URLSession.shared.dataTask return zero bytes
My goal is to call a http service that returns a json to be parsed as an array of NewsModel objects.
I defined a struct like that
struct NewsModel: Decodable {
var id: Int
var title: String
var content: String
}
and wrote this method in Service.swift class:
func getNews(pageSize: Int, pageCount: Int, completion: @escaping ([NewsModel]?) -> ()) {
guard let url = URL(string: "(Service.baseURLSSMService)/news?pageSize=(pageSize)&pageCount=(pageCount)") else {return}
var retVal = [NewsModel]()
// Create URLRequest
var request = URLRequest(url: url)
// Set headers and http method
request.httpMethod = "GET"
request.cachePolicy = URLRequest.CachePolicy.reloadIgnoringLocalCacheData
request.setValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")
let task = URLSession.shared.dataTask(with: request) { (data, response, error) in
guard let dataResponse = data,
error == nil else {
print(error?.localizedDescription ?? "Response Error")
completion(nil)
return }
do{
print("RESPONSE:(response.debugDescription)")
retVal = try
JSONDecoder().decode([NewsModel].self, from: dataResponse)
completion(retVal)
} catch let parsingError {
print("Error", parsingError)
completion(nil)
}
}
task.resume()
}
I need to call this method from my HomeViewController. I used this code in my viewDidLoad:
Service.sharedInstance.getNews(pageSize: 10, pageCount: 1) { (news) in
// I need the first element of the news array
// I save it into a global variable
self.homeNews = news?.first
DispatchQueue.main.async {
if self.homeNews != nil {
self.myLabel.text = self.homeNews?.title
}
else {
self.myLabel.text = "No data received."
}
}
}
When I run the code, it always happens that the getNews function returns 0 bytes so nothing can be parsed by the JSONDecoder. This is the error message:
Error dataCorrupted(Swift.DecodingError.Context(codingPath: ,
debugDescription: "The given data was not valid JSON.",
underlyingError: Optional(Error Domain=NSCocoaErrorDomain Code=3840
"No value." UserInfo={NSDebugDescription=No value.})))
If I call it twice the last time proper values are received. What am I doing wrong? Because I guess I'm doing wrong something but I cannot get it.
EDIT 1:
This is a json sample:
[
{
"id": 2048,
"title": "title-sample-1",
"content": "content-sample-1"
},
{
"id": 2047,
"title": "title-sample-2",
"content": "content-sample-2"
}
]
EDIT 2:
Here is the response.debugDescription
RESPONSE:Optional(<NSHTTPURLResponse: 0x2830a1160> { URL: http://.../news?pageSize=1&pageCount=1 } { Status Code: 400, Headers {
Connection = (
close
);
Date = (
"Tue, 27 Nov 2018 15:38:38 GMT"
);
"Transfer-Encoding" = (
Identity
); } })
json swift urlsession nsurlsessiondatatask
asked Nov 27 '18 at 15:09
cicaletto79cicaletto79
979
|
show 11 more comments
My goal is to call a http service that returns a json to be parsed as an array of NewsModel objects.
I defined a struct like that
struct NewsModel: Decodable {
var id: Int
var title: String
var content: String
}
and wrote this method in Service.swift class:
func getNews(pageSize: Int, pageCount: Int, completion: @escaping ([NewsModel]?) -> ()) {
guard let url = URL(string: "(Service.baseURLSSMService)/news?pageSize=(pageSize)&pageCount=(pageCount)") else {return}
var retVal = [NewsModel]()
// Create URLRequest
var request = URLRequest(url: url)
// Set headers and http method
request.httpMethod = "GET"
request.cachePolicy = URLRequest.CachePolicy.reloadIgnoringLocalCacheData
request.setValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")
let task = URLSession.shared.dataTask(with: request) { (data, response, error) in
guard let dataResponse = data,
error == nil else {
print(error?.localizedDescription ?? "Response Error")
completion(nil)
return }
do{
print("RESPONSE:(response.debugDescription)")
retVal = try
JSONDecoder().decode([NewsModel].self, from: dataResponse)
completion(retVal)
} catch let parsingError {
print("Error", parsingError)
completion(nil)
}
}
task.resume()
}
I need to call this method from my HomeViewController. I used this code in my viewDidLoad:
Service.sharedInstance.getNews(pageSize: 10, pageCount: 1) { (news) in
// I need the first element of the news array
// I save it into a global variable
self.homeNews = news?.first
DispatchQueue.main.async {
if self.homeNews != nil {
self.myLabel.text = self.homeNews?.title
}
else {
self.myLabel.text = "No data received."
