Swift: Can't figure out how to save how user left tableview - ios

Question

Using Swift 3
I've been working on a blog reader app for a while but I've been stuck on how to save the tableview like how the user left it.
The app works by me inputing data into the mysql database which is sent using php and received with json and swift 3 to populate the tableview. I expect to update this database everyday. There are two sections in the tableview, top one is followedArray and second is mainArray which is where all the objects are after being in jsonArray. When the user clicks the follow button, that single cell is moved into followedArray where the user can see the blog being updated and receive notifications.
I've tried using UserDefaults by saving the whole array into an object but it didn't work out as it was way to complicated creating the NSData objects using NSCoding, when there is no need to save the entire array (my guess).
My question, is there a simple way that I can save how the user left the tableview?
For example: In the 'All Objects Section' lets say I have 3 cells and the user clicks the follow button on 2 cells, those 2 cells are now in the 'Followed Section' with 1 cell in 'All Objects Section'. How do I save the state of this tableview. I want to save in which section the followed cell is in now and the changed button which is now a Followed Button instead of Follow Button (saving the hidden enabled code as I hide one button to show the other).
Do I use UserDefaults or CoreData? Maybe a CocoaPod library? Do I save the entire array or just which section its in and the .hidden code? How will updating and adding new objects affect it?
I'm fairly new to Swift so if you can help it would be appreciated. Any code that you need to understand how the app works, just ask for it as I don't know what code is necessary to show. I know you're not supposed to ask for code but if you can it would be great as I've been trying for months with no progress. Thank you!
Here is how I handle incoming json data:
MainController.swift
var jsonArray: NSMutableArray = []
var mainArray = [Blog]()
var followedArray = [Blog]()
var filteredArray = [Blog]()
// Title for Header
func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
if !(searchController.isActive && searchController.searchBar.text != "") {
if section == 0 {
return "Followed Blogs"
}
else {
return "All Blogs"
}
}
return "Filtered Blogs"
}
// Number of Rows in Section
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if !(searchController.isActive && searchController.searchBar.text != "") {
if section == 0 {
return followedArray.count
}
else if (section == 1) {
return mainArray.count
}
}
return filteredArray.count
}
public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let CellIdentifier = "Cell"
var cell = tableView.dequeueReusableCell(withIdentifier: CellIdentifier) as! CustomCell
if cell != cell {
cell = CustomCell(style: UITableViewCellStyle.default, reuseIdentifier: CellIdentifier)
}
// Configuring the cell
var blogObject: Blog
if !(searchController.isActive && searchController.searchBar.text != "") {
if indexPath.section == 0 {
blogObject = followedArray[indexPath.row]
cell.populateCell(blogObject, isFollowed: true, indexPath: indexPath, parentView: self)
}
else if indexPath.section == 1 {
blogObject = mainArray[indexPath.row]
cell.populateCell(blogObject, isFollowed: false, indexPath: indexPath, parentView: self)
}
}
else {
blogObject = filteredArray[indexPath.row]
cell.populateCell(blogObject, isFollowed: false, indexPath: indexPath, parentView: self)
}
return cell
}
#IBAction func followButtonClick(_ sender: UIButton!) {
// Adding row to tag
let buttonPosition = (sender as AnyObject).convert(CGPoint.zero, to: self.myTableView)
if let indexPath = self.myTableView.indexPathForRow(at: buttonPosition) {
// Showing Status Labels
let cell = self.myTableView.cellForRow(at: indexPath) as! CustomCell
cell.firstStatusLabel.isHidden = false
cell.secondStatusLabel.isHidden = false
// Change Follow to Following
(sender as UIButton).setImage(UIImage(named: "follow.png")!, for: .normal)
cell.followButton.isHidden = true
cell.followedButton.isHidden = false
// Checking wether to import from mainArray or filteredArray to followedArray
if !(searchController.isActive && searchController.searchBar.text != "") {
self.myTableView.beginUpdates()
// ----- Inserting Cell to followedArray -----
followedArray.insert(mainArray[indexPath.row], at: 0)
myTableView.insertRows(at: [IndexPath(row: 0, section: 0)], with: .fade)
// ----- Removing Cell from mainArray -----
mainArray.remove(at: indexPath.row)
let rowToRemove = indexPath.row
