How to manage section in UITableView - swift

Question

I'm trying to create an application with sections in my TableView.
But actually, I don't know how to manage sections.
I create sections and it works fine but when I try to add a new row in my section I got a problem.
Example:
I Create a new Item in my first section.
The section name is "Aucun" and the rows label is going to set to "Test 1"
It works!
So, now I want to add something else
The section name is "Produits Laitiers" and the row label is "Test2"
FAIL :( The section is create but the row is not the good one
There is my code for the moment
func numberOfSections(in tableView: UITableView) -> Int {
return arraySection.count
}
func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
return arraySection[section]
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return numberOfRowsInSection[section]
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "customCell")
cell?.textLabel?.text = "\(String(describing: products[indexPath.row]["Name"]!))"
cell?.textLabel?.adjustsFontSizeToFitWidth = true
cell?.textLabel?.font = UIFont(name: "Arial", size: 14)
return cell!
}
numberOfRowsInSection is an array of int where I store the number of products which have to be in this section.

Answer 1

You are getting "Test 1" each time, because you have sections, but you are always trying to get a value by using an index of a row without checking an index of a section:
\(String(describing: products[indexPath.row]["Name"]!))
If all your values for cells are storing in a single array, then you should get a value from an array by using the section number:
\(String(describing: products[indexPath.section]["Name"]!))
But this will work only if each section will have only one row. Otherwise you will have to get the number of section first to detect the section where current row is allocated and then get the number of row.
If you have an array of sections with array of rows for each section, that will look like this:
let arraySection = [ [section #0 values], [section #1 values], ...
]
Then you can get the value for each row by using this:
let value = arraySection[indexPath.section][indexPath.row]
========EDIT===========
But there is a much better way - use objects or structs
struct Row {
var value: String = ""
}
struct Section {
var name: String = ""
var values: [Row] = []
}
So, using this structs, your code will be changed:
//your array of sections will contain objects
let arraySection: [Section] = []
func numberOfSections(in tableView: UITableView) -> Int {
return arraySection.count
}
func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
//get the name of the section
return arraySection[section].name
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
//check the count of rows for each section
return arraySection[section].values.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "customCell")
// now we can get the value for current row by checking sections and then rows
cell?.textLabel?.text = arraySection[indexPath.section].values[indexPath.row].value
cell?.textLabel?.adjustsFontSizeToFitWidth = true
cell?.textLabel?.font = UIFont(name: "Arial", size: 14)
return cell!
}

Answer 2

I think the problem is with the products array in the UITableViewDataSource method cellForRowAt. You are accessing the same array element for the first object in each section with
products[indexPath.row]["Name"]!
Probably you need to adjust your model to handle the indexPath.section.

Answer 3

The first thing I going to creates a Section model to keep track of the sections, like the following:
/// Defines a section in data source
struct Section {
// MARK: - Properties
/// The title of the section
let title: String
/// The items in the section
var items: [String]
}
Then I going to use a UITableViewController with an Add right button to insert new section/rows to the UITableView, to add new sections/row I going to use a UIAlertController for the sake of brevity with two UITextField's inside where you need to put the name of the section and the name of the row. At the end should look like the following image:
In case the section already exist is going to add the new row to the section, otherwise, is going to create the new section and row dynamically.
DynamicTableViewController
class DynamicTableViewController: UITableViewController {
// MARK: - Properties
/// The data source for the table view
var dataSource = [Section(title: "Section 1", items: ["Row 1"])]
// MARK: - UIViewController
override func viewDidLoad() {
super.viewDidLoad()
}
// MARK: - Table view data source
override func numberOfSections(in tableView: UITableView) -> Int {
return dataSource.count
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return dataSource[section].items.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
cell.textLabel?.text = dataSource[indexPath.section].items[indexPath.row]
return cell
}
override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
return dataSource[section].title
}
#IBAction func didTapAddButton(_ sender: Any) {
presentAlerController()
}
}
extension DynamicTableViewController {
func add(_ sectionName: String?, _ row: String?) {
guard let name = sectionName, let rowName = row,
!name.isEmpty, !rowName.isEmpty else {
return
}
if let index = dataSource.index(where: { $0.title == name }) {
dataSource[index].items.append(rowName)
} else {
dataSource.append(Section(title: name, items: [rowName]))
}
tableView.reloadData()
}
func presentAlerController() {
let alertController = UIAlertController(title: "Add", message: "Add new Section/Row", preferredStyle: .alert)
let addAction = UIAlertAction(title: "Add", style: .default) { [weak self] _ in
let sectionTextField = alertController.textFields![0] as UITextField
let rowTextField = alertController.textFields![1] as UITextField
self?.add(sectionTextField.text, rowTextField.text)
}
let cancelAction = UIAlertAction(title: "Cancel", style: .cancel) { _ in }
alertController.addTextField { textField in
textField.placeholder = "Add a new section name"
}
alertController.addTextField { textField in
textField.placeholder = "Add a new row"
}
alertController.addAction(addAction)
alertController.addAction(cancelAction)
present(alertController, animated: true, completion: nil)
}
}
In the above example, I'm not checking for the existence of duplicate row, you can do it is very easy. Also, I'm using the reloadData(), but you can use too if you want :
// insert the new section with row of the row in the existent section
tableView.beginUpdates()
// insert new section in case of any
insertSections(_ sections: IndexSet, with animation: UITableViewRowAnimation)
// insert new row in section using:
// insertRows(at: [IndexPath], with: UITableViewRowAnimation)
tableView.endUpdates()
Also you need to create a new UIBarButtonItem and connect it to the #IBAction I create it to be able to present the UIAlertController and add new section/row to the UITableView.
I hope this helps you.