I wanted to write a weather app using OpenWeatherMap Api. Everything looks fine for me. The app was written using an tutorial on the web and everything looks 1:1.
let weatherURL = URL(string: "http://api.openweathermap.org/data/2.5/weather?q=Warsaw,pl?&units=imperial&APPID=cb9325925ed023b38a64c3d8da3c345c")!
let dataTask = session.dataTask(with: weatherURL) {
(data: Data?, response: URLResponse?, error: Error?) in
if let error = error {
print("Error:\n\(error)")
} else {
if let data = data {
let dataString = String(data: data, encoding: String.Encoding.utf8)
print("All the weather data:\n\(dataString!)")
if let jsonObj = try? JSONSerialization.jsonObject(with: data, options: .allowFragments) as? NSDictionary {
if let mainDictionary = jsonObj.value(forKey: "main") as? NSDictionary {
if let temperature = mainDictionary.value(forKey: "temp") {
DispatchQueue.main.async {
self.weatherLabel.text = "Temperatura w Warszawie: \(temperature)°C"
}
}
} else {
print("Error: unable to find temperature in dictionary")
}
} else {
print("Error: unable to convert json data")
}
} else {
print("Error: did not receive data")
}
}
}```
The problem is that your code
let weatherURL = ...
let dataTask = ...
...needs to be inside some method of some struct or class. If you look at the original tutorial, you'll see that that's the case. Your code is just hanging out loose in the open, in a place where executable code is not permitted.
Related
I am using in my project safari content blocker extension. when i set the rule in blockerList.json file statically and run the project every thing is working fine. Now i want to set my rule dynamically using the technic as it describes in below.
Guys please help me out to set the rule dynamically at run time.
I try this but i am getting an error when
load from viewcontroller class
fileprivate func saveRuleFile() {
let ruleList = [["trigger":["url-filter": ".*"],"action":["type": "block"]]]
let encoder = JSONEncoder()
encoder.outputFormatting = .prettyPrinted
if let encoded = try? encoder.encode(ruleList) {
let sharedContainerURL = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "group.****.***")
print("sharedContainerURL = \(String(describing: sharedContainerURL))")
if let json = String(data: encoded, encoding: .utf8) {
print(json)
}
if let destinationURL = sharedContainerURL?.appendingPathComponent("Rules.json") {
do {
try encoded.write(to: destinationURL)
} catch {
print (error)
}
}
}
}
And write this in ContentBlockerRequestHandler class
func beginRequest(with context: NSExtensionContext) {
let sharedContainerURL = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "group.****.***")
let sourceURL = sharedContainerURL?.appendingPathComponent("Rules.json")
let ruleAttachment = NSItemProvider(contentsOf: sourceURL)
let item = NSExtensionItem()
item.attachments = ([ruleAttachment] as! [NSItemProvider])
context.completeRequest(returningItems: [item], completionHandler: nil)
}
i try to load using
SFContentBlockerManager.reloadContentBlocker(withIdentifier: "com.app.*****", completionHandler: {(error) in
if error != nil{
print("error: \(error.debugDescription)")
}
})
when try to execute 3rd number block at run time i'm getting an error. But i go to the file path and checked the json is absolutely fine, its a valid json there.
Error Domain=WKErrorDomain Code=2 "(null)" UserInfo={NSHelpAnchor=Rule list compilation failed: Failed to parse the JSON String.}
Try to use JSONSerialization. It work great for me :)
fileprivate func saveRuleFile() {
let ruleList = [["trigger":["url-filter": ".*"],"action":["type": "block"]]]
let jsonAsData = try! JSONSerialization.data(withJSONObject: ruleList)
let sharedContainerURL = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "group.****.***")
print("sharedContainerURL = \(String(describing: sharedContainerURL))")
if let destinationURL = sharedContainerURL?.appendingPathComponent("Rules.json") {
do {
try jsonAsData.write(to: destinationURL)
} catch {
print (error)
}
}
}
I am writing a piece of code in Swift to hit a public API endpoint to pull back data in JSON and use it in the application. I am using URLSession to do the request and am using an async/await similar paradigm to extract data out of the URLSession callback and place it in a local variable. Then, the function returns the optional dictionary returned by JSONSerialization to the caller.
This code executes perfectly fine outside of a function and run as part of the main program, but as soon as it is moved to a function, the return statement produces a "SIGILL" exit.
I breakpointed to the return statement and found that it is exactly what is throwing this error. Since this is an optional dictionary, I tried just returning an unwrapped version of the dictionary and found the same results. I also tried just returning a blank dictionary and I still get a SIGILL
Functioning:
let url = URL(string: <endpointURL>)!
var tenant: [String: Any]? = nil;
let sem = DispatchSemaphore(value: 1)
sem.wait()
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
if let data = data {
do {
let json = try JSONSerialization.jsonObject(with: data, options: []) as? [String: Any]
if let json = json {
print(json)
tenant = json
sem.signal()
} else {
print("ERR: Null JSON")
}
} catch let error as NSError {
print("ERR: " + error.localizedDescription)
}
} else if let error = error {
print("ERR: " + error.localizedDescription);
} else {
print("ERR: Unknown")
}
}
print("resuming")
task.resume()
print("waiting: ")
sem.wait()
print("done waiting")
print(tenant!["tenant_name"]!)
