I'm having trouble successfully setting local data for Siesta in Swift. My goal is to set a UIImage for a URL locally, so that this local image can be displayed with no download time.
To do this, I'm setting the image data for the URL as such:
let resource = CustomRemoteImageView.imageCache.resource(myPhoto.url.absoluteString)
let imageData = UIImagePNGRepresentation(image)! // I've also tried putting the UIImage directly in there, because the transformation chain doesn't apply to local data, right?
let entity: Entity<Any> = Entity(content: imageData, contentType: "*/*") // I've played around with the content type too!
resource.overrideLocalData(with: entity)
I'm then using a custom Service that always tries to parse content as an Image:
private let imageTransformer =
ResponseContentTransformer
{ Image(data: $0.content)}
convenience init() {
self.init(standardTransformers: [])
configure {
$0.pipeline[PipelineStageKey.parsing].add(self.imageTransformer, contentTypes: ["*/*"])
}
}
This system is working great for all remote images, but it always seems to fail to parse this overridden local image. It seems like it's trying to parse but just fails every time.
i.e. I'm getting a Siesta.ResourceEvent of
(Siesta.ResourceEvent) $R20 = newData {
newData = network
}
but the actual .typedContent is nil.
overrideLocalData and overrideLocalContent do not interact with the pipeline at all. Siesta won’t try to parse what you pass; what you override is what your resource gets.
Furthermore, overrideLocalData and overrideLocalContent don’t fail. They always update the resource’s content. If you call those methods, the resource content will match what you passed.
So … the problem isn’t parsing. What might it be?
Entity.typedContent is a shortcut for applying as? to a resource’s entity’s content. If you're getting nil, it means that either (1) the content of the entity you passed to the overrideLocalData was nil or (2) the contextual type in which you’re calling typedContent doesn’t match the content’s actual runtime type.
What do you see if you print resource.latestData.content? That will show you what’s actually there, and will rule out type conversion issues with typedContent.
If it’s not nil, compare its value from a network request and get the types to match.
If it is nil, then either something else cleared the content or you passed nil content in the first place. Try SiestaLog.Category.enabled = .common and see if you can spot where it is or isn’t getting set to the right thing.
Related
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Returning data from async call in Swift function
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I am building a mobile app with swift, and am having some syntax issues as I am not a developer. The structure and logic of the application is really rough and surely incorrect, however we just need something that functions. (It is a school project and my team got no devs).
Anyways, we have a MySQL database that will be used as a middleman between our badge server/admin app, and our mobile app. Currently when you go to https://gatekeeperapp.org/service.php , you will see the current database data, taken by a php script and hosted there as JSON. Currently in Swift I have a struct with a function that takes this JSON data, and maps it to variables. The idea is to then pass these pulled variables into a separate set of functions that will check the pulled long/lat against the mobile devices location, and then return whether they match or not. This value would be updated, re-encoded to JSON, and pushed to a web service that would go about changing the values in the database so the badge server could use them.
Where I am currently I can see that values are being pulled and mapped and I can set a variable in a separate function to the pulled value, but then I can only seem to output this value internally, rather than actually use it in the function. I get a type error saying that the pulled values are of type (). How can I properly use these values? Ultimately I think I would want to convert the () to a double, so I could properly compare it to the Long/Lat of the device, and then will need to re-encode the new values to JSON.
Swift Code -- struct function
Swift code -- JSON struct
Swift code -- using pulled data
Your closure is called asynchronously, which means that the outer function where you are expecting to use the values has already returned by the time the closure is called. Instead, you probably need to call some other function from the closure, passing the values you've received.
class MyClass {
func fetchUserData() {
UserData().fetchUser { [weak self] user, error in
DispatchQueue.main.async {
if let user = user {
self?.handleSuccess(userID: user)
} else if let error = error {
self?.handleError(error)
}
}
}
}
private func handleSuccess(userID: String) {
print(userID)
// Do something with userID. Maybe assign it to a property on the class?
}
private func handleError(_ error: Error) {
print(error)
// Handle the error. Maybe show an alert?
