You could just add userId parameter as a parameter inside your state.

url: '/{id}/{name}', //assuming user object has `id` property which has unique id.

So while making an ajax you could directly get the user id from the user object before making an ajax.

Controller

friendProfileService.loadProfile($stateParams.id).then(function(response) {
  $scope.user_profile = response.data;
  console.log ($scope.user_profile)
})

Factory

app.factory('friendProfileService', ['$http', '$stateParams', function($http) {
  return {
    loadProfile: function(id) {
      return $http.get('/users/'+ id +'json');
    }
  };
}])

You could just add id parameter of user inside state so that it can be easily readable from the $stateParams.

url: '/{id}/{name}', //assuming user object has `id` property which has unique id.

So while making an ajax you could directly get the user id from the user object before making an ajax.

Controller

friendProfileService.loadProfile($stateParams.id).then(function(response) {
  $scope.user_profile = response.data;
  console.log ($scope.user_profile)
})

Factory

app.factory('friendProfileService', ['$http', '$stateParams', function($http) {
  return {
    loadProfile: function(id) {
      return $http.get('/users/'+ id +'json');
    }
  };
}])