How to Implement User-Specific Favourites using Firestore? - ios

Question

My project contains an array of MealPlans. Right now, a user can star a MealPlan and that will update the isStarred Bool value in the MealPlan document. However, this just updates the database that every user currently accesses.
How can I code it so that a user has their own personal set of isStarred MealPlans?
I'm currently using Firebase Authentication and Firestore. This is my MealPlan struct:
struct MealPlan {
var docID:String?
var title:String?
var recipeSource:String?
var estimatedTime:String?
var coverImageView:String?
var equipment:[String]?
var instructions:[String]?
var isStarred:Bool?
}
My User struct:
struct User {
var userId:String?
var firstName:String?
var lastName:String?
var email:String?
}
My data model:
class MealPlanModel {
var delegate:MealPlanProtocol?
var listener:ListenerRegistration?
func getMealPlans(_ starredOnly:Bool = false) {
// Detach any listener
listener?.remove()
// Get a reference to the database
let db = Firestore.firestore()
var query:Query = db.collection("mealPlans")
// If filtering for starred Meal Plans, update the query
if starredOnly {
query = query.whereField("isStarred", isEqualTo: true)
}
self.listener = query.addSnapshotListener({ (snapshot, error) in
// Check for errors
if error == nil && snapshot != nil {
var mealPlans = [MealPlan]()
// Parse documents into mealPlans
for doc in snapshot!.documents {
let m = MealPlan(
docID: doc["docID"] as? String,
title: doc["title"] as! String,
recipeSource: doc["recipeSource"] as? String,
estimatedTime: doc["estimatedTime"] as? String,
coverImageView: doc["coverImageView"] as? String,
ingredientsProduce: doc["ingredientsProduce"] as? [String],
ingredientsProtein: doc["ingredientsProtein"] as? [String],
ingredientsSpices: doc["ingredientsSpices"] as? [String],
ingredientsOther: doc["ingredientsOther"] as? [String],
equipment: doc["equipment"] as? [String], instructions: doc["instructions"] as? [String],
isStarred: doc["isStarred"] as? Bool)
mealPlans.append(m)
}
// Call the delegate and pass back the notes in the main thread
DispatchQueue.main.async {
self.delegate?.mealPlansRetrieved(mealPlans: mealPlans)
}
}
})
}
func updateStarredStatus(_ docId:String, _ isStarred:Bool) {
let db = Firestore.firestore()
db.collection("mealPlans").document(docId).updateData(["isStarred":isStarred])
}
}
And the method for starring in my View Controller:
#IBAction func starButtonTapped(_ sender: Any) {
// Toggle the star filter status
isStarFiltered.toggle()
// Run the query
if isStarFiltered {
model.getMealPlans(true)
}
else {
model.getMealPlans()
}
// Update the starButton
setStarFilterButton()
}
Would it involve copying the docID of a starred MealPlan into a key in the Users struct? And then displaying those MealPlans when filtering for starred MealPlans?
Any help/guidance is much appreciated!

Answer 1

A solution is for each user to track their own meal plans. You could create a collection that stores the meal plan id's within the users document so it would look like this
meals
meal_0 //auto generated documentId
//meal ingredients
meal_1
//meal ingredients
meal_2
//meal ingredients
and then
users
user_0 //the documentId is the users uid
//user info
my_meals (collection)
meal_0: true
mean_2: true
That being said, it's often a good idea to keep data at a high level to reduce the amount of reads and simplify queries so this structure may be better instead of storing the users meals within the users document
starred_meals
user_0 //the documentId is the users uid
meal_0: true
mean_2: true
When a use logs in, read their document from the starred_meals collection.
To expand on that a little bit, sometimes a user will want to store other information with their meal so instead the above, how about this
starred_meals
user_0
starred_meal_0 (auto generated documentId)
meal_id: meal_0
wine_pairing: "Cabernet Sauvignon"
starred_meal_1
meal_id: meal_2
wine_pairing: "Barolo"
with that you could store all kinds of other information associated with each meal, per user