Swift 2.0, UITableView: Fetch index of 'checked' rows - swift

Question

I have a UITableView in a UIViewController. I have a button at the bottom of this view controller. All the table cells contain a checkbox, which is a subclass of UIButton and a UILabel. When the button is pressed, I want to fetch the text of labels for all the 'checked' cells. Now I can't use cellForRowAtIndexPath because that returns a nil value for cells that are not visible. I therefore want to index my datasource. But the problem is, since UIButton does not have a UIButtonDelegate like UITextfield, I don't know how to capture the button clicks and store the indexPath rows for the cells for which the checkbox was checked. Please help! Thanks a lot!
This is my checkbox code, for reference
class CheckBox: UIButton {
/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func drawRect(rect: CGRect) {
// Drawing code
}
*/
// images
var checkedImage = UIImage(named: "check")
var unCheckedImage = UIImage(named: "uncheck")
// bool property
var isChecked: Bool = false {
didSet {
if isChecked == true {
self.setImage(checkedImage, forState: .Normal)
} else {
self.setImage(unCheckedImage, forState: .Normal)
}
}
}
override func awakeFromNib() {
self.addTarget(self, action: "buttonClicked:", forControlEvents: UIControlEvents.TouchUpInside)
self.isChecked = false
}
func buttonClicked(sender: UIButton) {
if (sender == self) {
if isChecked == true {
isChecked = false
} else {
isChecked = true
}
}
}
}

Answer 1

You can implement a tableviewcell. In that you have to create all elements in you cell. And in that cell class you have to maintain this variables
var indexofRow // Set this at the time of setting cell for UITableView .
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) - > UITableViewCell {
let cell: yourFeedCell = tableView.dequeueReusableCellWithIdentifier("yourTableCell") as!yourFeedCell
cell.indexofRow = indexPath.row;
}
/*Code in you cell class*/
//Maintain one dictonary Globally
var listOfCheckedCells = [Int: Bool]()
// bool property
var isChecked: Bool = false {
didSet {
if isChecked == true {
self.setImage(checkedImage, forState: .Normal)
listOfCheckedCells[self.indexofRow] = true
} else {
self.setImage(unCheckedImage, forState: .Normal)
listOfCheckedCells[self.indexofRow] = false
}
}
}
Hope this will Help

Answer 2

You have already subclassed from UIButton. AFAICS, you need a method call in order to be aware when the button is pressed. There is a method on UIControl (which is also applicable to UIButton):
func sendAction(_ action: Selector,
to target: AnyObject?,
forEvent event: UIEvent?)
UIControl implements this method to forward an action message to the
singleton UIApplication object (in its
sendAction:to:fromSender:forEvent: method) for dispatching it to the
target or, if there is no specified target, to the first object in the
responder chain that is willing to handle it. Subclasses may override
this method to observe or modify action-forwarding behavior. The
implementation of sendActionsForControlEvents: might call this method
repeatedly, once for each specified control event.
You can override the method, call the super's implementation and let your observers/delegates know that the associated action is about to be performed.

Answer 3

Table view cells are populated only when they're visible so if you wanna save a value of a cell and keep it around even when its not visible, create a dictionary with the index path as key and the content of the cell as value. Then just update the dictionary when the check box is checked and unchecked. Finally when 'the button at the bottom of the view' is clicked fetch your data from the dictionary. here is somewhat a sample
var textOfLabels:[NSIndexPath:String]?
func buttonClicked(sender: UIButton) {
let view = sender.superview!
let cell = view.superview as! UITableViewCell //or your custom cell name
let indexPath = itemTable.indexPathForCell(cell)
if (sender == self) {
if isChecked == true {
isChecked = false
textOfLabels?.updateValue(theLableText, forKey: indexPath)
} else {
isChecked = true
textOfLabels?.removeValueForKey(indexPath)
}
}
}