showing an error as has need to conform the protocol - ios

Question

This is my code:-
Model:-
class QuestionListModel: NSObject {
var optionsModelArray:[OptionsModel] = []
var question:String!
init(dictionary :JSONDictionary) {
guard let question = dictionary["question"] as? String
else {
return
}
if let options = dictionary["options"] as? [String]{
print(options)
print(options)
for values in options{
print(values)
let optionmodel = NH_OptionsModel(values: values)
self.optionsModelArray.append(optionmodel)
}
}
self.question = question
// print(self.dataListArray33)
}
}
optionModel:-
class OptionsModel: NSObject {
var values:String?
init(values:String) {
self.values = values
print( self.values)
}
}
in viewmodel:-
var questionsModelArray:Array<NH_QuestionListModel>? = []
init(withdatasource newDatasourceModel:NH_QuestionDataSourceModel) {
datasourceModel = newDatasourceModel
print(datasourceModel.dataListArray?.count)
self.questionsModelArray = datasourceModel.dataListArray
print(self.questionsModelArray)
print(datasourceModel.dataListArray)
}
func numberOfSections() -> Int{
return (self.questionsModelArray?.count)!
}
func titleForHeaderInSection(atindexPath indexPath: IndexPath) -> QuestionListModel {
return self.questionsModelArray![indexPath.row]
}
func numberOfRowsInSection(indexPath:IndexPath) -> Int {
if let questionModel = self.questionsModelArray?[indexPath.section]{
return questionModel.optionsModelArray.count
}
else{
return 0
}
}
func datafordisplay(atindex indexPath: IndexPath) -> OptionsModel{
let questionModel = self.questionsModelArray?[indexPath.section]
return questionModel!.optionsModelArray[indexPath.row]
}
And in ViewController:-
func numberOfSections(in tableView: UITableView) -> Int {
return questionViewModel.numberOfSections()
}
func tableView(_ tableView: UITableView, viewForHeaderInSection section: IndexPath) -> UIView? {
// let headercell = Bundle.main.loadNibNamed("HeaderCell", owner: self, options: nil)?.first as! NH_questionheader
let identifier = "HeaderCell"
var headercell: NH_questionheader! = tableView.dequeueReusableCell(withIdentifier: identifier) as? NH_questionheader
if headercell == nil {
tableView.register(UINib(nibName: "NH_questionheader", bundle: nil), forCellReuseIdentifier: identifier)
headercell = tableView.dequeueReusableCell(withIdentifier: identifier) as? NH_questionheader
}
headercell.setReviewData(reviews:questionViewModel.titleForHeaderInSection(atindexPath:section))
return headercell
}
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return 150
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: IndexPath) -> Int {
return questionViewModel.numberOfRowsInSection(indexPath: section)
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let identifier = "Cell"
var cell: CellTableViewCell! = tableView.dequeueReusableCell(withIdentifier: identifier) as? CellTableViewCell
if cell == nil {
tableView.register(UINib(nibName: "CellTableViewCell", bundle: nil), forCellReuseIdentifier: identifier)
cell = tableView.dequeueReusableCell(withIdentifier: identifier) as? CellTableViewCell
}
cell.contentView.backgroundColor = UIColor.clear
cell.setOptions(Options1: questionViewModel.datafordisplay(atindex: indexPath))
print("Section \(indexPath.section), Row : \(indexPath.row)")
return cell
}
my json file:-
{
"data":[
{
"question": "Gender",
"options": ["Male","Female"]
},
{
"question": "How old are you",
"options": ["Under 18","Age 18 to 24","Age 25 to 40","Age 41 to 60","Above 60"]
}, {
"question": "I am filling the Questionnaire for?",
"options": ["Myself","Mychild","Partner","Others"]
}
]
}
This is my data .So i need to display the questions in header and options in the cell for index .But showing as error as UITableview has need to conform the protocol UITableviewDataSource.
Also showing error as Index out of range.
How to do.....

