I have some code right now that gets what cells were selected. The following is my code for doing that:
if let selectedUserRows = self.tableView.indexPathsForSelectedRows {
self.groupUserArray.append(selectedUserRows)
for index in selectedUserRows {
let text = groupUserArray[index.row]
print(text)
}
}
The new error is saying that the index is out of range!
I was trying to use the logic for grabbing one selected cells text but it does not work. So I was wondering if anyone knew how to grab multiple selected cell's text?
Any help would be appreciated!
self.tableView.indexPathsForSelectedRows returns a [IndexPath]? so if you obtain an array of all the rows and sections of you selected rows. I suppose you are using some sort of collection to populate your tableView (in my example I will call it textArray: [String] ) so you can do something like that to get all the text you need:
if let selectedUserIndexes = self.tableView.indexPathsForSelectedRows {
for index in selectedUserIndexes {
let text = textArray[index.row]
}
}
Related
I've got a collection view and I'm using a custom class for the cells. Each cell has two text view, chapterTitleTextView and chapterBodyTextView. I've added placeholders to both text views like so:
class CustomWriterPageCell: UICollectionViewCell, UITextViewDelegate {
// When the user taps on a text view
func textViewDidBeginEditing(_ textView: UITextView) {
if textView.textColor == .gray {
textView.text = nil
textView.textColor = .black
}
}
// When the user taps out of a text view or taps on the done button in the toolbar
func textViewDidEndEditing(_ textView: UITextView) {
// If the chapter title text view is empty
if chapterTitleTextView.text.isEmpty {
chapterTitleTextView.text = "Chapter Title"
chapterTitleTextView.textColor = .gray
}
// If the chapter body text view is empty
if chapterBodyTextView.text.isEmpty {
chapterBodyTextView.text = "Chapter Body"
chapterBodyTextView.textColor = .gray
}
}
}
How this works is that, the text color is initially gray and there is some text, when the user taps on the text view, the color changes to black and the text in the text view is removed.
Now there is this problem with using dequeueReusableCell, it’s that it reuses the cells, this caused problem number 1: Whatever I type on the text view in the first cell appears on the 4th cell, to solve this problem I had to create 2 global lists to hold whatever I type and this gets displayed in the text views of the cells, here’s the code:
Global Lists:
var chapterTitleText = Array(repeating: "", count: 4) // To store the chapter title text
var chapterBodyText = Array(repeating: "", count: 4) // To store the chapter body text
The following code snippet is inside the textViewDidEndEditing from earlier
// Append the chapter body text to the chapterBodyText array
let titleText = chapterTitleTextView.text
let titleRow = textView.tag //This the indexPath.row
chapterTitleText[titleRow] = titleText!
// Append the chapter title text to the chapterTitleText array
let bodyText = chapterBodyTextView.text
let bodyRow = textView.tag
chapterBodyText[bodyRow] = bodyText!
And in cellForItemAt:
cell.chapterBodyTextView.tag = indexPath.row
cell.chapterTitleTextView.tag = indexPath.row
cell.chapterTitleTextView.text = chapterTitleText[indexPath.row]
cell.chapterBodyTextView.text = chapterBodyText[indexPath.row]
This got rid of problem number 1 (text in the text views duplicating). But then I got a new problem, remember the placeholder text I was talking about? When I type something in the one of the textviews of the first cell, the text color of the text view in the fourth cell changes.
Here is a GIF replicating the problem:
Following your chain of questions, I suggest you to do this every time you're dealing with UICollectionView or UITableView.
Define a method in your cell class and take whatever data it needs to display itself as arguments:
func configure(text : String?) { //text is optional here which means it can be nil.
//However, from my previous answer you can replace it with an empty string condition.
if let txt = text { //or if text != ""
self.chapterTitleTextView.text = txt
self.chapterTitleTextView.text.textColor = .black
}
else {// As others mentioned make sure to always handle else because cells are reusable.
self.chapterTitleTextView.text = "Chapter Title"
self.chapterTitleTextView.text.textColor = .gray
}
}
The intuition behind reusable cells are that since they are reusable, you should reconfigure them completely and not to expect that the configuration is saved or attached to the cell.
