i am building a table view with custom cells. in time the cell should contain various labels, but for the moment, there is only one label (serves as a test).
when I run the app, everything looks ok, however the cell.textLabel.text does not appear in the app. Each cell is blank.
for the data displayed, I built a model in a separate file visible here :
import Foundation
class CountryDataModel {
let countryName: String
let casesData: String
let deathsData: String
let recoveriesData: String
init(country: String, cases: String, deaths: String, recoveries: String) {
countryName = country
casesData = cases
deathsData = deaths
recoveriesData = recoveries
}
}
here is the view controller for the table view :
import UIKit
class PaysTableViewController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Uncomment the following line to preserve selection between presentations
listOfCountryAndRelatedData()
}
//MARK: - Relevant data
var countryList = [CountryDataModel]()
// MARK: - Table view data source
override func numberOfSections(in tableView: UITableView) -> Int {
// #warning Incomplete implementation, return the number of sections
return 0
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
return countryList.count
}
//
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
// Configure the cell...
let indexPath = countryList[indexPath.row]
cell.textLabel?.text = indexPath.countryName
return cell
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
print("success")
}
func listOfCountryAndRelatedData() {
let country1 = CountryDataModel(country: "Algeria", cases: "0", deaths: "0", recoveries: "0")
countryList.append(country1)
let country2 = CountryDataModel(country: "Bahamas", cases: "0", deaths: "0", recoveries: "0")
countryList.append(country2)
let country3 = CountryDataModel(country: "Seychelles", cases: "0", deaths: "0", recoveries: "0")
countryList.append(country3)
}
}
set the numberOfSections as 1
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
Then refresh the your Table after add data to your countryList
func listOfCountryAndRelatedData() {
//add your data to arry
self.tableView.reloadData()
}
Related
I have a function which prints all the objects in my realm table to a table view. I would like to be able to filter these objects by their "muscle" property.
Here's my DB helper functions:
func getMusclesCount()-> Int {
let storedExercise = realm.objects(StoredExercise.self)
return storedExercise.count
}
//MARK:- getAllMuscelsNames
func getAllMusclesNames()-> [String] {
var musclesName = [String]()
let storedExercise = realm.objects(StoredExercise.self)
for exercise in storedExercise {
print("Muscle = \(exercise.muscle)")
musclesName.append(exercise.name)
}
return musclesName
}
Here's my Table View Controller class :
class TableViewController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return DBHelper.shared.getAllMusclesNames().count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
if cell == nil {
cell = UITableViewCell(style: .default, reuseIdentifier: "cell")
}
let muscle = DBHelper.shared.getAllMusclesNames()[indexPath.row]
cell.textLabel?.text = muscle
return cell
}
I've tried adding .Filter to 'let storedExercise' but I'm not sure how to set it up correctly. Any assitance would be greatly appreciated, thanks.
If your StoredExercise model looks like this
class StoredExercise: Object {
#objc dynamic var muscle = ""
}
then to get all of the exercises that are for the biceps, it's this
let bicepResults = realm.objects(StoredExercise.self).filter("muscle == 'biceps'")
This is my code:-
Model:-
class QuestionListModel: NSObject {
var optionsModelArray:[OptionsModel] = []
var question:String!
init(dictionary :JSONDictionary) {
guard let question = dictionary["question"] as? String
else {
return
}
if let options = dictionary["options"] as? [String]{
print(options)
print(options)
for values in options{
print(values)
let optionmodel = NH_OptionsModel(values: values)
self.optionsModelArray.append(optionmodel)
}
}
self.question = question
// print(self.dataListArray33)
}
}
optionModel:-
class OptionsModel: NSObject {
var values:String?
init(values:String) {
self.values = values
print( self.values)
}
}
in viewmodel:-
var questionsModelArray:Array<NH_QuestionListModel>? = []
init(withdatasource newDatasourceModel:NH_QuestionDataSourceModel) {
datasourceModel = newDatasourceModel
print(datasourceModel.dataListArray?.count)
self.questionsModelArray = datasourceModel.dataListArray
print(self.questionsModelArray)
print(datasourceModel.dataListArray)
}
func numberOfSections() -> Int{
return (self.questionsModelArray?.count)!
