Is it possible to define a class function in an extension in swift, just like in an objective-C category you can also define class functions?
Example in objective-c
@implementation UIColor (Additions)
+ (UIColor)colorWithHexString:(NSString *)hexString
{
// create color from string
// ... some code
return newColor;
}
@end
what would be the equivalent in swift?
Yes, it possible and very similar, the main difference is that Swift extensions are not named.
extension UIColor {
class func colorWithHexString(hexString: String) -> UIColor {
// create color from string
// ... some code
return newColor
}
}
For the record. Here's the code for above's solution:
import UIKit
extension UIColor {
convenience init(hexString:String) {
// some code to parse the hex string
let red = 0.0
let green = 0.0
let blue = 0.0
let alpha = 1.0
self.init(red:red, green:green, blue:blue, alpha:alpha)
}
}
Now I can use:
swift:
let clr:UIColor = UIColor(hexString:"000000")
and theoretically I should be able to use in objective-c:
UIColor *clr = [UIColor colorWithHexString:@"000000"];
init fail-able when invalid hexString is provided.