Answer 1

I think you are not assign a datasource to your view controller. So please assign it in your ViewDidLoad of your view controller
override func viewDidLoad() {
super.viewDidLoad()
self.yourtableview.delegate = self
self.yourtableview.dataSource = self
// Do any additional setup after loading the view.
}

Answer 2

This error usually occurs when you fail to implement the required methods of a protocol. In this case the methods would be :
cellForRowAt
numberOfRowsInSection
Since you already have them implemented in your view controller chances are that you might have failed to set the datasource for the table view.
Refer to this
https://developer.apple.com/documentation/uikit/uitableviewdatasource

Answer 3

your view controller cannot find the data source and delegate for the table view. make sure you have assigned the data source and delegate
self.yourtableview.delegate = self
self.yourtableview.dataSource = self
and also make sure that your controller also inherit the UITableViewDelegate and UITableViewDataSource like this
class ViewController: UIViewController,UITableViewDelegate,UITableViewDataSource

Answer 4

To achieve what you want, you should set your VC as the delegate and datasource of your table.
Option 1, do it dynamically:
override func viewDidLoad() {
super.viewDidLoad()
self.tableView.delegate = self
self.tableView.dataSource = self
}
Option 2, from your storyboard (example below):
After this, you should use the following datasource functions of UITableView:
// return number of questions
func numberOfSections(in tableView: UITableView) -> Int
// return number of options per question (indicated by section)
func tableView(UITableView, numberOfRowsInSection: Int) -> Int

Answer 5

You haven't correctly declared the numberOfRowsInSection function; section is an Int, not an IndexPath. As a result you have not implemented the mandatory functions of UITableViewDataSource.
You want:
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return questionViewModel.numberOfRowsIn(section: section)
}
With an appropriate change in your view model:
func numberOfRowsIn(section:Int) -> Int {
return self.questionsModelArray?[section].optionsModelArray.count ?? 0
}
I would also suggest that you review your use of implicitly unwrapped optionals and force unwrapping; this is just asking for crashes.
For example, there is no reason for the question property of QuestionListModel to be String!; just declare it as String and make your initialiser failable. Better yet, use Codable to create your model from JSON and get rid of all of that code.
You can eliminate the force unwrapping in numberOfSections too:
func numberOfSections() -> Int {
return self.questionsModelArray?.count ?? 0
}
I would also suggest you make QuestionListModel a struct rather than an NSObject subclass.
If I were you I would re-factor to remove the view model, it is adding unnecessary complexity in this case, and use Codable for your JSON deserialisation:
struct Questions: Codable {
enum CodingKeys: String, CodingKey {
case questions = "data"
}
var questions: [Question]
}
struct Question: Codable {
var question: String
var options: [String]
}
Your view controller then becomes much simpler:
class ViewController: UIViewController, UITableViewDatasource {
var questionData: Questions?
override func viewDidLoad() {
super.viewDidLoad()
tableView.register(UINib(nibName: "NH_questionheader", bundle: nil), forCellReuseIdentifier: "HeaderCell")
tableView.register(UINib(nibName: "CellTableViewCell", bundle: nil), forCellReuseIdentifier: "Cell")
// You don't show how you load your JSON, but assuming you have it in an instance of `Data` called `jsonData`:
do {
self.questionData = try JSONDecoder().decode(Questions.self, from: jsonData)
} catch {
print("Error decoding JSON: \(error.localizedDescription)")
}
}
func tableView(_ tableView: UITableView, viewForHeaderInSection section: IndexPath) -> UIView? {
let identifier = "HeaderCell"
guard let questionData = self.questionData,
let headercell = tableView.dequeueReusableCell(withIdentifier: identifier) as? NH_questionheader else {
return nil
}
headercell.label.text = questionData.questions[section].question
return headercell
}
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return 150
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.questionData?.questions[section].options.count ?? 0
}
func numberOfSections(in tableView: UITableView) -> Int {
return self.questionData?.questions.count ?? 0
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let identifier = "Cell"
// Note, I have used force unwrapping and a forced downcast here as if either of these lines fail you have a serious problem and crashing is the simplest way of finding it during development
let option = self.questionData!.questions[indexPath.section].options[indexPath.row]
let cell = tableView.dequeueReusableCell(withIdentifier: identifier, for: indexPath ) as! CellTableViewCell
cell.contentView.backgroundColor = .clear
cell.label.text = option
return cell
}
}
Once you have this basic approach working you can try and add a view model if you like.