Swift: Make vertical scrolling feed with programmatically sized UIViews - ios

Question

I'm building a scrolling feed in my app with data grabbed from a database (firebase). I'm not very experienced in Swift as most of the stuff I do is web design. What I'm looking for is a good way to size the height of my UIViews. Here is what I currently have (fixed height):
Here's my code UIView class:
class eventView: UIView {
let eventDate : UILabel = {
let eventDate = UILabel()
eventDate.translatesAutoresizingMaskIntoConstraints = false
eventDate.numberOfLines = 0
eventDate.textAlignment = .center
return eventDate
}()
let eventTitle : UILabel = {
Same thing as eventDate
}()
let eventDesc : UILabel = {
same thing as eventDate
}()
override init(frame: CGRect) {
super.init(frame: frame)
self.backgroundColor = UIColor.lightGray
self.layer.cornerRadius = 10
self.addSubview(eventDate)
eventDate.leftAnchor.constraint(equalTo: self.leftAnchor).isActive = true
eventDate.rightAnchor.constraint(equalTo: self.rightAnchor).isActive = true
self.addSubview(eventTitle)
eventTitle.leftAnchor.constraint(equalTo: self.leftAnchor).isActive = true
eventTitle.rightAnchor.constraint(equalTo: self.rightAnchor).isActive = true
eventTitle.topAnchor.constraint(equalTo: eventDate.bottomAnchor).isActive = true
self.addSubview(eventDesc)
eventDesc.leftAnchor.constraint(equalTo: self.leftAnchor).isActive = true
eventDesc.rightAnchor.constraint(equalTo: self.rightAnchor).isActive = true
eventDesc.topAnchor.constraint(equalTo: eventTitle.bottomAnchor).isActive = true
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
Here is my for list that displays these UIViews:
var i = 0
for data in self.eventViewData {
let view = eventView(frame: CGRect(x: 0, y: ( CGFloat(170 * i)), width: self.scrollView.frame.width - 20, height: CGFloat(150)))
view.center.x = self.scrollView.center.x
view.eventDate.text = data.date
view.eventTitle.text = data.title
view.eventDesc.text = data.description
self.scrollView.addSubview(view)
i += 1
}
I usually am using HTML div's and such so I'm having a hard time figuring out how to style these. Any information or links to tutorials on how to programmatically adjust constraints to the UILabels in my eventViews are also appreciated.

Answer 1

How to calculate the desired height seems to be the question. While there are a lot of ways to do this one approach would be something like this:
func heightForView(text:String, font:UIFont, width:CGFloat) -> CGFloat{
let label:UILabel = UILabel(frame: CGRectMake(0, 0, width, CGFloat.greatestFiniteMagnitude))
label.numberOfLines = 0
label.lineBreakMode = NSLineBreakMode.byWordWrapping
label.font = font
label.text = text
label.sizeToFit()
return label.frame.height
}
let font = UIFont(name: "Helvetica", size: 20.0)
var height = heightForView("This is just a load of text", font: font, width: 100.0)
// apply height to desired view
I prefer to put the heightForView function in an extension myself but it isn't required.

Answer 2

I assumed you're using table view, why not do dynamic height? Good reference https://www.raywenderlich.com/1067-self-sizing-table-view-cells
In essense, you use auto layout to define your top and bottom constraint accordingly for every element in your cell, and your table view delegation/data source method for heightforrow and estimatedheightforrow, return UITableViewAutomaticDimension