}
func titleForHeaderInSection(atindexPath indexPath: IndexPath) -> QuestionListModel {
return self.questionsModelArray![indexPath.row]
}
func numberOfRowsInSection(indexPath:IndexPath) -> Int {
if let questionModel = self.questionsModelArray?[indexPath.section]{
return questionModel.optionsModelArray.count
}
else{
return 0
}
}
func datafordisplay(atindex indexPath: IndexPath) -> OptionsModel{
let questionModel = self.questionsModelArray?[indexPath.section]
return questionModel!.optionsModelArray[indexPath.row]
}
And in ViewController:-
func numberOfSections(in tableView: UITableView) -> Int {
return questionViewModel.numberOfSections()
}
func tableView(_ tableView: UITableView, viewForHeaderInSection section: IndexPath) -> UIView? {
// let headercell = Bundle.main.loadNibNamed("HeaderCell", owner: self, options: nil)?.first as! NH_questionheader
let identifier = "HeaderCell"
var headercell: NH_questionheader! = tableView.dequeueReusableCell(withIdentifier: identifier) as? NH_questionheader
if headercell == nil {
tableView.register(UINib(nibName: "NH_questionheader", bundle: nil), forCellReuseIdentifier: identifier)
headercell = tableView.dequeueReusableCell(withIdentifier: identifier) as? NH_questionheader
}
headercell.setReviewData(reviews:questionViewModel.titleForHeaderInSection(atindexPath:section))
return headercell
}
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return 150
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: IndexPath) -> Int {
return questionViewModel.numberOfRowsInSection(indexPath: section)
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let identifier = "Cell"
var cell: CellTableViewCell! = tableView.dequeueReusableCell(withIdentifier: identifier) as? CellTableViewCell
if cell == nil {
tableView.register(UINib(nibName: "CellTableViewCell", bundle: nil), forCellReuseIdentifier: identifier)
cell = tableView.dequeueReusableCell(withIdentifier: identifier) as? CellTableViewCell
}
cell.contentView.backgroundColor = UIColor.clear
cell.setOptions(Options1: questionViewModel.datafordisplay(atindex: indexPath))
print("Section \(indexPath.section), Row : \(indexPath.row)")
return cell
}
my json file:-
{
"data":[
{
"question": "Gender",
"options": ["Male","Female"]
},
{
"question": "How old are you",
"options": ["Under 18","Age 18 to 24","Age 25 to 40","Age 41 to 60","Above 60"]
}, {
"question": "I am filling the Questionnaire for?",
"options": ["Myself","Mychild","Partner","Others"]
}
]
}
This is my data .So i need to display the questions in header and options in the cell for index .But showing as error as UITableview has need to conform the protocol UITableviewDataSource.
Also showing error as Index out of range.
How to do.....
I think you are not assign a datasource to your view controller. So please assign it in your ViewDidLoad of your view controller
override func viewDidLoad() {
super.viewDidLoad()
self.yourtableview.delegate = self
self.yourtableview.dataSource = self
// Do any additional setup after loading the view.
}
This error usually occurs when you fail to implement the required methods of a protocol. In this case the methods would be :
cellForRowAt
numberOfRowsInSection
Since you already have them implemented in your view controller chances are that you might have failed to set the datasource for the table view.
Refer to this
https://developer.apple.com/documentation/uikit/uitableviewdatasource
your view controller cannot find the data source and delegate for the table view. make sure you have assigned the data source and delegate
self.yourtableview.delegate = self
self.yourtableview.dataSource = self
and also make sure that your controller also inherit the UITableViewDelegate and UITableViewDataSource like this
class ViewController: UIViewController,UITableViewDelegate,UITableViewDataSource
To achieve what you want, you should set your VC as the delegate and datasource of your table.
Option 1, do it dynamically:
override func viewDidLoad() {
super.viewDidLoad()
self.tableView.delegate = self
self.tableView.dataSource = self
}
Option 2, from your storyboard (example below):
After this, you should use the following datasource functions of UITableView:
// return number of questions
func numberOfSections(in tableView: UITableView) -> Int
// return number of options per question (indicated by section)
func tableView(UITableView, numberOfRowsInSection: Int) -> Int
You haven't correctly declared the numberOfRowsInSection function; section is an Int, not an IndexPath. As a result you have not implemented the mandatory functions of UITableViewDataSource.
