This is a bit of a continuation of this question, but basically I am trying to figure out how I can return no cell if the result of a function is nil.
This is my code:
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCellWithIdentifier("rideCell", forIndexPath: indexPath) as! RideCell
var ride = DataManager.sharedInstance.getRideByName(favouritesArray[indexPath.row] as! String)
println(ride)
if ride != nil {
cell.rideNameLabel.text = ride!.name
var dateFormat = NSDateFormatter()
dateFormat.dateFormat = "h:mm a"
cell.updatedLabel.text = dateFormat.stringFromDate(ride!.updated!)
if ride!.waitTime! == "Closed" {
cell.waitTimeLabel.text = ride!.waitTime!
} else {
cell.waitTimeLabel.text = "\(ride!.waitTime!)m"
}
}
return cell
}
So at the moment everything works, however wherever ride does equal nil, I just get the prototype cell returned, whereas I would like it to return nothing.
I have tried hiding or changing the height of these cells to nil, but it just seems like messy solution. Anyone know a better one?
Thanks.
determine the number of rows by implementing tableView(_ tableView: UITableView, numberOfRowsInSection section: Int)
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) {
if section == 0 {
return arrayName.count
}
return 0
}
I figured out a solution. As a few people mentioned, I had to figure out what to display before dealing with cellForRowAtIndexPath.
Basically I added some code to figure out which favourites could be found in the array and put it in viewWillAppear.
for index in 0...favouritesArray.count - 1 {
var ride = DataManager.sharedInstance.getRideByName(favouritesArray[index] as! String)
if ride != nil {
favouritesFound.append(ride!.name!)
println(favouritesFound)
}
}
Works perfectly now! Thanks everyone.
It is assumed that you always know how many valid rows do you have and you publish this number by implementing UITableViewDataSource's tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int method. So if at some moment number of rows changes you should call UITableView.reloadData not to try to hide excess rows.
To get an array of valid rides try something like:
var newArray:[String] = []
for str in favouritesArray where DataManager.sharedInstance.getRideByName(str!) != nil
{
newArray += [str]
}
Related
Ok first thing first, what am I trying to do? Well I am trying to run something that is like a tag system where it filters out the data with the post by using a dictionary String, [String] type and displays it to the screen. I already figured this out on the console level, but I am stumped on how to do it with this which is kind of weird. I try and it returns nil inside the UI ,but works perfectly on the console level.
Simplified. I want the quick tags filtered array to show up in the tableview
I am repeating this again, console works perfect, but the UI gets wacky and returns nil or does nil. Ok here is the code.
Not 100% sure about this area causing problems ,but I displayed here just in case.
//this is the part where I add the stuff into the console
//and add the dictionary part.
#IBAction func ReplyAction(_ sender: UIButton) {
if !(TextFieldForComments.text?.isEmpty)! && TextFieldForComments.text != nil
{
CommentGlobals.shared.addToCommentSection(newElement: TextFieldForComments.text!)
let tagCheck = TextViewForComment.text
if !quickTags.FilteredComments.keys.contains(TextViewForComment.text){
quickTags.FilteredComments.updateValue(["\(String(describing: TextFieldForComments.text))"], forKey: tagCheck!)
print("Hey here is the dictinary you wanted \(quickTags.FilteredComments)")
}
else {
quickTags.FilteredComments[tagCheck!]?.append(CommentGlobals.shared.commentSection.last!)
print("Hey here is the dictinary you wanted wo wo \(quickTags.FilteredComments)")
}
TextFieldForComments.text = ""
//this line of code is important or it
//won't insert the table view right.
