How to override read-only property from Objective-C in Swift?

Question

This is how it is defined in objective-c:

@interface AFHTTPRequestOperation : AFURLConnectionOperation

@property (readonly, nonatomic, strong) id responseObject;

How to assign sth to this property?

I would like to mock this property for later usage. So I need there my own responseObject overriden in Swift. Any ideas how to do this? I can subclass, extend or whatever. The only thing is it must by type of AFHTTPRequestOperation.

class MyRequestOperation: AFHTTPRequestOperation {

    override var responseObject: [String: AnyObject]
}

It produces an error:

Getter for responseObject with Objective-C selector responseObject conflicts with getter for responseObject from superclass AHTTPRequestOperation with the same Objective-C selector

then try without the initialization part: [link](https://stackoverflow.com/questions/25005259/objective-c-setter-overriding-in-swift) — The Paramagnetic Croissant, Aug 06 '15 at 12:25
As property type in superclass is declared as `id` in swift version you should probably use AnyObject, not any stricter type — Vladimir, Aug 06 '15 at 12:29
@The Paramagnetic Croissant - example from question is not about `read-only` property — Bartłomiej Semańczyk, Aug 06 '15 at 12:30
@Vladimir, it doesn't work... The same error as I wrote in question — Bartłomiej Semańczyk, Aug 06 '15 at 12:30
It is good to have immutable readonly property. Create some method that creates a new object with modified property like [NSString stringByAppendingString:] which does not return the same string, but does some change on the original value or simply create a method inside the class to change the attribute. — Sandeep, Aug 06 '15 at 12:31
@BartłomiejSemańczyk if you change `var` to `let`, it will represent a read-only property. — The Paramagnetic Croissant, Aug 06 '15 at 12:37

score 19 · Answer 1 · answered Aug 06 '15 at 12:36

So, the answer is simple as @Atul Mishra said:

class MyRequestOperation: AFHTTPRequestOperation {

    var myOverridenResponseObject: AnyObject?

    override var responseObject: AnyObject? {

        get {
            return myOverridenResponseObject
        }

        set {
            myOverridenResponseObject = newValue
        }
    }
}

score 7 · Answer 2 · answered Aug 06 '15 at 12:30

You can present an inherited read-only property as a read-write property by providing both a getter and a setter in your subclass property override.but however you cannot provide an inherited read-write property as read-only property. for better clarification refer https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Inheritance.html#//apple_ref/doc/uid/TP40014097-CH17-XID_300

How to override read-only property from Objective-C in Swift?

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