For some reason when I call
GetQueryableAsync I get the error
ObjectDisposedException: Cannot access a disposed context instance.
But in the same class, if I call GetListAsync - it works fine - under the hood it looks like both methods are called GetDbContextAsync from the UnitOfWorkDbContextProvider
Can't figure out why one would work and the other doesn't
I really don't want to use the unit of work at all, so I have this
Configure<AbpUnitOfWorkDefaultOptions>(options =>
{
options.TransactionBehavior = UnitOfWorkTransactionBehavior.Disabled;
});
My code is like this
MyAppService : ApplicationService
{
public virtual IEnumerable<Setting> LoadByKey(string key)
{
//this works
return _repo.GetListAsync(x => x.Key.ToUpper() == key.ToUpper()).Result;
}
public IQueryable<Setting> GetAll()
{
// doesn't work, disposed context error
return _repo.GetQueryableAsync().Result;
}
}
Related
I'm attempting to employ a custom endpoint that adds a specific claim based on a parameter passed to LocalApiController.
I'm following help at:
http://docs.identityserver.io/en/latest/topics/add_apis.html
I configured startup.cs:
services.AddLocalApiAuthentication(principal =>
{
principal.Identities.First().AddClaim(new Claim("additional_claim", "additional_value"));
return Task.FromResult(principal);
});
and my receiving controller:
[Route("localApi")]
[Authorize(LocalApi.PolicyName)]
public class LocalApiController : ControllerBase
{
public IActionResult Get()
{
var claims = from c in User.Claims select new { c.Type, c.Value };
return new JsonResult(claims);
}
}
[Authorize(LocalApi.PolicyName)] works and fires the helper configured in startup.cs which logically fires before the controllers get method.
I don't see how I can pass the controller's {id} parameter to the helper method (that will become the value of the claim I'm to add, replacing the "additional_value" constant).
Any suggestions?
Basically what i try to do is to hit my API once and save the result inside global variable in my Service, and then share and modify this value in my parent and child component with two helpers functions.
repairs.service.ts
public myItems:any[];
public GetRepairs = ():Observable<any> => {
this.headers = new Headers();
this.headers.set('Authorization', 'Bearer' + ' ' + JSON.parse(window.localStorage.getItem('token')));
return this._http.get(this.actionUrl +'repairs'{headers:this.headers})
.map((res) => {return res.json();
}).map((item) => {
let result:Array<any> = [];
if (item.items) {
item.items.forEach((item) => {
result.push(item);
});
}
this.myItems = result;
return this.myItems;
});
};
public GetItems() {
return this.myItems;
};
public UpdateItems(data:any[]) {
this.myItems = data;
};
And then in my main component i do
repairs.component.ts
export class RepairsComponent implements OnInit {
public myItems:any[];
constructor(private _userService:UserService,
private _RepairsService:RepairsService,
public _GlobalService:GlobalService) {
}
ngOnInit() {
this._userService.userAuthenticate();
this.getAllItems();
}
private getAllItems():void {
this._RepairsService
.GetRepairs()
.subscribe((data) => {
this._RepairsService.UpdateItems(data);
},
error => console.log(error),
() => {
this.myItems = this._RepairsService.GetItems();
});
}
}
This work just fine but when i try to invoke GetItems() in child component i get undefinded. I try to do it inside constructor and ngOnInit with the same result.
child.component.ts
export class ChildComponent {
private items:any[] = [];
constructor(private _RepairsService:RepairsService,
private _Configuration:Configuration) {
this.items = this._RepairsService.GetItems();
// undefinded
}
ngOnInit() {
this.items = this._RepairsService.GetItems();
// undefinded
}
}
From what i can see in the limited amount of code you shared, it would seem you are trying to get the items before the http get call finishes and saves the data. I think a better design pattern would be to make the GetItems() function also an observable or promise, and check if the data is there, if not call the http get call, and once that completes send the data back to the different components that need it.
As #MSwehli mentioned with async code execution you can't rely on the order of code lines. In this code:
ngOnInit() {
this.items = this._RepairsService.GetItems();
// undefinded
}
the async code in GetItems(); is scheduled for later execution into the event queue and then continued with the sync code. The scheduled code will be executed eventually but it's not determined when. It depends on the response of the server in this example.
