@vanepp I finally have a pair of reasonably functional (still incomplete) parts for demonstration. Also for discussion on bugs and limitations. I think that should go into a thread on fritzing-app issues. It is a lot more code related than parts creation. Before starting documentation and categorizing of related bugs though, could you have a close look at the parts? See if I did something wrong/different/non-standard that could be impacting the functionality. And perceived bugs.
I am including a sample sketch setup similar to the earlier sample here, along with separate parts files. The shield is placed over the Uno in breadboard view, connecting the matching pins.
I found an issue with that. It seemed like each time I recreated one one the parts, Fritzing chose a random connection to base the align to grid on. Only rarely could I get the parts to connect when align to grid was turned on. One non-standard thing I have, is blocks of definitions in the fsp file commented out. Things that are not needed yet, but intended either for use later, or for documentation. FritzingCheckPart warns about them (multiple times), but they should be valid for xml.
In schematic view, I added minimal extra power connections and wires. Just enough to get the ratsnest wires to go reasonable directions. pcb view should be standard. Assuming the parts themselves checkout valid, things to discuss are where it should be possible to add a real wire, and where Fritzing shows existing connections. What it highlights when mouse held down on a connection. Which is different in each view. I am seeing some unexpected cases, but want other part builder eyes on the parts before pointing and saying bug.
shield test.fzz (39.7 KB)
arduino_uno_for_shields.fzpz (27.2 KB) dragino_lora_shield.fzpz (9.6 KB)