Setting up equatable for PFObject

Question

I m getting error when setting up equatable in swift

extension PFObject : Equatable {}

public func ==(lhs:PFObject,rhs:PFObject) -> Bool {

return lhs.objectId == rhs.objectId
}

Below the following error I m getting

Redundant conformance of 'PFObject' to protocol 'Equatable'

Is there any solution for this error?

score 3 · Answer 1 · answered Sep 08 '15 at 21:07

3

A change in Swift 2 makes every NSObject conform to Equatable through the isEqual implementation which simply compares pointer values (read more here).

You can use the following extension to override the default implementation of isEqual:

extension PFObject {
  public override func isEqual(object: AnyObject?) -> Bool {
    if (object as? PFObject)?.objectId == self.objectId {
      return true
    } else {
      return super.isEqual(object)
    }
  }
}

answered Sep 08 '15 at 21:07

Ben-G

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It might be a good idea to also compare the types since I believe `objectId` is not necessarily unique across different subclasses of `PFObject`. – Ben Packard Jul 31 '18 at 16:20

score 0 · Answer 2 · answered Aug 24 '15 at 14:53

0

PFObject inherits from NSObject so it is already conforming to Equatable.

Instead of adding Equatable to a class that already implements it, you should subclass it and override the default implementation.

answered Aug 24 '15 at 14:53

Sulthan

128,090
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@Vimlan.G I added an answer with the implementation that I'm using. – Ben-G Sep 08 '15 at 21:07

score 0 · Answer 3 · answered Aug 11 '18 at 20:49

Here's an example implementation of isEqual that also checks the object is of the same Parse object type.

extension PFObject {
    open override func isEqual(_ object: Any?) -> Bool {
        if let parseObject = object as? PFObject {
            return parseObject.parseClassName == self.parseClassName && parseObject.objectId == self.objectId
        } else {
            return super.isEqual(object)
        }
    }
}

Setting up equatable for PFObject

3 Answers3