self.myTableView.deleteRows(at: [IndexPath(row: rowToRemove, section: 1)], with: .fade)
self.myTableView.endUpdates()
myTableView.reloadData()
}
else {
self.myTableView.beginUpdates()
// ----- Inserting Cell to followedArray -----
let blogObject: Blog = filteredArray[indexPath.row]
let indexOfObjectInArray = mainArray.index(of: blogObject)
followedArray.insert(blogObject, at: 0)
// ----- Removing Cell from filteredArray -----
filteredArray.remove(at: indexPath.row)
blogArray.remove(at: indexOfObjectInArray!)
let rowToRemove = indexPath.row
self.myTableView.deleteRows(at: [IndexPath(row: rowToRemove, section: 0)], with: .fade)
self.myTableView.endUpdates()
myTableView.reloadData()
}
}
}
func retrieveDataFromServer() {
let getDataURL = "http://exampleblog.com/receiving.php"
let url: NSURL = NSURL(string: getDataURL)!
do {
let data: Data = try Data(contentsOf: url as URL)
jsonArray = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as! NSMutableArray
// Looping through jsonArray
for i in 0..<jsonArray.count {
// Create Blog Object
let bID: String = (jsonArray[i] as AnyObject).object(forKey: "id") as! String
let bName: String = (jsonArray[i] as AnyObject).object(forKey: "blogName") as! String
let bStatus1: String = (jsonArray[i] as AnyObject).object(forKey: "blogStatus1") as! String
let bStatus2: String = (jsonArray[i] as AnyObject).object(forKey: "blogStatus2") as! String
let bURL: String = (jsonArray[i] as AnyObject).object(forKey: "blogURL") as! String
// New
let bType: String = (jsonArray[i] as AnyObject).object(forKey: "blogType") as! String
let bDate: String = (jsonArray[i] as AnyObject).object(forKey: "blogDate") as! String
let bPop: String = (jsonArray[i] as AnyObject).object(forKey: "blogPop") as! String
// Add Blog Objects to mainArray
mainArray.append(Blog(blogName: bName, andBlogStatus1: bStatus1, andBlogStatus2: bStatus2, andBlogURL: bURL, andBlogID: bID, andBlogType: bType, andBlogDate: bDate, andBlogPop: bPop))
}
}
catch {
print("Error: (Retrieving Data)")
}
myTableView.reloadData()
}
CustomCell.swift - How the cells are being populatedenter code here
class CustomCell: UITableViewCell {
#IBOutlet weak var firstStatusLabel: UILabel!
#IBOutlet weak var secondStatusLabel: UILabel!
#IBOutlet weak var followButton: UIButton!
#IBOutlet weak var followedButton: UIButton!
override func awakeFromNib() {
super.awakeFromNib()
self.followButton.isHidden = true
self.followedButton.isHidden = true
}
func populateCell(_ blogObject: Blog, isFollowed: Bool, indexPath: IndexPath, parentView: Any) {
// Loading Status Labels
self.firstStatusLabel.text = blogObject.blogStatus1
self.secondStatusLabel.text = blogObject.blogStatus2
self.firstStatusLabel.isHidden = true
self.secondStatusLabel.isHidden = true
if isFollowed {
self.followedButton.tag = indexPath.row
self.followedButton.addTarget(parentView, action: #selector(MainController.followedButtonClick(_:)), for: .touchUpInside)
self.followedButton.isHidden = false
self.followButton.isHidden = true
// Status Labels
self.firstStatusLabel.isHidden = false
self.secondStatusLabel.isHidden = false
}
else {
self.followButton.tag = indexPath.row
self.followButton.addTarget(parentView, action: #selector(MainController.followButtonClick(_:)), for: .touchUpInside)
self.followedButton.isHidden = true
self.followButton.isHidden = false
// Status Labels
self.firstStatusLabel.isHidden = true
self.secondStatusLabel.isHidden = true
}
}
}
Blog.swift
class Blog: NSObject {
// Strings
var blogName: String?
var blogStatus1: String?
var blogStatus2: String?
var blogURL: String?
var blogID: String?
var blogType: String?
var blogDate: String?
var blogPop: String?
override init() {
}
// Converting Strings into Objects
init(blogName bName: String,
andBlogStatus1 bStatus1: String,
andBlogStatus2 bStatus2: String,
andBlogURL bURL: String,
andBlogID bID: String,
andBlogType bType: String,
andBlogDate bDate: String,
andBlogPop bPop: String)
{
super.init()
self.blogName = bName
self.blogStatus1 = bStatus1
self.blogStatus2 = bStatus2
self.blogURL = bURL
self.blogID = bID
self.blogType = bType
self.blogDate = bDate
self.blogPop = bPop
}
}

Answer 1

There are lots of different ways to accomplish what you want, both storing the information locally or remotely. If the blog ids are unique, you could store them in the defaults as an array of strings:
UserDefaults.standard.set(followedBlogIds, forKey: "followedBlogIds")
You can then grab them anytime, just make sure to unwrap/cast them appropriately:
if let storedBlogIds = UserDefaults.standard.object(forKey: "followedBlogIds") as? [String] {
//filter your blogs by id and put them in the appropriate
//arrays for your table
}