If you return a Promise you can use .then(...) the chain the execution so that your code is only executed when the async execution is completed.
There are two errors/inconsistencies in your code:
userAuthenticate() call followed with getAllItems() call. These calls are async, user is not yet authenticated by the time getAllItems() is called, getAllItems will fail.
Solution here is to chain calls using rxjs flatMap:
//assuming userAuthenticate returns Observable
userService.userAuthenticate().flatMap(()=>{
return repairsService.GetRepairs();
}).subscribe(..process repairs..);
getAllItems() is called nearly at the same time as GetItems(). In most cases it fails also, because previous http request is not completed when GetItems() is called.
In my opinion early initialization is not necessary here, use service directly:
//ChildComponent
ngOnInit() {
this._RepairsService.GetRepairs().subscribe(..do anything with list of repairs i.e. assign to bindable property..);
}
You could add console.log statements in each part of the code to see the order of events in your app.
I'm trying to test that the model returned from my Nancy application is as expected. I have followed the docs here but whenever I call the GetModel<T> extension method it throws a KeyNotFoundException.
System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.
I know what the error means but I'm failing to see why it's being thrown.
Here's my module
public class SanityModule : NancyModule
{
public SanityModule()
{
Get["sanity-check"] = _ => Negotiate.WithModel(new SanityViewModel { Id = 1 })
.WithStatusCode(HttpStatusCode.OK);
}
}
my view model
public class SanityViewModel
{
public int Id { get; set; }
}
and here's my test
[TestFixture]
public class SanityModuleTests
{
[Test]
public void Sanity_Check()
{
// Arrange
var browser = new Browser(with =>
{
with.Module<SanityModule>();
with.ViewFactory<TestingViewFactory>();
});
// Act
var result = browser.Get("/sanity-check", with =>
{
with.HttpRequest();
with.Header("accept", "application/json");
});
var model = result.GetModel<SanityViewModel>();
// Asset
model.Id.ShouldBeEquivalentTo(1);
}
}
Debugging this test shows that the module is hit and completes just fine. Running the application shows that the response is as expected.
Can anyone shed some light on this?
Thanks to the lovely guys, albertjan and the.fringe.ninja, in the Nancy Jabbr room we've got an explanation as to what's going on here.
TL;DR It makes sense for this to not work but the error message should be more descriptive. There is a workaround below.
The issue here is that I am requesting the response as application/json whilst using TestingViewFactory.
Let's take a look at the implementation of GetModel<T>();
public static TType GetModel<TType>(this BrowserResponse response)
{
return (TType)response.Context.Items[TestingViewContextKeys.VIEWMODEL];
}
This is simply grabbing the view model from the NancyContext and casting it to your type. This is where the error is thrown, as there is no view model in NancyContext. This is because the view model is added to NancyContext in the RenderView method of TestingViewFactory.
public Response RenderView(string viewName, dynamic model, ViewLocationContext viewLocationContext)
{
// Intercept and store interesting stuff
viewLocationContext.Context.Items[TestingViewContextKeys.VIEWMODEL] = model;
viewLocationContext.Context.Items[TestingViewContextKeys.VIEWNAME] = viewName;
viewLocationContext.Context.Items[TestingViewContextKeys.MODULENAME] = viewLocationContext.ModuleName;
viewLocationContext.Context.Items[TestingViewContextKeys.MODULEPATH] = viewLocationContext.ModulePath;
return this.decoratedViewFactory.RenderView(viewName, model, viewLocationContext);
}
My test is requesting json so RenderView will not be called. This means you can only use GetModel<T> if you use a html request.
Workaround
My application is an api so I do not have any views so changing the line
with.Header("accept", "application/json");
to
with.Header("accept", "text/html");
will throw a ViewNotFoundException. To avoid this I need to implement my own IViewFactory. (this comes from the.fringe.ninja)
public class TestViewFactory : IViewFactory
{
#region IViewFactory Members
public Nancy.Response RenderView(string viewName, dynamic model, ViewLocationContext viewLocationContext)
{
viewLocationContext.Context.Items[Fixtures.SystemUnderTest.ViewModelKey] = model;
return new HtmlResponse();
}
#endregion
}
Then it is simply a case of updating
with.ViewFactory<TestingViewFactory>();
to
with.ViewFactory<TestViewFactory>();
Now GetModel<T> should work without needing a view.
