2.2 changelog questions

Hi Knime-devs,

thanks for the new 2.2 release. :slight_smile:

I’ve read through the changelog and would love if you could further comment on some of the changes. (Generally, most questions might be obsolete if you could hyper-link the changes to the according tracker-issues).

Add flow variables port to each node (enables control on execution order)
Where is it? I can’t find any additional ports in any node.

Enh 2254: Support for workflow-local files
Could you give us an example how this works? I definitely like the idea, because so far knime-workflows were hardly portable between different OSs.

Bug 2318: Define extension point for aggregation method
From what I see in AggregationMethods, core-knime doesn’t use this nice feature but hard-wires all aggregation methods. Is there an example in the codebase? What is necessary to hook a new method in the GroupBy-node?

Bug 2184: Extension point for distance functions
Same thing here: I’ve searched in the trunk but couldn’t find any example. What is necessary to hook an an own metric, and which nodes make use of it?

Cheers, Holger

Concerning the distance functions there is currently no plugin in the public release that makes use of it. The standard distance functions are hard-coded (and probably will continue to be) and other distance functions are currently only used in some internal projects.

Registering your own distance functions is fairly easy. The description of the extension point states that you need to extend org.knime.base.distance.Distance and simply state this class in the extension in your plugin.  The distance function is than available on the Distance Matrix Calculator.