let todoEndpoint: String ="http://localhost:16789/api/product"
guard let url = NSURL(string: todoEndpoint) else {
print("Error: cannot create URL")
return
}
let urlRequest = NSURLRequest(url: url as URL)
let config = URLSessionConfiguration.default
let session = URLSession(configuration: config)
let task = session.dataTask(with: urlRequest as URLRequest) {
(data, response, error) in
guard let responseData = data else {
print("Error: did not receive data")
return
}
guard error == nil else {
print("error calling GET")
print(error)
return
}
do{
self.users = try JSONSerialization.jsonObject(with: responseData, options: []) as? Array}
catch{
print("Error parsing")
}
}
task.resume()
this is my Output my API
[{"ProductId":2,"Category":"Laptop","Brand":"Apple","ModelName":"MacBook Pro","SerialNumber":"Test1","DatePurchased":"2016-08-12T00:00:00","EmployeeName":"Vismita Shetty","DateAssigned":"2017-01-17T00:00:00"},{"ProductId":4,"Category":"Keyboard","Brand":"Logitech","ModelName":"K200","SerialNumber":"TestKeyboard1","DatePurchased":"2017-01-23T03:02:13.247","EmployeeName":"Vismita Shetty","DateAssigned":"2017-01-17T00:00:00"},{"ProductId":5,"Category":"Keyboard","Brand":"Logitech","ModelName":"K200","SerialNumber":"testkeyboard2","DatePurchased":"2017-01-23T03:03:26.07","EmployeeName":"Suraj Pangam","DateAssigned":"2017-01-17T00:00:00"}]
What I currently trying to do convert user into different variable which will be of type Array of dictionaries in swift. So that Each object can be accessed by key. I want to make it generic so that even some properties got changed it won't matter as it won't be accessed by providing property name. Like (users[indexPath.row] as? [String: AnyObject])?["EmployeeName"] as! String!.
Instead if i make it to dictionary i will be easily do it by running for (key,value) loop for array of dictionary.
Related
I'm trying to set up POST requests to connect my Swift Project to my SQL server. I found a lot of good resources on how to create the POST requests, and my code seems to create the request fine. However, it always returns a null string instead of the desired output string. How can I get the request to submit with the correct string?
My POST function:
func addString() {
// declare the parameter as a dictionary that contains string as key and value combination. considering inputs are valid
let parameters: [String: Any] = ["textstring":"Testing..."]
// create the url with URL
let url = URL(string: "http://localhost:3000/strings")! // change server url accordingly
// create the session object
let session = URLSession.shared
// now create the URLRequest object using the url object
var request = URLRequest(url: url)
request.httpMethod = "POST" //set http method as POST
// add headers for the request
request.addValue("application/json", forHTTPHeaderField: "Content-Type") // change as per server requirements
do {
// convert parameters to Data and assign dictionary to httpBody of request
request.httpBody = try JSONSerialization.data(withJSONObject: parameters, options: .prettyPrinted)
} catch let error {
print(error.localizedDescription)
return
}
// create dataTask using the session object to send data to the server
let task = session.dataTask(with: request) { data, response, error in
if let error = error {
print("Post Request Error: \(error.localizedDescription)")
return
}
// ensure there is valid response code returned from this HTTP response
guard let httpResponse = response as? HTTPURLResponse,
(200...299).contains(httpResponse.statusCode)
else {
print("Invalid Response received from the server")
return
}
// ensure there is data returned
guard let responseData = data else {
print("nil Data received from the server")
return
}
do {
// create json object from data or use JSONDecoder to convert to Model struct
if let jsonResponse = try JSONSerialization.jsonObject(with: responseData, options: .mutableContainers) as? [String: Any] {
print(jsonResponse)
// handle json response
} else {
print("data maybe corrupted or in wrong format")
throw URLError(.badServerResponse)
}
} catch let error {
print(error.localizedDescription)
}
}
// perform the task
task.resume()
}
My Object TextString that emulates the SQL table (Table "strings" has two columns: "id" (SERIAL PRIMARY KEY) and "textstring" (VARCHAR(255))
struct TextString: Codable, Hashable, Identifiable {
var id: Int
var textString: String
enum CodingKeys: String, CodingKey {
case id = "string_id"
case textString = "textstring"
}}
My response output:
["string_id": 28, "textstring": <null>]
I'm thinking that the issue is with the serialization but the code is taken almost directly from a youtube video where the test cases are shown and they work. Does anyone know why the output returns "textstring" as null and not "Testing..."?
Thanks in advance!
I have some trouble with the code below.
Though it works, there is some timing problem.
First let me say what I expect, I suppose the completion handler should be run when the data download is complete and my image ready to use. But reality seems to be quite different. When I try it the completion handler is called right away (I can see 'All OK' in the console) as if everything was instantaneous. But the image gets actually displayed much later. What am I missing?
let imageURL = URL(string: myURLString)
session = URLSession.shared,
_ = session.dataTask(with: imageURL) {[weak self]
(data: Data?, response: URLResponse?, error: Error?) in
if error == nil {
print("All OK")
self?.theImage = UIImage(data: data!)
self?.theView.image = self?.theImage
} else {print(error!)}
DispatchQueue.main.async {
self?.activityIndicator.stopAnimating()
self?.theView.setNeedsDisplay()
}
}.resume()
Can you try this code?
