I have a UIVIewController with a collection View and a custom cell showing some data form an API endpoint.
This data is retrieve from this code:
private func getItems() {
self.ItemsStartFetch(Text: "Fetching rooms", noItems: noRoomsViewContainer, itemsViewer: collectionContainer)
let roomsController: RoomsController = RoomsController()
roomsController.GetRooms { (status, items) in
// Start Legacy Code
RoomsController.rooms = items
// End Legacy Code
self.items = items
self.ItemsRetrieved(noItemsView: self.noRoomsViewContainer, itemsViewer: self.collectionContainer , showViewer: (items.count > 0))
self.roomCollection.reloadData()
}
}
Now i need to create an exact same view where the difference will be retrieving the data from another endpoint, with the same estructure, but this time it comes from
private func getItems() {
self.ItemsStartFetch(Text: "Fetching designs", noItems: noDesignsViewContainer, itemsViewer: collectionContainer)
let designsController: DesignsController = DesignsController()
designsController.GetDesigns { (status, items) in
// Start Legacy Code
DesignsController.Designs = items
// End Legacy Code
self.items = items
self.ItemsRetrieved(noItemsView: self.noDesignsViewContainer, itemsViewer: self.collectionContainer , showViewer: (items.count > 0))
self.designsCollection.reloadData()
}
}
How can I inject into the UIViewConroller the controller to use?
Related
Currently Paging library handles when to load the data automatically when a user scrolls down. But what if you want to give the user full authority for when they want the next page of data to be loaded i.e when button is clicked show next page of movies. How can you handle this in Paging library? See below how I've implemented the paging to load data as a user scrolls down
Here below this how I implemented the Paging to load next page when user scrolls down
class MoviesPagingDataSource(
private val repo: MoviesRepository,
) : PagingSource<Int, Movies>() {
override fun getRefreshKey(state: PagingState<Int, Movies>): Int? {
return state.anchorPosition?.let { anchorPosition ->
val anchorPage = state.closestPageToPosition(anchorPosition)
anchorPage?.prevKey?.plus(1) ?: anchorPage?.nextKey?.minus(1)
}
}
override suspend fun load(params: LoadParams<Int>): LoadResult<Int, Movies> {
return try {
val nextPageNumber = params.key ?: 0
val response = repo.getMovies(page = nextPageNumber, size = 10)
LoadResult.Page(
data = response.content,
prevKey = null,
nextKey = if (response.content.isNotEmpty()) response.number + 1 else null
)
} catch (e: Exception) {
LoadResult.Error(e)
}
}
}
This is how I emit the state in ViewModel for the UI to observe
#HiltViewModel
class MoviesViewModel #Inject constructor(
private val moviesRepository: MoviesRepository
): ViewModel {
....
//emitting the data to the UI to observe
val moviesPagingDataSource = Pager(PagingConfig(pageSize = 10)) {
MoviesPagingDataSource(moviesRepository)
}.flow.cachedIn(viewModelScope)
}
How I'm observing it in the UI
#Composable
fun MoviesList(viewModel: MoviesViewModel) {
val moviesList = viewModel.moviesPagingDataSource.collectAsLazyPagingItems()
LazyColumn {
items(moviesList) { item ->
item?.let { MoviesCard(movie = it) }
}
when (moviesList.loadState.append) {
is LoadState.NotLoading -> Unit
LoadState.Loading -> {
item {
LoadingItem()
}
}
is LoadState.Error -> {
item {
ErrorItem(message = "Some error occurred")
}
}
}
when (moviesList.loadState.refresh) {
is LoadState.NotLoading -> Unit
LoadState.Loading -> {
item {
Box(
modifier = Modifier.fillMaxSize(),
contentAlignment = Center
) {
CircularProgressIndicator()
}
}
}
is LoadState.Error -> TODO()
}
}
}
So currently I'm adding 1 to the previous page every time a user clicks the button to load more movies then saving this movies to the list state. Also making sure the current page is greater than or equal to total pages before loading more data and adding to the list state of previous loaded movies
you can use Channel to block LoadResult returning from load, when user clicks the button, send an element to the Channel. here is the simple
class MoviesPagingDataSource(
private val repo: MoviesRepository
) : PagingSource<Int, Movies>() {
private val channel: Channel<Unit> = Channel(1, BufferOverflow.DROP_LATEST)
override fun getRefreshKey(state: PagingState<Int, Movies>): Int? {
return state.anchorPosition?.let { anchorPosition ->
val anchorPage = state.closestPageToPosition(anchorPosition)
anchorPage?.prevKey?.plus(1) ?: anchorPage?.nextKey?.minus(1)
}
}
override suspend fun load(params: LoadParams<Int>): LoadResult<Int, Movies> {
return try {
val nextPageNumber = params.key ?: 0
// load initial page
if (nextPageNumber == 0) loadNextPage()
val response = repo.getMovies(page = nextPageNumber, size = 10)
/*
* block next page data return, when user click the button,
* call loadNextPage. if you don't want to automatically
* request data as the user scrolls toward the end of the
* loaded data. put this line above the repo.getMovies.
