Couldn't use JSON Data in an viewController extension? - arrays

Question

could anybody please let me know what I did wrong here?
I couldn't pass the JSON data from URLSession.shared.dataTask to outer extension
Nor could bring the
func numberOfSections .. etc to be used in the URLSession.shared.dataTask
Any help appreciated, thank you for your time.
Swift
struct getSubData: Decodable {
let id: Int
let name: String
}
struct Section: Decodable {
let id: Int
let name: String
let subData: [getSubData]
}
class indexViewController: UIViewController {
#IBOutlet weak var tableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
let url = "https://nabulsi.com/nabulsi_app/main_sections_v4.json"
let urlObj = URL(string: url)
URLSession.shared.dataTask(with: urlObj!){(data, response, error) in
do {
let sections = try JSONDecoder().decode([Section].self, from: data!)
for section in sections {
print(section.name)
let sectionName = section.name
for data in section.subData {
print(data.name)
let subSectionName = data.name
}
}
} catch {
print("We got an error")
}
}.resume()
}
}
extension indexViewController: UITableViewDataSource, UITableViewDelegate {
func numberOfSections(in tableView: UITableView) -> Int {
return sectionName.count
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return sectionName[section].subSectionName?.count ?? 0
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.textLabel?.text = sectionName[indexPath.section].subSectionName?[indexPath.row]
return cell
}
}

Answer 1

JsonDecoder class has no chance to parse your data just because of the received JSON text from the server is not a valid format.
Here is your endpoint, open it in the web browser: https://nabulsi.com/nabulsi_app/main_sections_v4.json
And here is the JSON validator tool: https://jsonlint.com
Copy and paste to validate your server response to the JSON validator tool called jsonlint, and you will see where is your wrong.
Probably it's not your fault. It's about your backend developer if you didn't write by yourself. Contact him to fix the JSON format. After fixing the issue please notify me. I am gonna fix your parse codes if it's still not working as you expected.
EDIT: After fixing problem, the related codes here:
[0] - Parsed json values assigned to local variable.
class indexViewController: UIViewController {
#IBOutlet weak var tableView: UITableView!
var sections: [Section] = []
override func viewDidLoad() {
super.viewDidLoad()
let url = "https://nabulsi.com/nabulsi_app/main_sections_v4.json"
let urlObj = URL(string: url)
URLSession.shared.dataTask(with: urlObj!){(data, response, error) in
do {
let sections = try JSONDecoder().decode([Section].self, from: data!)
self.sections = sections // [0]
DispatchQueue.main.async {
self.tableView.reloadData()
}
} catch {
print("We got an error")
}
}.resume()
}
}
Look at the code and follow these brief explanation:
[1] - Return every rows in section, from local array
[2] - Assigned the name variable to label for current row
[3] - Assigned the name variable to header for current section
extension indexViewController: UITableViewDataSource, UITableViewDelegate {
func numberOfSections(in tableView: UITableView) -> Int {
return sections.count
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
let subDatas = sections[section].subData // [1]
return subDatas.count ?? 0
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
// [2]
let currentSection = sections[indexPath.section]
let currentSubdata = currentSection.subData[indexPath.row]
cell.textLabel?.text = currentSubdata.name
return cell
}
func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
let view = UIView(frame: CGRect(x: 0, y: 0, width: tableView.frame.width, height: 40))
view.backgroundColor = #colorLiteral(red: 1, green: 0.3653766513, blue: 0.1507387459, alpha: 1)
let lbl = UILabel(frame: CGRect(x: 0, y: 0, width: view.frame.width - 15, height: 40))
lbl.font = UIFont.systemFont(ofSize: 20)
lbl.text = sections[section].name // [3]
lbl.textAlignment = .right
view.addSubview(lbl)
return view
}
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return 40
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 40
}
}
Happy Coding! =]

Answer 2

Just take you section Array outside your function. Keep it as property of your controller.
class indexViewController: UIViewController {
#IBOutlet weak var tableView: UITableView!
var sections: [Section] = []
override func viewDidLoad() {
super.viewDidLoad()
let url = "https://nabulsi.com/nabulsi_app/main_sections_v4.json"
let urlObj = URL(string: url)
URLSession.shared.dataTask(with: urlObj!) {
[weak self](data, response, error) in
do {
self?.sections = try JSONDecoder().decode([Section].self, from: data!)
for section in sections {
//your code goes here
}
}
catch {
print("We got an error")
}
}.resume()
}