Assuming that obj
is your new user, and it contains the title, last name, and first name of the new user, all you have to do is set the values of the x-editable objects:
$('#title').editable('setValue', obj.title);
$('#lastName').editable('setValue', obj.lastName);
$('#firstName').editable('setValue', obj.firstName);
The reason why your example is not working is because x-editable separates the display from the actual value. Your display
function is called whenever the user changes an x-editable value. By default, x-editable displays whatever the value is set to. But perhaps the internal value is different from a displayed value, that is what the display
function is used for - it has no impact on the actual value, just the display of the value.
X-Editable has a lot of different methods you can take advantage of, you can find them on the 'Methods' tab here: http://vitalets.github.io/x-editable/docs.html#editable