(Swift 3,4,5...) Decode Base64 Image String (GIF, JPG, etc.) and Save to File

I have an XML response that includes a base 64 encoded image string (UPS label). It's a huge string and I need to save it as a gif file on my users pc.

This example shows how to do it..

Chilkat Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    let bd = CkoBinData()!

    // I created an extra-small GIF image for this example..
    var success: Bool = bd.loadFile("qa_data/gif/xsmall.gif")
    if success != true {
        print("Failed to load GIF image file.")
        return
    }

    // Show GIF bytes as base64:
    print("\(bd.getEncoded("base64")!)")

    // This particular GIF in base64 is this:
    // R0lGODlhBQAFAMQAAAAAAP////z8/PHx8evr6+jo6OHh4d7e3sPDw8LCwpqamo2NjWxsbGRkZFpaWk1NTUtLS0hISCwsLCQkJP///wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACH5BAEAABQALAAAAAAFAAUAAAUTYCAYQUBAU1lI0TIgztE8jFImIQA7

    // Let's begin with an XML string:
    var x: String? = "<abc><def>R0lGODlhBQAFAMQAAAAAAP////z8/PHx8evr6+jo6OHh4d7e3sPDw8LCwpqamo2NjWxsbGRkZFpaWk1NTUtLS0hISCwsLCQkJP///wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACH5BAEAABQALAAAAAAFAAUAAAUTYCAYQUBAU1lI0TIgztE8jFImIQA7</def></abc>"

    let xml = CkoXml()!
    success = xml.load(x)

    // Get the base64 string:
    var gifBase64: String? = xml.getChildContent("def")

    print("\(gifBase64!)")

    // Load bd with the base64 decoded bytes.  
    bd.clear()
    bd.appendEncoded(gifBase64, encoding: "base64")

    // Save to a GIF file.
    success = bd.writeFile("qa_output/xsmall.gif")

}