How to pass optional URL to Kingfisher 6's new KF shorthand?

[dhritzkiv]

Using the 'old' UIImageView.kf.setImage API, I was able to pass in an optional URL (a result of, for example, when a user never uploaded a photo to their profile), and rely on placeholder to set a placeholder/fallback image, even in the case of a missing image url:

old way:

imageView.kf.setImage(
    // `user.pictureUri` (`URL?`) is `nil` here
    with: user.pictureUri,
    placeholder: UIImage(named: "UserPlaceholderImage")
)

new way (expected):

KF.url(user.pictureUri)
            .placeholder(UIImage(named: "UserPlaceholderImage"))
            .set(to: imageView)

However, KF#url requires URL and does not work with URL?

---

I can work around this by re-writing the code as:

imageView.image = UIImage(named: "UserPlaceholderImage")

if let url = user.pictureUri {
    KF.url(url).set(to: imageView)
}

which, while still fairly clean, doesn't benefit from using KF's new chainable API for all my UIImageView needs

---

If this was a deliberate decision, that's okay, too! I was merely expecting the two APIs to be identical in their capabilities.

[onevcat]

Umm, it is a trade-off between strictness and flexibility. The reason is I was receiving a bunch of issues that complains the image is not loaded. And at last, I have to ask them to check whether the URL is nil or not again and again.

But on the other hand, I guess yes, you are right on it. In this particular case, flexibility is more important.

Converting a non-optional parameter to an optional one does not break the current API and I guess I can do it very soon. Stay tuned!

[onevcat]

Done in #1617 and I will find a good time to release it.