Undo/Redo and the state of edit session.

[razvan oprea]

For a short explanation i want to replicate the behavior of sublime text when it comes to the state of the document (has changes/has no changes) in order to know if i have to promt the user with a save/yes/no dialog.

Related solutions that i found on the internet:

http://stackoverflow.com/questions/19670178/ace-editor-change-event   -very old post

http://stackoverflow.com/questions/30493065/ace-js-editor-enable-disable-undo-and-redo-buttons-in-editor  -newer but this does not seem to work.

The second solution (which seems to be up to date with documentation) does not work, and here is an example:

//can use 'change' also with no effect

editor.on("input", function() {

     var is_dirty = editor.session.getUndoManager().hasUndo();

     //...

});

`is_dirty` does not work properly after writing a couple of letters and then doing an undo (plain old Ctrl+z). Maybe i'm doing something wrong here, in that case i need a way to debug this.

Considering that i found no documentation on the order of events (input/change) and when UndoManager gets updated it would help to have a documented solution for this. Here is one way it could work:

Have two events passed to the UndoManager 'undo_stack_changed' and 'redo_stack_changed' (or it could be just one for both) emitted when any stacks change by any input/change, undo, redo or reset operations. The events have to be sent after all stack operations are done inside undo manager so that hasUndo() and hasRedo() return correct values

Thanks,

Razvan.