It appears to me that the documentation PubNub has for getting started in Swift don't apply to versions earlier than PubNub 4.0. I can't successfully establish a callback to register with PubNub.
My code:
class Communicator: NSObject, PNObjectEventListener {
var pubNubClient: PubNub
override init(){
let config = PNConfiguration(
publishKey: "my_publish_key",
subscribeKey: "my_subscribe_key"
)
pubNubClient = PubNub.clientWithConfiguration(config);
super.init()
pubNubClient.addListener(self)
pubNubClient.subscribeToChannels(["my_channel"], withPresence: false)
}
func didReceiveMessage(client: PubNub!, message: PNMessageResult!){
/* THIS METHOD NEVER GETS REACHED */
}
}
Digging into the PubNub source a bit, this is the area that seems to be having problems:
- (void)addListener:(id <PNObjectEventListener>)listener {
dispatch_async(self.resourceAccessQueue, ^{
if ([listener respondsToSelector:#selector(client:didReceiveMessage:)]) {
/* this block is never reached!!! */
[self.messageListeners addObject:listener];
}
/* Remaining Lines Stripped Away */
});
}
I'm still relatively new to Swift and integrating with Objective C. I'm curious if there's a problem with the respondsToSelector since the Objective C code is referencing Swift code.
The messages are definitely getting passed; there's another lower level function in the PubNub library that's logging all the messages received.
Any help would be much appreciated.
Versions prior to 4.0 are deprecated and wont work exactly how they used to.
I would recommend migrating over to the newest (4.0) SDK entirely, the new iOS SDK has removed a lot of bloat and compiles much faster. To get started view this tutorial.
To summarize, instantiating a PubNub client look as follows:
let config = PNConfiguration(
publishKey: "Your_Pub_Key",
subscribeKey: "Your_Sub_Key")
client = PubNub.clientWithConfiguration(config)
client?.addListener(self)
client?.subscribeToChannels(["Your_Channel"], withPresence: false)
And the new didReceiveMessage function looks as follows:
func client(client: PubNub!, didReceiveMessage message: PNMessageResult!, withStatus status: PNErrorStatus!) {
//Do Something like
//println(message)
}
Resolved by adding:
func client(client: PubNub!, didReceiveMessage message: PNMessageResult!) {
}
The documentation on how to parse the received PNMessageResult is scant. Here's how I handled it:
func client(client: PubNub!, didReceiveMessage message: PNMessageResult!) {
let encodedMessage = message.data.valueForKey("message") as! NSDictionary
let messageType = encodedMessage["meta"]! as! String
let messageString = encodedMessage["data"]!["msg"]! as! String
print("PubNub: [\(messageType)] \(messageString)")
}
add _ client works for me!
func client(_ client: PubNub, didReceiveMessage message: PNMessageResult) {
print("Pubnub Message: \(message)")
}
Related
I am creating a messaging app with SwiftUI, and I want to add video calling function to that. I used SkyWay webRTC API (https://webrtc.ecl.ntt.com/en/) to achieve this and I could build an example project written in swift code. Now what I am trying is linking local stream with SKWVideo view and wrapping it up into UIViewRepresentable. But I got stuck with bellow error message.
import SwiftUI
import SkyWay
import UIKit
struct ContentView: View {
#State var video = SKWVideo()
var body: some View {
VideoView(localStreamView: $video)
}
}
struct VideoView: UIViewRepresentable {
#Binding var localStreamView: SKWVideo
func makeUIView(context: Context) -> SKWVideo {
let option: SKWPeerOption = SKWPeerOption.init()
option.key = "xxxx"
option.domain = "localhost"
let peer = SKWPeer(options: option)
SKWNavigator.initialize(peer!)
let constraints: SKWMediaConstraints = SKWMediaConstraints()
let localStream = SKWNavigator.getUserMedia(constraints)
localStream?.addVideoRenderer(localStreamView, track: 0)
return localStreamView
}
func updateUIView(_ uiView: SKWVideo, context: Context) {
//
}
}
I got this error
Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Modifications to the layout engine must not be performed from a background thread after it has been accessed from the main thread.'
I ran it on a iPhone 7 real device, and I wrote plist settings. I have completely no idea right now. Please help me..
iOS 13.0
xcode 11.0
I am using WebRTC and its using AVCaptureSession. It works fine a few times but sometimes its getting crashed with this Exception.
