I am using swift 4.2 so I am not sure if my code is outdated because many of the examples are not for the latest.
I have been trying many of the examples I have found here on stack but it seems they are outdated because of many references not valid working anymore.
I am trying to get the innerText of an element with a particular ID. Unfortunately I produce no results in successfully getting the value. Then I am trying to take result and put it in Firebase. If I use something like "test" instead of result it works fine, but I need result
Here is my code.
override func viewDidLoad() {
super.viewDidLoad()
ref = Database.database().reference()
webView.evaluateJavaScript("document.getElementById('get_this_user').innerText") { (result, error) in
self.ref?.child("users").child("usernames").setValue(["get_this_user": result])
}
}
Related
This question already has answers here:
Returning data from async call in Swift function
(13 answers)
Closed last year.
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?
}
}
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 am currently going through the processes of migrating swift 2.3 to 3 using the most updated Kinvey SDK (version 3.3.5). They have done a ton of updates since the 1x versions. My question is has anyone successfully been able to query on the PersistableKeyID field and pull multiple objects?
I use to be able to use the "loadObjects" function which would take an array of strings as an argument. This function has since been depreciated and replaced with find(byId). See below:
dataStore.find(byId: "only takes one") { uClass, error in
if let uClass = uClass {
//succeed
print("UClass: \(uClass)")
} else {
//fail
}
The issue is, it will only take a single string as an argument. I have attempted to use the query functionality, but I cannot get it to take the "_id" field as a parameter. Using the following code:
//Just statically creating the sectionID array for now. This will dynamically be created
testIDs = ["58668307206c11177e5ab0d4", "58668307206c11177e5ab0d4", "57ad00a505a2bb55632659c3"]
let sectionStore = DataStore<Section>.collection()
let sectionQuery = Query(format: "_id IN %#", testIDs)
sectionStore.find(sectionQuery) {sectionResult, error in
if let sectionResult = sectionResult {
self.sectionsTest = sectionResult
self.sectionCollectionView.reloadData()
} else{
//Error
}
}
I receive the error:
'Invalid property name', reason: 'Property '_id' not found in object of type 'Section'
Anyone have an idea on how to perform this now that "loadObjects" has been depreciated? There is no delivered "find(byIds)" that I could find.
Jbone107,
I was able to get results with this, let me know if the below works for you.
let id:[String] = ["5855026650a816ec29012908","5855024a21400c5b492bea20"]
let query = Query(format: "_id IN %#", id)
dataStore.find(query) { data, error in
if let data = data {
//succeed
print(“Data: \(data)")
} else {
//fail
print("fetching failed")
}
}
Thanks,
Pranav,
Kinvey
Answered: Per the Data Store Guide for iOS, by default the ".collection()" is of type "cache". The "Cache" type will store data locally. This must be why "Realm" is now included with the version 3x SDK.
I updated my DataStore collection to:
let sectionStore = DataStore<Section>.collection(.network)
I added ".network" to force the query to pull from the backend rather than the cache file. This actually identified "_id" as a property and the query worked successfully. For some reason the "cache" file isn't storing this as a property.
Additional SDK Question Answered
I was having an issue pulling NSNumber from the Kinvey backend. This ended up being a similar issue related to the "cache" query. I reviewed the Realm support site as a last resort effort to try and figure this out. I found that Realm doesn't actually support type "NSNumber".
Excerpt taken from: https://realm.io/docs/swift/latest/
Realm supports the following property types: Bool, Int8, Int16, Int32, Int64, Double, Float, String, NSDate, and NSData.
Unfortunately, Kinvey doesn't support "Int" types. As a work around, I have changed them to string and am just converting back to "Double" or another type after I pull the data. However, if I just use ".network" collection types, then NSNumber still works.
Thanks,
James
I'm new to this forum, and – more importantly – I'm also new to the Swift (2) language – and actually in coding at all.
So at the moment I'm trying to work with Parse in Xcode 7 (Swift 2). To be more specific: I'm working with a PFQueryTableView to display the data, I set up in the Parse class, in the app. But my problem is that when I update this data on the Parse website and I run the app in the simulator, the tableview with data isn't up-to-date with my new data from the Parse-website.
After going through other topic-related posts, this is the code I came up with:
let query = PFQuery(className: "myClass")
query.findObjectsInBackgroundWithBlock { (objects, error) -> Void in
if error == nil {
print("Successfully retrieved: \(objects)")
} else {
print("Error: \(error)")
}
}
Now, when I run the app I can see the right data in the Target Output, but in the simulator it's still the old data. So I guess there must be a line of code in the "if error == nil { }"-section. I already tried several lines of codes which I got from other threads, but they all didn't work. And like I said before: I'm still a beginner in coding, so I just can't figure out myself how to do this.
Hopefully one of you guys can help me out. And if I need to be more specific or something, just ask!
Thanks in advance!
