cet-is » art

This feature is almost complete. Interestingly, this issue is slightly coupled to issue #20063 as enabling configuration validation has induced a change in how the random number engines are configured. Once that issue is resolved, I will mark this one as resolved, too.

To enable configuration validation and description, one will need to provide the 'Parameters' type, which is an alias to art::MixFilterTable<Config>, per the usual pattern:

class MyMixFilterDetail {
public:
  struct Config{
    fhicl::Atom<bool> someFlag{fhicl::Name{"someFlag"}};
    // ...
  }
  using Parameters = art::MixFilterTable<Config>;
  explicit MyMixFilterDetail(Parameters const& p,
                             art::MixHelper&);

  // ...
}

Providing the Parameters type does the following:

• Adds the EDFilter parameters to the allowed configuration
• Adds the MixHelper parameters to the allowed configuration
• Adds the detail parameters to the allowed configuration
• Requires users to specify the Parameters type in the detail constructor

In essence, unlike bare modules, providing the Parameters type not only provides configuration description, but it also requires configuration validation. For bare modules, it is allowed to provide the Parameters type (i.e. enable configuration description) but the user can still specify fhicl::ParameterSet as the constructor argument type (i.e. not enable configuration validation). Description and validation cannot be separated for MixFilter detail classes.

Implemented with commit art:d00ef23.