Fails:
let _ = HttpHelper.getTenantFor(tenantId: <someUUID>)
class HttpHelper {
static func getTenantFor(tenantId: String) -> [String:Any]? {
let url = URL(string: <endpointURL>)!
var tenant: [String: Any]? = nil;
let sem = DispatchSemaphore(value: 1)
sem.wait()
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
if let data = data {
do {
let json = try JSONSerialization.jsonObject(with: data, options: []) as? [String: Any]
if let json = json {
print(json)
tenant = json
sem.signal()
} else {
print("ERR: Null JSON")
}
} catch let error as NSError {
print("ERR: " + error.localizedDescription)
}
} else if let error = error {
print("ERR: " + error.localizedDescription);
} else {
print("ERR: Unknown")
}
}
print("resuming")
task.resume()
print("waiting: ")
sem.wait()
print("done waiting")
return [String:Any]()
}
}
On the functioning code, the app outputs the proper value for the "tenant_name" key in the JSON object and in the failed code I get the following:
Process finished with exit code 132 (interrupted by signal 4: SIGILL)
I'm having an issue printing data from Weather Underground. My code works with other data sources, just not Weather Underground. I have even tried replacing the URL with actual data (i.e. https://api.wunderground.com/api/APIKEY/forecast/geolookup/forecast/q/94129.json"), but it doesn't print.
Any suggestions on what it could be?
import Foundation
import UIKit
class APIManager {
func weatherJSON(zip: String, completion: #escaping ([Weather]) -> Void) {
let baseUrlString = "https://api.wunderground.com/api/APIKEY/forecast/geolookup/forecast/q/\(zip).json"
guard let url = URL(string: baseUrlString) else { return }
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
guard error == nil, let data = data else { return }
do {
guard let json = try JSONSerialization.jsonObject(with: data, options: []) as? [[String: Any]] else { return }
// MARK: Print JSON
print(json)
var weatherList = [Weather]()
for item in json {
if let weather = Weather.create(from: item) {
weatherList.append(weather)
}
}
completion(weatherList)
} catch {
print("Uh oh. You have an error with \(zip)!")
}
}
task.resume()
}
}
EDIT: SOLVED
I have used the code posted below and am now seeing errors.
I'd suggest changing this to report errors:
enum WeatherError Error {
case badURL
case invalidJSON
}
func weatherJSON(zip: String, completion: #escaping ([Weather]?, Error?) -> Void) {
let baseUrlString = "https://api.wunderground.com/api/APIKEY/forecast/geolookup/forecast/q/\(zip).json"
guard let url = URL(string: baseUrlString) else {
completion(nil, WeatherError.badURL)
return
}
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
guard error == nil, let data = data else {
completion(nil, error)
return
}
do {
guard let json = try JSONSerialization.jsonObject(with: data, options: []) as? [[String: Any]] else {
completion(nil, WeatherError.invalidJSON)
return
}
// MARK: Print JSON
print(json)
var weatherList = [Weather]()
for item in json {
if let weather = Weather.create(from: item) {
weatherList.append(weather)
}
}
completion(weatherList, nil)
} catch let parseError {
print("Uh oh. You have an error with \(zip)!")
if let responseString = String(data: data, encoding: .utf8) {
print("responseString = \(responseString)")
}
completion(nil, parseError)
}
}
task.resume()
}
Then, when you call it, you can see what the error was
weatherJSON(zip: something) { weatherReports, error in
guard let weatherReports = weatherReports, error == nil else {
print(error)
return
}
// use weatherReports here
}
This won't solve your problem, but it will help you diagnose what the issue is.
For some reason whenever I try to update my label with the current temperature using self.infoLabel.text = String(temp!) inside of the DispatchQueue code block, I get the following fatal error message:
unexpectedly found nil while unwrapping an Optional value.
I'd appreciate if someone could help me figure out why the code below isn't working. Thanks.
func getCurrentTemp(city: String){
let weatherRequestURL = URL(string: "\(openWeatherMapBaseURL)?APPID=\(openWeatherMapAPIKey)&q=\(city)")!
// The data task retrieves the data.
URLSession.shared.dataTask(with: weatherRequestURL) { (data, response, error) in
if let error = error {
// Case 1: Error
print("Error:\n\(error)")
}
else {
//print("Raw data:\n\(data!)\n")
//let dataString = String(data: data!, encoding: String.Encoding.utf8)
//print("Human-readable data:\n\(dataString!)")
do {
// Try to convert that data into a Swift dictionary
let weather = try JSONSerialization.jsonObject(with: data!, options:.allowFragments) as! [String:AnyObject]
if let main = weather["main"] as? [String: Any] {
let temp = main["temp"] as? Double
print("temp\(temp!)")
