How to communicate with parent application while it's in background? - xamarin.ios

I'm trying to develop watchOS 3 with Xamarin. My watch is communicating with parent application while it's active. When iOS app is killed or in background state, my watch doesn't receive any updated data. I'm sending request from the watch every 10 seconds in order to get updated data. I'm using WCSession for connection. The question is: is it possible to activate parent application from watch extension?
My functions for connectivity:
public void StartSession()
{
if (session != null)
{
session.Delegate = this;
session.ActivateSession();
Console.WriteLine($"Started Watch Connectivity Session on {Device}");
}
}
public override void SessionReachabilityDidChange(WCSession session)
{
Console.WriteLine($"Watch connectivity Reachable:{(session.Reachable ? '✓' : '✗')} from {Device}");
// handle session reachability change
if (session.Reachable)
{
// great! continue on with Interactive Messaging
}
else {
// 😥 prompt the user to unlock their iOS device
}
}
#region Application Context Methods
public void UpdateApplicationContext(Dictionary<string, object> applicationContext)
{
// Application context doesnt need the watch to be reachable, it will be received when opened
if (validSession != null)
{
try
{
var NSValues = applicationContext.Values.Select(x => new NSString(JsonConvert.SerializeObject(x))).ToArray();
var NSKeys = applicationContext.Keys.Select(x => new NSString(x)).ToArray();
var NSApplicationContext = NSDictionary<NSString, NSObject>.FromObjectsAndKeys(NSValues, NSKeys);
NSError error;
var sendSuccessfully = validSession.UpdateApplicationContext(NSApplicationContext, out error);
if (sendSuccessfully)
{
Console.WriteLine($"Sent App Context from {Device} \nPayLoad: {NSApplicationContext.ToString()} \n");
}
else
{
Console.WriteLine($"Error Updating Application Context: {error.LocalizedDescription}");
}
}
catch (Exception ex)
{
Console.WriteLine($"Exception Updating Application Context: {ex.Message}");
}
}
}
public override void DidReceiveApplicationContext(WCSession session, NSDictionary<NSString, NSObject> applicationContext)
{
Console.WriteLine($"Receiving Message on {Device}");
if (ApplicationContextUpdated != null)
{
var keys = applicationContext.Keys.Select(k => k.ToString()).ToArray();
var values = applicationContext.Values.Select(v => JsonConvert.DeserializeObject(v.ToString())).ToArray();
var dictionary = keys.Zip(values, (k, v) => new { Key = k, Value = v })
.ToDictionary(x => x.Key, x => x.Value);
ApplicationContextUpdated(session, dictionary);
}
}
#endregion