The control should not be actually going inside the handler at first call. And I think there are a few mistakes in your code as well which I pointed out earlier, especially the main thread is required for updating UI.
let session : URLSession
let config = URLSessionConfiguration.default
var resultFromServer: Any?
let responseResultData = [String:Any]()
session = URLSession(configuration: config, delegate: nil, delegateQueue: nil)
session.dataTask(with: request) { (data, response, error ) in
if error != nil {
DispatchQueue.main.async(execute: {
session.invalidateAndCancel()
})
}else{
let httpResponse: HTTPURLResponse = response as! HTTPURLResponse
do{
resultFromServer = try JSONSerialization.jsonObject(with: data!, options: JSONSerialization.ReadingOptions.mutableContainers)
if httpResponse.statusCode == 200 || httpResponse.statusCode == 201 || httpResponse.statusCode == 202 || httpResponse.statusCode == 204 || httpResponse.statusCode == 203 {
if let respArr = resultFromServer as? [Any]{
//resp is array
}else if let respdict = resultFromServer as? [String : Any] {
//resp is dict
}else{
//resp is something else maybe string, etc
}
}
else {
//error status code something like 500, 404, etc
}
}
catch let error as NSError {
DispatchQueue.main.async(execute: {
session.invalidateAndCancel()
})
}
}
session.finishTasksAndInvalidate()
}.resume()
I have the following code snippet to load an image from an url:
let url = NSURL(string: imageUrl)
let data = NSData(contentsOfURL: url!)
let image = UIImage(data: data!)
In case that my variable imageUrl has a valid string value, what is the most secure way to protect this code against possible edge cases?
Following code seems not to be very handy:
if let url = NSURL(string: imageUrl) {
if let data = NSData(contentsOfURL: url) {
if let image = UIImage(data: data) {
// success -> do something with the image...
}
else {
// print error message
}
}
else {
// print error message
}
}
else {
// print error message
}
The best practice is not to use a synchronous method like contentsOfURL to load data from over the network.
The recommended way is NSURLSession which works asynchronously.
This is a simple example with a completion block and an enum with associated types,
it catches all possible errors
enum Result {
case Success(UIImage), Failure(NSString)
}
func loadImage(string : String, completion: (Result) -> ()) {
guard let url = NSURL(string: string) else {
completion(.Failure("Bad URL"))
return
}
NSURLSession.sharedSession().dataTaskWithURL(url) { (data, response, error) in
if error != nil {
completion(.Failure(error!.localizedDescription))
} else {
guard let image = UIImage(data: data!) else {
completion(.Failure("Could not load image data"))
return
}
completion(.Success(image))
}
}.resume()
}
Call it with:
loadImage("http://myserver.com/path/to/image.png") { result in
switch result {
case .Success(let image) :
// do something with the image
case .Failure(let error) :
print(error)
}
}
My server (CakePHP) is responding like so:
$this->response->statusCode('400');
$this->response->type('json');
$this->response->body(json_encode(array('message' => 'Bookmark already exists')));
The Postman output looks like what you would expect:
{"message":"Bookmark already exists"}
The problem is that I cannot find a way to access this message from the failure handler (Alamofire 3.1.3 + SwiftyJSON 2.3.2)
Alamofire.request(.POST...
.validate()
.responseJSON { response in
switch response.result {
case .Success(_):
// All good
case .Failure(let error):
// Status code 400
print(response.request) // original URL request
print(response.response) // URL response
print(response.data) // server data
print(response.result)
I cannot find a way to cast response.data to JSON as a I simply get nil and the result returns just FAILURE.
Is there a way to access this server message from the failure handler ?
The data is not parsed in the .Failure case per the Alamofire 3.0 migration guide. However, server data is still available in response.data and can be parsed.
Below should work to parse this manually:
Alamofire.request(.POST, "https://example.com/create", parameters: ["foo": "bar"])
.validate()
.responseJSON { response in
switch response.result {
case .Success:
print("Validation Successful")
case .Failure(_):
var errorMessage = "General error message"
if let data = response.data {
let responseJSON = JSON(data: data)
if let message: String = responseJSON["message"].stringValue {
if !message.isEmpty {
errorMessage = message
}
}
}
print(errorMessage) //Contains General error message or specific.
}
}
}
This uses SwiftyJSON which provides the JSON struct to convert NSData. Parsing NSData to JSON can done without SwiftyJSON, answered here.
Another cleaner option might be to write a Custom Response Serializer.
A method with the router and no SwiftyJSON:
Alamofire.request(APIRouter.Register(params: params)).validate().responseJSON { response in
switch response.result {
case .Success(let json):
let message = json["clientMessage"] as? String
completion(.Success(message ?? "Success"))
case .Failure(let error):
var errorString: String?
if let data = response.data {
if let json = try? JSONSerialization.jsonObject(with: data, options: []) as? [String: String] {
errorString = json["error"]
}
}
completion(.Error(errorString ?? error.localizedDescription))
}
}
I have used the following lines to read the response body from a Alamofire request.
