iOS/Swift: Dynamic UITableViewCell row height with embedded UITableView not working - ios

I have a UITableViewCell which contains a UICollectionView on top and a UITableView on the bottom. The idea is that a dynamic amount of cells will be created in the inner UITableView and the parent UITableViewCell that encloses the two subviews will increase its height proportionally.
I am trying to take advantage of the estimatedRowHeight + UITableViewAutomaticDimentionfeature of the UITableViewCell that will allow the cell height to increase dynamically. However, it is not working. It completely removes the embedded UITableView from view.
I have not made any constraints that limit the height of the enclosed UITableView, so I am not sure why it is not working.
Here is the implementation that attempts to make a dynamically sized UITableViewCell:
class OverviewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
override func viewDidLoad() {
super.viewDidLoad()
navigationItem.title = "Enclosed Table View Example"
}
func numberOfSections(in tableView: UITableView) -> Int {
return 3
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1
}
func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
return 325 // Height for inner table view with 1 cell
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return UITableViewAutomaticDimension
}
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return 45
}
func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
let cell = tableView.dequeueReusableCell(withIdentifier: "appHeaderCell") as! AppHeaderCell
return cell
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "appCell", for: indexPath) as! AppCell
return cell
}
}
My only guess is that the constraint bottom = Inner Table View.bottom + 7 is causing the issue, but the entire view falls apart when this constraint is removed.
What can I do to make the complex outer UITableViewCell dynamically adjust height based on the number of cells in the embedded UITableView?

Although it may seem like a good idea, the use of UITableViewAutomaticDimension in conjunction with estimatedRowHeight is not good to use in scenarios like this where we have general content inside table view cells. Making use of the heightForRowAt method, you can calculate the size of each individual cell before it centers the table.
Once we know how many cells will be in the inner table, you need to create an array whose elements correspond to the number inner cells that will ultimately determine the height of the outer cell, as all other content is constant.
let cellListFromData: [CGFloat] = [3, 1, 4]
This array will give us the number of sections in our outer table view:
func numberOfSections(in tableView: UITableView) -> Int {
return cellListFromData.count
}
We will convert each element in this array to a cell height in the following way:
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
let prototypeCell = tableView.dequeueReusableCell(withIdentifier: "appCell") as! AppCell
let baseHeight = betweenCellSpacing + prototypeCell.innerCollectionView.contentSize.height + prototypeCell.innerTableView.sectionHeaderHeight + outerTableView.sectionHeaderHeight
let dynamicHeight = prototypeCell.innerTableView.contentSize.height - prototypeCell.innerTableView.sectionHeaderHeight
return baseHeight + (dynamicHeight * cellListFromData[indexPath.section])
}
That is, inside of the heightForRowAt method, we dequeue a prototype cell that will not be used in the resulting view (as dequeueReusableCell is not called inside cellForRowAt in this case). We use this prototype cell to extract information about what is constant and what is dynamic about the cell's content. The baseHeight is the accumulated height of all the constant elements of the cell (plus the between-cell spacing) and the dynamicHeight is the height of an inner UITableViewCell. The height of each cell then becomes baseHeight + dynamicHeight * cellListFromData[indexPath.section].
Next, we add a numberOfCells variable to the class for the custom cell and set this in the cellForRowAt method in the main table view:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "appCell", for: indexPath) as! AppCell
cell.numberOfCells = Int(cellListFromData[indexPath.section])
cell.innerTableView.reloadData()
return cell
}
numberOfCells is set with the same cellListFromData that we used to get the height of the cell. Also, it is critical to call reloadData() on the inner table view after setting its number of cells so that we see that update in the UI.
Here is the full code:
class OverviewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
#IBOutlet weak var outerTableView: UITableView!
let cellSpacing: CGFloat = 25
let data: [CGFloat] = [3, 1, 4]
override func viewDidLoad() {
super.viewDidLoad()
}
func numberOfSections(in tableView: UITableView) -> Int {
return data.count
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
let prototypeCell = tableView.dequeueReusableCell(withIdentifier: "appCell") as! AppCell
let baseHeight = cellSpacing + prototypeCell.innerCollectionView.contentSize.height + prototypeCell.innerTableView.sectionHeaderHeight + outerTableView.sectionHeaderHeight
let dynamicHeight = prototypeCell.innerTableView.contentSize.height - prototypeCell.innerTableView.sectionHeaderHeight
return baseHeight + (dynamicHeight * data[indexPath.section])
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "appCell", for: indexPath) as! AppCell
cell.numberOfCells = Int(data[indexPath.section])
cell.innerTableView.reloadData()
return cell
}
}
class AppCell: UITableViewCell, UITableViewDataSource, UITableViewDelegate {
#IBOutlet weak var innerCollectionView: UICollectionView!
#IBOutlet weak var innerTableView: UITableView!
var numberOfCells: Int = 0
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return numberOfCells
}
func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
let cell = tableView.dequeueReusableCell(withIdentifier: "featureHeaderCell") as! BuildHeaderCell
return cell
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "innerCell", for: indexPath) as! InnerCell
return cell
}
}
Methods relating to configuring the inner collection view is not included here as it is not related to the problem.

