S/O - Proxy

• Category: structural
• Type: object
• Motivation: a proxy is a wrapper to forward the real object request and/or provide additional logic

do {
    let proxy = ProxyInternet()
    proxy.connect("hello.com")
    proxy.connect("foo.com")
}

protocol Internet
{
    func connect(_ host: String)
}

class RealInternet: Internet
{
    func connect(_ host: String)
    {
        print("conecting to \(host)")
    }
}

class ProxyInternet: Internet
{
    let internet = RealInternet()

    func connect(_ host: String)
    {
        if ["foo.com"].contains(host) { // the work of proxy
            print("Access Denied")
            return
        }
        internet.connect(host)
    }
}