TLDR: I'm getting an EXC_BAD_ACCESS error using swift in XCode 6.1 building for iOS8.1. I believe the issue is likely a compiler error.
I am making an app wherein the user is allowed to add (Korean) words from a dictionary (in the English sense) to a word list. I have the following classes that define a word (with associated definitions, audio files, user-interaction statistics, etc.) and a word list (with an associated list of words and methods to add/remove words to the list, alphabetize the list, etc):
class Word: NSObject, NSCoding, Printable {
var hangul = String("")
var definition = String("")
// ...
}
class WordList: NSObject, NSCoding {
var title = ""
var knownWords = Dictionary<String,String> ()
// ...
func addWordToList(wordName: String, wordDefinition: String) {
// Debug statements
println("I am WordList \"\(self.title)\" and have the following knownWords (\(self.knownWords.count) words total): ")
for (_wordName,_wordDefinition) in self.knownWords {
println("\t\"\(_wordName)\" : \(_wordDefinition)")
}
println("\nI am about to attempt to add the word \"\(wordName)\" with definition \"\(wordDefinition)\" to the above dictionary")
// Add word to wordList, including the 'let' fix
fix_EXC_BAD_ACCESS_bug()
knownWords[wordName] = wordDefinition // EXC_BAD_ACCESS
}
func fix_EXC_BAD_ACCESS_bug() {
// This empty line attempts to solve a exc_bad_access compiler bug when adding a new value to a WordList dictionary
let newDic = self.knownWords
}
// ...
}
Next I have a UITableViewController with a UISearchBar that I use to display the dictionary (again in the English sense) of words to the user. The user adds words by tapping a button (which is displaying an image) on the right of each cell, which calls the #IBAction func addWord() in the viewController:
class AddingWordsToWordList_TableViewController: UITableViewController, UISearchResultsUpdating {
var koreanDictionary = KoreanDictionary() // Custom class with method 'getWord(index: Int)' to return desired Word
var filteredSearch = [Word]()
// ...
// Add word
#IBAction func addWord(sender: UIButton) {
// Add word
if self.resultSearchController.active {
let word = filteredSearch[sender.tag]
wordList.addWordToList(word.hangul, definition: word.definition) // Enter addWordToList() here
} else {
let word = koreanDictionary.getWord(sender.tag)
wordList.addWordToList(word.hangul, definition: word.definition)
}
// Set image to gray
sender.imageView?.image = UIImage(named: "add133 gray")
// Save results
wordList.save()
// Reload table data
tableView.reloadData()
}
// ...
At first the app compiles and seems to run fine. I can add a new word list and start adding words to it, until I add the 8th word. I (always on the 8th word) get a EXC_BAD_ACCESS error in (WordList) addWordToList with the following println information:
I am WordList "School" and have the following knownWords (7 words total):
"방학" : school vacation
"대학원" : graduate school
"학년" : school year
"고등학생" : high school student
"초등학교" : elementary school
"학생" : student
"학교" : school
I am about to attempt to add the word "대학생" with definition "college student" to the above dictionary
Note that the order in which I add the words appears irrelevant (i.e. the word "college student" can be added successfully if it is one of the first 7 words). There is nowhere in the code where I explicitly change behavior based on the number of words in a word list (except to display the words in a word list as cells in a UITableView), or any dependencies that would (to my knowledge) make the 8th word a special number. And indeed this number can change by using the let hack= solution (see below) to a different number, but for a particular build is always the same number.
At this point I'm at a complete loss of what to do. I'm relatively new to swift and have spent quite a few hours looking up how to fix exc_bad_access errors. I've come to the following point:
It seems exc_bad_access errors usually mean one of three things (http://www.touch-code-magazine.com/how-to-debug-exc_bad_access/)
An object is not initialized
An object is already released
Something else that is not very likely to happen
I don't feel like either 1 or 2 can be the case for me, as right before we get the access error we can print out the contents of the dictionary in question (knownWords). However, as is always the case it is highly likely I'm missing something obvious, so please let me know if this is indeed true.
If the error is caused by 3 above ("something else") I have tried the following:
(From EXC_BAD_ACCESS on iOS 8.1 with Dictionary and EXC_BAD_ACCESS when updating Swift dictionary after using it for evaluate NSExpression solutions)
I have tried different variations of the let stupidHack = scenario, and it does sometimes change the results, but only the number of entries allowed before crashing (i.e. I can sometimes get to the ~15th/16th entry in the dictionary before the error). I have not been able to find an actual, bug-free solution using this method, however.
I have rebuilt using both Release and Debug modes; the error appears in both. Note I am only using the simulator and do not have a developer's license to try it on an actual device.
I have turned off (set to "None") compiler optimization (it was already off for the Debug build anyway).
I have tried building to iOS 8.0 with the same error results.
Any way to get around this issue is appreciated. A let hack = solution is acceptable, but preferably a solution will at least guarantee to not produce the error in the future under different build conditions.
Thanks!