optional::Dependencies(3pm)