Precondition:
The user has opened the app on a key-controlled device and made a selection of elements on his own map A that he wants to copy and paste into his own map B.
Main success scenario:
The user copies the selection on map A.
The user opens map B.
The user clicks anywhere on map B.
The user pastes the copied selection into map B.
The pasted selection of elements is placed in map B at the user's last click position right before pasting.
The user logs in.
The user fails to paste the elements he copied in his previous session because they are removed from the 'copy-storage'.
Error scenarios:
The user attempts to copy and paste a selection but the app is experiencing technical difficulties and is unable to complete the request, displaying an error message.
Postconditions:
The user's map contains the copied and pasted selection of elements.
The user's map A still contains the same elements as before the copying and pasting into map B.
The user's map B contains the pasted selection of elements which he copied from his map A.
For performance reasons and to minimize potential sources of error, the copied selection of elements should be persisted locally on the client side, i.e. in the browser's local storage.
The new storage, i.e. the local storage, should be used for every Copy & Paste scenario to store and retrieve the latest copied elements.
To avoid inconsistencies of all sorts, the new storage with the copied elements in it, should not be persisted beyond a user's session, i.e. it should cleared upon the user's next login.