How to close browser tab with Xamarin.Android? - xamarin.android

So, I wrote a Nuget that allows dev in my company to quickly setup authorization using OIDC. Part of that, of course, is handing off the authentication step to a browser so I'm simply invoking Browse.OpenAsync with LaunchMode = BrowserLaunchMode.SystemPreferred. I also set up a HTTP listener that awaits the ahtority's authorization code callback. All works find but the browser window is of course still sitting at the top, hiding the initiating app.
I do realise I can use deep linking to simply "call up" the app again but that has two implications I would like to avoid: The need to register custom URI schema with the mobile OS and, above all, the need to register that (custom) callback URI with my company's API management system (which doesn't like anything but "http" or "https" URI schemes). Those requirements makes it more complicated for our devs to get started and, like I mentioned, it doesn't work very well with our API management system, so I'm looking for a simpler solution.
For iOS I can simply fetch the key window's view controller and dismiss it, like so:
async Task<Outcome> IPlatformService.TryCloseTopWindowAsync(bool isModalWindow, bool animated)
{
var window = UIApplication.SharedApplication.KeyWindow;
var viewController = window?.RootViewController;
if (viewController is null)
return Outcome.Fail("Couldn't obtain top window view controller");
try
{
if (isModalWindow)
{
viewController.DismissModalViewController(animated);
return Outcome.Success();
}
await viewController.DismissViewControllerAsync(animated);
return Outcome.Success();
}
catch (Exception ex)
{
return Outcome.Fail(ex);
}
}
Unfortunately, I'm not very good with Android's (Java based) APIs so I'm wondering if it's possible to do something similar here? Can I get the top app (activated by my own app) and dismiss it? If so; how?

Related

Async Function Fails when called as part of a Constructor

I'm rather new to Blazor, but I am currently trying to get access to some classes from within a class library that I've created and deployed as a Nuget package. As background, the Nuget package is an Api library, which allows me to talk to a webservice (I don't know if this is relevant or not). However, every time I go to the page where I'm testing, the page never loads and instead I left looking at the browser loading circle until I navigate away or close the application. During my testing here, it seems like it's the #inject call of my interface into the Blazor component which is causing the issue as when I remove it and try to load the page normally, the page does so.
So to demonstrate what I have setup, here is where I've added the Singletons to the DI:
builder.Services.AddSingleton<IApiConfigHelper, ApiConfigHelper>();
builder.Services.AddSingleton<IApiHelper, ApiHelper>();
builder.Services.AddSingleton<ISystemEndpoint, SystemEndpoint>();
Then on the blazor page, I have the following declarations at the top of my page:
#using Library.Endpoints
#using Library.Models
#page "/"
#inject ISystemEndpoint _systemEndpoint
Now I am leaning towards is this something to do with the Nuget package and using it with DI. I have tested the library away from this project (In a console application) and can confirm it's working as it should.
I have also created a local class library as a test to, to see if I could inject a data access class into the page and I can confirm that this works without an issue, which suggests to me that DI is working, just not with my Nuget package.
I did have a look into CORS, given that the Nuget package is accessing an external domain, and setup the following simple CORS policy in the app:
builder.Services.AddCors(policy =>
{
policy.AddPolicy("OpenCorsPolicy", opt =>
opt.AllowAnyOrigin()
.AllowAnyHeader()
.AllowAnyMethod());
});
Which is added to the app after the AddRouting call like so:
app.UseCors("OpenCorsPolicy");
However again, this wasn't the solution so if anyone is able to point me in the right direction with where I may be going wrong with this or offer any advice, I would be most grateful.
EDIT 1 - Provides details #mason queried
Regarding SystemEndpoint, the constructor is being injected with 2 things, as below:
public SystemEndpoint(IApiHelper apiHelper, IOptions<UriConfigModel> uriOptions)
{
_apiHelper = apiHelper;
_uriOptions = uriOptions.Value;
}
My Nuget Library is dependant on the following:
Azure.Identity
Azure.Security.KeyVault.Secrets
Microsoft.AspNet.WebApi.Client
Microsoft.Extensisons.Options.ConfigurationExtensions
EDIT 2 - Doing some further testing with this I have added a simple Endpoint class to my Nuget library, which returns a string with a basic message, as well as returning the values of the 2 UriConfig properties as below. I added this test to 1) sanity check that my DI was working correctly, and 2) check the values that are being assigned from appsettings to my UriConfig Object.
public class TestEndpoint : ITestEndpoint
{
private readonly IOptions<UriConfigModel> _uriConfig;
public TestEndpoint(IOptions<UriConfigModel> uriConfig)
{
_uriConfig = uriConfig;
}
public string TestMethod()
{
return $"You have successfully called the test method\n\n{_uriConfig.Value.Release} / {_uriConfig.Value.Version}";
}
}
However when adding in the dependency of IApiHelper into the Ctor, the method then breaks and fails to load the page. Looking into ApiHeloer, the Ctor has a dependency being injected into it of IApiConfigHelper. Looking at the implementation, the Ctor of ApiConfigHelper is setting up the values and parameters of the HttpClient that should make the REST calls to the external Api.
Now I believe what is breaking the code at this point is a call I'm making to Azure Key Vault, via REST, to pull out the secret values to connect to the Api. The call to KeyVault is being orchestrated via the following method, making use of the Azure.Security.KeyVault.Secrets Nuget Package, however I assume that at the heart of it, it's making a REST call to Azure on my behalf:
private async Task<KeyVaultSecret> GetKeyVaultValue(string secretName = "")
{
try
{
if (_secretClient is not null)
{
var result = await _secretClient.GetSecretAsync(secretName);
return result.Value;
}
}
catch (ArgumentException ae)
{
Console.WriteLine(ae.Message);
}
catch (Azure.RequestFailedException rfe)
{
Console.WriteLine(rfe.Message);
}
return new(secretName, "");
}
So that's where I stand with this at the moment. I still believe it could be down to CORS, as it seems to be falling over when making a call to an external service / domain, but I still can say 100%. As a closing thought, could it be something as simple as when I call call the above method, it's not being awaited????
So after persisting with this it seems like the reason it was failing was down to "awaiting" the call to Azure KeyVault, which was happening indirectly via the constructor of ApiConfigHelper. The resulting method for getting KeyVault value is now:
private KeyVaultSecret GetKeyVaultValue(string secretName = "")
{
try
{
if (_secretClient is not null)
{
var result = _secretClient.GetSecret(secretName);
if (result is not null)
{
return result.Value;
}
}
}
catch (ArgumentException ae)
{
Console.WriteLine(ae.Message);
}
catch (Azure.RequestFailedException rfe)
{
Console.WriteLine(rfe.Message);
}
return new(secretName, "");
}
I am now able to successfully make calls to my library and return values from the Api it interacts with.
I can also confirm that this IS NOT a CORS issue. Once I saw that removing the await was working, I then removed the CORS policy declarations from the service and the app in my Blazor's start-up code and everything continued to work without an issue.
As a final note, I must stress that this is only seems an issue when using the library with Blazor (possibly webApi projects) as I am able to use the library, awaiting the Azure call just fine in a console application.