**/
channel.receive()
LoadResult.Page(
data = response.content,
prevKey = null,
nextKey = if (response.content.isNotEmpty()) response.number + 1 else null
)
} catch (e: Exception) {
LoadResult.Error(e)
}
}
suspend fun loadNextPage() {
channel.send(Unit)
}
}
I'm trying to import a large data set of around 80k objects. I'm trying to follow Apple example
I have two issues:
In the code example there is a comment:
// taskContext.performAndWait runs on the URLSession's delegate queue
// so it won’t block the main thread.
But in my case I'm not using URLSession to fetch the JSON. The file is bundled with the app. In this case how to make sure the import won’t block the main thread. Should I create a custom queue ? Any example ?
In the example it's just importing an array of entities. But in my case I need to import just one entity that has 70k object in a relation to many.
So what I want to achieve is:
If there is a ContactBook don't import anything because we have already imported the JSON.
If there is no ContactBook create one and import all the 70k Contact object to the contacts relation of the ContactBook. This should happen in batches like in the example and should not block the UI.
What I have tried:
private func insertContactbookIfNeeded() {
let fetch: NSFetchRequest<Contactbook> = ContactBook.fetchRequest()
let contactBookCount = (try? context.count(for: fetch)) ?? 0
if contactBookCount > 0 {
return
}
let contacts = Bundle.main.decode([ContactJSON].self, from: "contacts.json")
// Process records in batches to avoid a high memory footprint.
let batchSize = 256
let count = contacts.count
// Determine the total number of batches.
var numBatches = count / batchSize
numBatches += count % batchSize > 0 ? 1 : 0
for batchNumber in 0 ..< numBatches {
// Determine the range for this batch.
let batchStart = batchNumber * batchSize
let batchEnd = batchStart + min(batchSize, count - batchNumber * batchSize)
let range = batchStart..<batchEnd
// Create a batch for this range from the decoded JSON.
let contactsBatch = Array(contacts[range])
// Stop the entire import if any batch is unsuccessful.
if !importOneBatch(contactsBatch) {
assertionFailure("Could not import batch number \(batchNumber) range \(range)")
return
}
}
}
private func importOneBatch(_ contactsBatch: [ContactJSON]) -> Bool {
var success = false
// Create a private queue context.
let taskContext = container.newBackgroundContext()
taskContext.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy
// NOT TRUE IN MY CASE: (Any suggestion ??)
// taskContext.performAndWait runs on the URLSession's delegate queue
// so it won’t block the main thread.
print("isMainThread: \(Thread.isMainThread)") // prints true
taskContext.performAndWait {
let fetchRequest: NSFetchRequest<ContactBook> = ContactBook.fetchRequest()
fetchRequest.returnsObjectsAsFaults = true
fetchRequest.includesSubentities = false
let contactBookCount = (try? taskContext.count(for: fetchRequest)) ?? 0
var contactBook: ContactBook?
if contactBookCount > 0 {
do {
contactBook = try taskContext.fetch(fetchRequest).first
} catch let error as NSError {
assertionFailure("can't fetch the contactBook \(error)")
}
} else {
contactBook = ContactBook(context: taskContext)
}
guard let book = contactBook else {
assertionFailure("Could not fetch the contactBook")
return
}
// Create a new record for each contact in the batch.
for contactJSON in contactsBatch {
// Create a Contact managed object on the private queue context.
let contact = Contact(context: taskContext)
// Populate the Contact's properties using the raw data.
contact.name = contactJSON.name
contact.subContacts = NSSet(array: contactJSON.subContacts { subC -> Contact in
let contact = Contact(context: taskContext)
contact.name = subC.name
})
book.addToContacts(contact)
}
// Save all insertions and deletions from the context to the store.
if taskContext.hasChanges {
do {
try taskContext.save()
} catch {
print("Error: \(error)\nCould not save Core Data context.")
return
}
// Reset the taskContext to free the cache and lower the memory footprint.
taskContext.reset()
}
success = true
}
return success
}
The problem is that this is very slow because in each batch I fetch the workbook (which is getting bigger in each iteration) to be able to insert new batch of contacts in the contact book. Is there a efficient way to avoid fetching the workbook in each batch ? also any suggestion to make this is faster ? increase the batch size ? create a background queue ?
