NAME
Bread::Board::Service::WithDependencies - Services with dependencies
VERSION
version 0.37
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) 2019, 2017, 2016, 2015, 2014, 2013, 2011, 2009 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.