Want indexed tableview with reference back to source array

Question

In iOS/Swift I've created an indexed "client" UITableView based on the clientName property in my Client class. I created a dictionary with A to Z as the sections. The indexed tableview works great. However, I'm trying to figure out a way to determine which row it is in the original source array, when the user selects a row. I was thinking of building some type of cross reference array, except that the dictionary ends up sorted to match the sections, so I don't know which section/row combo matches which original array entry. Is there a common approach to handling this issue?

In an attempt to clarify...

class Client {
    var clientId             : Int!
    var firstName            : String!
    var lastName             : String!
    var email                : String!
    var phone                : String!
    ...

    init() {

    }
}

var clients: [Client] = []

// clients array loaded from web service
...

// Create dictionary to be source for indexed tableview
func createClientDict() {
    clientDict          = [String: [String]]()
    clientSectionTitles = [String]()

    var clientNames:[String] = []
    for i in 0..<clients.count {
        let client = clients[i]

        let clientName = "\(client.lastName), \(client.firstName)"
        clientNames.append(clientName)
    }

    for name in clientNames {
        var client: Client  = Client()

        // Get the first letter of the name and build the dictionary
        let clientKey = name.substringToIndex(name.startIndex.advancedBy(1))
        if var clientValues = clientDict[clientKey] {
            clientValues.append(name)
            clientDict[clientKey] = clientValues
        } else {
            clientDict[clientKey] = [name]
        }
    }

    // Get the section titles from the dictionary's keys and sort them in ascending order
    clientSectionTitles = [String](clientDict.keys)
    clientSectionTitles = clientSectionTitles.sort { $0 < $1 }
}

Now, when the user taps a row in the tableview, I can get the section and row (indexPath). However, how can I determine which row in the clients array is the match, assuming there could be duplicate names? Is there some way to create a cross reference of indexed section/row mapped to row in source array on the fly? I was going to try to do that while building the dictionary, except that the dictionary gets sorted after, so nothing would match up. Maybe I should somehow be including the source row number in/with the dictionary??

Here is the tableview code:

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCellWithIdentifier("Cell") as! ClientCell

    let clientKey = clientSectionTitles[indexPath.section]
    if let clientValues = clientDict[clientKey] {
        cell.clientName.text = clientValues[indexPath.row]
    }

    return cell
}

func numberOfSectionsInTableView(tableView: UITableView) -> Int {
    return clientSectionTitles.count
}

func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    let clientKey = clientSectionTitles[section]
    if let clientValues = clientDict[clientKey] {
        return clientValues.count
    }

    return 0
}

func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
    return clientSectionTitles[section]
}

func sectionIndexTitlesForTableView(tableView: UITableView) -> [String]? {
    return clientIndexTitles
}

func tableView(tableView: UITableView, sectionForSectionIndexTitle title: String, atIndex index: Int) -> Int {

    guard let index = clientSectionTitles.indexOf(title) else {
        return -1
    }

    return index
}

func tableView(tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
    return 20
}

func tableView(tableView: UITableView, willDisplayHeaderView view: UIView, forSection section: Int) {
    let headerView   = view as! UITableViewHeaderFooterView

    headerView.contentView.backgroundColor = UIColor ( red: 0.0, green: 0.3294, blue: 0.6392, alpha: 1.0 )
    headerView.textLabel?.textColor = UIColor.greenColor()
    headerView.textLabel?.font = UIFont(name: "Noteworthy-bold", size: 15.0)
}

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
    selectedIndex = indexPath

    // In the following prepare for segue, I need to somehow use the selected indexpath to find the correct entry
    // in the clients array and pass it along.

    performSegueWithIdentifier("clientDetailSegue", sender: self)
}

Answer 1

I figured it out. I didn't realize (until I recently tried it) that you could nest an array of any class in a dictionary. When I changed my dictionary to have my clients array nested in it, all was solved. I changed my function as shown below.

func createClientDict() {
    // Declared for view controller. Re-initialized here.
    clientDict          = [String: [Client]]()
    clientSectionTitles = [String]()

    clients.sortInPlace ({ $0.lastName < $1.lastName })

    for c in clients {
        let clientName = "\(c.lastName), \(c.firstName)"

        // Get the first letter of the name and build the dictionary
        let clientKey = clientName!.substringToIndex(clientName!.startIndex.advancedBy(1))
        if var clientValues = clientDict[clientKey] {
            clientValues.append(c)
            clientDict[clientKey] = clientValues
        } else {
            clientDict[clientKey] = [c]
        }
    }

    // Get the section titles from the dictionary's keys and sort them in ascending order
    clientSectionTitles = [String](clientDict.keys)
    clientSectionTitles = clientSectionTitles.sort { $0 < $1 }
}

However, this line was the key to the solution:

let clientDict = [String: [Client]]()