Copy RLMObject ,Modify and then save - ios

So what im trying to do is, retrieve the object that is already saved on Realm, modify some properties and then save it again, keeping only one record on the database.
Heres my code :
Getting the Realm already saved user
if let user = User.query() {
user.latitude = String(latitude)
user.longitude = String(longitude)
user.save()
}
User query func, inside User Obj
static func query() -> User? {
return User.allObjects().toArray(User.self).first
}
func save() -> User {
RealmPersister.saveObjects([self])
return self
}
And the RealmPersister class func
class func saveObjects(objects: [RLMObject]?) {
autoreleasepool {
guard let objects = objects where objects.count > 0 else { return }
do {
let realm = RealmEncrypted.realm()
realm.beginWriteTransaction()
realm.addObjects(objects)
try realm.commitWriteTransaction()}
catch {
print("Realm did not write objects! \(objects)")
}
}
}
class func deleteObjects(objects: [RLMObject]?) {
autoreleasepool {
guard let objects = objects where objects.count > 0 else { return }
do {
let realm = RealmEncrypted.realm()
realm.beginWriteTransaction()
realm.deleteObjects(objects)
try realm.commitWriteTransaction()
} catch {
print("Realm did not delete objects! \(objects)")
}
}
}

This appears that you need to be using primary keys on the User object. This way you can retrieve the same object quickly via the primary key, modify it, and then save it without the possibility of creating duplicates.

Related

how to update realm object based on the certain property in Realm?

I have products in my Realm database like this
I want to update my realm database based on productID, so I don't need to add another product over and over again. let say I want to update quantity of product that has productID = "a" to be 5.
I have tried to write something like this.
let selectedProductID = "a"
let productsInRealmDatabase = realm.objects(Product.self)
let productIndex = productsInRealmDatabase.index(where: {$0.productID == selectedProductID})
if let productIndex = productIndex {
do {
try realm.write {
var productRealm = productsInRealmDatabase[productIndex]
productRealm.quantity = 5
productsInRealmDatabase[productIndex] = productRealm // ERROR HERE
}
} catch {
// error Handling
}
}
but I got error in : productsInRealmDatabase[productIndex] = productRealm
Error Message: Cannot assign through subscript: subscript is get-only
so how to update realm object based on the certain property in Realm?
You should use Realm's own filter method which accepts an NSPredicate and returns an auto-updating Results instance rather than Swift's filter when operating on Realm collections. Than either update the properties of the fetched prouduct or create a new one and save that to Realm.
let selectedProductID = "a"
let productsInRealmDatabase = realm.objects(Product.self)
let matchingProduct = productsInRealmDatabase.filter("productID == %#", selectedProductID).first
if let matchingProduct = matchingProduct {
do {
try realm.write {
matchingProduct.quantity = 5
}
} catch {
// error Handling
}
} else {
let newProduct = Product()
newProduct.productID = selectedProductID
newProduct.quantity = 5
do {
try realm.write {
realm.add(newProduct)
}
} catch {
// error Handling
}
}
If you want your Products to be unique based on their productID property, you use also set productID as the primaryKey of your Object subclass.
class Product:Object {
#objc dynamic var productID = ""
...
override static func primaryKey() -> String? {
return "productID"
}
}
Try this -
let selectedProductID = "a"
let productsInRealmDatabase = realm.objects(Product.self)
let filteredProducts = productsInRealmDatabase.filter("productID = \(selectedProductID)")
do {
try realm.write {
filteredProducts.forEach { product in
product.quantity = 5
}
}
} catch {
// error Handling
}
While inserting data to your database inside the insert function mark update key as true and then try updating the value. eg:
static func insertData() {
//Your insertion code//
try! realm.write {
realm.add(request, update: true)
}
}
static func updateData(productId: String, quantity: Int) {
let product = self.getProductData(prodId: productId)
let realm = try! Realm()
try! realm.write {
product?.quantity = quantity
}
}
Hope this helps you out.