Related

UITableView cells not displaying all data

Populating the UITableView first from JSON file. Everything seems to be loading and there are no crashes but the table cells do not contain all of the data. They are cut off at the bottom.
HeroViewController
class HeroViewController: UIViewController, UITableViewDataSource, UITableViewDelegate, WCSessionDelegate {
// code
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return messageObject.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let tableCell : HeroTableViewCell = tableView.dequeueReusableCell(withIdentifier: "MessageCell") as? HeroTableViewCell ?? HeroTableViewCell(style: UITableViewCell.CellStyle.default, reuseIdentifier: "MessageCell")
let row = indexPath.row
let rowObj = messageObject[row]
tableCell.one.text = rowObj.title as String?
tableCell.two.text = rowObj.speaker as String?
tableCell.three.text = rowObj.from as String?
tableCell.four.text = rowObj.to as String?
return tableCell
}
}
your cells don't seem to have enough height. you can set it by over-ridding this method:
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 100; //return the cell height you desire
}

Custom cell don't appear in tableView

My custom cell don't appear in my table View and I didn't find anything to answer that.
Here's my storyboard that contains the TableView :
This is my listController :
extension MatchListViewController: UITableViewDataSource {
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return matchArray.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
guard let cell = tableView.dequeueReusableCell(withIdentifier: "MatchCell", for: indexPath) as? MatchTableViewCell else {
return UITableViewCell()
}
let match = matchArray[indexPath.row]
cell.configure(nomDuMatch: match.matchName, scoreFinal: match.finalScore)
return cell
}
}
(I've configured the dataSourceDelegate by storyboard)
the customCell identifier is correct and I really don't understand why nothing appears at launch..
Feel free to ask me more pictures / infos !
Edit :
This is the result :
You need to implement
func tableView(_ tableView: UITableView,
heightForRowAt indexPath: IndexPath) -> CGFloat {
return 100 // or any value
}
or use automatic cell and set constraints properly in IB as it seems that you have a constraints problem and set this in viewDidLoad
tableView.estimatedRowHeight = 100
tableView.rowHeight = UITableViewAutomaticDimension

Get the row height in the HeightForRowAt

I have a UITableViewController with a custom UITableViewCell. Each cell has 2 labels. When the cell is selected it expands to a fixed value, I do it via tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat . I also have set the rowHeight = UITableViewAutomaticDimension , as some cells have to display multiple lines of text.
What I want to achieve is when a cell needs to be expanded I want to add 50 points to its current height. So here's the question, how can I get current height of the cell, when the rowHeight = UITableViewAutomaticDimension is set?
Here's my code for the fixed height for the selected state:
override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
if selectedIndexPath == indexPath {
return selectedHeight
}else{
return tableView.estimatedRowHeight
}
}
EDIT: I also need to change it after that, by adding some variable to it.
Building on HamzaLH's answer you might do something like this...
import UIKit
class TableViewController: UITableViewController {
var selectedRow: Int = 999 {
didSet {
tableView.beginUpdates()
tableView.endUpdates()
}
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 5
}
override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
if indexPath.row == selectedRow { //assign the selected row when touched
let thisCell = tableView.cellForRow(at: indexPath)
if let thisHeight = thisCell?.bounds.height {
return thisHeight + 50
}
}
return 60 //return a default value in case the cell height is not available
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
selectedRow = indexPath.row
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "reuseIdentifier", for: indexPath)
cell.detailTextLabel?.text = "test"
return cell
}
}
I'm animating the expansion of the height with a didSet when a the selectedRow is altered.
Also, don't forget you may still need to connect your dataSource and delegate by dragging the outlets in Interface Builder to your View Controller in the storyboard. After that you still need to add this to ViewDidLoad in your ViewController's swift file.
tableView.delegate = self
tableView.dataSource = self
I also have an Outlet declared for the tableView like below, and connected in Interface Builder storyboard.
#IBOutlet weak var tableView: UITableView!
You need to get the cell using cellForRow and then get the height of the cell.
let cell = tableView.cellForRow(at: indexPath)
let height = cell.bounds.height

How to make footer UITableViewCell not static?

