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 / 
Bread-Board-0.34
River stage two • 12 direct dependents • 18 total dependents
30 ++
/ Bread::Board::Service::WithDependencies

NAME

Bread::Board::Service::WithDependencies - Services with dependencies

VERSION

version 0.34

DESCRIPTION

This is a sub-role of Bread::Board::Service, for services with dependencies. It provides the mechanism to recursively resolve dependencies.

ATTRIBUTES

dependencies

Hashref, constrained by Bread::Board::Service::Dependencies. Values must be instances of Bread::Board::Dependency, but can be coerced from various other types, see the type's docs.

METHODS

add_dependency

  $service->add_dependency(name=>$dep);

Adds a new dependency.

get_dependency

  my $dep = $service->get_dependency('name');

Gets a dependency by name.

has_dependency

  if ($service->has_dependency('name')) { ... }

Returns true if this service has a dependency with the given name.

has_dependencies

  if ($service->has_dependencies) { ... }

Returns true if this service has any dependency.

get_all_dependencies

  my %deps = $service->get_all_dependencies;

Returns all the dependencies for this service, as a key-value list.

init_params

Builder for the service parameters, augmented to inject all the resolved dependencies into the params attribute, so that get can use them.

get

After the get method, the params attribute is cleared, to make sure that dependencies will be resolved again on the next call (of course, if the service is using a singleton lifecycle, the whole "getting" only happens once).

resolve_dependencies

  my %name_object_map = $self->resolve_dependencies;

For each element of "dependencies", calls its service method to retrieve the service we're dependent on, then tries to instantiate the value of the service. This can happen in a few different ways:

the service is not locked, and does not require any parameter

just call get on it

the service is not locked, requires parameters, but the dependency has values for them

call $service->get(%{$dependency->service_params})

the service is not locked, requires parameters, and we don't have values for them

we can't instantiate anything at this point, so we use a Bread::Board::Service::Deferred::Thunk instance, on which you can call the inflate method, passing it all the needed parameters, to get the actual instance

the service is locked

we return a Bread::Board::Service::Deferred that will proxy to the instance that the service will eventually return; yes, this means that in many cases circular dependencies can be resolved, at the cost of a proxy object

AUTHOR

Stevan Little <stevan@iinteractive.com>

BUGS

Please report any bugs or feature requests on the bugtracker website https://github.com/stevan/BreadBoard/issues

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.

COPYRIGHT AND LICENSE

This software is copyright (c) 2016 by Infinity Interactive.

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