Add / Update custom object dictionaries array in swift 4

I have an array of dictionary with custom object in swift.
Now I am comparing the object for add & update.
The logic is as simple to add the data if not exist and update if any change in dictionary.
User is custom object type:
#objc public class User: NSObject , Mappable
from the getUserID i can able to get userID
The below code is execute in for loop from where i am passing User object.
var peopleList = [User]()
if self.peopleList.count > 0 {
if self.peopleList.contains(where: {$0.getUserID() == users.getUserID()})
{
// check for any update in dist
if let index = self.peopleList.index(of: users)
{
if users.isEqual(self.peopleList[index])
{
print("equal no updates")
}
else
{
print("need to updates objects..")
}
}
//already exist room
}
else
{
self.peopleList.append(users)
}
}
I know it may be related to equatable
so I am using below fuction
func isEqual<T: Equatable>(type: T.Type, a: Any, b: Any) -> Bool? {
guard let a = a as? T, let b = b as? T else { return nil }
return a == b
}
But I am getting index = nil.
Is there any idea or suggestion to solve it.
If any other way to do it efficiently them most welcome.
I think this simplified version should work
if self.peopleList.isEmpty, let user = self.peopleList.first(where: { $0.getUserID() == users.getUserID() }) {
if user == users {
// is equal
} else {
// do update
}
} else {
self.peopleList.append(users)
}

Removing Custom Objects from List in UserDefaults

I am trying to remove an element from a list which is stored in NSUserDefaults. The getAll function is implemented below:
func getAllOrders() -> [Order] {
var orders = [Order]()
if let userDefaults = UserDefaults(suiteName: "group.com.johndoe.SoupChef.Shared") {
if let ordersData = userDefaults.data(forKey: "Orders") {
orders = try! JSONDecoder().decode([Order].self, from: ordersData)
}
}
return orders
}
And here is the code for deleting the order.
func delete(order :Order) {
var persistedOrders = getAllOrders()
persistedOrders.removeAll { persistedOrder in
persistedOrder.identifier.uuidString == order.identifier.uuidString
}
}
After deleting the order in the code above when I call getAllOrders I still see all the elements, meaning I don't see the order being deleted.
That's because you don't save your changes. Once you've performed the removal you need to turn persistedOrders back into JSON and then:
userDefaults.set(json, forKey:"Orders")
You need to use jsonEncoder and encode the edited array then store it again the user defaults
func delete(order :Order) {
var persistedOrders = getAllOrders()
persistedOrders.removeAll { persistedOrder in
persistedOrder.identifier.uuidString == order.identifier.uuidString
}
do {
let data = try JSONEncoder().encode(persistedOrders)
userDefaults.set(data, forKey:"Orders")
}
catch {
print(error)
}
}
You have to store correctly your UserDefaults
UserDefaults.standard.set(json, forKey:"Orders")
Now, you can remove them using:
UserDefaults.standard.removeObject(forKey: "Orders")

Updating an entity record instead of creating a new record with CoreData using Swift

I need to fetch some information from the server.
and then I need to save them using CoreData.
The problem is that the same record with same attributes is saved several times.
I want to save just new records to the CoreData and update the existing ones.
func saveChanges() throws {
var error: ErrorType?
mainQueueContext.performBlockAndWait () {
if self.mainQueueContext.hasChanges {
do {
try self.mainQueueContext.save()
} catch let saveError {
error = saveError
}
}
}
if let error = error {
throw error
}
}
func fetchRecentPosts(completion completion: (PostResult) -> Void){
.
.
.
do{
try self.coreDataStack.saveChanges()
print("now data is saved in this device")
}
catch let error {
result = .Failure(error)
}
.
.
.
}
My idea is to check if that id was saved. If it was saved before I should not add another record. Then how can I update the existing one?
And is it a good way to solve this problem?
First check if your record exists in DB
static func getMyRecord(with id : String, context : NSManagedObjectContext) -> MyRecord? {
let fetchRequest: NSFetchRequest< MyRecord> = MyRecord.fetchRequest()
fetchRequest.predicate = NSPredicate(format: "id = %#", id)
let foundRecordsArray = try! context.fetch(fetchRequest)
if foundRecordsArray.count > 0 {
return foundRecordsArray[0]
}
return nil
}
While inserting if available update it else create new record.
static func insertRecord(_ record : MyRecord, context : NSManagaedObjectContext) {
let foundRecord = DataInserterClass. getMyRecord(with: yourID, context: context)
if foundRecord == nil {
//create new record
}
else {
//update foundRecord
}
try! context.save()
}