Update:
I have tried to create a ContactBook once in insertWordbookIfNeeded and pass it to importOneBatch with each iteration but I get:
Thread 1: Exception: "Illegal attempt to establish a relationship
'contactBook' between objects in different contexts
I have a VC where I fetch data for only the 1st object in an array of objects. so I only fetch arrayOfObjects[0] then when I enter a second VC I need to fetch all the other data associated with the other objects in that same array. But then I have a problem where I end up fetching that first bit of data I already had again. So my array would look like, data1, data1, data2, data3 ... which is not what I want of course.
Currently what I had tried to fix this issue, was to do the following: MainObject?.arrayOfSubObjects.remove(at: 0), this however means that on the first go it works well, but every time I go back to the preceding VC and then back I subtract one of the objects that I want to be there. So I end up with: data2, data3 ...
So my question is how can I remove that extra object from the beginning, but not delete anything after its been deleted?
Some things i have tried:
if selectedPost?.media[0].videoURL != nil {
if selectedPost?.media[0].videoURL == selectedPost?.media[1].videoURL {
selectedPost?.media.remove(at: 0)
} else {
print("NO!!!!!! they are not the same ")
}
} else if selectedPost?.media[0].image != nil {
if selectedPost?.media[0].image == selectedPost?.media[1].image {
selectedPost?.media.remove(at: 0)
} else {
print("NO!!! they are not the same ")
}
}
This however does not do anything, it always ends up going into the else. I have also tried stuff like setting number schemes, but this failed because the VC kept reloading
You can try to do it like this:
guard let selectedPost = selectedPost else { return }
if selectedPost.media.contains(where: {$0.image == image}) { return } // Here the $0.image should be replaced with $0.mediaURL == mediaURL for the videos or however you videoURL is called in Media
selectedPost.media.append(Media(image: image, timeStamp: Double(timeStamp)))
self.tableView.reloadData()
Try conforming Hashable in you Media class:
class Media : Hashable {
var hashValue : Int {
return image.hashValue
}
var image = UIImage()
// .....
static func == (lhs: Media, rhs: Media) -> Bool {
return lhs.hashValue == rhs.hashValue
}
}
Then you can compare two media objects with ==, So you can do something similar to the top part of this answer. Good luck
I have following code to handle pull to refresh response
let copyData = data.reversed() // it is pull to refresh response (load page 1)
for (_,element) in copyData.enumerated() {
let foundElement = allObjects.filter{$0.id == element.id} // Find element in main array
if let firstElement = foundElement.first, let index = allObjects.index(of: firstElement) {
allObjects[index] = element // Replace if found
} else {
allObjects.insert(element, at: 0) // Insert if not found
}
}
self.arrayPosts = allObjects
Where data is codable class which is API response of pull to refresh. allObjects is preloaded data with pagination
Question : Suppose In allObjects i have 50 Object (5 Pages of 10 ID is (1 to 50))
User pull to refresh And I load first Page from API (ID 1,2,3,4,5,6,7,10,11) then how to identify which object is deleted (8,9) ?
Should I compare allObjects 's 10th index with data's 10th index object's ID ?
Is it better way to handle this ? Please suggest
Don't compare pages (i.e. 10 items at a time) - if an item is added/deleted the pages will get out of sync, and you'll end up with missing / duplicate objects.
Presumably your objects are sorted by some key / date, etc.
Take the value of the key in your last downloaded object.
Copy all the existing objects with keys <= that last key into a new array.
Compare your downloaded array against this sub-array.
Objects in the downloaded array that are not in the sub-array should be removed.
