javascript - angular factory, return statement in then() promise returns undefined -

i call following factory in controller makebusmarkers(orderedfiltereddata).

console.log(mark) returns valid object (called right before return statement).
i presume simple answer, doing wrong?

.factory('makebusmarkers', ['busesbydepot', '$timeout', 'cameltostring', function(busesbydepot, $timeout, cameltostring){  // make leaflet map markers filtered data  return function(orderedfiltereddata){     var mark = {};      busesbydepot.then(function(keymap){              orderedfiltereddata.foreach(function(currentval){             mark[currentval.num] = {                 message : '#' + currentval.num.tostring()             }              ...some additional code here...          console.log(mark);         return mark;     }); }  }]) 

correct,

the factory returns promise object. thank you.

.factory('makebusmarkers', ['busesbydepot', '$timeout', 'cameltostring', function(busesbydepot, $timeout, cameltostring){  // make leaflet map markers filtered data  return function(orderedfiltereddata){ var mark = {};  return busesbydepot.then(function(keymap){          orderedfiltereddata.foreach(function(currentval){         mark[currentval.num] = {             message : '#' + currentval.num.tostring()         }          ...some additional code here...      console.log(mark);     return mark; }); }  }])