diff -r 1f340f3597a8 -r ea92f4fe783d client/src/selectors/coreSelectors.js
--- a/client/src/selectors/coreSelectors.js	Tue Oct 09 19:07:47 2018 +0200
+++ b/client/src/selectors/coreSelectors.js	Mon Oct 08 18:35:47 2018 +0200
@@ -1,34 +1,62 @@
-import Immutable from 'immutable';
-import { ActionEnum } from '../constants'
+import { ActionEnum } from '../constants';
+import * as R from 'ramda';
+
+const actionFilter = R.propEq('action');
+
+// export const getSessions = state => state.get('sessions')
+export const getSessions = R.prop('sessions')
+
+// export const getNotes = state => state.get('notes')
+export const getNotes = R.prop('notes');
 
+// const getSessionMapSelector = actionVal => state =>
+//   state.sessions
+//     .filter(s => s.action === actionVal)
+//     .reduce(
+//       (res, obj) => {
+//         res[obj._id] = obj;
+//         return res;
+//       },
+//       {}
+//     );
+
+const groupById = R.reduceBy(R.nthArg(1), {}, R.prop('_id'));
 
-const getSessionMapSelector = actionVal => state =>
-  state.get('sessions')
-    .filter(s => s.get('action') === actionVal)
-    .reduce(
-      (res, obj) => {
-        return res.set(obj.get('_id'), obj);
-      },
-      Immutable.Map()
-    );
+const getSessionMapSelector = actionVal => R.compose(
+  groupById,
+  R.filter(actionFilter(actionVal)),
+  getSessions
+  );
+
+// const getNoteMapSelector = actionVal => state => {
+//   const deletedSessions = state.sessions
+//     .filter(s => s.action === ActionEnum.DELETED)
+//     .reduce(
+//       (res, obj) => {
+//         res[obj._id] = obj;
+//         return res;
+//       },
+//       {}
+//     );
+//   return state.notes
+//     .filter(n => (n.action === actionVal && !(n.session in deletedSessions)))
+//     .reduce(
+//       (res, obj) => {
+//         res[obj._id] = obj;
+//         return res;
+//       },
+//       {}
+//     );
+// }
 
 const getNoteMapSelector = actionVal => state => {
-  const deletedSessions = state.get('sessions')
-    .filter(s => s.get('action') === ActionEnum.DELETED)
-    .reduce(
-      (res, obj) => {
-        return res.set(obj.get('_id'), obj);
-      },
-      Immutable.Map()
-    );
-  return state.get('notes')
-    .filter(n => (n.get('action') === actionVal && !deletedSessions.has(n.get('session'))))
-    .reduce(
-      (res, obj) => {
-        return res.set(obj.get('_id'), obj);
-      },
-      Immutable.Map()
-    );
+  const deletedSessions = getSessionMapSelector(ActionEnum.DELETED)(state);
+  return R.compose(
+   groupById,
+   R.reject(R.propSatisfies(R.has(R.__, deletedSessions), 'session')),
+   R.filter(actionFilter(actionVal)),
+   getNotes
+  )(state)
 }
 
 
@@ -44,20 +72,27 @@
 
 export const getDeletedNotes = getNoteMapSelector(ActionEnum.DELETED);
 
-export const getActiveSessions = state => state.get('sessions').filter(session => session.get('action') !== ActionEnum.DELETED)
+const testActionNotDeleted = R.complement(R.propEq('action', ActionEnum.DELETED));
+
+// export const getActiveSessions = state => getSessions(state).filter(session => session.action !== ActionEnum.DELETED)
+export const getActiveSessions = R.compose(R.filter(testActionNotDeleted), getSessions);
 
-export const getSessions = state => state.get('sessions')
-export const getNotes = state => state.get('notes')
+// export const getSession = (sessionId, state) => {
+//   const sessions = getSessions(state);
+//   return sessions.find(session => session._id === sessionId)
+// }
+const findById = R.compose(R.find,R.propEq('_id'));
+export const getSession = R.uncurryN(2,R.partialRight(R.useWith(R.compose, [findById, R.always(getSessions)]), [null,]))
 
-export const getSession = (sessionId, state) => {
-  const sessions = getSessions(state);
-  return sessions.find(session => session._id === sessionId)
-}
+// export const getSessionNotes = (sessionId, state) => {
+//   const notes = getNotes(state);
+//   let filteredNotes = notes.filter(note => {
+//     return (note.session === sessionId && note.action !== ActionEnum.DELETED);
+//   });
+//   filteredNotes.sort((a,b) => a.startedAt - b.startedAt);
+//   return filteredNotes;
+// }
+const filterSessionNote = R.partial(R.useWith(R.both, [R.always(testActionNotDeleted), R.propEq('session')]),[null,]);
 
-export const getSessionNotes = (sessionId, state) => {
-  const notes = getNotes(state);
-  return notes.filter(note => {
-    return (note.get('session') === sessionId && note.get('action') !== ActionEnum.DELETED);
-  }).sortBy( n => n.get('startedAt') );
-}
+export const getSessionNotes = R.uncurryN(2,R.converge(R.compose, [R.always(R.sortBy(R.prop('startedAt'))), R.useWith(R.filter, [filterSessionNote,]), R.always(getNotes)]));