Here How I handle this. Code is quite complex for first time read but added comments to understand it
func handleResponse(page:Int,isForRefersh:Bool = false, data:Array<InspirePost>) {
guard data.count != 0 else {
// Check if we are requesting data from pull to referesh and First page is empty then we don't have data to show change state to empty
if self.arrayPosts.count == 0 || (isForRefersh && page == 1) {
self.state = .empty
self.tableView.reloadData()
} else {
self.state = .populated(posts: self.arrayPosts)
}
return
}
// Now we need to check if data called by referesh control then
//1) Replace object in array other wise just append it.
var allObjects = self.state.currentPost
if isForRefersh {
// If both array Has same number of element i.e both has page one loaded
if data.count >= allObjects.count {
allObjects = data
} else {
let copyData = data.reversed()
for (_,element) in copyData.enumerated() {
if let index = allObjects.firstIndex(where: {$0.id == element.id}) {
allObjects[index] = element // Replace if found
} else {
allObjects.insert(element, at: 0) // Insert if not
}
}
let minID = data.min(by: {$0.id ?? 0 < $1.id ?? 0})?.id
// DELETE item
let copyAllObject = allObjects
for (_,element) in copyAllObject.enumerated() {
guard let id = element.id, id >= minID ?? 0 else {
continue
}
if !data.contains(element) {
if let indexInMainArray = allObjects.index(where: {$0.id == id}) {
allObjects.remove(at: indexInMainArray)
}
}
}
}
//When we pull to refersh check the curent state
switch self.state {
case .empty,.populated : // if empty or populated set it as populated (empty if no record was avaiable then pull to refersh )
self.state = .populated(posts: allObjects)
case .error(_, let lastState) : // If there was error before pull to referesh handle this
switch lastState {
case .empty ,.populated: // Before the error tableview was empty or popluated with data
self.state = .populated(posts: allObjects)
case .loading,.error: // Before error there was loading data (There might more pages if it was in loading so we doing paging state ) or error
self.state = .paging(posts: allObjects, nextPage: page + 1)
case .paging(_,let nextPage): // Before error there was paging then we again change it to paging
self.state = .paging(posts: allObjects, nextPage: nextPage)
}
case .loading: // Current state was loading (this might not been true but for safety we are adding this)
self.state = .paging(posts: allObjects, nextPage: page + 1)
case .paging(_,let nextPage): // if there was paging on going don't break anything
self.state = .paging(posts: allObjects, nextPage: nextPage)
}
self.arrayPosts = allObjects
} else {
allObjects.append(contentsOf: data)
self.isMoreDataAvailable = data.count >= self.pageLimit
if self.isMoreDataAvailable {
self.state = .paging(posts: allObjects, nextPage: page + 1)
} else {
self.state = .populated(posts: allObjects)
}
self.arrayPosts = self.state.currentPost
}
self.tableView.reloadData()
}
Where I have
indirect enum PostListStatus {
case loading
case paging(posts:[InspirePost],nextPage:Int)
case populated(posts:[InspirePost])
case error (error:String,lastState:PostListStatus) // keep last state for future if we need to know about data or state
case empty
var currentPost:[InspirePost] {
switch self {
case .paging(let posts , _):
return posts
case .populated( let posts):
return posts
case .error( _, let oldPost) :
switch oldPost {
case .paging(let posts , _):
return posts
case .populated( let posts):
return posts
default:
return []
}
default:
return []
}
}
var nextPage : Int {
switch self {
case .paging(_, let page):
return page
default:
return 1
}
}
}
You may make set for both allObjects and data. Then use subtracting(_:) method in set to find the missing one.
Remove those missing ones from the main array and use it. Once you have correct main array elements, page them while displaying.
I'm trying to write a test script using automation in xcode 4.5.
I have a UICollectionView and I want to click on some cell not currently visible.
Per documentation, I should expect cells to return all cells in the collection view, and visibleCells to return only the currently visible ones.
Instead what I'm seeing is that cells returns only the currently visible cells, and calling visibleCells stops the script on 'undefined' is not a function (evaluating 'collection.visibleCells()')
var target = UIATarget.localTarget();
var collection = target.frontMostApp().mainWindow().collectionViews()[0];
UIALogger.logMessage("Looking in collection: " + collection);
UIALogger.logMessage("Cells: " + collection.cells() + " length " + collection.cells().length);
UIALogger.logMessage("Visible cells: " + collection.visibleCells());
The code above returns the right UICollectionView, second log line prints:
Cells: [object UIAElementArray] length 12
although I have 100 items in the collection view, and third log line crashes script.
Is this a documentation/UIACollectionView bug?
Any ideas how can I tell the automation to scroll until it sees a cell with the name "My cell"?
I've tried using someCell.scrollToVisible, but I need to have the cell to do that, and I don't since I can't get it from cells.
EDIT:
As suggested by Jonathan I've implemented a scroll-till-found function.
it's a bit implementation specific, so you'll probably need to tweak isCellWithName.
