How can I group TableView items from a dictionary in swift? - ios

Question

Lets consider this example:
import UIKit
class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
#IBOutlet weak var tableView: UITableView!
var names = ["Vegetables": ["Tomato", "Potato", "Lettuce"], "Fruits": ["Apple", "Banana"]]
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell{
let cell: UITableViewCell = UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier:"test")
return cell
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int{
return ???
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int{
return names.count
}
func sectionIndexTitlesForTableView(tableView: UITableView) -> [AnyObject]!{
return ???
}
func tableView(tableView: UITableView,
titleForHeaderInSection section: Int) -> String?{
return ????
}
}
let's assume that we need that the keys (fruits and vegetables) of the dictionary are the number of sections, plus they will be the titles of the sections. The items of the keys (eg apples and banana) will be the rows of each section. How can I implement this in my code? I know it might be easy but I couldn't figure it out my self.

Answer 1

You can use struct for that and here is example:
import UIKit
class TableViewController: UITableViewController {
var names = ["Vegetables": ["Tomato", "Potato", "Lettuce"], "Fruits": ["Apple", "Banana"]]
struct Objects {
var sectionName : String!
var sectionObjects : [String]!
}
var objectArray = [Objects]()
override func viewDidLoad() {
super.viewDidLoad()
for (key, value) in names {
println("\(key) -> \(value)")
objectArray.append(Objects(sectionName: key, sectionObjects: value))
}
}
// MARK: - Table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return objectArray.count
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return objectArray[section].sectionObjects.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! UITableViewCell
// Configure the cell...
cell.textLabel?.text = objectArray[indexPath.section].sectionObjects[indexPath.row]
return cell
}
override func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
return objectArray[section].sectionName
}
}

Answer 2

Swift 2
you dictionary example
var dic:Dictionary<String,String> = ["key":"value","key1":"value2"]
Your table
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell{
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! UITableViewCell
var key = Array(self.dic.keys)[indexPath.row]
var value = Array(self.dic.values)[indexPath.row]
cell.text = key + value
}

Answer 3

If you want it sorted use the global sorted function to sort the dictionary.
import UIKit
class TableViewController: UITableViewController {
var names = ["Vegetables": ["Tomato", "Potato", "Lettuce"], "Fruits": ["Apple", "Banana"]]
var namesSorted = [String, Array<String>]()
override func viewDidLoad() {
super.viewDidLoad()
// Sort names
namesSorted = sorted(names) { $0.0 < $1.0} // namesSorted = ["Fruits": ["Apple", "Banana"], "Vegetables": ["Tomato", "Potato", "Lettuce"]]
}
// MARK: - Table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return namesSorted.count
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return namesSorted[section].1.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! UITableViewCell
// Configure the cell...
cell.textLabel?.text = namesSorted[indexPath.section].1[indexPath.row]
return cell
}
override func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
return namesSorted[section].0
}
}

Answer 4

All collection types must be Array
var names = [["Tomato", "Potato", "Lettuce"], ["Apple", "Banana"]]
var sectionNames = ["Vegetables", "Fruits"]
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int{
return names[section].count
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int{
return names.count
}
func sectionIndexTitlesForTableView(tableView: UITableView) -> [AnyObject]!{
return sectionNames
}
func tableView(tableView: UITableView,
titleForHeaderInSection section: Int) -> String?{
return sectionNames[section]
}

Answer 5

From Apple Documentation :
var keys: LazyForwardCollection<MapCollectionView<Dictionary<Key, Value>, Key>> { get }
Description: A collection containing just the keys of self. Keys appear in the same order as they occur as the .0 member of key-value pairs in self. Each key in the result has a unique value.
names.keys.array returns an Array of the keys.
SO:
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int{
return names.keys.array[section].count
}
func sectionIndexTitlesForTableView(tableView: UITableView) -> [AnyObject]!{
return names.keys.array
}
func tableView(tableView: UITableView,
titleForHeaderInSection section: Int) -> String?{
return names.keys.array[section]
}
This will work on Any Dictionary with any amount of data(even if it is unknown to the programmer

Answer 6

An easier way to solve this problem is to copy your dictionary into a temporary variable. Use removeFirst to extract the values from the array inside the dictionary.
var itemList=["Grocery":["soap","flour","carrots"],"Vehicles":["oil change","gas","tire rotation"],"Household":["Cable","Tv","cellphone"]]
var itemListTmp :[String:[String]] = [:]
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.textLabel?.text=itemListTmp[keysItem[indexPath.section]]?.removeFirst()
//cell.textLabel?.text=itemList[indexPath.section].items[indexPath.row]
return cell
}
Another way of solving this problem is to extract keys and values in separate arrays:
var task=[String](itemList.keys)
var tobeDone=[[String]](itemList.values)
override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
return task[section]
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.textLabel?.text=tobeDone[indexPath.section][indexPath.row]
return cell
}

Answer 7

Similar to https://stackoverflow.com/a/31136537/11098567 answer I would use classes instead of structs, so that you can manipulate or add to your values after it has been placed into the array.
#objc func addToInitialClassInstance() {
let classInstance = Class(property1: String, property2: [CLass2.init(property1: String, property2: String)])
let isAvailable = initialClassInstance.contains { (classInArray) -> Bool in
if classInArray.property == classInstance.property {
classInArray.property2.append(classInstance.property2[0])
return true
}
return false
}
if !isAvailable {
initialClassInstance.append(classInstance)
}
tableView.reloadData()
}