What I want to implement is as follow:
A-app (calling app) : request the return value of a-string sent as parameter : request(a-string) -> b-string.
B-app (plug-in installed separately by me or others, it plays the role of dictionary or database ) : search a-string from database and return the result (b-string).
With successful experiences of plug-in on android and with Apple's confident rhetoric of plug-in, I thought plug-in, of course, run on iOS. After a lot of hard work, however, I finally found out:
* Note : The creation and use of loadable bundles is not supported in iOS.*
Nonetheless, not giving up, I finally made it with custom URl and pasteboard:
A-app : write a-string and false state to pasteboard & call B-app via custom URL.
B-app : viewDidLoad runs following func and thereafter exit program ; func { read pasteboard and search from database & write the result(b-string) and true state to pasteboard }
A-app : while-loop detects whether state is false or true. if true, catch b-string from pasteboard.
Anyway it works but it's too long thus almost useless. Do you have any idea for better solutions? Why doesn't Apple allow plug-in for iOS? Any responses are welcome. Thank you.
I can't answer why Apple doesn't allow plug-ins, but I can offer some advice on what you're trying to achieve.
The common pattern for sending data back to your application is to implement a callback url, so the A-app would also implement a custom URI and add that to the uri sent to B-app.
B-app would then process the uri as you have already implemented, but then instead of exiting, it simply sends the data you requested in the uri passed to it.
See http://x-callback-url.com for more details and example implementations.
Related
Hi I am working on a Video Call Solution by using WebRTC directly. I have achieved 1-1 video call using firebase as Signaling service and using default google ICE Servers.
Core Req: Multiple users with in a Room using WebRTC at least 4 users using the default ice/stun servers available. I'm using pod 'GoogleWebRTC'
Issue comes when multiple users joins the same room ID.
So, I am maintaining Peerconnection reference as this
var peerConnection: RTCPeerConnection! = nil
When a new user i.e., remote user joins I set its description as below
self.peerConnection.setRemoteDescription(offer, completionHandler: {(error: Error?) in
if error == nil {
LOG("setRemoteDescription(offer) succsess")
self.makeAnswer() // Create Answer if setRemoteDescription succeeds
} else {
LOG("setRemoteDescription(offer) ERROR: " + error.debugDescription)
}
})
What I feel ? Issue is when third user joins again I set the remote Description with above mentioned code which makes my previous video stops to render sometimes or most of the times.
I looked for solutions and found need to maintain multiple peer connection references, but how? Any help with my requirement will be appreciated.
Just give me clue or sample code will be really great.
In case of multiple user call you should have multiple peerconnections, because it's isn't possible to set different sdps to one pc.
So you can use something like this
var peerConnectionMap = [String: RTCPeerConnection]()
Where String here is some constant user id.
When new user is joined to the room, then you create new pc and store it in this dictionary. Then you exchange with sdps as usual.
Don't forget that you should reuse local audio-video track created when first peerconnection is created.
I have a problem that my app crashes when it is opening a file from iCloud. If I open this file from my app with a Document Picker, everything is fine. But if I try to open from outside my app, for example from iCloud or safari download it crashes. If I open it from local storage "my iphone" it is also working. It is interesting because it was good one week ago :)
So in AppDelegate, I've implemented the following method:
func application(_ app: UIApplication, open url: URL, options: [UIApplication.OpenURLOptionsKey : Any] = [:]) -> Bool {}
According to the logs the crash occurs because the file does not exist.
file:///private/var/mobile/Library/Mobile%20Documents/com~apple~CloudDocs/Desktop/twic1121.pgn
This is the result if I print the URL from the parameter. I think this means that the file is there.
But if i do this: print(fm.fileExists(atPath: url.path)) then this is false.
So it is obvious that after let dataFromFile = fm.contents(atPath: url.path)
this is nil.
I have no idea what could be the problem here. So the real question here is why this is nil?
It appears that the error can be many things, all not related to the class you are applying the code (AppDelegate) nor the methods you are calling.
My guess is that the URL you are calling is not correctly built (not pointing to the correct object you are trying to point to). For many reasons.
See if one of this reasons fix your issue:
(1) The end of the URL you are calling had the suffix "pgn". If you are looking to load a picture, maybe the suffix is wrong. In that case it could have been some known and supported format like "png", "jpeg" or "jpg".
(2) The "%20"symbol at the middle of your code also lifts a flag. Does not seem to be a correct URL object of swift. Maybe the URL you are using is not represented in the correct way.
(3) com~apple~CloudDocs also lifts a flag, since it would unlikely have a "~" symbol in a URL passed. This also strongly suggests that maybe the URL you are using is not represented in the correct way.
I think your URL is not pointing to where you are trying to point to, resulting in the "does exist" method return false and the loading resulting in nil.
If all of this does not fix your issue, post more details of the code. Specially what method you are calling to build/create this URL object you are using, that points to: file:///private/var/mobile/Library/Mobile%20Documents/com~apple~CloudDocs/Desktop/twic1121.pgn
I have a code fragment which I want to unit test , this code depends upon callback from network stack on event of receipt of data. The network calls are made through a library its basically amazon iOT library, thus I am not directly interacting with iOS network framework but this library. I want to unit test this code, not sure if its possible if yes how.
