org.apache.nifi.parameter

Interface VerifiableParameterProvider

public interface VerifiableParameterProvider

Any Parameter Provider that implements this interface will be provided the opportunity to verify a given configuration of the Parameter Provider. This allows the Parameter Provider to provide meaningful feedback to users when configuring the dataflow.

Generally speaking, verification differs from validation in that validation is expected to be very quick and run often. If a Parameter Provider is not valid, its parameters cannot be fetched. However, verification may be more expensive or time-consuming to complete. For example, validation may ensure that a username is provided for connecting to an external service but should not perform any sort of network connection in order to verify that the username is accurate. Verification, on the other hand, may create resources such as network connections, may be more expensive to complete, and may be run only when a user invokes the action (though verification may later occur at other stages, such as when fetching the parameters).

The framework is not responsible for triggering the Lifecycle management stages, such as @OnScheduled before triggering the verification. Such methods should be handled by the verify(ConfigurationContext, ComponentLog) itself. The verify(ConfigurationContext, ComponentLog) method will only be called if the configuration is valid according to the validation rules (i.e., all Property Descriptors' validators and customValidate methods have indicated that the configuration is valid).

Method Summary

Modifier and Type	Method and Description
List<ConfigVerificationResult>	verify(ConfigurationContext context, ComponentLog verificationLogger) Verifies that the configuration defined by the given ConfigurationContext is valid.

Method Detail

verify

List<ConfigVerificationResult> verify(ConfigurationContext context,
                                      ComponentLog verificationLogger)

Verifies that the configuration defined by the given ConfigurationContext is valid.

Parameters:

context - the Configuration Context that contains the necessary configuration

verificationLogger - a logger that can be used during verification. While the typical logger can be used, doing so may result in producing bulletins, which can be confusing.

Returns:

a List of ConfigVerificationResults, each illustrating one step of the verification process that was completed