I'm not sure what @Paddy_B wants to implement but I also want to add some elements in the pallete and I agree that the Custom element example is unclear @philippfromme.
In this example the circle and the triangle are added in the pallete and when you drag them in the canvas they are drawn on the fly. I, and probably @Paddy_B, want to add elements with predefined icon, not to draw figures. Also, the circle and the triangle are only for visual purposes with no semantics (no menu item), I guess because they are not linked to any business object.
But in that case, how to add/edit a business object?
There's also the Nyan example but again in that example the "cat" simply replaces the "Service Task". What if I want the "cat" to represent a new element, not the existing ones?
@philippfromme, I see a lot of posts from the community users asking how to add custom elements. For you the "Custom element" example may be easy and clear, but could you explain a bit the logic behind? Personally I'm confused where to make changes. Shall I copy the "Custom element" example and edit there files like "CustomRenderer.js"? If I want to make any changes at the "diagram-js", which files are the ones that are normally customized? How is the relation of the visual part and the business objects? Any good documentation?
Thanks a lot in advance!