How to Fetch JSON to Swift to tableView as Sections and Rows? - ios

Question

I wanna ask how to implement the files as sections depends on userId then show all again in the tableview
I'm started build simple project i fetched json file as decoder and show all in table view
func fetchUsers(using url: String){
let url = URL(string: url)!
let _ = URLSession.shared.dataTask(with: url){ (data,response,error)
in
guard let data = data else {return}
do{
let objects = try JSONDecoder().decode([User].self, from: data) // decode * ( Codable )
self.users = objects
} catch{
print("error loading data cause: \(error)")
}
}.resume()
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if let cell = tableView.dequeueReusableCell(withIdentifier: "users",for: indexPath) as? customeCellTableViewCell{
let indexRow = users[indexPath.row]
cell.dataModel(forModel: indexRow)
return cell
}
return UITableViewCell()
}
private func numberOfUsers(in users: [User]) -> Int {
return 1
}
func numberOfSections(in tableView: UITableView) -> Int {
return numberOfUsers(in: self.users)
}

Answer 1

Like #vadian mentions tuples should be avoided for this so here is an improved solution.
Instead of a tuple we can use a struct to hold the grouped data
struct UsersByID {
let id: Int
var users : [User]
}
then change the load function to
func load(withUsers users: [User]) {
let dict = Dictionary(grouping: users) { return $0.userID }
usersByID = dict.map { (key, values) in
return UsersByID(id: key, users: values)
}.sorted(by: { $0.id < $1.id })
}
The rest of the code is the same but replace key with id and value with users
Old solution
First create a dictionary to hold your sections (keys) and rows (values) as a property in the view controller
var usersByID = [(key: Int, value: [User])]()
then fill that dictionary using grouping:by: using the array from json
func load(withUsers users: [User]) {
usersByID = Dictionary(grouping: users, by: { user in
user.userID }).sorted(by: { $0.0 < $1.0})
}
then the table view functions use this dictionary
override func numberOfSections(in tableView: UITableView) -> Int {
return usersByID.count
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return usersByID[section].value.count
}
override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
return String(usersByID[section].key)
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "LabelCell", for: indexPath)
let user = usersByID[indexPath.section].value[indexPath.row]
cell.textLabel?.text = user.title
//...
return cell
}

Answer 2

func numberOfSections(in collectionView: UICollectionView) -> Int {
return datesArr.count
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
if (contractsDict.keys.contains(datesArr[section])) {
return contractsDict[datesArr[section]]!.count
}
return 0
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! ContractsCollectionViewCell
DispatchQueue.main.async {
if (self.contractsDict.keys.contains(self.datesArr[indexPath.section])) {
for _ in 0..<(self.contractsDict[self.datesArr[indexPath.section]]!.count) {
cell.contract = self.contractsDict[self.datesArr[indexPath.section]]![indexPath.row]
cell.delegate = self
}
}
}
return cell
}
}
}
ContractServices.shared.fetchAllContracts(completion: { (contracts, err) in
DispatchQueue.main.async {
if (err != nil) {
print(err!, "1323")
return
}
for contract in (contracts?.data)! {
self.allContractsArr.append(contract)
if let callDate = contract.revdat {
let formatterGet = DateFormatter()
formatterGet.dateFormat = "yyyy-MM-dd HH:mm:ss"
let newFormat = DateFormatter()
newFormat.dateFormat = "dd MMM yyyy"
if let date = formatterGet.date(from: callDate) {
self.datesArr.append(newFormat.string(from: date))
}
}
}
for i in 0..<self.allContractsArr.count {
if let callDate = self.allContractsArr[i].revdat {
let formatterGet = DateFormatter()
formatterGet.dateFormat = "yyyy-MM-dd HH:mm:ss"
let newFormat = DateFormatter()
newFormat.dateFormat = "dd MMM yyyy"
if let date = formatterGet.date(from: callDate) {
self.allContractsArr[i].revdat = newFormat.string(from: date)
}
}
}
self.allContractsArr = self.allContractsArr.sorted(by: { ($0.revdat)! > ($1.revdat)! })
self.contractsDict = Dictionary(grouping: self.allContractsArr, by: { ($0.revdat)! })
let newFormat = DateFormatter()
newFormat.dateFormat = "dd MMM yyyy"
self.datesArr = Array(Set(self.datesArr))
self.datesArr = self.datesArr.sorted(by: { newFormat.date(from: $0)! > newFormat.date(from: $1)! })
self.contractListCV.reloadData()
DispatchQueue.main.async {
self.activityBackView.isHidden = true
self.activity.isHidden = true
self.activity.stopAnimating()
self.design()
}
}
})
This is how I'm doing.
Getting the data in array format, converting them into Dictionary by grouping(by:) method, and then operating everything related to the collectionview upon those dictionary data.