I'm using ReactiveCocoa 4.0.4 alpha 1 and Swift 2.1. I'm trying to write an extension that creates a max text limit on a UITextField.
extension RACStream {
public func max(textField: UITextField, max: Int) -> RACStream! {
return filter { next in
if let str = next as? String {
let ret = str.characters.count < max
if !ret {
textField.text = str[0..<max-1]
}
return ret
}
return true
}
}
}
self.inputTextField.rac_textSignal()
.max(self.inputTextField, max: 7)
.throttle(0.25)
.subscribeNext { (obj: AnyObject!) -> Void in
let input = Int(obj as! String)
print(input)
}
I get an error when I try to call max. It tells me Value of type RACStream has no member throttle. It gives a similar error if I call max after throttle.
I took a look at the RACStream class inspect filter. Being it returns Self!, which refers to RACStream, I would assume that when I extend the class, by return an RACStream! would result in similar behavior. Why won't the rest of my pipeline respond to my extended function?
According to source code methods throttle, subscribeNext are members of class RACSignal (it's a subclass of RACStream), but your extension method is intended for class RACStream and you call the method rac_textSignal() which returns type RACSignal . Therefore, In order to eliminate an error described in your question you should write an extension for RACSignal rather than RACStream.
extension RACSignal {
public func max(textField: UITextField, max: Int) -> RACSignal {
// method filter can be invoked since RACSignal is subclass of RACStream
return filter { next in
if let str = next as? String {
let ret = str.characters.count < max
if !ret {
textField.text = str[0..<max-1]
}
return ret
}
return true
}
} // Func
} // RacSignal Ext