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

Question

Lets consider this example:

import UIKit
class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource { 
    @IBOutlet weak var tableV         


        

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

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 3

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 4

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 5

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 6

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
    }
}