Passing to method geticon in SAPUI5

SAP UI supports custom formatter functions. formatter="function" is used to specify a function to format cell data prior to display.

formatter="function"

Try using formatter function as below −

icon : {
   parts : ["answer"],
   formatter : function(answerValue){
      return self.getIcon(answerValue);
   }
}

Refer below link to know more about custom formatter functions −

https://sapui5.hana.ondemand.com/#/topic/07e4b920f5734fd78fdaa236f26236d8