Vaadin 23 Ui.navigate from another thread

When I try to navigate a user asynchronously from the server-side via #Push like:
ListenableFuture<JobApplicationMatrix> listenableFuture = // some Async method invocation
var ui = UI.getCurrent();
listenableFuture.addCallback(jobApplicationMatrix -> {
ui.access(() -> {
ui.navigate(CandidateComplianceApplicationView.class, new RouteParameters(CandidateComplianceApplicationView.APPLICATION_UUID_PARAMETER, candidateApplicationUuid));
});
}
it is not working as expected. CandidateComplianceApplicationView is a secured View. When I execute ui.navigate from ui.access the system moves me to the Keycloak login page. Looks like the system doesn't understand that the user is logged in. So, is this possible to navigate to the secure view from ui.access and if so, what am I doing wrong here?
I also tried to change #PermitAll to #AnonymousAllowed on CandidateComplianceApplicationView. In such case the system moves me to the correct page but the actual content of the CandidateComplianceApplicationView is not rendered at all.
UPDATED
I use
#Push(transport = Transport.LONG_POLLING)

Is there a Lync API for creating add-ons that run as soon as the user signs into Lync?

I can see custom menu items and custom conversation windows and events inside them but nothing referring to how you'd execute code once a user signs into Lync. Does such an API exist?
I guess my alternative would be creating a Lync Automation object/my own client using the Suppressed ui and building whatever features I want into one of those?
There's nothing you can build into the Lync application, but you could run a separate application which can subscribe to the SignIn state of the user. That way, you'd know when a user signs-in, and could take appropriate action. You wouldn't need to create a SuppressedUI application for that, just something that ran in the background, or taskbar or something.
Here's a bare bones example:
namespace ThoughtStuff
{
class Program
{
static void Main(string[] args)
{
var client = LyncClient.GetClient();
client.StateChanged += client_StateChanged;
}
static void client_StateChanged(object sender, ClientStateChangedEventArgs e)
{
if (e.NewState == ClientState.SignedIn)
{
//do something on sign in
}
}
}
}
You might get errors if you try and attach to Lync in the SDK code using LyncClient.GetClient() if the Lync exe isn't running...but if you know that's likely to be a problem (such as if your application might be running before the user starts Lync), then you can gracefully handle it and retry in code.