You want:
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return questionViewModel.numberOfRowsIn(section: section)
}
With an appropriate change in your view model:
func numberOfRowsIn(section:Int) -> Int {
return self.questionsModelArray?[section].optionsModelArray.count ?? 0
}
I would also suggest that you review your use of implicitly unwrapped optionals and force unwrapping; this is just asking for crashes.
For example, there is no reason for the question property of QuestionListModel to be String!; just declare it as String and make your initialiser failable. Better yet, use Codable to create your model from JSON and get rid of all of that code.
You can eliminate the force unwrapping in numberOfSections too:
func numberOfSections() -> Int {
return self.questionsModelArray?.count ?? 0
}
I would also suggest you make QuestionListModel a struct rather than an NSObject subclass.
If I were you I would re-factor to remove the view model, it is adding unnecessary complexity in this case, and use Codable for your JSON deserialisation:
struct Questions: Codable {
enum CodingKeys: String, CodingKey {
case questions = "data"
}
var questions: [Question]
}
struct Question: Codable {
var question: String
var options: [String]
}
Your view controller then becomes much simpler:
class ViewController: UIViewController, UITableViewDatasource {
var questionData: Questions?
override func viewDidLoad() {
super.viewDidLoad()
tableView.register(UINib(nibName: "NH_questionheader", bundle: nil), forCellReuseIdentifier: "HeaderCell")
tableView.register(UINib(nibName: "CellTableViewCell", bundle: nil), forCellReuseIdentifier: "Cell")
// You don't show how you load your JSON, but assuming you have it in an instance of `Data` called `jsonData`:
do {
self.questionData = try JSONDecoder().decode(Questions.self, from: jsonData)
} catch {
print("Error decoding JSON: \(error.localizedDescription)")
}
}
func tableView(_ tableView: UITableView, viewForHeaderInSection section: IndexPath) -> UIView? {
let identifier = "HeaderCell"
guard let questionData = self.questionData,
let headercell = tableView.dequeueReusableCell(withIdentifier: identifier) as? NH_questionheader else {
return nil
}
headercell.label.text = questionData.questions[section].question
return headercell
}
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return 150
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.questionData?.questions[section].options.count ?? 0
}
func numberOfSections(in tableView: UITableView) -> Int {
return self.questionData?.questions.count ?? 0
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let identifier = "Cell"
// Note, I have used force unwrapping and a forced downcast here as if either of these lines fail you have a serious problem and crashing is the simplest way of finding it during development
let option = self.questionData!.questions[indexPath.section].options[indexPath.row]
let cell = tableView.dequeueReusableCell(withIdentifier: identifier, for: indexPath ) as! CellTableViewCell
cell.contentView.backgroundColor = .clear
cell.label.text = option
return cell
}
}
Once you have this basic approach working you can try and add a view model if you like.
I am trying to pass data from my Cheats struct into a new tableviewcontroller to populate the new table with the relevant info.
I have done research but am new to swift.
I do have experience in php but transferring my knowledge is proving quite difficult...
In my prepare for segue class i receive a few errors:
Definition conflicts with previous value:
var DataPass = CheatsArray[indexPath.row]
Cannot assign value type 'String' to '[String]':
DestViewController.CheatsArray = DataPass.name
Here is a copy of my current 3 files
Structs and arrays:
struct Game {
var name : String
var cheats : [Cheat]
}
struct Cheat {
var name : String
var code : String
var description : String
}
// Create Our Game Info And Cheats / Codes For Each Game!
//-------------------------------------------------------
let COD4 = Game(name: "Call Of Duty 4", cheats: [Cheat(name: "Cheat", code: "Code", description: "Description")])
let GTAV = Game(name: "Grand Theft Auto 5", cheats: [Cheat(name: "Cheat", code: "Code", description: "Description")])
// Place Our New Games Inside This Array!