Related

How to receive the ASPN Token in Xamarin Forms iOS-App

I followed this tutorial to implement Push-Notifications in my Xamarin-Forms App (especially the iOS part). Now my problem is, when I press the register-button, I get the error message "Unable to resolve token for APNS".
Stepping through the code in debug mode I could verify, that the Token property in DeviceInstallationService is indeed null.
So I've gone one step back, and identified that the Token is set only via RegisteredForRemoteNotification in AppDelegate.cs, but this method is never called when I run the App.
Here is some code: App-Delegate
using System;
using System.Diagnostics;
using System.Threading.Tasks;
using Foundation;
using Notes.iOS.Extensions;
using Notes.iOS.Services;
using Notes.Services;
using UIKit;
using UserNotifications;
using Xamarin.Essentials;
using System.Collections.Generic;
using System.Linq;
using Syncfusion.SfCalendar.XForms.iOS;
namespace Notes.iOS
{
[Register("AppDelegate")]
public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
{
IPushDemoNotificationActionService _notificationActionService;
INotificationRegistrationService _notificationRegistrationService;
IDeviceInstallationService _deviceInstallationService;
IPushDemoNotificationActionService NotificationActionService
=> _notificationActionService ??
(_notificationActionService =
ServiceContainer.Resolve<IPushDemoNotificationActionService>());
INotificationRegistrationService NotificationRegistrationService
=> _notificationRegistrationService ??
(_notificationRegistrationService =
ServiceContainer.Resolve<INotificationRegistrationService>());
IDeviceInstallationService DeviceInstallationService
=> _deviceInstallationService ??
(_deviceInstallationService =
ServiceContainer.Resolve<IDeviceInstallationService>());
public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
global::Xamarin.Forms.Forms.Init();
Bootstrap.Begin(() => new DeviceInstallationService());
if (DeviceInstallationService.NotificationsSupported)
{
UNUserNotificationCenter.Current.RequestAuthorization(
UNAuthorizationOptions.Alert |
UNAuthorizationOptions.Badge |
UNAuthorizationOptions.Sound,
(approvalGranted, error) =>
{
if (approvalGranted && error == null)
RegisterForRemoteNotifications();
});
}
LoadApplication(new App());
using (var userInfo = options?.ObjectForKey(
UIApplication.LaunchOptionsRemoteNotificationKey) as NSDictionary)
ProcessNotificationActions(userInfo);
return base.FinishedLaunching(app, options);
}
void RegisterForRemoteNotifications()
{
MainThread.BeginInvokeOnMainThread(() =>
{
var pushSettings = UIUserNotificationSettings.GetSettingsForTypes(
UIUserNotificationType.Alert |
UIUserNotificationType.Badge |
UIUserNotificationType.Sound,
new NSSet());
UIApplication.SharedApplication.RegisterUserNotificationSettings(pushSettings);
UIApplication.SharedApplication.RegisterForRemoteNotifications();
});
}
Task CompleteRegistrationAsync(NSData deviceToken)
{
DeviceInstallationService.Token = deviceToken.ToHexString();
return NotificationRegistrationService.RefreshRegistrationAsync();
}
void ProcessNotificationActions(NSDictionary userInfo)
{
if (userInfo == null)
return;
try
{
var actionValue = userInfo.ObjectForKey(new NSString("action")) as NSString;
if (!string.IsNullOrWhiteSpace(actionValue?.Description))
NotificationActionService.TriggerAction(actionValue.Description);
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
}
public override void RegisteredForRemoteNotifications(UIApplication application, NSData deviceToken)
=> CompleteRegistrationAsync(deviceToken).ContinueWith((task)
=> { if (task.IsFaulted) throw task.Exception; });
public override void ReceivedRemoteNotification(
UIApplication application,
NSDictionary userInfo)
=> ProcessNotificationActions(userInfo);
public override void FailedToRegisterForRemoteNotifications(
UIApplication application,
NSError error)
=> Debug.WriteLine(error.Description);
}
}
DeviceInstallationService:
using System;
using Notes.Models;
using Notes.Services;
using UIKit;
namespace Notes.iOS.Services
{
public class DeviceInstallationService : IDeviceInstallationService
{
const int SupportedVersionMajor = 13;
const int SupportedVersionMinor = 0;
public string Token { get; set; }
public bool NotificationsSupported
=> UIDevice.CurrentDevice.CheckSystemVersion(SupportedVersionMajor, SupportedVersionMinor);
public string GetDeviceId()
=> UIDevice.CurrentDevice.IdentifierForVendor.ToString();
public DeviceInstallation GetDeviceInstallation(params string[] tags)
{
if (!NotificationsSupported)
throw new Exception(GetNotificationsSupportError());
if (string.IsNullOrWhiteSpace(Token))
throw new Exception("Unable to resolve token for APNS");
var installation = new DeviceInstallation
{
InstallationId = GetDeviceId(),
Platform = "apns",
PushChannel = Token
};
installation.Tags.AddRange(tags);
return installation;
}
string GetNotificationsSupportError()
{
if (!NotificationsSupported)
return $"This app only supports notifications on iOS {SupportedVersionMajor}.{SupportedVersionMinor} and above. You are running {UIDevice.CurrentDevice.SystemVersion}.";
if (Token == null)
return $"This app can support notifications but you must enable this in your settings.";
return "An error occurred preventing the use of push notifications";
}
}
}
As you can see this is really 1:1 the example code, the only difference is that my project is called Notes.
I skipped the Firebase and Android-Part as I only need push-notifications for iOS so far and as far as I underestood these are not necessary for iOS only.
Thanks your help!
Some points to check if RegisteredForRemoteNotification not called:
Open Entitlements.plist and ensure that Enable Push Notifications is checked when viewed in the Entitlements tab. Then, ensure the APS Environment setting is set to development when viewed in the Source tab.
Make sure that you are testing the remote-notification in a real device instead of a simulator. A simulator does not support remote-notification.
Make sure that you agreed receiving notification permission.
Make sure the certification you use has enabled the push notification ability.
Refer: configuring-the-remote-notifications-environment
You can look at the message returned from the following function in your App Delegate AppDelegate.cs
public override void FailedToRegisterForRemoteNotifications(
UIApplication application,
NSError error)
For instance
no valid “aps-environment” entitlement string found for application

