NAME

Data::Resolver::Alternatives - resolver from other resolvers

SYNOPSIS

   use Data::Resolver::Alternatives;
   use Data::Resolver::FromDir;
   use Data::Resolver::FromTar;

   my $dir1 = Data::Resolver::FromDir->new(root => $path);
   my $dir2 = Data::Resolver::FromDir->new(root => $other_path);
   my $tar  = Data::Resolver::FromTar->new(root => $path_to_tar);

   # one to rule them all
   my $resolver = Data::Resolver::Alternatives->new(
      alternatives => [ $dir1, $dir2, $tar ]);

   my @list_of_asset_keys = $resolver->list_asset_keys;
   say 'have it' if $resolver->has_asset($key);
   my $asset = $resolver->get($key);

   my @list_of_sub_resolver_keys = $resolver->list_sub_resolver_keys;
   say 'have it' if $resolver->has_sub_resolver($srkey);
   my $sub_resolver = $resolver->get_sub_resolver($srkey);

DESCRIPTION

This class implements a resolver that relies upon a list of alternatives, which are in turn resolvers which are tried in order to complete the required operation.

Operations for individual keys (either check or retrieval) are performed by selecting the first candidate that supports the key and then applying the operation upon it. On the other hand, lists are collected from all alternatives, removing duplicates.

Resolvers appearing first in the provided "alternatives" will be tried first.

INTERFACE

This class inherits from Data::Resolver::Base, inheriting all of its methods and overloading the abstract ones, while keeping the expected semantics.

METHODS

alternatives

   my $array_ref = $obj->alternatives;

The list of alternatives that are used for operating.

get_asset

   sub get_asset              ($self, $key) { ... }

retrieve the asset associated to $key, as a Data::Resolver::Asset.

get_sub_resolver

   sub get_sub_resolver       ($self, $key) { ... }

retrieve the sub-resolver associated to $key.

Note that, in general, the sub-resolver will be of a different class from this one. This is considered a feature.

has_asset

   sub has_asset              ($self, $key) { ... }

test existence of asset for $key.

has_sub_resolver

   sub has_sub_resolver       ($self, $key) { ... }

test existence of sub-resolver for $key.

list_asset_keys

   sub list_asset_keys        ($self)       { ... }

return a list of asset names available from the resolver.

list_sub_resolver_keys

   sub list_sub_resolver_keys ($self)       { ... }

return a list of sub-resolver names available as sub-resolvers.

AUTHOR

Flavio Poletti <flavio@polettix.it>

COPYRIGHT AND LICENSE

Copyright 2023 by Flavio Poletti <flavio@polettix.it>

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

cpanm Data::Resolver

perl -MCPAN -e shell
install Data::Resolver