CommentFeed.insertRows(at: [IndexPath(row: CommentGlobals.shared.commentSection.count-1, section: 0)], with: .automatic)
}
Here is the problem area
//this is the problem area
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let ceal = CommentFeed.dequeueReusableCell(withIdentifier: "commentFeed", for: indexPath)
//guard let selectedDictionary = quickTags.FilteredComments["\(TextViewForComment)"] else {return ceal}
//this is the part that works, but noted it out for reference
//this doesn't work for what I am trying to do because
//I don't want to display the comments of every view
//ceal.textLabel?.text = "\(CommentGlobals.shared.commentSection[indexPath.row])"
//this is failure. I also tried another way ,but it just printed nil
//on to the UI
//ceal.textLabel?.text = "\(selectedDictionary[indexPath.row])"
return ceal
}
Ok if you need more information, please let me know.
Oh yea I can't say this enough it works on a console level perfectly, but not when I try to get it onto the UI.
I also stored the quick tags in a static array, and I stored the rest in a singleton
Here is the expected output (UI)
comment
comment
comment
the current output is like this(UI)
(it does nothing, runs nil, or crashes)
some other sources lead the thing to be like this
comment comment comment
all of them on the same line which is not what I want.
func numberOfSections(in tableView: UITableView) -> Int {
// #warning Incomplete implementation, return the number of sections
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
// return CommentGlobals.shared.commentSection.count
print(quickTags.FilteredComments.count)
return CommentGlobals.shared.commentSection.count
}
UITableViews do not contain their own data set, they take it from the dataSource. insertRows(at:, with:) is only for cell animation, and should be wrapped with begin/endUpdates().
class ViewController: UITableViewDataSource {
#IBAction func ReplyAction(_ sender: UIButton) {
// ...
CommentFeed.beginUpdates()
CommentFeed.insertRows(at: [IndexPath(row: CommentGlobals.shared.commentSection.count - 1, section: 0)], with: .automatic)
CommentFeed.endUpdates()
}
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return CommentGlobals.shared.commentSection.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "commentFeed", for: indexPath)
cell.textLabel?.text = CommentGlobals.shared.commentSection[indexPath.row]
return cell
}
}
Edit: Note that your data set's number of rows and sections MUST match the expected results at the end of the animation, or you will get an exception when calling endUpdates().
I use enum for building my UITableView cells:
enum VAXSections: Int
{
case Segmented = 0
case Scrollable = 1
case ScheduledMode = 2
case ScheduledFooter = 3
case SilentHours = 4
case SilentFooter = 5
}
here how I use it:
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
{
guard let unwrappedSection = VAXSections(rawValue: indexPath.section) else {
showFatalError()
return nil
}
Few problem here I want to guard my section value if it's out of max case in my enum. For example if indexPath.section will be bigger then 5 then app should fall back. But if you see we can't return nil here, as cellForRowAtIndexPath has to return cell in any case.
I can solve problem by providing more readability with replacing showFatalError() fiction with:
guard let unwrappedSection = VAXSections(rawValue: indexPath.section) else {
fatalError("Check \(String(VAXUnitDashboardViewController.self)) UITableView datasource or check \(String(VAXSections.self)) enum.")
}
then I don't need to return any value. But then I turned in another problem. As I need to specify at least 3 datasource functions of my UITableView I need to duplicate fatal error which I wish to replace with one function that do the same all the time:
fatalError("Check \(String(VAXUnitDashboardViewController.self)) UITableView datasource or check \(String(VAXSections.self)) enum.")
enum VAXItems: String {
case Item1
case Item2
case Item3
}
enum VAXSections: String {
case Segmented
case Scrollable
case ScheduledMode
case ScheduledFooter
case SilentHours
case SilentFooter
}
struct VAXModel {
var type: VAXSections
var items: [VAXItems]
}
Then on your UIViewController you can have:
class ViewController: UIViewController {
private var model: [VAXModel] = []
override func viewDidLoad() {
super.viewDidLoad()
model = [
VAXModel(type: .ScheduledMode, items: [.Item1, .Item2, .Item3]),
VAXModel(type: .SilentFooter, items: [.Item1])
]
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return model.count
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return model[section].items.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier(String(UITableViewCell), forIndexPath: indexPath)
let item = model[indexPath.section].items[indexPath.row]
switch item {
case .Item1: cell.textLabel?.text = item.rawValue
case .Item2: // Config
case .Item3: // Config
}
return cell
}
}
I don't think you need to have it in 3 places actually. Assuming that the 3 data source methods you are talking about are :
func numberOfSectionsInTableView(_ tableView: UITableView) -> Int
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
func tableView(_ tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
You actually need to have your guard in only one of them.