Assertion failed: (_internal->figCaptureSession == NULL), function
-[AVCaptureVideoPreviewLayer attachToFigCaptureSession:], file /BuildRoot/Library/Caches/com.apple.xbs/Sources/EmbeddedAVFoundation/EmbeddedAVFoundation-1187.37.2.1/Aspen/AVCaptureVideoPreviewLayer.m
I recently had this problem aswell. In my code i kept an instance of AVCaptureOutput and added and removed it. When trying to add the same AVCaptureOutput instance to the same capture session again, this error appeared.
This is how i solved it:
private var _captureOutput: AVCaptureOutput?
var captureOutput: AVCaptureOutput {
guard let captureOutput = _captureOutput else {
let photoOutput = AVCapturePhotoOutput()
photoOutput.isHighResolutionCaptureEnabled = true
_captureOutput = photoOutput
return photoOutput
}
return captureOutput
}
Initialize the instance once when needed and when removed, also nullify it.
captureSession.outputs.forEach { [weak self] output in
self?.captureSession.removeOutput(output)
self?._captureOutput = nil
}
Before using instance of RTCCameraPreviewView you have to nill'ify its captureSession and assert will go away. Faced same issue.
So far tvOS supports two ways to make tv apps, TVML and UIKit, and there is no official mentions about how to mix up things to make a TVML (that is basically XML) User Interface with the native counter part for the app logic and I/O (like playback, streaming, iCloud persistence, etc).
So, which is the best solution to mix TVML and UIKit in a new tvOS app?
In the following I have tried a solution following code snippets adapted from Apple Forums and related questions about JavaScriptCore to ObjC/Swift binding.
This is a simple wrapper class in your Swift project.
import UIKit
import TVMLKit
#objc protocol MyJSClass : JSExport {
func getItem(key:String) -> String?
func setItem(key:String, data:String)
}
class MyClass: NSObject, MyJSClass {
func getItem(key: String) -> String? {
return "String value"
}
func setItem(key: String, data: String) {
print("Set key:\(key) value:\(data)")
}
}
where the delegate must conform a TVApplicationControllerDelegate:
typealias TVApplicationDelegate = AppDelegate
extension TVApplicationDelegate : TVApplicationControllerDelegate {
func appController(appController: TVApplicationController, evaluateAppJavaScriptInContext jsContext: JSContext) {
let myClass: MyClass = MyClass();
jsContext.setObject(myClass, forKeyedSubscript: "objectwrapper");
}
func appController(appController: TVApplicationController, didFailWithError error: NSError) {
let title = "Error Launching Application"
let message = error.localizedDescription
let alertController = UIAlertController(title: title, message: message, preferredStyle:.Alert ) self.appController?.navigationController.presentViewController(alertController, animated: true, completion: { () -> Void in
})
}
func appController(appController: TVApplicationController, didStopWithOptions options: [String : AnyObject]?) {
}
func appController(appController: TVApplicationController, didFinishLaunchingWithOptions options: [String : AnyObject]?) {
}
}
At this point the javascript is very simple like. Take a look at the methods with named parameters, you will need to change the javascript counter part method name:
App.onLaunch = function(options) {
var text = objectwrapper.getItem()
// keep an eye here, the method name it changes when you have named parameters, you need camel case for parameters:
objectwrapper.setItemData("test", "value")
}
App. onExit = function() {
console.log('App finished');
}
Now, supposed that you have a very complex js interface to export like
#protocol MXMJSProtocol<JSExport>
- (void)boot:(JSValue *)status network:(JSValue*)network user:(JSValue*)c3;
- (NSString*)getVersion;
#end
#interface MXMJSObject : NSObject<MXMJSProtocol>
#end
#implementation MXMJSObject
- (NSString*)getVersion {
return #"0.0.1";
}
you can do like
JSExportAs(boot,
- (void)boot:(JSValue *)status network:(JSValue*)network user:(JSValue*)c3 );
At this point in the JS Counter part you will not do the camel case:
objectwrapper.bootNetworkUser(statusChanged,networkChanged,userChanged)
but you are going to do:
objectwrapper.boot(statusChanged,networkChanged,userChanged)
Finally, look at this interface again:
- (void)boot:(JSValue *)status network:(JSValue*)network user:(JSValue*)c3;
The value JSValue* passed in. is a way to pass completion handlers between ObjC/Swift and JavaScriptCore. At this point in the native code you do all call with arguments:
dispatch_async(dispatch_get_main_queue(), ^{
NSNumber *state = [NSNumber numberWithInteger:status];
[networkChanged.context[#"setTimeout"]
callWithArguments:#[networkChanged, #0, state]];
});
In my findings, I have seen that the MainThread will hang if you do not dispatch on the main thread and async. So I will call the javascript "setTimeout" call that calls the completion handler callback.