I'm also looking to add a break in case we didn't find the needed cell in the while loop, if anyone has ideas, feel free to edit this.
function isCellWithName(cell, name) {
return (cell.staticTexts()[0].name() == name);
}
function getCellWithName(array, name) {
for (var i = 0; i < array.length; i++) {
if (isCellWithName(array[i], name)) {
return array[i];
}
}
return false;
}
function scrollToName(collection, name) {
var found = getCellWithName(collection.cells(), name);
while (found === false) {
collection.dragInsideWithOptions({startOffset:{x:0.2, y:0.99}, endOffset:{x:0.2, y:0},duration:1.0});
found = getCellWithName(collection.cells(), name);
}
return found;
}
The documentation is apparently incorrect. There is no visibleCells() method on UIACollectionView. I figured this out by looping over all the collection view elements properties and printing out their names:
var target = UIATarget.localTarget();
var window = target.frontMostApp().mainWindow();
var collectionView = window.collectionViews()[0];
for (var i in collectionView) {
UIALogger.logMessage(i);
}
Table view elements, on the other hand, do list all the cells with the cells() method. I'm wondering if they choose not to do this because of the much more complicated nature of collection views. It could be very expensive to actually fetch all the collection view cells, build their representations and frames, and return the elements if you had a lot of them. That's what UI Automation does when it asks table views for all the cells. They have to all be instantiated and calculated in order to get the element representations.
But, to answer your larger question, how to scroll to a specific cell. Can you consistently scroll it into view with a swipe gesture? It's not the most convenient way to do it and we're "spoiled" by the ability to scroll to non-visible elements with table views. But from a user behavior testing standpoint, swiping a certain amount is what the user would have to do anyway. Could the test be structured to reflect this and would it address your need?
I couldn't get the the #marmor dragInsideWithOptions() bit to work in a generic fashion. Instead, I'm using the collectionView's value() function to get an index of the current page vs. last page, as in "page 3 of 11". Then I use collectionView's scrollUp() and scrollDown() methods to walk through the pages until we find what we're after. I wrote an extension for TuneUp's uiautomation-ext.js that seem to do the trick, and more:
function animationDelay() {
UIATarget.localTarget().delay(.2);
}
extend(UIACollectionView.prototype, {
/**
* Apple's bug in UIACollectionView.cells() -- only returns *visible* cells
*/
pageCount: function() {
var pageStatus = this.value();
var words = pageStatus.split(" ");
var lastPage = words[3];
return lastPage;
},
currentPage: function() {
var pageStatus = this.value();
var words = pageStatus.split(" ");
var currentPage = words[1];
//var lastPage = words[3];
return currentPage;
},
scrollToTop: function() {
var current = this.currentPage();
while (current != 1) {
this.scrollUp();
animationDelay();
current = this.currentPage();
}
},
scrollToBottom: function() {
var current = this.currentPage();
var lastPage = this.pageCount();
while (current != lastPage) {
this.scrollDown();
animationDelay();
current = this.currentPage();
}
},
cellCount: function() {
this.scrollToTop();
var current = this.currentPage();
var lastPage = this.pageCount();
var cellCount = this.cells().length;
while (current != lastPage) {
this.scrollDown();
animationDelay();
current = this.currentPage();
cellCount += this.cells().length;
}
return cellCount;
},
currentPageCellNamed: function(name) {
var array = this.cells();
for (var i = 0; i < array.length; i++) {
var cell = array[i];
if (cell.name() == name) {
return cell;
}
}
return false;
},
cellNamed: function(name) {
// for performance, look on the current page first
var foundCell = this.currentPageCellNamed(name);
if (foundCell != false) {
return foundCell;
}
if (this.currentPage() != 1) {
// scroll up and check out the first page before we iterate
this.scrollToTop();
foundCell = this.currentPageCellNamed(name);
if (foundCell != false) {
return foundCell;
}
}
var current = this.currentPage();
var lastPage = this.pageCount();
while (current != lastPage) {
this.scrollDown();
animationDelay();
current = this.currentPage();
foundCell = this.currentPageCellNamed(name);
if (foundCell != false) {
return foundCell;
}
}
return false;
},
/**
* Asserts that this collection view has a cell with the name (accessibility identifier)
* matching the given +name+ argument.
*/
assertCellNamed: function(name) {
assertNotNull(this.cellNamed(name), "No collection cell found named '" + name + "'");
}
});