Running a long operation within an event handler

I need to run some address validation on Customer Location addresses using a 3rd party API to determine if the address is residential or commercial. This validation should run whenever an address field is changed. In other words, the validation should be run in the Address_RowUpdated event handler.
Because the function is calling a 3rd party API, I believe that it should be done in a separate thread, using PXLongOperation so that it does not hold up address saving and fails gracefully if the API is unavailable or returns an error.
However, I am not sure if the architecture of running a long operation within an event handler is supported or if a different approach would be better.
Here is my code.
public class CustomerLocationMaint_Extension : PXGraphExtension<CustomerLocationMaint>
{
protected virtual void Address_RowUpdated(PXCache sender, PXRowUpdatedEventArgs e)
{
PX.Objects.CR.Address row = (PX.Objects.CR.Address)e.Row;
if (row != null)
{
Location location = this.Base.Location.Current;
PXCache locationCache = Base.LocationCurrent.Cache;
PXLongOperation.StartOperation(Base, delegate
{
RunCheckResidential(location, locationCache);
});
this.Base.LocationCurrent.Cache.IsDirty = true;
}
}
protected void RunCheckResidential(Location location, PXCache locationCache)
{
string messages = "";
PX.Objects.CR.Address defAddress = PXSelect<PX.Objects.CR.Address,
Where<PX.Objects.CR.Address.addressID, Equal<Required<Location.defAddressID>>>>.Select(Base, location.DefAddressID);
FValidator validator = new FValidator();
AddressValidationReply reply = validator.Validate(defAddress);
AddressValidationResult result = reply.AddressResults[0];
bool isResidential = location.CResedential ?? false;
if (result.Classification == FClassificationType.RESIDENTIAL)
{
isResidential = true;
} else if (result.Classification == FClassificationType.BUSINESS)
{
isResidential = false;
} else
{
messages += "Residential classification is: " + result.Classification + "\r\n";
}
location.CResedential = isResidential;
locationCache.Update(location);
Base.LocationCurrent.Update(location);
Base.Actions.PressSave();
// Display relevant messages
if (reply.HighestSeverity == NotificationSeverityType.SUCCESS)
String addressCorrection = validator.AddressCompare(result.EffectiveAddress, defAddress);
if (!string.IsNullOrEmpty(addressCorrection))
messages += addressCorrection;
}
PXSetPropertyException message = new PXSetPropertyException(messages, PXErrorLevel.Warning);
PXLongOperation.SetCustomInfo(new LocationMessageDisplay(message));
//throw new PXOperationCompletedException(messages); // Shows message if you hover over the success checkmark, but you have to hover to see it so not ideal
}
public class LocationMessageDisplay : IPXCustomInfo
{
public void Complete(PXLongRunStatus status, PXGraph graph)
{
if (status == PXLongRunStatus.Completed && graph is CustomerLocationMaint)
{
((CustomerLocationMaint)graph).RowSelected.AddHandler<Location>((sender, e) =>
{
Location location = e.Row as Location;
if (location != null)
{
sender.RaiseExceptionHandling<Location.cResedential>(location, location.CResedential, _message);
}
});
}
}
private PXSetPropertyException _message;
public LocationMessageDisplay(PXSetPropertyException message)
{
_message = message;
}
}
}
UPDATE - New Approach
As suggested, this code now calls the LongOperation within the Persist method.