Now, in the cellForItemAt:
let cell = ...
cell.configure(text : chapterTitleText[indexPath.row])
And remember, in this way, you do not need to define a global array. As I've told you previously, this array need to be only defined in your Controller and your cell does not need to know about it. Your cell only needs to know about one index of that array which is passed through configure function.
Although that global array will work, I'm talking about propriety in coding.
Comment your problems with this approach(if any), I will try to answer with patience but don't expect a (copy-paste)able code.
This happens because of the reuse mechanism of the UICollectionView and UITableView. Since you only update the color in one way, collection "remembers" previous color and upon new cell recreates its previous state. You have two basic solutions here.
First is to update cell state for both cases like:
if myCondition == true {
color = UIColor.gray
} else {
color = UIColor.black
}
Second is to utilize prepareForReuse method of the UICollectionViewCell
func prepareForReuse() {
// code that resets state of your cell to default
}
Method description in Apple Documentation
I have tableview where I need to show few sections. You should imagine this table like a playlist of your songs. In the top first section I need to display a cell with button which will add more songs to the playlist and other sections of tableview are header titles of Music category (like pop, rock and etc). Each of these sections contains cells which are songs names.
I have an array of songs called like this: var songsGroups = [SongGroup]. Which is actually my datasource.
SongGroup contains few properties:
var categoryName: String
var songs: [Songs]
But the problem appears on the next level. I every time need to check indexPath.section and do like this:
if indexPath.section == 0 {
// this is a section for ADD NEW SONG BUTTON cell no need in header title as there is no data repression only static text on the cell.
} else {
var musicCategoryName = songsGroups[indexPath.seciton - 1]. categoryName
headerTitle.title = musicCategoryName
}
As you see my code became magical by adding this cool -1 magical number. Which I replay don't love at all.
As an idea for sure I can try to combine my ADD NEW SONG BUTTON section (by adding some additional object) with songsGroups array and create NSArray for this purposes. Like in Objective-C as you remember. So then my datasource array will looks like this:
some NSArray = ["empty data for first cell", songsGroups[0], songsGroups[1]... etc]
So then there is no need to check any sections we can trust our array to build everything and even if I will add more empty data cells there is no need for me to handle my code via if block and adding tons of magical numbers.
But the issue I see here that we don't use explicit types of array and it's upset.
So maybe you know more beautiful solutions how to resolve my issue.
You can introduce a helper enum:
enum Section {
case empty
case songCategory(categoryName: String, songs: [String])
}
Your data source would then look something like this:
let datasource: [Section] = [.empty, .songCategory(categoryName: "Category1", songs: ["Song 1", "Song2"])]
So now you can use pattern matching to fill the table view:
let section = datasource[indexPath.section]
if case let .songCategory(categoryName, songs) = section {
headerTitle.title = categoryName
} else {
// this is a section for ADD NEW SONG BUTTON cell no need in header title as there is no data repression only static text on the cell.
}
I am not sure if I understand you right. But is seems to me that you want to display
1) something that lets the user add a new song by tapping a button, and
2) a table of songs, sectioned into groups.
If this is the case, why don’t you put the add new song button in the table header view, and all your song groups and songs in a 2-dim array used as your dataSource?
func convertPointToIndexPath(_ point: CGPoint) -> (UITableView, IndexPath)? {
if let tableView = [tableView1, tableView2, tableView3].filter({ $0.frame.contains(point) }).first {
let localPoint = scrollView.convert(point, to: tableView)
let lastRowIndex = focus?.0 === tableView ? tableView.numberOfRows(inSection: 0) - 1 : tableView.numberOfRows(inSection: 0)
let indexPath = tableView.indexPathForRow(at: localPoint) ?? IndexPath(row: lastRowIndex, section: 0)
return (tableView, indexPath)
}
return nil
}
So i got this method, which converts a CGPoint into the indexPath of the given uitableView. I struggle with the filter-Method on the array which contains uitableViews.