//---------------------------------------
let ArrayOfGames = [COD4,GTAV]
GameListController:
import Foundation
import UIKit
class GamesListViewController: UITableViewController {
var CheatsArray = [Game]()
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return ArrayOfGames.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = self.tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath)
cell.textLabel?.text = ArrayOfGames[indexPath.row].name
return cell
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
let indexPath : NSIndexPath = self.tableView.indexPathForSelectedRow!
let DestViewController = segue.destinationViewController as! CheatsListViewController
let DataPass : Game
var DataPass = CheatsArray[indexPath.row]
DestViewController.CheatsArray = DataPass.name
}
}
CheatListController:
class CheatsListViewController: UITableViewController {
var CheatsArray = [String]()
override func viewDidLoad() {
super.viewDidLoad()
}
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return CheatsArray.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = self.tableView.dequeueReusableCellWithIdentifier("cell2", forIndexPath: indexPath)
cell.textLabel?.text = CheatsArray[indexPath.row]
return cell
}
}
The first error is because you defined DataPass twice, one row after another. You can't do that in the same scope. Change the name of one.
The second error is because you cannot assign value type 'String' to '[String]'. Just looking at CheatsArray and name variables, it's clear the first is an array and the second is most likely a string. You might want to append the name to the array.
I'm loading about 150 elements from an array of arrays of dictionaries (tasks) and I can get all of the data into my tableview but when I scroll its stupid slow. When I print out the information of one of my functions to the console, it looks like I am getting all of the data back every time I scroll. Is this something I am not loading well (i.e. asynchronously) or do I need to change my functions?
func querySections() -> [String] {
var sectionsArray = [String]()
for task in tasks {
let dueTimes = task.dueTime
sectionsArray.append(dueTimes)
}
let uniqueSectionsArray = Array(Set(sectionsArray.sort()))
// print(uniqueSectionsArray)
return uniqueSectionsArray
}
func queryDueTimes(section:Int) -> [Task] {
var sectionItems = [Task]()
for task in tasks {
let dueTimes = task.dueTime
if dueTimes == querySections()[section] {
sectionItems.append(task)
}
}
print(sectionItems)
return sectionItems
}
// MARK: - Table view data source
override func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
return querySections()[section]
}
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return querySections().count
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return queryDueTimes(section).count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("TaskCell", forIndexPath: indexPath) as! TaskCell
// Configure the cell...
cell.selectionStyle = .None
let times = queryDueTimes(indexPath.section)
let task = times[indexPath.row]
cell.label.text = task.title
if task.done == true {
cell.checkBox.image = UIImage(named: "checkedbox")
cell.detailLabel.text = "Completed By: \(task.completedBy)"
}
else {
cell.checkBox.image = UIImage(named: "uncheckedbox")
cell.detailLabel.text = ""
}
cell.delegate = self
return cell
}
Basically, in querySections, I'm iterating through all of the dueTimes for each task and then changing them into an array of a set so I can filter out all of the duplicates. This is giving me all of my sections. For queryDueTimes, I'm iterating through the tasks and matching them to a section.
I had a thought about calling the functions in viewDidLoad but that isn't working (it keeps giving me an empty array when I try to pass it to another empty array thats more accessible outside of the function) and I can't access section (for queryDueTimes) in viewDidLoad (as far as what I know how to do).
Update 1:
I think the mistake is on my end. I said that I tasks is an array of arrays when its just an array of Tasks (a struct with all of the properties of each task). When I load the app, I append all of the tasks from my backend to a local array ("tasks"). Should I have an array of arrays for this to work or can I amend my code somehow and get it to work?
Update 2:
I'm getting sectionTimes and tasksInSectionArray as empty arrays when I print them.
var sectionTimes = [String]()
var tasksInSectionArray = [[Task]]()
var tasks = [Task]() {
didSet {
tableView?.reloadData()
}
}
func updateTableView() {
sectionTimes = Set(tasks.map{$0.dueTime}).sort()
tasksInSectionArray = sectionTimes.map{section in tasks.filter{$0.dueTime == section}}
print(sectionTimes)
print(tasksInSectionArray)
tableView.reloadData()
}
override func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
return sectionTimes[section]
}
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return sectionTimes.count
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return tasksInSectionArray[section].count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("TaskCell", forIndexPath: indexPath) as! TaskCell
// Configure the cell...
cell.selectionStyle = .None
let task = tasksInSectionArray[indexPath.section][indexPath.row]
Like you guessed, the data is being loaded and sorted over and over again, instead of only once. Save the results of querySelections and queryDueTimes and use that inside the table view data source methods.
