How do I add a new category to a custom node plugin - including a category description and customized icon?
I've just been editing the plugin.xml file for my node (as pasted below). I've tried adding a category extension point with a description and a valid reference to a local icon (which is getting included in the plugin). Unfortunately after I put my jar file into the KNIME dropins folder and restart the category appears as "Uncategorized" with no icon and no description. The good news is that the node itself is getting put in the right place with the right icon/description - it's just the category-level icon/description that are missing.
The "src" folder doesn't exist in the binary plug-in any more. I suggest you put the category icon into an "icons" folder in the root of the plug-in and reference this file. Make sure you include the "icons" folder in the binary build.
I continued to struggle with creating a new category extension point for KNIME to drop in my node, but I finally figured out the problem. It was because I was trying to use the old method of copying the content of the "plugin" folder to the "dropins" folder of the KNIME / Eclipse installation (to quote the Nov-2014 KNIME documentation).
The new method is to create an update site from which you can "Install New Software" from within KNIME. The steps are described by dllahr within this forum post (I'm repeating this information to help people get to the answer faster):
Another thing I figured out is that there is no category "description" as I thought from my original question. When you click on the category within KNIME the Node Description Help is cleverly populated with the abbreviated descriptions from each node found within the category.
The last observation I'll make is that using the "dropins" folder method still mostly works and it is a lot faster during the development process. Only package everything up into an update site when you are finished.