Set the value of UIPickerView right after its data is loaded - ios

Question

I have developed something very similar to DateCell Demo from Apple. https://developer.apple.com/library/ios/samplecode/DateCell/Introduction/Intro.html
The only difference is that I have a UIPickerView instead of a UIDatePicker. And whenever the cell is touched a new UIPickerView is instantiated and added to the cell below once touched again it is removed from the cell. And the part I have problem with is to select a specific item in the UIPickerView.
Here is some code:
var selectedPlatform = "Mac"
var platformPickerDataSource = ["iOS", "Mac", "PC", "Android"]
func updatePlatformPicker()
{
if let indexPath = platformPickerIndexPath {
let associatedPlatformPickerCell = tableView.cellForRowAtIndexPath(indexPath)
if let targetedPlatformPicker = associatedPlatformPickerCell?.viewWithTag(Constants.kPlatformPickerTag) as! UIPickerView? {
targetedPlatformPicker.dataSource = self
targetedPlatformPicker.delegate = self
// I cannot do selectRow(selectedPlatform, inComponent: 0,
animated : true) here since the row since the rows in the UIPickerView are not set
}
}
}
So my questions is, if you refer to the code from Apple, where can I set?
selectRow(selectedPlatform, inComponent: 0,
animated : true)
Edit: (I added the whole code, which is basically the swift version of Apple's DateCell Example and DatePicker replaced with a UIPickerView)
import UIKit
class PickerTableViewController: UITableViewController, UIPickerViewDataSource, UIPickerViewDelegate {
var platformPickerIndexPath : NSIndexPath?
var pickerCellRowHeight: CGFloat = 140
var selectedPlatform = "Mac"
var platformPickerDataSource = ["iOS", "Mac", "PC", "Android"]
private struct Constants {
static let kPlatformCellID: String = "platformCell"
static let kPlatformPickerID: String = "platformPicker"
static let kOtherCell: String = "otherCell"
static let kPlatformRow : Int = 1
static let kPlatformPickerTag : Int = 99
}
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
// MARK: - Table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
var rows = 3
if hasInlinePlatformPicker()
{
rows = 4
}
return rows
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell : UITableViewCell?
print("\(indexPath.row)")
var cellID = Constants.kOtherCell
if indexPathHasPicker(indexPath)
{
cellID = Constants.kPlatformPickerID
}
else if indexPathHasPlatform(indexPath)
{
cellID = Constants.kPlatformCellID
}
cell = tableView.dequeueReusableCellWithIdentifier(cellID)
var modelRow = indexPath.row
if (platformPickerIndexPath != nil && platformPickerIndexPath?.row <= indexPath.row) {
modelRow -= 1
}
if cellID == Constants.kPlatformCellID
{
cell?.textLabel?.text = "Select a platform"
cell?.detailTextLabel?.text = selectedPlatform
}
else if cellID == Constants.kOtherCell
{
cell?.textLabel?.text = "Other Cell"
}
return cell!
}
func indexPathHasPicker(indexPath: NSIndexPath) -> Bool
{
return hasInlinePlatformPicker() && platformPickerIndexPath?.row == indexPath.row
}
func indexPathHasPlatform(indexPath : NSIndexPath) -> Bool
{
var hasPlatform = false
if indexPath.row == Constants.kPlatformRow || (hasInlinePlatformPicker() && (indexPath.row == Constants.kPlatformRow + 1))
{
hasPlatform = true
}
return hasPlatform
}
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
let cell = tableView.cellForRowAtIndexPath(indexPath)
if cell?.reuseIdentifier == Constants.kPlatformCellID
{
displayInlinePlatformPickerForRowAtIndexPath(indexPath)
}
else
{
tableView.deselectRowAtIndexPath(indexPath, animated: true)
}
}
func displayInlinePlatformPickerForRowAtIndexPath(indexPath : NSIndexPath)
{
// display the platform picker inline with the table content
tableView.beginUpdates()
var before = false
if hasInlinePlatformPicker()
{
before = platformPickerIndexPath?.row < indexPath.row
}
let sameCellClicked = (platformPickerIndexPath?.row == indexPath.row + 1)
// remove any picker cell if it exists
if hasInlinePlatformPicker()
{
tableView.deleteRowsAtIndexPaths([NSIndexPath(forRow: platformPickerIndexPath!.row, inSection: 0)], withRowAnimation: .Fade)
platformPickerIndexPath = nil
}
if (!sameCellClicked)
{
// hide the old picker and display the new one
let rowToReveal = (before ? indexPath.row - 1 : indexPath.row)
let indexPathToReveal = NSIndexPath(forRow: rowToReveal, inSection: 0)
togglePlatformPickerForSelectedIndexPath(indexPathToReveal)
platformPickerIndexPath = NSIndexPath(forRow: indexPathToReveal.row + 1, inSection: 0)
}
tableView.deselectRowAtIndexPath(indexPath, animated: true)
tableView.endUpdates()
updatePlatformPicker()
}
func updatePlatformPicker()
{
if let indexPath = platformPickerIndexPath {
let associatedPlatformPickerCell = tableView.cellForRowAtIndexPath(indexPath)
if let targetedPlatformPicker = associatedPlatformPickerCell?.viewWithTag(Constants.kPlatformPickerTag) as! UIPickerView? {
targetedPlatformPicker.dataSource = self
targetedPlatformPicker.delegate = self
}
}
}
func togglePlatformPickerForSelectedIndexPath(indexPath: NSIndexPath)
{
tableView.beginUpdates()
let indexPaths = [NSIndexPath(forRow: indexPath.row + 1, inSection: 0)]
// check if 'indexPath' has an attached picker below it
if hasPickerForIndexPath(indexPath)
{
// found a picker below it, so remove it
tableView.deleteRowsAtIndexPaths(indexPaths, withRowAnimation: .Fade)
}
else
{
// didn't find a picker below it, so we should insert it
tableView.insertRowsAtIndexPaths(indexPaths, withRowAnimation: .Fade)
}
tableView.endUpdates()
}
func hasPickerForIndexPath(indexPath: NSIndexPath) -> Bool
{
var hasPlatformPicker = false
let targetedRow = indexPath.row + 1
let checkPlatformPickerCell = tableView.cellForRowAtIndexPath(NSIndexPath(forRow: targetedRow, inSection: 0))
let checkPlatformPicker = checkPlatformPickerCell?.viewWithTag(Constants.kPlatformPickerTag)
hasPlatformPicker = checkPlatformPicker != nil
return hasPlatformPicker
}
func hasInlinePlatformPicker() -> Bool
{
return platformPickerIndexPath != nil
}
override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return (indexPathHasPicker(indexPath) ? pickerCellRowHeight : tableView.rowHeight)
}
// MARK: - Platform Picker View Data Source and Delegates
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return platformPickerDataSource.count
}
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
return platformPickerDataSource[row]
}
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
print("Platform Selected: \(platformPickerDataSource[row])")
var targetedCellIndexPath: NSIndexPath?
if hasInlinePlatformPicker() {
// inline picker: update the cell's above the picker cell
//
targetedCellIndexPath = NSIndexPath(forRow: platformPickerIndexPath!.row - 1, inSection: 0)
}
let cell = tableView.cellForRowAtIndexPath(targetedCellIndexPath!)
cell?.detailTextLabel?.text = platformPickerDataSource[row]
}
}