If you start to create a node or edge but then hit cancel, it doesn't delete the partial node / edge

[jdanish]

Steps: click new edge, click cancel. OR
Steps: click new node, click cancel.

I'd expect the new node / edge to go away, but instead I have a node or an edge with a start and no finish.

[jdanish]

@benloh updated to reflect both node and edge (not just node). Can we add this to the "do in December" list or is it a major hurdle?

[benloh]

This is doable.

[jdanish]

Cool thanks.

[benloh]

@jdanish Upon looking into this a little more...this one might be a little more complex.

The basic problem is that we try to show the node immediately when you click "New Node". So as soon as you click the button, a new node is actually created, displayed on the graph, selected, and then node edit is enabled. While we don't show the edge immediately, an edge is also created immediately when you create the edge.

So if you want to cancel the creation of a new node / edge, what you actually have to do is delete the just-created node / edge.

Nodes

We can't simply use the "Cancel" button on Nodes to handle this because "Cancel" usually means abandon the previously saved changes without saving. So we'd have to add a "Delete" button for Nodes to be able to do this. And we'd want to decide if we want to allow node deletion in general, or only for just-created nodes. But the user would still also have to be conscious of the fact that "Cancel" is different from "Delete".

A second alternative would be to add a flag for a newly-created node so that clicking "Cancel" will delete the node for you. As soon as you click "Save", the flag will be cleared. so "Cancel" works like it did before.

A third alternative to this would be to add a new "mode" that allows you to edit a non-saved node, allow you to edit the node, and then only save it upon clicking "Save". This is a little more complex to implement, but should be doable. Though it's possible there may be some other reasons why we implemented it this way to begin with that would complicate things. I think the main challenge might be working through locking.

Edges

A "Delete" button already exists for edges so you can "Cancel" the new edge by clicking "Delete". If we stick with the "Delete" approach, then we probably want to disable the "Cancel" button until both Source and Target are defined (e.g. we have a valid edge and don't end up with a missing target).

On the other hand, if we use the new "mode" approach, we would remove the "Delete" button for new edges. "Delete" would only appear when editing a previously saved edge.

---

See also #38 and #56

[jdanish]

@benloh I vaguely recall that you were creating the node like that for a reason, and it might have been to allow the display while editing. So ... switching to the new "mode" seems likely to be complicated and messy.

I think the key thing is user experience - from a user's perspective, if they hit "new node" then "cancel" they expect it to go away.

I like the idea of setting the flag, and then allowing "cancel" of an in-process new node to essentially do a "delete" under the hood. Seems the cleanest and most intuitive to the user. As a note / reminder: For kids, we don't want to give them delete because they might delete without merging and make a mess of the network. This cancel allows them to undo a mistake that only impacts them without giving them full delete functionality.

For edges, it does seem counter-intuitive to have both a delete and cancel button now that you mention it. So having a similar cancel button as node during initial creation and then switching to delete in the future seems to make the most sense?

[benloh]

Implemented with #110