Data Plug-ins

Data plug-ins enable manipulation of incoming data before they are saved to the storage service or outgoing data right before they are exported.

Using Data Plug-ins

The Informatics Gateway allows you to configure data plug-ins in the following services:

• (DIMSE) MONAI Deploy DICOM Listener: Configure each listening AE Title with zero or more data plug-ins via the CLI or via the Configuration API.
• (DIMSE) DICOM Export: configure the Plug-inAssemblies with one or more data plug-ins in the ExportRequestEvent.
• (DICOMWeb) STOW-RS:
  • The Virtual AE endpoints (/dicomweb/vae/...) can be configured similarly to the DICOM listener using the DICOMWeb STOW API.
  • For the default /dicomweb/... endpoints, set zero or more plug-ins under InformaticsGateway>dicomWeb>plug-ins in the appsettings.json configuration file.
• (DICOMWeb) Export: configure the Plug-inAssemblies with one or more data plug-ins in the ExportRequestEvent.

Note

When one or more plug-ins are defined, the plug-ins are executed in the order as they are listed.

Available Plug-ins

The following plug-ins are available:

Name	Description	Fully Qualified Assembly Name
DicomDeidentifier	A plug-in that de-identifies a set of configurable DICOM tags with random data before DICOM data is exported.	Monai.Deploy.InformaticsGateway.PlugIns.RemoteAppExecution.DicomDeidentifier, Monai.Deploy.InformaticsGateway.PlugIns.RemoteAppExecution
DicomReidentifier	A plug-in to be used together with the DicomDeidentifier plug-in to restore the original DICOM metadata.	Monai.Deploy.InformaticsGateway.PlugIns.RemoteAppExecution.DicomReidentifier, Monai.Deploy.InformaticsGateway.PlugIns.RemoteAppExecution

Creating a Plug-in

To create an input data plug-in, implement the IInputDataPlugin interface and put the dynamic link library (DLL) in the plug-ins/ directories. Similarly, for output data plug-ins, implement the IOutputDataPlugin interface.

Refer to the Configuration API page to retrieve available input and output data plug-ins.

Database Extensions

If a plug-in requires presistent data in the database, extend the DatabaseRegistrationBase class to register your database context and repositories.

Refer to the Monai.Deploy.InformaticsGateway.PlugIns.RemoteAppExecution plug-in as a reference.

Important

The Informatics Gateway requires all plug-ins to extend both the Entity Framework (SQLite) and MongoDB databases.

Entity Framework

Implement the IDatabaseMigrationManagerForPlugIns interface to register your Entity Framework (EF) database context. A connectionString is provided to the Configure(...) function when you extend the DatabaseRegistrationBase class, allowing you to create your code-first EF database context and generate your migration code using the dotnet ef CLI tool.

The following example extends the DatabaseRegistrationBase class to register a new EF database context named RemoteAppExecutionDbContext.

In the method, you first register the database context, then register your Migration Manager by implementing the IDatabaseMigrationManagerForPlugIns interface. Lastly, you register your repository for the RemoteAppExecutions table.

public class DatabaseRegistrar : DatabaseRegistrationBase
{
    public override IServiceCollection Configure(IServiceCollection services, DatabaseType databaseType, string? connectionString)
    {
        Guard.Against.Null(services, nameof(services));

        switch (databaseType)
        {
            case DatabaseType.EntityFramework:
                Guard.Against.Null(connectionString, nameof(connectionString));
                services.AddDbContext<EntityFramework.RemoteAppExecutionDbContext>(options => options.UseSqlite(connectionString), ServiceLifetime.Transient);
                services.AddScoped<IDatabaseMigrationManagerForPlugIns, EntityFramework.MigrationManager>();

                services.AddScoped(typeof(IRemoteAppExecutionRepository), typeof(EntityFramework.RemoteAppExecutionRepository));
                break;
            ...
        }

        return services;
    }
}

MongoDB

Similar to the Entity Framework section above, for MongoDB you first register your Migration Manager by implementing the IDatabaseMigrationManagerForPlugIns interface and then register your repository for the RemoteAppExecutions collection.

public class DatabaseRegistrar : DatabaseRegistrationBase
{
    public override IServiceCollection Configure(IServiceCollection services, DatabaseType databaseType, string? connectionString)
    {
        Guard.Against.Null(services, nameof(services));

        switch (databaseType)
        {
            case DatabaseType.MongoDb:
                services.AddScoped<IDatabaseMigrationManagerForPlugIns, MongoDb.MigrationManager>();

                services.AddScoped(typeof(IRemoteAppExecutionRepository), typeof(MongoDb.RemoteAppExecutionRepository));
                break;
            ...
        }

        return services;
    }
}

In the MigrationManager, configure the RemoteAppExecutions collection.

public class MigrationManager : IDatabaseMigrationManagerForPlugIns
{
    public IHost Migrate(IHost host)
    {
        RemoteAppExecutionConfiguration.Configure();
        return host;
    }
}