If one switched through guest fast (e.g., keeping the down-arrow key
pressed) while staying on the snapshot panel, it could happen that
the previous view got already destroyed once the success callback of
the feature API request got executed.
Then the ExtJS ViewModels' set method got a "null" back from its
me.getStub(...) call, and tried to access members of that, resulting
in a TypeError exception.
Avoid that by checking if we're already destroyed or still around
before doing that call. During the time we are already in the
callback we shouldn't be able to get destroyed in parallel due to JS
single thread nature and no yield point here, so this is safe.
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
Use arrow functions to bring them in a more simple boolean expression
style. Further, we can reuse the "isSnapshot" formula in the
"canRollback" and "canRemove" ones.
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
using the better View, ViewModel, Controller style,
while doing this, make it generic so that we can use it for qemu and lxc
Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