protected virtual void Address_RowUpdated(PXCache sender, PXRowUpdatedEventArgs e)
{
PX.Objects.CR.Address row = (PX.Objects.CR.Address)e.Row;
if (row != null)
{
Location location = Base.Location.Current;
LocationExt locationExt = PXCache<Location>.GetExtension<LocationExt>(location);
locationExt.UsrResidentialValidated = false;
Base.LocationCurrent.Cache.IsDirty = true;
}
}
public delegate void PersistDelegate();
[PXOverride]
public virtual void Persist(PersistDelegate baseMethod)
{
baseMethod();
var location = Base.Location.Current;
PXCache locationCache = Base.LocationCurrent.Cache;
LocationExt locationExt = PXCache<Location>.GetExtension<LocationExt>(location);
if (locationExt.UsrResidentialValidated == false)
{
PXLongOperation.StartOperation(Base, delegate
{
CheckResidential(location);
});
}
}
public void CheckResidential(Location location)
{
CustomerLocationMaint graph = PXGraph.CreateInstance<CustomerLocationMaint>();
graph.Clear();
graph.Location.Current = location;
LocationExt locationExt = location.GetExtension<LocationExt>();
locationExt.UsrResidentialValidated = true;
try
{
// Residential code using API (this will change the value of the location.CResedential field)
} catch (Exception e)
{
throw new PXOperationCompletedWithErrorException(e.Message);
}
graph.Location.Update(location);
graph.Persist();
}
PXLongOperation is meant to be used in the context of a PXAction callback. This is typically initiated by a menu item or button control, including built-in actions like Save.
It is an anti-pattern to use it anytime a value changes in the web page. It should be used only when a value is persisted (by Save action) or by another PXAction event handler. You should handle long running validation when user clicks on a button or menu item not when he changes the value.
For example, the built in Validate Address feature is run only when the user clicks on the Validate Address button and if validated requests are required it is also run in a Persist event called in the context of the Save action to cancel saving if validation fails.
This is done to ensure user expectation that a simple change in a form/grid value field doesn't incur a long validation wait time that would lead the user to believe the web page is unresponsive. When the user clicks on Save or a specific Action button it is deemed more reasonable to expect a longer wait time.
That being said, it is not recommended but possible to wrap your PXLongOperation call in a dummy Action and asynchronously click on the invisible Action button to get the long operation running in the proper context from any event handler (except Initialize):
using PX.Data;
using System.Collections;
namespace PX.Objects.SO
{
public class SOOrderEntry_Extension : PXGraphExtension<SOOrderEntry>
{
public PXAction<SOOrder> TestLongOperation;
[PXUIField(DisplayName = "Test Long Operation", Visible = false, Visibility = PXUIVisibility.Invisible)]
[PXButton]
public virtual IEnumerable testLongOperation(PXAdapter adapter)
{
PXLongOperation.StartOperation(Base, delegate ()
{
System.Threading.Thread.Sleep(2000);
Base.Document.Ask("Operation Done", MessageButtons.OK);
});
return adapter.Get();
}
public void SOOrder_OrderDesc_FieldUpdated(PXCache sender, PXFieldUpdatedEventArgs e)
{
if (!PXLongOperation.Exists(Base.UID))
{
// Calling Action Button asynchronously so it can run in the context of a PXAction callback
Base.Actions["TestLongOperation"].PressButton();
}
}
}
}

