DSLoadable

Intro

To give the user a great user experience, we need to use non-blocking loaders for almost every element that does some asynchronous work. We tend to avoid handling this type of loading by blocking the whole view with a big loader. We don't want to manually add a loading view for each subview in the view controller, and managing them would be very hard. This repo provides fully customizable functions and methods which allows you to easily show loaders for any UIView. You can also plug in your favorite loading animation from another project!

Example

To run the example project, clone the repo, and run pod install from the Example directory first.

Requirements

Installation

DSLoadable is available through CocoaPods. To install it, simply add the following line to your Podfile:

pod 'DSLoadable'

Features

This repo provides a protocol which has default extension implementation for all views

public protocol DSLoadable {
    func loadableStartLoading(loadingViewType: UIView.Type, configuration: DSLoadableConfiguration?)
    func loadableStopLoading(loadingViewType: UIView.Type)
}

• loadingViewType: The view type of the loader that will be shown over the view
• configuration: You can manipulate the loading view in this function before placing it in the hierarchy

Showing the default loader for a button

If you want to use a simple loader with nothing fancy, you can use the built in one in the library. The above functionality can be implemented like this:

@IBOutlet weak var submitButton: UIButton!

@IBAction func submitDidPress(_ sender: Any?){
    submitButton.loadableStartLoading()
    DispatchQueue.main.asyncAfter(deadline: .now() + 2) {
        self.submitButton.loadableStopLoading()
    }
}

This loader automatically takes the text color and the background color of the button and updates the loading view accordingly. This configuration is declared public static in DSDefaults struct and you can use it for other things

static let buttonConfiguration: DSLoadableConfiguration = {
    selfView, loadingView in
    guard let lView = loadingView as? DSLoadingView, let selfButton = selfView as? UIButton else {
        return
    }
    lView.layer.cornerRadius = selfButton.layer.cornerRadius
    lView.clipsToBounds = selfButton.clipsToBounds
    lView.indicatorView.color = selfButton.titleColor(for: .normal)
    lView.indicatorView.backgroundColor = selfButton.backgroundColor
}

Adding a custom Loading View

You can integrate any loading view/library to the logic. In the above example, I'm using the awesome NVActivityIndicatorView which has a lot of amazing animations. The above example can be implemented using this code:

@IBOutlet weak var submitButton: UIButton!

@IBAction func submitDidPress(_ sender: Any?){
    submitButton.loadableStartLoading { (selfView) -> UIView in
        let activityView = NVActivityIndicatorView(frame: submitButton.bounds, type: .lineScale, color: UIColor.white, padding: 12)
        activityView.backgroundColor = submitButton.backgroundColor
        activityView.startAnimating()
        return activityView
    }
    DispatchQueue.main.asyncAfter(deadline: .now() + 2) {
        self.submitButton.loadableStopLoading(loadingViewType: NVActivityIndicatorView.self, configuration: {
            selfView, loadingView in
            guard let v = loadingView as? NVActivityIndicatorView else {
                return
            }
            v.stopAnimating()
        })
    }
}

It's important to note that there are 2 versions for loadableStartLoading function:

func loadableStartLoading(loadingViewType: UIView.Type, configuration: DSLoadableConfiguration?)

When you pass the loadingViewType for this function, the DSLoadable extension will automatically initialize the view type by calling init(frame:) and then adding it with constraints into the view hierarchy. In the above example, the NVActivityIndicatorView doesn't have an implemnetation for init(frame:). So, it will crash if we try to use this function. To solve this problem, we are using the function below.

func loadableStartLoading(configuration: DSLoadingViewFromConfiguration)

This function takes a configuration closure. This closure will return a UIView which will be added to the view hierarchy. In this way, we can call the custom initialization function for the NVActivityIndicatorView (init(frame:,type:,color:,padding:)) and return the final view from the closure. After the closure is executed, the NVActivityIndicatorView will automatically be added in the view hierarchy with constraints

Showing a loader for any view

Showing a loader for a UIView works exactly the same as showing the loader for a UIButton. You can use the default loader provided or you can add your custom one.

Author

MaherKSantina, maher.santina90@gmail.com

License

DSLoadable is available under the MIT license. See the LICENSE file for more info.