How to orderBy a value returned after function call which is in loop?

I am looping an object in view and calling a function which takes its members as parameters.

The function returns me a value every time the function is called.

I want to orderBy that returned value.

But my problem is, that value is returned after function call and I cannot store the values in an array so that I can sort.

    <div ng-repeat="member in current_project.members | orderBy : '?'"> 
     <span class="taskCompletionEst">
       Estimated time: 
             {{estimatedTimeSum(selected_date, member.id)}} hrs
     </span>

Controller

      $scope.estimatedTimeSum = function(date, member_id) {
       sum = 0
       angular.forEach($scope.projects[0].tasks[date], function(task, 
       projectname) {
        angular.forEach(task, function(value, key) {
         if (value["user_id"] == member_id) {
          if (value["completion"] != undefined) {
           sum += parseInt(value["estimation"])
          } 
         else {
          sum += parseInt(value["estimated_time"])
         }
        }
      });
    });
  return sum
 }

I need to orderBy Estimated time sum.

You should wrap your estimatedTimeSum function into intermediate sort function, which will be passed to orderBy filter:

angular.module('app', []).controller('ctrl', function($scope) {
  $scope.current_project = {
    members: [{
      id: 10
    }, {
      id: 250
    }, {
      id: 300
    }, {
      id: 150
    }, {
      id: 70
    }, {
      id: 800
    }]
  }; 

  $scope.sort = function(date) {
    return function(member){            
      return $scope.estimatedTimeSum(date, member.id);
    }    
  }

  $scope.estimatedTimeSum = function(date, member_id) {
    //only to  stub
    return member_id % (date || 1);
  }
})

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>

<div ng-app='app' ng-controller='ctrl'>
  <input type='number' ng-model='selected_date' ng-init='selected_date = 11'/>
  <div ng-repeat="member in current_project.members | orderBy : sort(selected_date)">
    <span class="taskCompletionEst">
       {{member.id}} Estimated time: {{estimatedTimeSum(selected_date, member.id)}} hrs
     </span>
  </div>
</div>