Add Parse array to dictionary swift - arrays

I have some objects in parse and I am getting the data successfully as [PFObjects]. The issue is that I am trying to add the array elements [PFObjects] to a dictionary as values. But I keep getting an empty dictionary, so the values are not added to the dictionary. The dictionary count is also 0.
This is what I tried so far:
var postDictionary = [String:[AnyObject]]()
query.findObjectsInBackground(block: { (posts: [PFObject]?, error:Error?) in
if let unwrappedPosts = posts {
for posts in unwrappedPosts {
if let postText = posts.object(forKey: "title") as?String {
self.titleArray.append(postText)
print("count", self.titleArray.count) // count 10
self.postDictionary["title"]?.append(self.titleArray as AnyObject)
**try to force unwrap **
self.postDictionary["title"]!.append(self.titleArray as AnyObject), and the app crashed
for (title, text) in self.postDictionary {
print("\(title) = \(text)")
}
print("Dictionay text count",self.postDictionary.count) // count is 0
}
}
}
})

This syntax is very confusing
self.titleArray.append(postText)
self.postDictionary["title"]?.append(self.titleArray as AnyObject)
You append a string to an array and then you are going to append the array to the array in the dictionary. I guess this is not intended.
I recommend to map the title strings and set the array for key title once
var postDictionary = [String:[String]]()
query.findObjectsInBackground(block: { (posts: [PFObject]?, error:Error?) in
if let unwrappedPosts = posts {
self.titleArray = unwrappedPosts.compactMap { $0.object(forKey: "title") as? String }
self.postDictionary["title"] = self.titleArray
for (title, text) in self.postDictionary {
print("\(title) = \(text)")
}
print("Dictionay text count",self.postDictionary.count) // count is 0
}
})
Never use AnyObject if the type is more specific.

The proper way of adding to a dictionary is using updateValue because as far as i can see that you don't have the key "title" in your dictionary and you are appending values to unknown key i guess.
This should help:
titleArray.append(postText)
postDictionary.updateValue(titleArray as [AnyObject], forKey: "title")
for (key,value) in postDictionary {
print("\(key) \(value)")
}
Finally this should print:
title [posts1, posts2, posts3]

Related

How to retrieve data held in an array from Firestore using Swift

this seems like it should be quite a simple thing to do, but can't seem to find a solution. I have some data in Firestore held in an array that I need to get and place into and two dimensional array inside my swift app. I'm pretty noob so apologies in advance!
This is the data I'm trying to get from Firestore
This is the code I'm using to query my documents and then loop through the result, extracting the data
fireStoreDatabase.collection("Posts").whereField("postedTo", arrayContains: userId).order(by: "date", descending: true).addSnapshotListener { (snapshot, error) in
if error != nil {
print(error?.localizedDescription)
} else {
if snapshot?.isEmpty != true && snapshot != nil {
print("Posted data got")
//clear the arrays to stop duplicates when we do an upload and pull in the data again
self.postedShoutTextArray.removeAll(keepingCapacity: false)
self.postedByArray.removeAll(keepingCapacity: false)
self.postedDateArray.removeAll(keepingCapacity: false)
self.postedQuestionsArray.removeAll(keepingCapacity: false)
//loop through the firestore
for document in snapshot!.documents {
//add data to the arrays
if let shoutText = document.get("shoutText") as? String {
self.postedShoutTextArray.append(shoutText)
}
if let postedBy = document.get("postedBy") as? String {
self.postedByArray.append(postedBy)
}
if let date = document.get("date") as? String {
self.postedDateArray.append(date)
}
if let pollQuestions = document.get("pollQuestions") as? [String] {
self.postedQuestionsArray = pollQuestions
} else {
print("no array data")
}
self.receivedCollectionView.reloadData()
}
} else {
print("GET POSTED MESSAGES no data")
}
}
}
So I'd like the data to go into a two dimensional array (if that's possible) containing the data from the pollQuestions array for each document I loop through (does that make sense?).
Been searching all over, and seen references to map etc, but had no luck finding a solution.
Any help appreciated!
Rather than storing each property in a separate array, you may want to consider representing it with a struct. Something like:
struct Item {
var shoutText: String?
var postedBy: String?
var date: String?
var pollQuestions : [String]
}
Then, on your view controller, declare a property:
var items: [Item] = []
Then, in your snapshot listener, you can populate that array:
func getData() {
Firestore.firestore().collection("Posts").whereField("postedTo", arrayContains: userId).order(by: "date", descending: true).addSnapshotListener { (snapshot, error) in
if error != nil {
print(error?.localizedDescription)
} else {
if let snapshot = snapshot, !snapshot.isEmpty {
print("Posted data got")
self.items = snapshot.documents.map { document in
Item(shoutText: document.get("shout") as? String,
postedBy: document.get("postedBy") as? String,
date: document.get("date") as? String,
pollQuestions: document.get("pollQuestions") as? [String] ?? [])
}
self.receivedCollectionView.reloadData()
} else {
print("GET POSTED MESSAGES no data")
}
}
}
}
Later, you can access this data:
self.items[itemIndex].pollQuestions[pollQuestionIndex]