I have 2 prototype dynamic cell called InvoiceDetailCell and TotalCostFooterCell. I make the TotalCostFooterCell as the Footer Cell View using viewForFooterInSection. here is the code I use to assign data to the UITableView
here is my code in UITableViewController.
extension InvoiceDetailVC : UITableViewDataSource {
// MARK: - UI Table View Datasource Methods
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return invoiceElements.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "InvoiceDetailCell", for: indexPath) as! InvoiceDetailCell
cell.invoiceElementData = invoiceElements[indexPath.row]
return cell
}
}
extension InvoiceDetailVC : UITableViewDelegate {
// MARK: - UI Table View Delegate Methods
func tableView(_ tableView: UITableView, viewForFooterInSection section: Int) -> UIView? {
let cell = tableView.dequeueReusableCell(withIdentifier: "invoiceDetailFooterCell") as! TotalCostFooterCell
cell.totalCost = singleInvoiceData.unpaid
return cell
}
}
but the result is not as I expected, I mean the footer cell is stick / not move. here is the .gif file : http://g.recordit.co/vf0iwCfEWX.gif
you can see the total cost (red colour) is sticky / static, I want that footer cell can be scrolled and always on the bottom. or do I have the wrong to implement what I want?
make the table style to grouped
you can do it in two ways:
In viewDidLoad() do tableView.style = .grouped
Select the table view from storyboard and in the attribute inspector change the style to grouped. Please refer attached image.
Can't you just make it as the last row of the table view? I mean, the view is already a table view cell, so it makes sense to use it as the last row.
First change this:
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return invoiceElements.count + 1
}
And then for cellForRowAt:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if indexPath.row == invoiceElements.count {
let cell = tableView.dequeueReusableCell(withIdentifier: "invoiceDetailFooterCell") as! TotalCostFooterCell
cell.totalCost = singleInvoiceData.unpaid
return cell
}
let cell = tableView.dequeueReusableCell(withIdentifier: "InvoiceDetailCell", for: indexPath) as! InvoiceDetailCell
cell.invoiceElementData = invoiceElements[indexPath.row]
return cell
}
You can set your custom view that you want by:
tableView.tableFooterView = yourCustomView
Or you can put everything inside your xib/storyboard like this:

how to set cell row height in table view if it exceed its indexpath.row?

I am trying to make a FAQ view controller using table view, I need little bit fix in the UI. here is the display of my FAQ VC right now
(please ignore the red line)
as we can see, basically there are 2 row height, 80 & 160. if the row is tapped (selected) the row height will expand from 80 (yellow line) to 160 (purple line).
I want to make the row height under the last question is still 80 not 160. I have tried but I can't set the row below the last question. here is my code I use
class FAQVC: UIViewController {
#IBOutlet weak var retryButton: DesignableButton!
#IBOutlet weak var tableView: UITableView!
var FAQs = [FAQ]()
var selectedIndexs: [IndexPath: Bool] = [:]
override func viewDidLoad() {
super.viewDidLoad()
getFAQData()
}
}
extension FAQVC : UITableViewDelegate, UITableViewDataSource {
// MARK: - Table View Delegate and Datasource
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return FAQs.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "FAQCell") as! FAQCell
cell.FAQData = FAQs[indexPath.row]
return cell
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
if self.cellIsSelected(indexPath: indexPath) {
return 160
} else {
return 80
}
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
let isSelected = !self.cellIsSelected(indexPath: indexPath)
selectedIndexs[indexPath] = isSelected
tableView.beginUpdates()
tableView.endUpdates()
}
func cellIsSelected(indexPath: IndexPath) -> Bool {
if let number = selectedIndexs[indexPath] {
return number
} else {
return false
}
}
}
Please put this code in your viewDidLoad() method of your controller.
YOUR_TABLE_VIEW.tableFooterView = UIView(frame: .zero)
this will remove extra separators.
Quickest way to do this would be to add an extra empty cell at the end with row height 80
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return FAQs.count + 1
}
Also, make sure you make a change to cellForRowAt method to accommodate this :
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if indexPath.row < FAQs.count {
let cell = tableView.dequeueReusableCell(withIdentifier: "FAQCell") as! FAQCell
cell.FAQData = FAQs[indexPath.row]
return cell
}
return UITableViewCell()
}
EDIT :
I just read that you don't really require separators after the last cell. In that case look here https://spin.atomicobject.com/2017/01/02/remove-extra-separator-lines-uitableview/

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