Attached is the code in question
static func subscribeForData(completionCallBack:((String,NSDictionary)->())?,errorCallBack:((NSError)->())?) {
let iotDataManager = AWSIoTDataManager.default()
let defaults = UserDefaults.standard
let login = .....
iotDataManager.subscribe(toTopic: "testNode/device/"+login, qoS: .messageDeliveryAttemptedAtLeastOnce, messageCallback: {
(payload) ->Void in
let stringValue = NSString(data: payload, encoding: String.Encoding.utf8.rawValue)!
})
}
The best way you can achieve this is through Dependency Injection (DI).
DI can be used as a mean to inject both the real networking code and the "mocked" one.
In order to deal with DI you need to modify your code. In particular an instance of AWSIoTDataManager should be passed to subscribeForData method instead of hardcoding it (why do you have a static method?).
There are different approaches in order to deal with this. One is described for example in The complete guide to Network Unit Testing in Swift. I think that if you read it, you will acquire something new useful for the feature.
Your "mocked" class (I put with "" since it could be defined as a stub or a spy) would have the same API provided by the real one.
As I stated previously, Unit Tests should be fast and should NOT depend on databases, real networks requests and so on.
I would like to be able to redirect my logging statements to a file so that I can retrieve them when my app runs standalone (i.e. is not attached to Xcode). I have discovered (thank you Stackoverflow) that freopen can be used to accomplish this.
If I create a new Xcode project and add the code to redirect stderr then everything works as expected.
However, when I add the redirection code to my existing, bluetooth project I am having trouble. The file is being created and I can retrieve it using iTunes or Xcode's Devices window, but it is of size 0. If I explicitly close the file then the text that I wrote actually makes it into the file. It is as though iOS is not flushing the file when the app is terminated. I suspect that the trouble stems from the fact that I have enabled background processing. Can anyone help me to understand this?
Here is my code:
let pathes = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true);
let filePath = NSURL(fileURLWithPath: pathes[0]).URLByAppendingPathComponent("Test.log")
freopen(filePath.path!, "a", stderr);
fputs("Hello, Samantha!\r\n", stderr);
struct StderrOutputStream: OutputStreamType {
static let stream = StderrOutputStream()
func write(string: String) {fputs(string, stderr)}
}
var errStream = StderrOutputStream.stream
print("Hello, Robert", toStream: &errStream)
fclose(stderr) // Without this the text does not make it into the file.
I'd leave this as a comment, but have you looked into NSFileHandle? It sounds like you just need a way to append data to the end of a text file, correct?
Once you have a handle with something like NSFileHandle(forWritingToURL:), you can use .seekToEndOfFile() and .writeData(_:). As a side note, you'll need to convert your String to Data before writing it.
Admittedly, this will probably end up being more lines of code, and you'll almost certainly need to take threading into consideration.
I have started developing html applications for mutliple platforms. I recently heard about Cordova 2.0(PhoneGap) and ever since I have been curious to know how the bridge works.
After lot of code walking, i saw that the Exec.js is the code where call from JS -> Native happens
execXhr = execXhr || new XMLHttpRequest();
// Changeing this to a GET will make the XHR reach the URIProtocol on 4.2.
// For some reason it still doesn't work though...
execXhr.open('HEAD', "file:///!gap_exec", true);
execXhr.setRequestHeader('vc', cordova.iOSVCAddr);
if (shouldBundleCommandJson()) {
execXhr.setRequestHeader('cmds', nativecomm());
}
execXhr.send(null);
} else {
execIframe = execIframe || createExecIframe();
execIframe.src = "gap://ready";
But want to understand how that works, what is the concept here, what does file:///!gap_exec or gap://ready do? and how does the call propgate to the lower layers (native code layers)
thanks a bunch in advance.
The trick is easy:
There is a webview. This displays your app. The webview will handle all navigation events.
If the browser navigates to:
file:///!gap_exec
or
gap://
the webview will cancel the navigation. Everything behind these strings is re-used as an identifier, to get the concrete plugin/plugin-method and parameter:
pseudo-url example:
gap://echoplugin/echothistext?Hello World
This will cause phonegap to look for an echoplugin and call the echothistext method to send the text "Hello World" to the (native) plugin.
update
The way back from native to javascript is (or may be) loading a javascript: url into the webview.
The concrete implementation is a little bit more complex, because the javascript has to send a callback-id to native code. There could be more than one native call are running at the same time. But in fact this is no magic at all. Just a number to get the correct JSON to the right javascript-callback.
There are different ways to communicate between the platform and javascript. For Android there are three or four different bridges.
I am trying to figure this out in more detail, too. Basically there are 2 Methods on the iOS side that can help ...
- webView:shouldStartLoadWithRequest:navigationType: and
- stringByEvaluatingJavaScriptFromString:script
From the sources it seems cordova sends a "READY" message using webView:shouldStartLoadWithRequest:... and then picks up results with the second message, but I am not sure.
Cordova Sources iOSExec
There is much to learn there.