Accept function name as argument for "prettify"

[zopyx]

prettify currently accepts only a function object. It would be handy when prettify could accept the name of a formatter function as well or the function definition as string.

Background: vue-form-generator supports ion.rangeSlider. Forms in vue-form-generator are expressed as Javascript or can be loaded as JSON over AJAX. So with JSON over AJAX we can not specify a custom prettify function.

So supporting the following case would be nice

prettify: function (val) {  }  
prettify: "function (val) {  }"
prettify : "my_prettify"

[IonDen]

Hi, good idea.