I got an array outside of this method which contains any number of uitableViews. For example:
public var littleKanbanColumnsAsTableViews: [UITableView] = []
So i got to make a change inside of the method. Like this:
if let tableView = littleKanbanColumnsAsTableViews.filter({ $0.frame.contains(point)}).first { ... }
Now when i click on any tableView on the gui, i track the coordinates of the point and transform it on the belonging tableview with the frame.contains(point) method.
My problem is that the filter is not working, it always gives me the first tableView back, no matter which tableview is clicked. Why it doesn't work with my littleKanbanColumnsAsTableViews-Array?
One hint:
let tableView = littleKanbanView.littleKanbanColumnsAsTableViews[3]
When i indexing its direct then it works. But i want it depending on which tableView is containing the clicked point.
Here is my array with the tableViews, in this case the array contains 5 tableviews.
array containing tableviews
Now i want to filter the tableView out of them, which includes the point from tapping on this tableView. How can i achieve this?
For more understanding, i add the ui, here is it:
UI of my app
When i click on this tableView it works, because it is the first element in my array of tableViews. So for this case the convertPointToIndexPath-Method is working.
But when i scroll horizontally to the second tableView for example and click on that, it doesn't work. Because I think the method gives me always the first element back, but i thought it filters it with the given condition.
What is the problem, why doesn't work the condition{ $0.frame.contains(point)}? It have to localize the tableView when the coordinates of the point are tracked.
Preferred Solution:
In this case the moment the first satisfying condition is met, the rest of the elements are not traversed.
if let tableView = littleKanbanColumnsAsTableViews.first(where: { $0.frame.contains(point) }) {
}
Not so efficient solution:
In this case all the elements in the array are traversed to build an array of table views that satisfy the condition. Then the first element of that filtered array is chosen.
if let tableView = (littleKanbanColumnsAsTableViews.filter{ $0.frame.contains(point)}).first {
}
I am trying to create a collection view with custom collection view cells.
I want to keep track of the number of times each cell is tapped and store in an array. So, my custom cell has a label, IBAction and an array.
I am able to do this by appending 1 to the array inside IBAction and printing out the count.
However, I want to access this data outside the custom cell view class. I want to have an array specific to each cell i.e. by the name
self.titleLabel.text!
Of course, I can't use a variable for the name of an array! (I wish I could)
How do I store data in such case?
Where and how do I need to define the array to easily store and process data?
You may declare Dictionary that holds tap count in your UIViewController:
var tapCounts = [NSIndexPath: Int]()
let collectionView = UICollectionView()
func tapAction(sender: UICollectionViewCell) {
if let indexPath = collectionView.indexPathForCell(sender) {
tapCounts[indexPath] = (tapCounts[indexPath] ?? 0) + 1
}
}
I want to pass table cell's textLabel data of UITableViewController to NSArray. Those cell have identifier name Cells and accessory type checkmark
Code that does exactly what you asked is here:
func getCellsData() -> [String] {
var dataArray: [String] = []
for section in 0 ..< self.tableView.numberOfSections() {
for row in 0 ..< self.tableView.numberOfRowsInSection(section) {
let indexPath = NSIndexPath(forRow: row, inSection: section)
let cell = self.tableView.cellForRowAtIndexPath(indexPath)!
if cell.reuseIdentifier == "Cells" && cell.accessoryType == UITableViewCellAccessoryType.Checkmark {
dataArray.append(cell.textLabel!.text!)
}
}
}
return dataArray
}
But I would like to recommend you find different approach, because this is the rude traverse of tableView. You probably have your dataSource model that can give you ll data you need. Additionally, this code doesn't check for errors, for example if there is no text in cell at some indexPath
Two things I'd advise.
First, looks like you're using the checkmark accessory to indicate multiple selections. It's really intended for single selection, like a radio button. Better to use the allowMultipleSelectionsoption on the tableview. This will allow...
...the second thing. Copying text from cells into an array is the wrong way round to do it. Better to ask the table view and call it's - (NSArray *)indexPathsForSelectedRows this will give you an array of index paths to selected cells then you can ask for each cell and grab any data you want from it. This gives you better live data and prevents you unknowingly creating a circular reference from the view controller of the tableview and the content in the tableview cells.