Appending dictionary values to array in Swift

I have a dictionary of type
[String: Object], where MyObject is an array of AnotherObject. I need to have it sorted as I need to fill an UITableView with Keys.countnumber of sections and Object.count number of rows in each section. I put all the keys in an array, but when I try to append the values into another array I get Thread 1: EXC_BAD_ACCESS (code=1, address=0x8).
This is the code I'm using
var dictionary = [String: MyObject]()
var sortedKeys: [String]?
var sortedValues = [MyObject]()
func sortItems() {
self.sortedKeys = self.dictionary.keys.sorted(by: >)
let sortedDict = self.dictionary.sorted(by: {$0.key > $1.key})
for (_, value) in sortedDict {
print(value)
self.sortedValues.append(value)
}
}
In the for loop, when I don't try to append the values to the array, it prints all the sorted values, the problem comes when I want to have them in an Array.
Edit
The dictionary is like this:
struct Object: Decodable {
let elements: [AnotherObject]
}
struct AnotherObject: Decodable {
let time, Id, Status: Int?
let date, startTime, endTime: String?
}
dictionary: [String: Object]
So the keys are numbers (representing days) and every day has an Object with (at least) one anotherObject.
I get the JSON from the API.
Thanks in advance
You should only sort the keys and then use that array to select from the dictionary and append your sortedValues array. I made the sortedKeys into a local variable
func sortItems() {
let sortedKeys = self.dictionary.keys.sorted(by: >)
for key in sortedKeys {
if let obj = dictionary[key] {
self.sortedValues.append(obj)
}
}
}
I don't know if this will make a difference in regard to the crash but another way is to let the function return an array
func sortItems() -> [Object] {
let sortedKeys = self.dictionary.keys.sorted(by: >)
var result: [Object]()
for key in sortedKeys {
if let obj = dictionary[key] {
result.append(obj)
}
}
return result
}
and then call it
self.sortedValues = sortItems()
You don't use sortedKeys at all and the result of sorting a dictionary is an array of tuples so the dictionary enumeration syntax for (key, value) in is wrong
Probably you want this
func sortItems() {
let sortedKeys = self.dictionary.keys.sorted(by: >)
for key in sortedKeys {
let value = self.dictionary[key]!
print(value)
self.sortedValues.append(value)
}
}
Force unwrapping the value is 100% safe as the key clearly exists.

Swift append array value not showing outside statement

My scenario from my get call I received values and I appended with var nameData = [String]() array. nameData array values not showing outside statement. Please check my below code
// Global Declarions
var nameData = [String]()
// GET Call values append
if let content = result["contacts"] as? [[String:AnyObject]] {
for category in content {
self.nameData.append(category["name"] as! String)
}
print(self.nameData) // here I am getting
}
}
self.addDropDown()
print(self.nameData) // Empty array showing
Now, My dropdown code below, Here I want to assign nameData array
func addDropDown(){
print(self.nameData) // Empty array showing why???
// For Top textField
let dropDownTop = VPAutoComplete()
dropDownTop.dataSource = self.nameData -->// Here I need to assign nameData values if i do its showing empty values.
dropDownTop.onTextField = emailTF
dropDownTop.onView = self.view
dropDownTop.show { (str, index) in
print("string : \(str) and Index : \(index)")
self.emailTF.text = str
}
}
Try this:
if let content = result["contacts"] as? [[String:AnyObject]] {
for category in content {
self.nameData.append(category["name"] as! String)
}
DispatchQueue.main.async { self.addDropDown() }
}
}
Add the drop down just after you fill the nameData array.