Iterate through a custom Parse column in Swift app

I want to know how I could store the entire custom column (the user Pointer<_User> column from a custom class) and put them all in an array variable so that I can see if a the user exists in that class or not. This is what I have:
Old Code
var objectUserIdArray = [String]()
let objectUserIdQuery : PFQuery = PFQuery(className: "Scores")
objectUserIdQuery.findObjectsInBackgroundWithBlock {
(objects : [PFObject]? , error : NSError?) -> Void in
var objectID = objects! as [PFObject]
for i in 0..<objectID.count {
objectUserIdArray.append(objectID[i].objectId!)
}
for _ in objectID {
print(objectUserIdArray)
}
New Code
func saveScoresOnParse() {
objectUserIdQuery.whereKey("User", equalTo: PFObject(withoutDataWithClassName: "_User", objectId: userID))
objectUserIdQuery.findObjectsInBackgroundWithBlock {
(objects : [PFObject]? , error : NSError?) -> Void in
if error == nil {
//var objectID = objects! as [PFObject]
/*for i in 0..<objectID.count {
self.objectUserIdArray.append( objectID[i].objectId! )
}*/
for _ in objects! {
print(objects)
}
// The score key has been incremented
for (var i = 0 ; i < self.objectUserIdArray.count ; i++) {
if self.userID != objects![i] {
print("New Scores")
print("R: \(self.rightAnswers)")
print("W: \(self.wrongAnswers)")
print("S: \(self.skippedQuestions)")
self.scores["User"] = PFUser.currentUser()
self.scores["Right"] = self.rightAnswers
self.scores["Wrong"] = self.wrongAnswers
self.scores["Skipped"] = self.skippedQuestions
self.scores.saveInBackground()
} else if self.userID == objects![i] {
print("Updated Scores")
self.scores.incrementKey("Right", byAmount: 1)
self.scores.incrementKey("Wrong", byAmount: 1)
self.scores.incrementKey("Skipped", byAmount: 1)
print("R: \(self.rightAnswers)")
print("W: \(self.wrongAnswers)")
print("S: \(self.skippedQuestions)")
self.scores.saveInBackgroundWithBlock {
(success: Bool, error: NSError?) -> Void in
if (success) {
// The score key has been incremented
} else {
// There was a problem, check error.description
}
}
} else {
print("Error")
}
}
} else {
print(error)
}
}
But it only stores the objectId column and not the Pointer<_User> column. I know this because when I print the stuff that is inside, it prints out the objectIds.
This is what happens, instead of just updating the current user's scores, it just makes new ones. I want the if statement to check if the user already exists in that column and if it does updates the scores and if it doesn't, make new ones. (The new code's if statement doesn't work, i have to bring it out for it to save...)
Your updated question make clearer what you are actually wanting to do;
Save or update a user's scores in your Parse Score object. To do this, there is no reason to retrieve any object Ids or loop through any results. More often than not you don't do use Object Ids explicitly when using Parse; you can simply pass the object itself with Parse working out the references for you.
I am not sure how you exactly want to change the scores; in your code above you increment in one case but set the scores explicitly in another, but the code below shows the general approach.
If you are frequently or repeatedly going to update a score record then you could make your code more efficient by holding a reference to the Scores object in a property after you find it the first time and simply update & save it subsequently.
func saveScoresOnParse() {
if let currentUser=PFUser.currentUser() {
let scoreQuery= PFQuery(className: "Scores")
scoreQuery.whereKey("User",equalTo:currentUser)
scoreQuery.getFirstObjectInBackgroundWithBlock {
(object : PFObject? , error : NSError?) -> Void in
if error == nil {
var scoreObject=object ?? PFObject.objectWithClassName("Scores")
if (scoreObject["User"]==nil) {
scoreObject["User"]=currentUser
}
scoreObject["Right"]=self.rightAnswers
scoreObject.saveInBackground()
} else {
print(error)
}
}
} else {
print("No current user!")
}
}

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