Caching in JavaFX WebView

We're developing a JavaFX 2.x application, which needs to provide some GIS support. We've come to conclusion that using GoogleMaps via an embedded WebView is the quickest option. The problem with it is that every time our application starts, the corresponding JavaScript libraries are downloaded. This makes development very difficult as it takes a couple of second before anything interactive can be done on the WebView panel.
The first thing that comes to mind is to have some sort of caching like web browsers do in order to store the libraries and read them locally when needed. How can this be achieved with WebView? Are there any alternatives to caching in our case?
Thanx.
The WebView component doesn't provide caching of web resources out of the box. However, it does utilize the java.net stack for network communications. What this means is you can install your own URL Handler that talks to a cache and serves resources from that cache. For example, put something like this block in your main() method before the JavaFX launch call:
URL.setURLStreamHandlerFactory(new URLStreamHandlerFactory() {
public URLStreamHandler createURLStreamHandler(String protocol) {
if ( "http".equals(protocol) ) {
return new URLStreamHandler() {
protected URLConnection openConnection(URL u) throws IOException {
if ( isCached(u) ) {
return new CachedStreamConnection(u);
}
return new MyURLConnection(u);
}
};
}
// Don't handle a non-http protocol, so just return null and let
// the system return the default one.
return null;
}
});
Of course the devil is in the details. You should take the cache policies returned by the HTTP headers (like ETags) into consideration when storing a resource in your cache. Another consideration is HTML meta tags. Here is a good resource on caching.
You may also want to consider a cookie management system to complement this cache management system.

Authenticating via oAUTH with providers using Phonegap for Blackberry

We are currently working on the finishing touches of an application which uses Phonegap and have hit some issues with the Blackberry port.
So far, we've been reviewing the content available online and can't find a really finale answer to this. Seems like the "right" way to make and oauth authentication process for either Twitter, Facebook or Foursquare would be to use the ChildBrowser plugin, instantiate a window and then use that to handle the process.
Rightly so, there seems to be a lack of a ChildBrowser plugin for Blackberry. We've been looking so far at a couple of private projects on Github that look like they build/use that capability but we are not sure on how to control the created window.
Most (or all?) of those plugins refer to invoking the native Blackberry browser to handle the URLS, but then how would be manage to work on the callbacks, get the tokens and close the windows since it's another process.
For example, we have this concept code:
function openWindow() {
if (typeof blackberry !== 'undefined') {
app_id = SOMETHING_HERE;
redirect = 'http://www.facebook.com/connect/login_success.html';
url = 'https://graph.facebook.com/oauth/authorizeclient_id='+app_id+'&redirect_uri='+redirect+'&display=touch&scope=publish_stream';
var args = new blackberry.invoke.BrowserArguments(url);
blackberry.invoke.invoke(blackberry.invoke.APP_BROWSER, args);
}
}
Which works for opening the URL, but that's it. Is there a way to get a handle on the window and inject some listener to events? What should be our correct approach?
Thanks!
I am not PhoneGap user, but we did have to handle a very similar scenario - native app invokes the mobile browser to prompt the oAuth flow and then be able to handle a callback to the aative app.
This is possible on the BlackBerry using the BrowserContentProviderRegistry API. You can register your app to be invoked whenever a particular MIME type is returned to the browser. Sounds complicated but its fairly straightforward when all the pieces are in play.
Here is the rough flow -
Native app invokes browser to the oAuth page. This is part is easy and seems like you got this part.
The oAuth redirect needs to go to a URL that you can control. Something like http://mycompany.com/oAuthRedirectHandler.asp.
The oAuthRedirectorHandler.asp has simple code like this (we chose classic ASP but this can be done in PHP or any language, you can also ignore the Android block below) -
<html><body>
<h1>Redirect page</h1>
If you are not re-directed, please open the application manually.
<% strUA = Request.ServerVariables("HTTP_USER_AGENT")
if (InStr(strUA, "BlackBerry")) then
Response.Write("Opening appplication on BlackBerry")
Response.ContentType="application/x-MyCustomApp"
elseif (InStr(strUA, "Android")) then
Response.Write("Opening appplication on Android")
Response.Redirect("MyCustomApp://mycompany.com")
end if %>
</body> </html>
In your BlackBerry code you want a new BrowserContentProvider like this -
final class CustomBrowserProvider extends BrowserContentProvider{
String[] ACCEPT = new String[]{"application/x-MyCustomApp};
String appName;
CustomBrowserProvider(String appName){
this.appName = ApplicationDescriptor.currentApplicationDescriptor().getModuleName();
//cache this appName from the constructor in the invocation code below.
}
public String[] getSupportedMimeTypes() { return ACCEPT;}
public String[] getAccept(RenderingOptions context){return ACCEPT;}
public BrowserContent getBrowserContent( BrowserContentProviderContext context) throws RenderingException {
//this is where the callback happens
//this is happening in a separate process, raise your main app here using the appName that got passed in
//I dont have a sanitized ready to go sample to post here on how to do this, but not too complicated
//as a hint use the ApplicationDescriptor and CodeModuleManager classes
return null;
}
}
Now, in your application initialization, register this new BrowserPlugin like this -
BrowserContentProviderRegistry converterRegistry = BrowserContentProviderRegistry.getInstance();
converterRegistry.register(new CustomBrowserProvider());
Hope this helps. This has worked pretty well for us. The one downside we've had here is that when the user returns to the browser app, they are left with an empty page and there is no good way to close that in the BB.

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