tinyMCE disable Undo/Redo function - tinymce

Question

I need to disable Undo/Redo function in tinyMCE. I saw the documentantion and I used this functions:
ed.onUndo.add(function(ed, e) {
tinymce.dom.Event.cancel(e);
e.preventDefault();
return false;
});
ed.onRedo.add(function(ed, e) {
tinymce.dom.Event.cancel(e);
e.preventDefault();
return false;
});
but without any success.
Note: ed is my active editor.

Answer 1

If you are using tinyMCE 4.*, you can disable Undo/Redo by returning false on BeforeAddUndo event:
ed.on('BeforeAddUndo', function(e) {
return false;
});

Answer 2

TinyMCE v4 - Just overwrite the default settings.
tinymce.init({
selector: '#content',
toolbar: 'bold italic strikethrough underline | quicklink | alignleft aligncenter alignright alignjustify | link ',
});

Answer 3

We had the same problem, but the solution is a bit hacky.
There is ajavascript class in the tinymce core that we needed to overwrite: tinymce.UndoManager.
We used a variable sticked to the editor object to decide if the creation of an undo step actually should take place or not: tinymce.activeEditor.disable_undo_creation.
Here is the code part of the overwritten class:
add : function(level) {
if (tinymce.activeEditor.disable_undo_creation) return;
var i, settings = editor.settings, lastLevel;
level = level || {};
level.content = getContent();
// Add undo level if needed
lastLevel = data[index];
if (lastLevel && lastLevel.content == level.content)
return null;
// Time to compress
if (settings.custom_undo_redo_levels) {
if (data.length > settings.custom_undo_redo_levels) {
for (i = 0; i < data.length - 1; i++)
data[i] = data[i + 1];
data.length--;
index = data.length;
}
}
// Get a non intrusive normalized bookmark
level.bookmark = editor.selection.getBookmark(2, true);
// Crop array if needed
if (index < data.length - 1)
data.length = index + 1;
data.push(level);
index = data.length - 1;
self.onAdd.dispatch(self, level);
editor.isNotDirty = 0;
return level;
},
When the editor is unable to create undo steps redo/undo won't work anymore.