Alamofire.request(.POST, serveraddress, headers: headers, encoding: .JSON)
.response{ request, response, data, error in
let responseData = String(data: data!, encoding: NSUTF8StringEncoding)
print(responseData)
}
With this body I can get my custom server response errormessage.
best regards
For Alamofire 4.0 and above :
Try this
response.response?.statusCode
url : "YOUR-URL"
parameters: "YOUR PARAMETER DICTIONARY"
headers: "YOUR HEADER DICTIONARY"
I am using SwiftyJSON for JSON Parsing
A sample request is here :
func createPostRequestWith(path: String?,
parameters: [String : Any]? = nil,
success : #escaping (Any?) -> (),
failure : #escaping (NSError) -> ()) {
if !(Alamofire.NetworkReachabilityManager()?.isReachable)! {
let error = NSError(domain: "", code: -1003, userInfo: nil)
failure(error)
} else {
guard let url = path else { return }
Alamofire.request(url, method: .post, parameters: parameters, encoding: JSONEncoding.default, headers: createCurrentHeader()).validate(statusCode: 200..<300).responseJSON {
response in
switch response.result {
//Remove loader here either after parsing or on error
case .success(let data):
success(data)
case .failure(let error):
print(error)
if let responseData = response.data {
var parsedResponseData = JSON.init(data: responseData)
let customError = NSError(domain: parsedResponseData["message"].stringValue, code: response.response?.statusCode ?? 555, userInfo: nil)
failure(customError as NSError)
} else {
failure(error as NSError)
}
}
}
}
}
Trying to pass an Authentication header in, using the recommended approach of a custom URLRequestConvertible.
So here is my URLRequestConvertible object that conforms to the protocol:
class SecureJSONRouter : URLRequestConvertible {
var type: String
var token: String
var parameters: [String: AnyObject]
init(typevar: String, tokenvar: String, parametersvar: [String: AnyObject]) {
type = typevar
token = tokenvar
parameters = parametersvar
}
var URLRequest: NSURLRequest {
let URL = NSURL(string: da_url)!
let URLRequesting = NSMutableURLRequest(URL: URL.URLByAppendingPathComponent(type))
let encoding = Alamofire.ParameterEncoding.JSON
URLRequesting.setValue(token, forHTTPHeaderField: "Authorization")
return encoding.encode(URLRequesting, parameters: parameters).0
}
}
It's basically a place to store a few things, like a bit of URL, and a token, and a way to create a NSURLRequest with a full URL, the JSON parameters, and the header field for authorization.
When I try to call it like this:
let myUrlRequest: URLRequestConvertible = SecureJSONRouter(typevar: "locations", tokenvar: token!, parametersvar: parameters)
Alamofire.request(myUrlRequest).response{ (req, resp, data, error) in
if (error != nil) {
println(req)
println(resp)
} else {
println("saved \(data)")
}
}
it won't compile, gives me a "Missing argument for parameter #2 in call" error, at the request line.
Any ideas?
PS: I did have my SecureJSONRouter thingy as the recommended Enum instead of a Class, but I got the same error. I was looking at the protocol definition, and figured there's no reason it can't be a simpler (class) in my case, so I changed it. Still the same error.
I think there's a few possible culprits here. First off, are you sure you're calling Alamofire and not AlamoFire? I've seen people make that mistake before.
As for the sample code you posted, it didn't compile for a few different reasons. I couldn't reproduce exactly the same compiler errors you were seeing, but here's a slightly modified version of you original post that does compile.
class SecureJSONRouter : URLRequestConvertible {
var type: String
var token: String
var parameters: [String: AnyObject]
init(typevar: String, tokenvar: String, parametersvar: [String: AnyObject]) {
type = typevar
token = tokenvar
parameters = parametersvar
}
var URLRequest: NSURLRequest {
let URL = NSURL(string: "http://httpbin.org")!
let URLRequesting = NSMutableURLRequest(URL: URL.URLByAppendingPathComponent(type))
let encoding = Alamofire.ParameterEncoding.JSON
URLRequesting.setValue(token, forHTTPHeaderField: "Authorization")
return encoding.encode(URLRequesting, parameters: parameters).0
}
}
Then here's an example of calling your SecureJSONRouter.
let token: String? = "my_fancy_token"
let parameters: [String: AnyObject] = ["sample_parameter": "sample_parameter_value"]
let myUrlRequest: URLRequestConvertible = SecureJSONRouter(typevar: "locations", tokenvar: token!, parametersvar: parameters)
Alamofire.request(myUrlRequest).response{ (req, resp, data, error) in
if (error != nil) {
println(req)
println(resp)
} else {
println("saved \(data)")
}
}
That is compiling with Xcode 6.1.1 against the Alamofire 1.1.3 release. Hope that helps!