Swift：带有完成按钮的文本框上的弹出DatePicker

I'm creating an app that has a UITextField on it, which, when tapped / clicked, will show a Date Picker that will flyout from the bottom. Said popup panel has a Done button, which will apply whatever date is selected (default to today) to the textfield upon click / tap, of preferably YYYY-MM-DD format.I'm creating an app that has a UITextField on i