deleting objects if string of object matches string in a separate array

I have an nsobject class with four strings
class Post: NSObject {
var author: String!
var postID: String!
var pathToImage: String!
var userID: String!
}
I also have a separate class viewcontroller which has a function grabbing posts from firebase. I have an array called posts = [Post](), which is filled by a seperate function going through firebase and grabbing data for each photo. I also have an array called removeArray which is array of strings, which the string is the postID of certain posts. Now this is my problem, I am trying to loop through removeArray, check if the each in removeArray = to the each in posts.postID and check if they are equal. Then either I delete that each in posts.postID post, or I create a new array that is posts - posts with postID's in removeArray. Here is my code now that does not work, it just keeps posts as is.
if posts != nil {
if var array = UserDefaults.standard.object(forKey: "removeArray") as? [String] {
for each in posts {
for one in array {
if one == each.postID {
new.append(each)
}
}
}
return self.posts.count
}
}
So if you have any idea how to take a string in an array, check if that string if eqaul to a string in an array of objects.postID, and remove that object from the array if it is equal. I have tried to research a way to filter it, but so far nothing. Please give me some feedback. Thanks
My problem = http://imgur.com/a/m5CiY
var posts = [p1,p2,p3,p4,p5]
let array = ["aaa","bbb"]
var new:Array<Post> = []
for each in posts {
for one in array {
if one == each.postID {
new.append(each)
}
}
}
print("This objects should be remvoed: \(new)")
posts = Array(Set(posts).subtracting(new))
print("After removing matching objects: \(posts)")
You could use reduce(_:_:)!
class Country {
var name: String!
init(name: String) {
self.name = name
}
}
let countries = [Country(name: "Norway"), Country(name: "Sweden"), Country(name: "Denmark"), Country(name: "Finland"), Country(name: "Iceland")]
let scandinavianCountries = ["Norway", "Sweden", "Denmark"]
// Store the objects you are removing here
var nonScandinavianCountries: [Country]?
let scandinavia = countries.reduce([Country](), {
result, country in
// Assign result to a temporary variable since result is immutable
var temp = result
// This if condition works as a filter between the countries array and the result of the reduce function.
if scandinavianCountries.contains(country.name) {
temp.append(country)
} else {
if nonScandinavianCountries == nil {
// We've reached a point where we need to allocate memory for the nonScandinavianContries array. Instantiate it before we append to it!
nonScandinavianCountries = []
}
nonScandinavianCountries!.append(country)
}
return temp
})
scandinavia.count // 3
nonScandinavianCountries?.count // 2
Resouces:
https://developer.apple.com/reference/swift/array/2298686-reduce

How to convert from a Swift String Set to an Array

I am trying to create an array of words from a string object retrieved from Parse. The object retrieved looks like this:
Then this line of code gives this.
let joinedWords = object["Words"] as! String
How do I convert joinedWords to an Array?
If you don't care about the order, you can use flatMap on the set:
var mySet = Set<String>()
for index in 1...5 {
mySet.insert("testwords\(index)")
}
let myArray = mySet.flatMap { $0 }
print(myArray) // "["testwords5", "testwords3", "testwords4", "testwords2", "testwords1"]"
If you want the list sorted alphabetically, you can make your array a var and use sortInPlace()
var myArray = mySet.flatMap { $0 }
myArray.sortInPlace()
print(myArray) // "["testwords1", "testwords2", "testwords3", "testwords4", "testwords5"]"
If object["Words"] is AnyObject, you will have to unwrap it.
if let joinedWordsSet = object["Words"] as? Set<String> {
var joinedWordsArray = joinedWordsSet.flatMap { $0 }
myArray.sortInPlace()
print(myArray)
}
Swift 3 note: sortInPlace() has been renamed sort().
Many thanks to #JAL for so much time on chat to solve this one. This is what we came up with. Its a bodge and no doubt there is a better way!
When uploading to Parse save the set as an array.
let wordsSet = (wordList?.words?.valueForKey("wordName"))! as! NSSet
let wordsArray = Array(wordsSet)
Then it saves to Parse - looking like a set, not an array or a dictionary.
let parseWordList = PFObject(className: "WordList")
parseWordList.setObject("\(wordsArray)", forKey: "Words")
parseWordList.saveInBackgroundWithBlock { (succeeded, error) -> Void in
if succeeded {
// Do something
} else {
print("Error: \(error) \(error?.userInfo)")
}
}
Then you can drop the [ ] off the string when its downloaded from Parse, and remove the , and add some "" and voila, there is an array that can be used e.g. to add to CoreData.
var joinedWords = object["Words"] as! String
joinedWords = String(joinedWords.characters.dropFirst())
joinedWords = String(joinedWords.characters.dropLast())
let joinedWordsArray = joinedWords.characters.split() {$0 == ","}.map{ String($0) } // Thanks #JAL!

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