You can do this in viewDidLoad - call both functions once and assign the results to a variable at the class level, and then call tableView.reloadData() (assuming you have a reference to the table view).
var sections: [String] = []
var data: [[Tasks]] = []
func updateTableView() {
sections = Set(tasks.map { $0.dueTime }).sort()
data = sections.map { section in tasks.filter { $0.dueTime == section } }
tableView.reloadData()
}
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return sections.count
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return data[section].count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let task = data[indexPath.section][indexPath.row]
// Cell configuration
}
This is basically what DMan said, but I've made an example for you.
I am working on a table view project I've seen in a tutorial, then I came across this piece of code that gives me the **error: Definition conflicts with previous value.**
The piece of code is:
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int, titleForHeaderInSection section:Int) -> String? {
// Return the number of rows in the section.
return animalSelectionTitles[section]
}
I have tried to change the String? into String or Int, but String gives me the same error and Int gives me an error on the return line.
Here's my complete code:
import UIKit
class AnimalTableViewController: UITableViewController {
var animalsDict = [String: [String]] ()
var animalSelectionTitles = [String] ()
let animals = ["Bear", "Black Swan", "Buffalo", "Camel", "Cockatoo", "Dog", "Donkey", "Emu", "Giraffe", "Greater Rhea", "Hippopotamus", "Horse", "Koala", "Lion", "Llama", "Manatus", "Meerkat", "Panda", "Peacock", "Pig", "Platypus", "Polar Bear", "Rhinoceros", "Seagull", "Tasmania Devil", "Whale", "Whale Shark", "Wombat"]
func createAnimalDict() {
for animal in animals {
let animalKey = animal.substringFromIndex(advance(animal.startIndex, 1))
if var animalValues = animalsDict[animalKey] {
animalValues.append(animal)
animalsDict[animalKey] = animalValues
} else {
animalsDict[animalKey] = [animal]
}
}
animalSelectionTitles = [String] (animalsDict.keys)
animalSelectionTitles.sort({ $0 < $1})
animalSelectionTitles.sort( { (s1:String, s2:String) -> Bool in
return s1 < s2
})
}
override func viewDidLoad() {
super.viewDidLoad()
createAnimalDict()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
// Return the number of sections.
return animalSelectionTitles.count
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int, titleForHeaderInSection section:Int) -> String? {
// Return the number of rows in the section.
return animalSelectionTitles[section]
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! UITableViewCell
// Configure the cell...
cell.textLabel?.text = animals[indexPath.row]
// Convert the animal name to lower case and
// then replace all occurences of a space with an underscore
let imageFilename = animals[indexPath.row].lowercaseString.stringByReplacingOccurrencesOfString(" ", withString: "_", options: nil, range: nil)
cell.imageView?.image = UIImage(named: imageFilename)
return cell
}
Two things:
1)
You should change your line
let animalKey = animal.substringFromIndex(advance(animal.startIndex, 1))
Currently it substrings from the 2nd character, which means that for the input Black Swan then animalKey would be equal to lack Swan. Instead you should use the following line:
let animalKey = animal.substringToIndex(advance(animal.startIndex, 1))
2)
There is no method in the UITableViewDataSource Protocol which is called tableView:numberOfRowsInSection:titleForHeaderInSection. Instead you need to split it into the following two methods:
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
let title = animalSelectionTitles[section]
return animalsDict[title]!.count
}
override func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
return animalSelectionTitles[section]
}
UPDATE 1:
In your tableView:cellForRowAtIndexPath, you should also update the retrieving of the animal name to reflect what is stored in the dictionary like so:
// Configure the cell...
let secTitle = animalSelectionTitles[indexPath.section]
let animalName = animalsDict[secTitle]![indexPath.row]
cell.textLabel?.text = animalName