}
}
I am trying to add Apple Pencil support to my mind mapping app. I already use Core Data within my app for data persistence which all works fine without any bugs.
I have my Apple Pencil features working fine but I'm having trouble storing the Apple Pencil data.
Ive tried to add a PKDrawing object to my MindMap data model but I keep getting a compile time error 'cannot find type 'PKDrawing' in scope'
As far as I am away I can store the PKDrawing object into core data and then fetch it back out when the app loads. But I'm obviously not doing something right.
Any help is greatly appreciated folks.
Thank you
Update:
So I've used:
func convertToData(pkdrawing: PKDrawing) -> Data {
let data = pkdrawing.dataRepresentation()
return data
}
Then updated my model data and savedContext which all seems to work ok. The problem is when I try and initialise the data on opening the app. I have:
func createDrawing(data: Data) -> PKDrawing {
var loadedDrawing: PKDrawing
do {
try loadedDrawing = PKDrawing.init(from: data as! Decoder)
return loadedDrawing
} catch {
print("Error loading drawing object")
return PKDrawing()
}
}
which gives me error:
Could not cast value of type 'Foundation.Data' (0x1f3851a98) to 'Swift.Decoder' (0x1ee5381a8).
2021-09-24 06:22:58.912173+0100 MindMappingApp[1137:612856] Could not cast value of type 'Foundation.Data' (0x1f3851a98) to 'Swift.Decoder' (0x1ee5381a8).
I tried:
try loadedDrawing = PKDrawing.init(from: data as! Decoder)
as:
try loadedDrawing = PKDrawing.init(from: data)
but I kept getting:
Argument type 'Data' does not conform to expected type 'Decoder'
any ideas? Thanks in advance :)
Instead of trying to store the PKDrawing directly, store the Data associated with it instead.
Your Core Data model will have a field with the type Data (or Binary Data if you're using the GUI).
When you need to actually use that data and covert to/from the PKDrawing, you can use:
init(data:) https://developer.apple.com/documentation/pencilkit/pkdrawing/3281882-init
dataRepresentation() https://developer.apple.com/documentation/pencilkit/pkdrawing/3281878-datarepresentation
I would like to use INImage.init(url:) for displaying a user profile image in a notification.
This initializer is documented with:
A URL that specifies an image file on a remote server. The image file can be in any format supported by the system, but it is recommended that you use PNG images.
However, as far as I can tell, this simply does not work – the image in the URL is never displayed. I have seen many other posts claiming that it does not work for them either.
Am I missing something or is this simply a bug?
I am working around it right now with the following extension:
extension INImage {
convenience init?(contentsOf url: URL) {
if let data = try? Data(contentsOf: url) {
self.init(imageData: data)
} else {
return nil
}
}
}
This doesn't seem great, because the image isn't cached and has to be downloaded every time a notification comes in, which seems really bad.
So my goal is to get rid of these bugs completely. I am in a dilemma where each decision leads to a bug.
The first thing I can do that eventually becomes an issue is use a String-interpolated collection path in all my query functions like so:
func getEventName() {
listener = db.collection("school_users/\(user?.uid)/events").order(by: "time_created", descending: true).addSnapshotListener(includeMetadataChanges: true) { (querySnapshot, error) in
if let error = error {
print("There was an error fetching the data: \(error)")
} else {
self.events = querySnapshot!.documents.map { document in
return EventName(eventName: (document.get("event_name") as! String))
}
self.tableView.reloadData()
}
}
}
The thing with this is, when I run the app on the simulator, I am restricted from pressing buttons and then sometimes I can press them and then sometimes they get restricted again. This bug is so confusing because it makes no sense where it springs from.
The other issue is I can use a Constants value in all the query functions in my collections path.
static let schoolCollectionName = "school_users/\(user?.uid)/events"
This is nested in a Firebase struct within the Constants struct. In order to keep Xcode from giving errors I create a let users = Auth.auth().currentUser variable outside the Constants struct. The issue with this value is that when I put that in all of my query functions collection paths, all the buttons are accessible and selectable all the time, but when a user logs out and I log in as a new user, the previous user's data shows up in the new user's tableview.
