lar::SimpleServiceProviderWrapper< PROVIDER > Class Template Reference

Service returning a provider. More...

#include "ServiceProviderWrappers.h"

Public Types
using	provider_type = PROVIDER
	type of the service provider More...
using	Parameters = art::ServiceTable< typename provider_type::Config >
	Type of configuration parameter (for art description) More...

Public Member Functions
	SimpleServiceProviderWrapper (Parameters const &config, art::ActivityRegistry &)
	Constructor (using a configuration table) More...
provider_type const *	provider () const
	Returns a constant pointer to the service provider. More...

Private Attributes
std::unique_ptr< provider_type >	prov
	service provider More...

Detailed Description

template<class PROVIDER>
class lar::SimpleServiceProviderWrapper< PROVIDER >

Service returning a provider.

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Template Parameters

PROVIDER

type of service provider to be returned

This class provides the simplest possible art service to wrap a LArSoft service provider. The service is not reacting to any framework events.

The configuration is passed directly to the provider.

The simplest way to create an art service with this template is:

#include "larcore/CoreUtils/ServiceProviderWrappers.h"
#include "path/to/MyProvider.h"

#include "art/Framework/Services/Registry/ServiceMacros.h"

namespace myprov {

  using MyService = lar::SimpleServiceProviderWrapper<MyProvider>;

}

DECLARE_ART_SERVICE(myprov::MyService, LEGACY)

An implementation file is necessary too, that will look like:

#include "path/to/MyService.h"

DEFINE_ART_SERVICE(myprov::MyService)

If callback registration is needed, a class can derive from this template and still gain a bit of boilerplate facility. That is:

• a provider_type definition (required by lar::providerFrom())
• a provider() method to access the provider (required by lar::providerFrom())
• a Parameters definition (used by art to print accepted configuration)
• a constructor supporting FHiCL configuration validation
• transparent life management of the provider instance

Requirements on the service provider:

• a data type Config being the configuration object. This is the object wrapped by fhicl::Table when performing FHiCL validation.
• a constructor with as argument a constant reference to a Config object. The provider should be configured by that constructor.

Definition at line 90 of file ServiceProviderWrappers.h.

Member Typedef Documentation

template<class PROVIDER >

using lar::SimpleServiceProviderWrapper< PROVIDER >::Parameters = art::ServiceTable<typename provider_type::Config>

Type of configuration parameter (for art description)

Definition at line 96 of file ServiceProviderWrappers.h.

template<class PROVIDER >

using lar::SimpleServiceProviderWrapper< PROVIDER >::provider_type = PROVIDER

type of the service provider

Definition at line 93 of file ServiceProviderWrappers.h.

Constructor & Destructor Documentation

template<class PROVIDER >

lar::SimpleServiceProviderWrapper< PROVIDER >::SimpleServiceProviderWrapper ( Parameters const &  config, art::ActivityRegistry &    )

inline

Constructor (using a configuration table)

Definition at line 101 of file ServiceProviderWrappers.h.

         : prov(std::make_unique<provider_type>(config()))
         {}

Member Function Documentation

template<class PROVIDER >

provider_type const* lar::SimpleServiceProviderWrapper< PROVIDER >::provider ( ) const

inline

Returns a constant pointer to the service provider.

Definition at line 107 of file ServiceProviderWrappers.h.

{ return prov.get(); }

Member Data Documentation

template<class PROVIDER >

std::unique_ptr<provider_type> lar::SimpleServiceProviderWrapper< PROVIDER >::prov

private

service provider

Definition at line 112 of file ServiceProviderWrappers.h.

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The documentation for this class was generated from the following file:

• larcore/v06_21_02/source/larcore/CoreUtils/ServiceProviderWrappers.h