Removal of the node's edge removes the placeholder for the operator

[hubertp]

I'm not sure if there is any easy to way to remedy this but just wanted to bring this to the attention of UX.
Removing the edge removes the _ placeholder and the only way to bring it back is to add it manually.
Maybe there are better ways to deal with it?

Kazam_screencast_00011.webm

[farmaazon]

Technically, we could add a similar mechanism to adding elements to a list. But so far there was no much demand for that.

[farmaazon]

Hmm, but when removing connection, we are normally leaving _ there

Not quite. Reconnecting has currently a logic of removing target port. We leave _ only when it's impossible without losing information needed to connect to the port again: for example, when you remove the second-last operand in some + (or whatever operator) chain (. also counts as operator - old UFCS remains. That's why disconnecting self port leaves _). And actually, this is the only case I know.

So, as you see, this logic has an assumption that there's no problem in restoring a removed element, and SpanTree has logic needed to do that: just the views never show the proper "insertion" ports.

[wdanilo]

Ok, @hubertp @farmaazon @sylwiabr – according to your feelings from user-perspective, purely UX perspective, how should it behave in your opinions?

[kazcw]

Right now, when the edge is clicked on the target side (to disconnect the source end), the target port is removed from the expression and we're left holding an edge to nowhere. In that case at least, I think we should keep a placeholder so that the edge is still valid and can be attached to a new source.

[wdanilo]

@kazcw I believe that @Frizi is right now chaining this behavior in such a way, that if you disconnect the end of the edge, the code is not changed until you drop the edge / connect it somewhere else. @Frizi can you confirm it, please?

[Frizi]

Yes, I'm currently working on that. The goal is such that when the edge is clicked on the target side, the code will remain unchanged until you do something with that edge (either connect or drop). The behavior will be unchanged when you are holding an edge connected to a source port.

I believe that the original issue could be adressed by having an insertion point inbetween chain elements, similar to how we have it right now in lists. Though making it look good and intuitive is probably another whole thing.

[farmaazon]

Closing stale discussion. I propose to not implement removing operands from operator chains, and see if we actually need it.