It would obviously make more sense to use the Constants value because you prevent typos in the future, but I can't figure out how to get rid of the bug where the old user's data shows up in the new user's tableview. Thanks in advance.
The user id should definitely not be a constant. What it sounds like is that right now, you have no reliable way to change users -- your setup probably depends on which user is logged in at app startup, since that's where your variable gets set.
I would do something more like this:
func getEventName() {
guard let user = Auth.auth().currentUser else {
//handle the fact that you don't have a user here -- don't go on to the next query
return
}
listener = db.collection("school_users/\(user.uid)/events").order(by: "time_created", descending: true).addSnapshotListener(includeMetadataChanges: true) { (querySnapshot, error) in
Note that now, user.uid in the interpolated path doesn't have the ? for optionally unwrapping it (which Xcode is giving you a warning for right now). It will also guarantee that the correct query is always made with the currently-logged-in user.
Regarding being able to press the buttons, that sounds like an unrelated issue. You could run your app in Instruments and check the Time Profiler to see if you have long-running tasks that are gumming up the main/UI thread.
I was hoping that someone can help a coding newbie with what might be considered a stupid question. I'm making a blog type app for a community organization and it's pretty basic. It'll have tabs where each tab may be weekly updates, a table view with past updates and a tab with general information.
I setup cloudkit to store strings and pictures, and then created a fetchData method to query cloud kit. In terms of the code (sample below) it works and gets the data/picture. My problem is that it takes almost 5-10 seconds before the text and image update when I run the app. I'm wondering if that's normal, and I should just add an activity overlay for 10 seconds, or is there a way to decrease the time it takes to update.
override func viewDidLoad() {
fetchUpcoming()
}
func fetchUpcoming() {
let container = CKContainer.defaultContainer()
let publicData = container.publicCloudDatabase
let query = CKQuery(recordType: "Upcoming", predicate: NSPredicate(format: "TRUEPREDICATE", argumentArray: nil))
publicData.performQuery(query, inZoneWithID: nil) { results, error in
if error == nil { // There is no error
println(results)
for entry in results {
self.articleTitle.text = entry["Title"] as? String
self.articleBody.text = entry["Description"] as? String
let imageAsset: CKAsset = entry["CoverPhoto"] as! CKAsset
self.articlePicture.image = UIImage(contentsOfFile: imageAsset.fileURL.path!)
self.articleBody.sizeToFit()
self.articleBody.textAlignment = NSTextAlignment.Justified
self.articleTitle.adjustsFontSizeToFitWidth = true
}
}
else {
println(error)
}
}
}
Another question I had is about string content being stored on cloud kit. If I want to add multiple paragraphs to a blood entry (for example), is there a way to put it in one record, or do I have to separate the blog entry content into separate paragraphs? I may be mistaken but it seems like CloudKit records don't recognize line breaks. If you can help answer my questions, I'd be really appreciative.
It looks like you might be issuing a query after creating the data, which isn't necessary. When you save data, as soon as your completion block succeeds (with no errors) then you can be sure the data is stored on the server and you can go ahead and render it to the user.
For example, let's say you're using a CKModifyRecordsOperation to save the data and you assign a block of code to the modifyRecordsCompletionBlock property. As soon as that block runs and no errors are passed in, then you can render your data and images to your user. You have the data (strings, images, etc.) locally because you just sent them to the server, so there's no need to go request them again.
This provides a quicker experience for the user and reduces the amount of network requests and battery you're using on their device.
If you are just issuing normal queries when your app boots up, then that amount of time does seem long but there can be a lot of factors: your local network, the size of the image you're downloading, etc. so it's hard to say without more information.
Regarding the storage of paragraphs of text, you should consider using a CKAsset. Here is a quote from the CKRecord's documentation about string data:
Use strings to store relatively small amounts of text. Although
strings themselves can be any length, you should use an asset to store
large amounts of text.
You'll need to make sure you're properly storing and rendering line break characters between the user input and what you send to CloudKit.