如何在运行时更改导出流的属性？

Question

The Dynamic application composition topic says that

Properties can also be added, updated, or removed at runtime, and so can subscriptions. The compile-time properties and subscriptions just serve as initial settings.

but it doesn't say how to do that. So, how do you do that?

Answer 1

In the operator that exports the stream, call

setOutputPortExportProperties({property1_name=value, property2_name=value, ...},
  portNumber);

In the operator that imports the stream, call

setInputPortImportSubscription(subscription_string, portNumber);

SPL sample project 042_dynamic_import_export_api_at_work provides an example.