}
}
}
When I run the code, it always happens that the getNews function returns 0 bytes so nothing can be parsed by the JSONDecoder. This is the error message:
Error dataCorrupted(Swift.DecodingError.Context(codingPath: ,
debugDescription: "The given data was not valid JSON.",
underlyingError: Optional(Error Domain=NSCocoaErrorDomain Code=3840
"No value." UserInfo={NSDebugDescription=No value.})))
If I call it twice the last time proper values are received. What am I doing wrong? Because I guess I'm doing wrong something but I cannot get it.
EDIT 1:
This is a json sample:
[
{
"id": 2048,
"title": "title-sample-1",
"content": "content-sample-1"
},
{
"id": 2047,
"title": "title-sample-2",
"content": "content-sample-2"
}
]
EDIT 2:
Here is the response.debugDescription
RESPONSE:Optional(<NSHTTPURLResponse: 0x2830a1160> { URL: http://.../news?pageSize=1&pageCount=1 } { Status Code: 400, Headers {
Connection = (
close
);
Date = (
"Tue, 27 Nov 2018 15:38:38 GMT"
);
"Transfer-Encoding" = (
Identity
); } })
json swift urlsession nsurlsessiondatatask
asked Nov 27 '18 at 15:09
cicaletto79cicaletto79
979
It looks like your JSON doesn't match with your struct. Can you add your JSON please?
– Robert Dresler
Nov 27 '18 at 15:13
Have you tested your url in a web browser?
– Joakim Danielson
Nov 27 '18 at 15:13
Alsocompletion(retVal)needs to be within your do catch block
– Scriptable
Nov 27 '18 at 15:14
@RobertDresler I added a json sample in the EDIT 1 block. But I wonder why the second time the call works if the json doesn't not match my struct...
– cicaletto79
Nov 27 '18 at 15:22
add acompletion(nil)afterprint("Error", parsingError)andcompletion(retVal)afterretVal = try ...and removeDispatchQueue.main.async { completion(retVal) }
– Leo Dabus
Nov 27 '18 at 15:23
|
show 11 more comments
My goal is to call a http service that returns a json to be parsed as an array of NewsModel objects.
I defined a struct like that
struct NewsModel: Decodable {
var id: Int
var title: String
var content: String
}
and wrote this method in Service.swift class:
func getNews(pageSize: Int, pageCount: Int, completion: @escaping ([NewsModel]?) -> ()) {
guard let url = URL(string: "(Service.baseURLSSMService)/news?pageSize=(pageSize)&pageCount=(pageCount)") else {return}
var retVal = [NewsModel]()
// Create URLRequest
var request = URLRequest(url: url)
// Set headers and http method
request.httpMethod = "GET"
request.cachePolicy = URLRequest.CachePolicy.reloadIgnoringLocalCacheData
request.setValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")
let task = URLSession.shared.dataTask(with: request) { (data, response, error) in
guard let dataResponse = data,
error == nil else {
print(error?.localizedDescription ?? "Response Error")
completion(nil)
return }
do{
print("RESPONSE:(response.debugDescription)")
retVal = try
JSONDecoder().decode([NewsModel].self, from: dataResponse)
completion(retVal)
} catch let parsingError {
print("Error", parsingError)
completion(nil)
}
}
task.resume()
}
I need to call this method from my HomeViewController. I used this code in my viewDidLoad:
Service.sharedInstance.getNews(pageSize: 10, pageCount: 1) { (news) in
// I need the first element of the news array
// I save it into a global variable
self.homeNews = news?.first
DispatchQueue.main.async {
if self.homeNews != nil {
self.myLabel.text = self.homeNews?.title
}
else {
self.myLabel.text = "No data received."