How to remove thread safe error in aspnet core middleware invoke method?

Getting exception "A second operation started on this context before a previous operation completed. Any instance members are not guaranteed to be thread safe."
Below is the code.
public Task Invoke(HttpContext context)
{
try
{
var userId =context.Session.GetString("UserId");
if (userId != null)
{
var user =_context.Users.Where(u => u.Id == userId).FirstOrDefault();
user.TimeStamp = DateTime.Now;
_context.SaveChanges();
}
else
{ }
}
catch(Exception ex)
{
_logger.LogError(ex.Message);
}
// Call the next delegate/middleware in the pipeline
return this._next(context);
}
I can't tell from your code but I'm guessing:
_context is your db context
you're injecting it via the ctor
As you've discovered, this probably won't work.
Instead, inject your db context via the Invoke method.
public Task Invoke(HttpContext context, YourDbContext dbContext)
{
try
{
var userId = context.Session.GetString("UserId");
if (userId != null)
{
var user = dbContext.Users.Where(u => u.Id == userId).FirstOrDefault();
...
}
}
catch(Exception ex){...}
}
This ensures you have a scoped instance of your db context, which should be threadsafe.

dynamics crm plugin delete entity during update message

Is it possible to delete entity while same is still in plugin update transaction?
It seems following code is not working. I need to delete entity when its get updated and some other circumstances
Something like:
protected void ExecutePosAnnotationtUpdate(LocalPluginContext localContext)
{
if (localContext == null)
{
throw new ArgumentNullException("localContext");
}
if (localContext.PluginExecutionContext.Depth > 1) return;
Entity postEntityImage = null;
if (localContext.PluginExecutionContext.PostEntityImages.Contains("PostImage"))
{
if (localContext.PluginExecutionContext.PostEntityImages["PostImage"] != null)
{
postEntityImage = localContext.PluginExecutionContext.PostEntityImages["PostImage"];
}
}
Entity preEntityImage = null;
if (localContext.PluginExecutionContext.PreEntityImages.Contains("PreImage"))
{
if (localContext.PluginExecutionContext.PreEntityImages["PreImage"] != null)
{
preEntityImage = localContext.PluginExecutionContext.PreEntityImages["PreImage"];
}
}
if ((bool)postEntityImage.Attributes["isdocument"])
{
if ( some condition )
localContext.OrganizationService.Delete(postEntityImage.LogicalName, postEntityImage.Id);
}
}
`
Since you're updating, the record is there in Target.
public void Execute(IServiceProvider serviceProvider)
{
var context = (IPluginExecutionContext)serviceProvider.GetService(typeof(IPluginExecutionContext));
var serviceFactory = (IOrganizationServiceFactory)serviceProvider.GetService(typeof(IOrganizationServiceFactory));
var service = serviceFactory.CreateOrganizationService(context.UserId);
var target = context.InputParameters["Target"] as Entity;
var condition = /* whatever */
if(condition)
{
service.Delete(target.LogicalName, target.Id);
}
}
Works as expected when attached to Update message, Post-Operation, Asynchronous. Works inside the Sandbox, also.
Records will not disappear at once, it takes some time (~20 seconds on my on-premise playground). If you make it Synchronous it will still work but alerts are going to come up because data disappears while being handled by the CRM during the update.

Background Task in WP 8.1 run more than once

Im trying to implement windows phone 8.1 notification background task.
it is implemented with one bug!
the toast notification message will appear in the action center more than once. sometimes 9times.
here is my code:
public sealed class my_bg_notifier: IBackgroundTask
{
public async void Run(IBackgroundTaskInstance taskInstance)
{
var deferral = taskInstance.GetDeferral();
bool status = await notificationChecker.check();
if (status)
{
populateNotification(notificationChecker.count);
}
deferral.Complete();
}
}
I tried to debug so I put a breakpoint over the line status.
and I was surprised that it is called more than once and that is why my notification will pop-up more than one time.
and the message that is showed from the debugger breakpoint clearly states that there are multiple threads doing the same job simultaneously.
so i thought to prevent running the method by more than one thread by using a boolean flag as follow:
public sealed class my_bg_notifier: IBackgroundTask
{
private static bool isNotBusy = true;
public async void Run(IBackgroundTaskInstance taskInstance)
{
if (isNotBusy)
{
isNotBusy = false;
var deferral = taskInstance.GetDeferral();
bool status = await notificationChecker.check();
if (status)
{
populateNotification(notificationChecker.count);
}
deferral.Complete();
}
isNotBusy = true;
}
}
but again that didn't work.
my question is :
why would a background task run more than once by multiple thread simultanously.
and How can I block this behavioud? should I use lock keyword?
Okkkkk!!! It was my fault. In my code i registered the background task on each app launch without checking if it is already registered.
So i used code as below to check if my task is registered then no need to register it again.
var taskRegistered = false;
var exampleTaskName = "ExampleBackgroundTask";
foreach (var task in Background.BackgroundTaskRegistration.AllTasks)
{
if (task.Value.Name == exampleTaskName)
{
taskRegistered = true;
break;
}
}
Source: http://msdn.microsoft.com/en-us/library/windows/apps/xaml/hh977055.aspx

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