DispatchQueue.main.sync(execute: {
self.infoLabel.text = String(temp!)
})
//return temp as? String
//let temp_max = main["temp_max"] as? Double
//print("temp\(temp_max!)")
//let temp_min = main["temp_min"] as? Double
//print("temp\(temp_min!)")
}
}
catch let jsonError as NSError {
// An error occurred while trying to convert the data into a Swift dictionary.
print("JSON error description: \(jsonError.description)")
}
}
}
.resume()
}
There are two possibilities here: 1) either temp is nil (and it shouldn't be because you already force unwrap it in the print statement above) 2) or infoLabel is nil which happens if you broke your outlet connection.
Its easy to check; make a breakpoint above your assignment and in the debug console you can type:
po self.infoLabel
to see if its nil. For good measure you an also check temp.
You can also add a print statement to check self.infoLabel or an assert.
Alright, so I found a makeshift solution to this issue (See Below). Rather than placing the code inside of the function I made, I placed it in the viewDidLoad() function. For whatever reason, self.infoLabel? would be nil anywhere inside of the function I made.
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
print("Sucessful launched weather page.")
let weatherRequestURL = URL(string: "\(openWeatherMapBaseURL)?APPID=\(openWeatherMapAPIKey)&q=\(city)")!
// The data task retrieves the data.
URLSession.shared.dataTask(with: weatherRequestURL) { (data, response, error) in
if let error = error {
// Case 1: Error
print("Error:\n\(error)")
}
else {
//print("Raw data:\n\(data!)\n")
//let dataString = String(data: data!, encoding: String.Encoding.utf8)
//print("Human-readable data:\n\(dataString!)")
do {
// Try to convert that data into a Swift dictionary
let weather = try JSONSerialization.jsonObject(with: data!, options:.allowFragments) as! [String:AnyObject]
if let main = weather["main"] as? [String: Any] {
let temp = main["temp"] as? Double
print("temp\(temp!)")
var tempInFarenheit = ((9/5)*((temp!)-273) + 32).rounded()
DispatchQueue.main.sync(execute: {
self.infoLabel.text = "\(tempInFarenheit) + °"
})
}
}
catch let jsonError as NSError {
// An error occurred while trying to convert the data into a Swift dictionary.
print("JSON error description: \(jsonError.description)")
}
}
}
.resume()
}
Although this isn't the most effective way of doing things, hopefully it can help others who are having the same problem. If I find a more effective way of doing this, I'll be sure to edit this post and include it.
I wanted to be a type of variable to send to the dictionary server but But on the line I was faced with the problem let task = session.dataTaskWithRequest(todosUrlRequest) error : Cannot convert value of type 'NSURL' to expected argument type 'NSURLRequest'
I had two questions
1) What is this error?
2)Is there a procedure that I used for POST is that right? doesn't need anything else. ??
thank you for help
func data_request (){
let url = "http://sample.com/api/Flight/GetTicketInformation"
guard let todosUrlRequest = NSURL(string: url) else {
print("Error: cannot create URL")
return
}
let request = NSMutableURLRequest(URL: todosUrlRequest)
request.HTTPMethod = "POST"
request.cachePolicy = NSURLRequestCachePolicy.ReloadIgnoringCacheData
let newTodo = ["Roundtrip": roundTrip,
"OneWay": oneWay,
"MultiWay": multiWay,
"Adult": numberAdults,
"Child": numberchild,
"Baby": numberinfant,
"SourceCityId": cityIDOrigin,
"DestinationCityId": cityIDPurpose,
"DepartingDate": raftDate,
"ReturningDate": bargashtDate ]
let jsonTodo: NSData
do {
jsonTodo = try NSJSONSerialization.dataWithJSONObject(newTodo, options: [])
request.HTTPBody = jsonTodo
} catch {
print("Error: cannot create JSON from todo")
return
}
request.HTTPBody = jsonTodo
let config = NSURLSessionConfiguration.defaultSessionConfiguration()
let session = NSURLSession(configuration: config)
let task = session.dataTaskWithRequest(todosUrlRequest) {
(data, response, error) in
guard let responseData = data else {
print("Error: did not receive data")
return
}
guard error == nil else {
print("error calling POST on /todos/1")
print(error)
return
}
// parse the result as JSON, since that's what the API provides
do {
guard let receivedTodo = try NSJSONSerialization.JSONObjectWithData(responseData,
options: []) as? [String: AnyObject] else {
print("Could not get JSON from responseData as dictionary")
return
}
print("The todo is: " + receivedTodo.description)
} catch {
print("error parsing response from POST on /todos")
return
}
}
task.resume()
}
request instead of todosUrlRequest on the line let task = session.dataTaskWithRequest(todosUrlRequest)
for the second question, no idea . sorry
I can recommend you Alamofire for all requests, instead of writing all code on your own.
https://github.com/Alamofire/Alamofire