}
}
}
When I run the code, it always happens that the getNews function returns 0 bytes so nothing can be parsed by the JSONDecoder. This is the error message:
Error dataCorrupted(Swift.DecodingError.Context(codingPath: ,
debugDescription: "The given data was not valid JSON.",
underlyingError: Optional(Error Domain=NSCocoaErrorDomain Code=3840
"No value." UserInfo={NSDebugDescription=No value.})))
If I call it twice the last time proper values are received. What am I doing wrong? Because I guess I'm doing wrong something but I cannot get it.
EDIT 1:
This is a json sample:
[
{
"id": 2048,
"title": "title-sample-1",
"content": "content-sample-1"
},
{
"id": 2047,
"title": "title-sample-2",
"content": "content-sample-2"
}
]
EDIT 2:
Here is the response.debugDescription
RESPONSE:Optional(<NSHTTPURLResponse: 0x2830a1160> { URL: http://.../news?pageSize=1&pageCount=1 } { Status Code: 400, Headers {
Connection = (
close
);
Date = (
"Tue, 27 Nov 2018 15:38:38 GMT"
);
"Transfer-Encoding" = (
Identity
); } })
json swift urlsession nsurlsessiondatatask
asked Nov 27 '18 at 15:09
cicaletto79cicaletto79
979
My goal is to call a http service that returns a json to be parsed as an array of NewsModel objects.
I defined a struct like that
struct NewsModel: Decodable {
var id: Int
var title: String
var content: String
}
and wrote this method in Service.swift class:
func getNews(pageSize: Int, pageCount: Int, completion: @escaping ([NewsModel]?) -> ()) {
guard let url = URL(string: "(Service.baseURLSSMService)/news?pageSize=(pageSize)&pageCount=(pageCount)") else {return}
var retVal = [NewsModel]()
// Create URLRequest
var request = URLRequest(url: url)
// Set headers and http method
request.httpMethod = "GET"
request.cachePolicy = URLRequest.CachePolicy.reloadIgnoringLocalCacheData
request.setValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")
let task = URLSession.shared.dataTask(with: request) { (data, response, error) in
guard let dataResponse = data,
error == nil else {
print(error?.localizedDescription ?? "Response Error")
completion(nil)
return }
do{
print("RESPONSE:(response.debugDescription)")
retVal = try
JSONDecoder().decode([NewsModel].self, from: dataResponse)
completion(retVal)
} catch let parsingError {
print("Error", parsingError)
completion(nil)
}
}
task.resume()
}
I need to call this method from my HomeViewController. I used this code in my viewDidLoad:
Service.sharedInstance.getNews(pageSize: 10, pageCount: 1) { (news) in
// I need the first element of the news array
// I save it into a global variable
self.homeNews = news?.first
DispatchQueue.main.async {
if self.homeNews != nil {
self.myLabel.text = self.homeNews?.title
}
else {
self.myLabel.text = "No data received."
}
}
}
When I run the code, it always happens that the getNews function returns 0 bytes so nothing can be parsed by the JSONDecoder. This is the error message:
Error dataCorrupted(Swift.DecodingError.Context(codingPath: ,
debugDescription: "The given data was not valid JSON.",
underlyingError: Optional(Error Domain=NSCocoaErrorDomain Code=3840
"No value." UserInfo={NSDebugDescription=No value.})))
If I call it twice the last time proper values are received. What am I doing wrong? Because I guess I'm doing wrong something but I cannot get it.
EDIT 1:
This is a json sample:
[
{
"id": 2048,
"title": "title-sample-1",
"content": "content-sample-1"
},
{
"id": 2047,
"title": "title-sample-2",
"content": "content-sample-2"
}
]
EDIT 2:
Here is the response.debugDescription
RESPONSE:Optional(<NSHTTPURLResponse: 0x2830a1160> { URL: http://.../news?pageSize=1&pageCount=1 } { Status Code: 400, Headers {
Connection = (
close
);
Date = (
"Tue, 27 Nov 2018 15:38:38 GMT"
);
"Transfer-Encoding" = (
Identity
); } })
json swift urlsession nsurlsessiondatatask
json swift urlsession nsurlsessiondatatask
asked Nov 27 '18 at 15:09
cicaletto79cicaletto79
979
asked Nov 27 '18 at 15:09
cicaletto79cicaletto79
979
edited Nov 27 '18 at 15:42
cicaletto79
asked Nov 27 '18 at 15:09
cicaletto79cicaletto79
979
asked Nov 27 '18 at 15:09
cicaletto79cicaletto79
979
asked Nov 27 '18 at 15:09
cicaletto79cicaletto79
979
979
It looks like your JSON doesn't match with your struct. Can you add your JSON please?
