I've set:
graph.setHtmlLabels(true);
but when I double click on the cell with an HTML label to edit it in a simple example (http://codepen.io/anon/pen/bECmn) any HTML markup is shown as well. I was expecting when I click on the bold label 1 text to not see the strong tags.
Have I configured something wrongly in my example or is it up to me to apply some HTML editor I choose to display under this condition?
There will be an example for in-place editing on HTML labels in the next release (scheduled for later this week).