numberOfSectionsInTableView is the first method that will be called, so if you fail here, the other two methods won't be called. If the number of sections is based on some calculations, you can also cut off the value, something like this : if calculatedNumberOfSections > 6 { return 6 } else { return calculatedNumberOfSections } (remember that section numbering is 0 based)
numberOfRowsInSection - if you guard here you have two options - either fail with fatalError or (better in my opinion) - return 0 if a section number higher than 5 gets passed. Returning 0 will result in cellForRowAtIndexPath not being called with that section.
cellForRowAtIndexPath - you already got this :)
I am trying to create a contacts page where you can see all your contacts with a friend request cell showing up when you receive a friend request, but not there when you do not have any. At the moment, both custom cells work fine. The issue I have is that the contactRequestTableViewCell overlaps the first cell of the contactListTableViewCell.
I have researched other questions about two custom tableviewcells and none are quite having the same issues that I am facing.
Here is my executing code at the moment, I am returning 2 sections in the table view.
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! ContactListTableViewCell
let requestCell = tableView.dequeueReusableCellWithIdentifier("requestCell", forIndexPath: indexPath) as! ContactRequestsTableViewCell
let user = OneRoster.userFromRosterAtIndexPath(indexPath: indexPath)
if (amountOfBuddyRequests > 0) {
if (indexPath.section == 0) {
requestCell.hidden = false
cell.hidden = false
requestCell.friendRequestLabel.text = "test"
} else if (indexPath.section >= 1) {
cell.contactNameLabel!.text = user.displayName;
cell.contactHandleLabel!.text = "# " + beautifyJID(user.jidStr)
cell.contactHandleLabel!.textColor = UIColor.grayColor()
OneChat.sharedInstance.configurePhotoForImageView(cell.imageView!, user: user)
}
return cell;
}
else { // if buddy requests == 0
requestCell.hidden = true
cell.contactNameLabel!.text = user.displayName;
cell.contactHandleLabel!.text = "# " + beautifyJID(user.jidStr)
cell.contactHandleLabel!.textColor = UIColor.grayColor()
print ("This is how many unreadMessages it has \(user.unreadMessages)")
// If there is unread messages for a person highlight it blue
// However this feature isn't working right now due to unreadMessages bug
if user.unreadMessages.intValue > 0 {
cell.backgroundColor = .blueColor()
} else {
cell.backgroundColor = .whiteColor()
}
OneChat.sharedInstance.configurePhotoForCell(cell, user: user)
return cell;
}
}
This is the current output that I have right now, my cells that have "test" are covering up other contactListTableViewCells.
The function tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell should always return one and the only one TableViewCell you want at indexPath, so you don't want to always return cell of type ContactListTableViewCell.
According to documentation, the cellForRowAtIndexPath tableView method asks for the cell at the indexPath, which means literally there can only be one cell at certain row of a certain section, so returning two cells is not an option.
I suggest you use two arrays to store the requests and contacts information. For example, you have arrays requests and contacts. Then you can tell the tableView how many rows you want:
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// Return the number of rows in the section.
return requests.count + contacts.count
}
and then in cellForRowAtIndexpath you do something like:
override func tableView(_ tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
if indexPath.row < requests.count {
// return a request cell
}
else {
// return a contact cell
}
}
I'm only using one tableView section here. If you still want two sections you can simply return 2 in numberOfSections function and add if statements in cellForRowAtIndexPath for indexPath.section.
Hope this helps.
It turns out that the issue was dealing with the data sources. My data sources were not pointing to the correct tableviewcell. This resulted in them pointing to an incorrect cell. This issue was fixed by remaking the data sources system that was in place. This issue will not affect most as the data sources will point to the correct tableviewcell by default.