– Robert Dresler
Nov 27 '18 at 15:13
Have you tested your url in a web browser?
– Joakim Danielson
Nov 27 '18 at 15:13
Alsocompletion(retVal)needs to be within your do catch block
– Scriptable
Nov 27 '18 at 15:14
@RobertDresler I added a json sample in the EDIT 1 block. But I wonder why the second time the call works if the json doesn't not match my struct...
– cicaletto79
Nov 27 '18 at 15:22
add acompletion(nil)afterprint("Error", parsingError)andcompletion(retVal)afterretVal = try ...and removeDispatchQueue.main.async { completion(retVal) }
– Leo Dabus
Nov 27 '18 at 15:23
|
show 11 more comments
It looks like your JSON doesn't match with your struct. Can you add your JSON please?
– Robert Dresler
Nov 27 '18 at 15:13
Have you tested your url in a web browser?
– Joakim Danielson
Nov 27 '18 at 15:13
Alsocompletion(retVal)needs to be within your do catch block
– Scriptable
Nov 27 '18 at 15:14
@RobertDresler I added a json sample in the EDIT 1 block. But I wonder why the second time the call works if the json doesn't not match my struct...
– cicaletto79
Nov 27 '18 at 15:22
add acompletion(nil)afterprint("Error", parsingError)andcompletion(retVal)afterretVal = try ...and removeDispatchQueue.main.async { completion(retVal) }
– Leo Dabus
Nov 27 '18 at 15:23
It looks like your JSON doesn't match with your struct. Can you add your JSON please?
– Robert Dresler
Nov 27 '18 at 15:13
It looks like your JSON doesn't match with your struct. Can you add your JSON please?
– Robert Dresler
Nov 27 '18 at 15:13
Have you tested your url in a web browser?
– Joakim Danielson
Nov 27 '18 at 15:13
Have you tested your url in a web browser?
– Joakim Danielson
Nov 27 '18 at 15:13
Also
completion(retVal) needs to be within your do catch block– Scriptable
Nov 27 '18 at 15:14
Also
completion(retVal) needs to be within your do catch block– Scriptable
Nov 27 '18 at 15:14
@RobertDresler I added a json sample in the EDIT 1 block. But I wonder why the second time the call works if the json doesn't not match my struct...
– cicaletto79
Nov 27 '18 at 15:22
@RobertDresler I added a json sample in the EDIT 1 block. But I wonder why the second time the call works if the json doesn't not match my struct...
– cicaletto79
Nov 27 '18 at 15:22
add a
completion(nil) after print("Error", parsingError) and completion(retVal) after retVal = try ... and remove DispatchQueue.main.async { completion(retVal) }– Leo Dabus
Nov 27 '18 at 15:23
add a
completion(nil) after print("Error", parsingError) and completion(retVal) after retVal = try ... and remove DispatchQueue.main.async { completion(retVal) }– Leo Dabus
Nov 27 '18 at 15:23
|
show 11 more comments
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It looks like your JSON doesn't match with your struct. Can you add your JSON please?
– Robert Dresler
Nov 27 '18 at 15:13
Have you tested your url in a web browser?
– Joakim Danielson
Nov 27 '18 at 15:13
Also
completion(retVal)needs to be within your do catch block– Scriptable
Nov 27 '18 at 15:14
@RobertDresler I added a json sample in the EDIT 1 block. But I wonder why the second time the call works if the json doesn't not match my struct...
– cicaletto79
Nov 27 '18 at 15:22
add a
completion(nil)afterprint("Error", parsingError)andcompletion(retVal)afterretVal = try ...and removeDispatchQueue.main.async { completion(retVal) }– Leo Dabus
Nov 27 '18 at 15:23