Hide and Expand UITableView Sections - ios

Question

I am trying to implement a feature where if a user clicks on one of the items in my UICollectionView (that is embedded within a UITableViewCell) it causes another section to appear in the UITableView (below the UICollectionView) with information about that item. I'm having problems with the height of the section that is to appear when clicked. If I set it to 0 initially in heightForRowAtIndexPath there doesn't seem to be a way to alter the cells height later on. I tried giving the cell an initial height then hiding it with cell.hidden but that still leaves the section visible. Maybe there is an alternative way to do this, but after a lot of googling i'm coming up short.
override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
if indexPath.section == 3 {
return 90
}
else if indexPath.section == 1 {
return 185
}
else if indexPath.section == 2 {
return 155
}
else if indexPath.section == 4 {
return 100
}
return UITableViewAutomaticDimension
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
...
}
else if indexPath.section == 3 {
let cell = tableView.dequeueReusableCellWithIdentifier("weeklyCell", forIndexPath: indexPath) as! WxTableViewCell
cell.selectionStyle = UITableViewCellSelectionStyle.None
cell.forecastCollectionView.delegate = self
cell.forecastCollectionView.dataSource = self
cell.forecastCollectionView.reloadData()
cell.forecastCollectionView.tag = indexPath.row
cell.forecastCollectionView.showsHorizontalScrollIndicator = false
return cell
}
else if indexPath.section == 4 {
let cell = tableView.dequeueReusableCellWithIdentifier("dailyInformation", forIndexPath: indexPath) as! WxTableViewCell
cell.hidden = true
cell.contentView.hidden = true
return cell
}
...
}
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
let index = NSIndexPath(forRow: 0, inSection: 3)
let myindex = NSIndexPath(forRow: 0, inSection: 4)
var myTable = self.tableView
var lastCell = myTable.cellForRowAtIndexPath(index)
var dailyCell = myTable.cellForRowAtIndexPath(myindex)
var myView = UIView(frame: CGRectMake(20, 0, lastCell!.frame.width, lastCell!.frame.height))
dailyCell.frame.size = myView.frame.size
}

Answer 1

Never use indexPath numbers directly to address cells and sections in a switch/case. It's hard to handle when you want add/remove a row/section in the middle. Instead create an enum which have all sections and use an array that contains sections to be shown. You can have cell or section properties like cell identifiers or height in that enum.
enum FileDetailsCell: Printable {
case FileName, Location, Size
var description: String {
switch self {
case .FileName: return "noname"
case .Location: return"Location"
case .Size: return "Size"
}
}
var defaultValue: String {
switch self {
case .Location: return "/"
case .Size: return "Unknown"
default: return ""
}
}
var cellIdentifier: String {
switch self {
case .FileName: return "fileNameCell"
default: return "detailCell"
}
}
}
Here I use description for Cell title. defaultValue for initial value of cell and cellIdentifier is obvious for which purpose.
Then define an array which contains active cells:
var cellsArray: [FileDetailsCell] = [.FileName, .Size]
you can modify this array when you want change visible cells. Now, Location cell is hidden but you can make it visible later only by appending ".Location" to this array and reload tableView.
For tableview delegate:
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1;
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return cellsArray.count;
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cellInfo = cellsArray[indexPath.row]
let cell = tableView.dequeueReusableCellWithIdentifier(cellInfo.cellIdentifier, forIndexPath: indexPath) as! UITableViewCell
switch cellInfo {
case .FileName:
cell.textLabel?.text = item.fileName;
case .Location:
cell.textLabel?.text = cellInfo.description
cell.detailTextLabel?.attributedText = item.locationFormatted ?? cellInfo.defaultValue;
case .Size:
cell.textLabel?.text = cellInfo.description
cell.detailTextLabel!.text = item.size ?? cellInfo.defaultValue;
}
return cell
}
In this example I assumed sections are only one to avoid confusion. You can get similar approach for sections.