Contrary to what another poster said, you can in fact display two or more custom cells in a single table. This is how I fixed the tableView display issues:
var friendRequests = ["FriendRequest1", "FriendRequest2"]
var contacts = ["User1","User2","User3","User4"]
var amountOfBuddyRequests = 1
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
if (amountOfBuddyRequests > 0) {
return 2
}
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if (amountOfBuddyRequests > 0) {
if (section == 0) {
return friendRequests.count
}
}
return contacts.count
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
if (amountOfBuddyRequests > 0) {
if (indexPath.section == 0) {
let requestCell = tableView.dequeueReusableCellWithIdentifier("requestCell") as! ContactRequestsTableViewCell
requestCell.friendRequestLabel.text = friendRequests[indexPath.row]
requestCell.onButtonTapped = {
self.friendRequests.removeAtIndex(indexPath.row)
self.tableView.reloadData()
}
requestCell.addButtonTapped = {
self.addUser(self.friendRequests[indexPath.row])
self.friendRequests.removeAtIndex(indexPath.row)
self.tableView.reloadData()
}
return requestCell
}
}
let friendCell = tableView.dequeueReusableCellWithIdentifier("FriendCell") as! ContactListTableViewCell
friendCell.contactNameLabel.text = contacts[indexPath.row]
return friendCell
}
I know that I can query for, lets say, users that have emailVerified equal to true and present them into a tableView, but I was having trouble getting a single Parse object of type array into a tableView. I couldn't find anything online about this specific problem, but after putting a few answers together, I got it to work my answer is below for those also having trouble with this.
Here is what I found based on my question. I have an object in Parse called "my_classes" that is of type array. I want to get the items from the array into a tableView.
1) Create a variable: var myClassesResults : NSMutableArray = []
2) Create the function or place the code where necessary:
func getUserData() {
if PFUser.currentUser()!.objectForKey("my_classes") != nil {
let classes = PFUser.currentUser()!.objectForKey("my_classes")!
myClassesResults = classes as! NSMutableArray
self.noClasses = false
self.tableView.reloadData()
} else {
self.noClasses = true
self.tableView.reloadData()
}
}
3) tableView functions:
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.myClassesResults.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath)
cell.textLabel!.text = myClassesResults[indexPath.row] as? String
return cell
}
I want to show 25 of the songs I have in my library. This is my code:
var allSongsArray: [MPMediaItem] = []
let songsQuery = MPMediaQuery.songsQuery()
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 25 //allSongsArray.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell")
let items = allSongsArray[indexPath.row]
cell?.textLabel?.text = items.title
cell?.detailTextLabel?.text = items.artist
cell?.imageView?.image = items.artwork?.imageWithSize(imageSize)
return cell!
}
When I run this, it crashes, because:
fatal error: Index out of range
I tried to change the numberOfRowsInSection to allSongsArray.count, but it ends up with the same error.
You should return allSongsArray.count and to avoid being returned empty cells use yourTableView.reloadData after you fill your allSongsArray.
When you first create the array it is empty. Hence, it will give you out of bound error.
Try to return the count of the songs array instead.
1st you need to get the data into the array and then update the table view.
Here is a sample code:
#IBAction private func refresh(sender: UIRefreshControl?) {
if myArray.count > 0 {
self.tableView.reloadData()
sender?.endRefreshing()
} else {
sender?.endRefreshing()
}
}
In case your app crashes in
let items = allSongsArray[indexPath.row]
as you check if the allSongsArray.count, u can safe guard it by making sure that the [indexPath.row] doesn't exceed your array count. so u can write a simple if condition as;
if allSongsArray.count > 0 && indexPath.row < allSongsArray.count {
//Do the needful
}
Please return the actual array count instead of static
return allsongsarray.count
For folks looking for a solution to swiping on a filtered list, you need to provide the section as well as the row or xcode throws this error.
func swipe(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let myRow = filteredList[indexPath.section].items[indexPath.row]
}
not
func swipe(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let myRow = filteredList[indexPath.row]
}