populate hell

src/resources/activity/activityControllers.js

-const { crudControllers } = require('../../utils/crud')
 const { Activity } = require('./activityModel')
 const { User } = require('../user/userModel')
 const { Attendance } = require('../attendance/attendanceModel')
 const { Comment } = require('../comment/commentModel')
 const { omit, pick } = require('lodash')
 
+// Config
 const pickedKeys = [
   '_id',
   'title',
@@ -12,13 +12,44 @@ const pickedKeys = [
   'date',
   'type',
   'createdAt',
+  'updatedAt',
   'attendance',
   'comment',
 ]
 
-exports.default = crudControllers(Activity, pickedKeys)
+const activitySelector =
+  '_id title description date type createdAt updatedAt attendance comment'
+const commentSelector = '_id creator _creator text createdAt'
+const attendanceSelector = '_id user state'
+const creatorSelector = '-_id fullName nickName schacc'
+
+// Overwrites the given field with the populated User
+// field: populate on this
+// byPopulate: user schacc field name
+async function populateUsersOnField(fieldToPopulate, byPopulate) {
+  let newField = []
+  for (let field of fieldToPopulate) {
+    const populated = await User.findOne({
+      schacc: field[byPopulate],
+    })
+      .lean()
+      .exec()
+
+    field[byPopulate] = pick(populated, creatorSelector.split(' '))
+    newField.push(field)
+  }
+  return newField
+}
+
+async function populateCommentsandAttendances(activity) {
+  activity.comment = await populateUsersOnField(activity.comment, 'creator')
+  activity.attendance = await populateUsersOnField(activity.attendance, 'user')
+  return activity
+}
 
-exports.default.createOne = async (req, res) => {
+// Controller
+
+module.exports.createOne = async function createOne(req, res) {
   try {
     // Invalid Date provided
     if (!req.body.date || Date.parse(req.body.date) < new Date().getTime())
@@ -59,22 +90,22 @@ exports.default.createOne = async (req, res) => {
     await activity
       .populate({
         path: 'comment',
-        select: '_id creator text createdAt',
+        select: commentSelector,
       })
       .populate({
         path: 'attendance',
-        select: '_id user state',
+        select: attendanceSelector,
       })
       .execPopulate()
 
-    // conver to JS Object to overwrite .creator
-    let objActivity = activity.toObject()
-    objActivity.creator = objActivity._creator
+    const populatedActivity = await populateCommentsandAttendances(
+      activity.toObject()
+    )
 
-    res
+    return res
       .status(200)
       .json({
-        data: pick(objActivity, pickedKeys),
+        data: pick(populatedActivity, pickedKeys),
       })
       .end()
   } catch (err) {
@@ -91,32 +122,33 @@ exports.default.createOne = async (req, res) => {
   }
 }
 
-exports.default.getOne = async (req, res) => {
+module.exports.getOne = async function getOne(req, res) {
   try {
     const activity = await Activity.findOne({ _id: req.params.id })
       .populate({
         path: 'comment',
-        select: '_id creator text createdAt',
+        select: commentSelector,
       })
       .populate({
         path: 'attendance',
-        select: '_id user state',
+        select: attendanceSelector,
       })
-      .select('-__v')
       .lean()
       .exec()
 
     if (!activity)
       return res.status(404).json({ messages: ['No such activity.'] })
 
-    return res.status(200).json({ data: pick(activity, pickedKeys) })
+    const populatedActivity = await populateCommentsandAttendances(activity)
+
+    return res.status(200).json({ data: pick(populatedActivity, pickedKeys) })
   } catch (err) {
     console.error(err)
     return res.status(500).json({ message: err.message })
   }
 }
 
-exports.default.getMany = async (req, res) => {
+module.exports.getMany = async function getMany(req, res) {
   try {
     const activity = await Activity.find()
       .populate({
@@ -135,9 +167,12 @@ exports.default.getMany = async (req, res) => {
       return res.status(404).json({ message: 'Activity not found!' })
 
     res.status(200).json({
-      data: activity.map(function pickKeys(doc) {
-        return pick(doc, pickedKeys)
-      }),
+      data: await Promise.all(
+        activity.map(async function pickKeys(doc) {
+          const populatedActivity = await populateCommentsandAttendances(doc)
+          return pick(populatedActivity, pickedKeys)
+        })
+      ),
     })
   } catch (err) {
     console.error(err)
@@ -145,7 +180,7 @@ exports.default.getMany = async (req, res) => {
   }
 }
 
-exports.default.removeOne = async (req, res) => {
+module.exports.removeOne = async function removeOne(req, res) {
   try {
     const activity = await Activity.findByIdAndDelete({
       _id: req.params.id,
@@ -181,7 +216,7 @@ exports.default.removeOne = async (req, res) => {
   }
 }
 
-exports.default.updateOne = async (req, res) => {
+module.exports.updateOne = async function updateOne(req, res) {
   try {
     const activity = await Activity.findOneAndUpdate(
       { _id: req.params.id },

src/resources/activity/activityRouter.js

@@ -7,14 +7,14 @@ const router = Router()
 // /api/item
 router
   .route('/')
-  .get(isLoggedIn, controllers.default.getMany)
-  .post(isLoggedIn, isMentor, controllers.default.createOne)
+  .get(isLoggedIn, controllers.getMany)
+  .post(isLoggedIn, isMentor, controllers.createOne)
 
 // /api/item/:id
 router
   .route('/:id')
-  .get(isLoggedIn, controllers.default.getOne)
-  .put(isLoggedIn, isMentor, controllers.default.updateOne)
-  .delete(isLoggedIn, isMentor, controllers.default.removeOne)
+  .get(isLoggedIn, controllers.getOne)
+  .put(isLoggedIn, isMentor, controllers.updateOne)
+  .delete(isLoggedIn, isMentor, controllers.removeOne)
 
 exports.default = router