So the approach I have used here is:
Use JSExportAs to take car of methods with named parameters and avoid to camel case javascript counterparts like callMyParam1Param2Param3
Use JSValue as parameter to get rid of completion handlers. Use callWithArguments on the native side. Use javascript functions on the JS side;
dispatch_async for completion handlers, possibly calling a setTimeout 0-delayed in the JavaScript side, to avoid the UI to freeze.
[UPDATE]
I have updated this question in order to be more clear. I'm finding a technical solution for bridging TVML and UIKit in order to
Understand the best programming model with JavaScriptCode
Have the right bridge from JavaScriptCore to ObjectiveC and
viceversa
Have the best performances when calling JavaScriptCode from Objective-C
This WWDC Video explains how to communicate between JavaScript and Obj-C
Here is how I communicate from Swift to JavaScript:
//when pushAlertInJS() is called, pushAlert(title, description) will be called in JavaScript.
func pushAlertInJS(){
//allows us to access the javascript context
appController!.evaluateInJavaScriptContext({(evaluation: JSContext) -> Void in
//get a handle on the "pushAlert" method that you've implemented in JavaScript
let pushAlert = evaluation.objectForKeyedSubscript("pushAlert")
//Call your JavaScript method with an array of arguments
pushAlert.callWithArguments(["Login Failed", "Incorrect Username or Password"])
}, completion: {(Bool) -> Void in
//evaluation block finished running
})
}
Here is how I communicate from JavaScript to Swift (it requires some setup in Swift):
//call this method once after setting up your appController.
func createSwiftPrint(){
//allows us to access the javascript context
appController?.evaluateInJavaScriptContext({(evaluation: JSContext) -> Void in
//this is the block that will be called when javascript calls swiftPrint(str)
let swiftPrintBlock : #convention(block) (String) -> Void = {
(str : String) -> Void in
//prints the string passed in from javascript
print(str)
}
//this creates a function in the javascript context called "swiftPrint".
//calling swiftPrint(str) in javascript will call the block we created above.
evaluation.setObject(unsafeBitCast(swiftPrintBlock, AnyObject.self), forKeyedSubscript: "swiftPrint" as (NSCopying & NSObjectProtocol)?)
}, completion: {(Bool) -> Void in
//evaluation block finished running
})
}
[UPDATE] For those of you who would like to know what "pushAlert" would look like on the javascript side, I'll share an example implemented in application.js
var pushAlert = function(title, description){
var alert = createAlert(title, description);
alert.addEventListener("select", Presenter.load.bind(Presenter));
navigationDocument.pushDocument(alert);
}
// This convenience funnction returns an alert template, which can be used to present errors to the user.
var createAlert = function(title, description) {
var alertString = `<?xml version="1.0" encoding="UTF-8" ?>
<document>
<alertTemplate>
<title>${title}</title>
<description>${description}</description>
</alertTemplate>
</document>`
var parser = new DOMParser();
var alertDoc = parser.parseFromString(alertString, "application/xml");
return alertDoc
}
You sparked an idea that worked...almost. Once you have displayed a native view, there is no straightforward method as-of-yet to push an TVML-based view onto the navigation stack. What I have done at this time is:
let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
appDelegate.appController?.navigationController.popViewControllerAnimated(true)
dispatch_async(dispatch_get_main_queue()) {
tvmlContext!.evaluateScript("showTVMLView()")
}
...then on the JavaScript side:
function showTVMLView() {setTimeout(function(){_showTVMLView();}, 100);}
function _showTVMLView() {//push the next document onto the stack}
This seems to be the cleanest way to move execution off the main thread and onto the JSVirtualMachine thread and avoid the UI lockup. Notice that I had to pop at the very least the current native view controller, as it was getting sent a deadly selector otherwise.
