CODEWITHSUNDEEP
swiftsubclass
PatriciaW
PatriciaW

Reputation: 913

Swift: Is it possible to use a variable for a custom class name?

I am attempting to use CoreData variables for most of my app code but have not been able to use them for the names of custom classes. Here is an example of my code:

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> CREWWorkCell {
    let cell = tableView.dequeueReusableCellWithIdentifier(cellName) as! CREWWorkCell

I want to use a string for CREWWorkCell. Is this possible?

Upvotes: 0

Views: 305

Answers (1)

ielyamani
ielyamani

Reputation: 18591

UITableViewController doesn't have a function that returns CREWWorkCell that you could override. Use the default UITableViewCell as a return value and everything would work fine with custom cells.

In your UITableViewController class use the following function:

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell { // Note that the return value is UITableViewCell and not CREWWorkCell

        //get the class name from the database and put it in a variable called myClassName. Then 

        if myClassName == "CREWWorkCell" {
            let cell : CREWWorkCell = tableView.dequeueReusableCellWithIdentifier("cell identifier 1", forIndexPath: indexPath) as! CREWWorkCell //of course you should cast to your custom class to be able to use it
            return cell
        } else if myClassName == "AnotherCellClass" {
            let cell : AnotherCellClass = tableView.dequeueReusableCellWithIdentifier("cell identifier 2", forIndexPath: indexPath) as! AnotherCellClass
            return cell
        }

        //do the same if you have other custom classes etc...

        return UITableViewCell()
    }

With Swift you can't cast to a dynamic type (have a look here). Therefore, you can't cast to a Type that you put in a variable using for example :

var myClassName = CREWWorkCell.self

or 

var myClassName = CREWWorkCell().dynamicType

because myClassName would be evaluated at runtime, in other words it is a dynamic type. But the casting operator expects a its right hand side a static type, a type that is already known and doesn't need to be evaluated at runtime. This feature allows Swift to enforce type safety.

I would suggest you to rethink the way you create custom cells, in a much simpler way.

Upvotes: 1

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