Does anybody know how handlers (blocks) work in swift? I am trying to get this code running but i can't find any documentation of the right syntax for the completionHandler.
let url:NSURL = NSURL(string:"some url")
let request:NSURLRequest = NSURLRequest(URL:url)
let queue:NSOperationQueue = NSOperationQueue()
NSURLConnection.sendAsynchronousRequest(request:request, queue:queue, completionHandler handler:((NSURLResponse!, NSData!, NSError!) -> Void)!)
Like this:
NSURLConnection.sendAsynchronousRequest(request, queue: queue, completionHandler:{ response, data, error in /* Your code */ })
Or more verbose variant.
NSURLConnection.sendAsynchronousRequest(request, queue: queue, completionHandler:{ (response: NSURLResponse!, data: NSData!, error: NSError!) -> Void in
/* Your code */
})
You need to use this code:
NSURLConnection.sendAsynchronousRequest(request,queue:queue,completionHandler:{response,data,error in /* code goes here */ })
For more info, you can refer to this tutorial, or or check the answers to How to parse a JSON file in swift?.
sendAsynchronousRequest has been deprecated in newer versions of Swift. Move to dataTaskWithRequest, luckily it is used pretty much the same way
let request:NSURLRequest = NSURLRequest(URL:NSURL(string:"http://YOUR_DESIRED_URL.com")!)
let config = NSURLSessionConfiguration.defaultSessionConfiguration()
let session = NSURLSession(configuration: config)
let task = session.dataTaskWithRequest(request, completionHandler: {(data, response, error) in
});
task.resume()
The right term you are looking for here is Closure. Closures in Swift are similar to blocks in C and Objective-C. In addition to Tomáš's answer there is another short version to use the completion handler here:
NSURLConnection.sendAsynchronousRequest(request, queue: queue, completionHandler: {$0; $1; $2})
Here I have used Shorthand Argument Names. I am accessing response as $0, data as $1 and error as $3. I find this syntax more easy to read and write unless the parameters are large in number otherwise the code will become unreadable.
I'm currently using WCF in monotouch to call an existing service and a custom UIAlertView.
The problem is that if I create an UIAlertView as class instance and the I do the following:
public override void ViewDidAppear()
{
_alertView.Message = "Loading...";
_alertView.Show();
_client.GetDataAsync("test");
_client.GetDataCompleted += GetDataCompletedDelegate;
base.ViewDidAppear();
}
void GetDataCompletedDelegate(object sender, GetDataEventArgs)
{
// do someting with data
_alertView.Hide();
}
it works but this advice is written in console : UIAlertView: wait_fences: failed to receive reply: 10004003
else, if I try to run this code:
public override void ViewDidAppear()
{
using(CustomAV _alertView = new CustomAV())
{
_alertView.Message = "Loading...";
_alertView.Show();
_client.GetDataAsync("test");
_client.GetDataCompleted += delegate{
InvokeOnMainThread(delegate{
// do someting with data
_alertView.Hide();
});
};
}
base.ViewDidAppear();
}
the first time the code run, but now alert is shown. The second time the simulator can't startup. Couldn't register "com.yourcompany.wcftest" with the bootstrap server. Error: unknown error code. This generally means that another instance of this process was already running or is hung in the debugger.StackTrace. In this case I have to reboot the machine.
Thank you in advance.
EDIT:
Thank you Geoff, I've checked my code and into GetDataCompletedDelegate I've inserted a function that runs inside the UI Thread.
InvokeOnMainThread(delegate{
doSomething();
});
private void doSomething()
{
// do stuff here
_alertView.Hide();
}
The fency error continues to appear. If I use your solution inside doSomething() method, it works
_alertView.InvokeOnMainThread(delegate{
_alertView.Hide();
});
Why? Maybe I didn't understand, but in the first snippet of code do something() works in the UI thread!! Isn't true?
You have 2 seperate problems here.
1: _alertView.Hide () is not running on the UI thread (this is what causes the fences error)
2: In your second example you're disposing the UIAlertVeiw immediately after creating it, but you have a instance delegate dangled off it. This crashes the runtime in a hard way, and then when you run it again since the old crashed process is still running the simulator wont let you start a second instance.
Use case #1 but do _alterView.InvokeOnMainThread (delegate { _alertView.Hide (); });