I'm trying to wrap the Event Async Programming model used in RIA Services in a Task.
I have followed the standard way of using a TaskCompletionSource and implemented the following extension method:
public static Task<IEnumerable<T>> LoadAsync<T>(this DomainContext source, EntityQuery<T> query) where T : Entity
{
TaskCompletionSource<IEnumerable<T>> taskCompletionSource = new TaskCompletionSource<IEnumerable<T>>();
source.Load(
query,
loadOperation =>
{
if (loadOperation.HasError && !loadOperation.IsErrorHandled)
{
taskCompletionSource.TrySetException(loadOperation.Error);
loadOperation.MarkErrorAsHandled();
}
else if (loadOperation.IsCanceled)
{
taskCompletionSource.TrySetCanceled();
}
else
{
taskCompletionSource.TrySetResult(loadOperation.Entities);
}
},
null);
return taskCompletionSource.Task;
}
I then use this in the following way:
var task = _context.LoadAsync(_context.GetPlayersQuery());
task.Start();
task.Result;
The problem though is that I get an InvalidOperationException stating that "Start may not be called on a promise-style task". I have tried not starting the task, but then the loadOperation callback never fires.
Can anyone see what I am doing wrong here?
Thanks in advance
Problem is solved. Under the hood the DomainContext.Load() method is already operating in an asynchronous manner. There must have been some conflict with trying to wrap an already asynchronous method in a task.
However, even if I still follow the EAP correctly with the code below, I still get the InvalidOperationException of 'start cannot be called on a promise-style task'
public static Task<IEnumerable<T>> LoadAsync<T>(this DomainContext source, EntityQuery<T> query) where T : Entity
{
TaskCompletionSource<IEnumerable<T>> taskCompletionSource = new TaskCompletionSource<IEnumerable<T>>();
var loadOperation = source.Load(query);
loadOperation.Completed += (obj, args) =>
{
if (loadOperation.HasError && !loadOperation.IsErrorHandled)
{
taskCompletionSource.TrySetException(loadOperation.Error);
loadOperation.MarkErrorAsHandled();
}
else if (loadOperation.IsCanceled)
{
taskCompletionSource.TrySetCanceled();
}
else
{
taskCompletionSource.TrySetResult(loadOperation.Entities);
}
};
return taskCompletionSource.Task;
}
Try this instead
var result = await _context.LoadAsync(_context.GetPlayersQuery());
Try using
task.ContinuewWith(Action<Task<T>> continuation)
That worked for me, as I too got that exception when using task.Start
I'm facing a serious problem of deadlock in a multithreaded desktop/windows application. I fear I'm not using the correct approach to delegates in a very async environment. Also, even though I "sink" my events into the calling UI thread, if possible, I still have to Invoke on the UI thread to see some action. Follows, is the details.
The application is basically a client for users of an online file storage service. That service exposes functionality through REST calls. I first created a managed code wrapper DLL for such calls that allows for a .NET consumer to create a static instance of this DLL and call the functions. I'll take the file upload operation as an example.
Now, in the wrapper, here is the public interface for a file upload:
public Int32 UploadFile(FileSystemObject FolderToUploadTo, FileInfo LocalFileAndPath, OperationProgressReportEventHandler onOperationProgressReport, FileSystemObjectUploadCompletedEventHandler onOperationCompleted) {
Int32 ReplyNumber = 0;
try {
var TheOperation = new UploadFileObjectOperation(FolderToUploadTo, LocalFileAndPath, _User.APIKey) {
onProgressReport = onOperationProgressReport,
onUploadCompleted = onOperationCompleted
};
//Add it to the pool of operations
OperationPool.Add(TheOperation);
//Start the operation through the factory
OperationFactory.StartNew(() => {
TheOperation.Start();
});
//Chain the *actual* TPL Task to flush after usage
TheOperation.InnerTask.ContinueWith(t => {
t.Dispose(); //Dispose the inner task
OperationPool.Remove(TheOperation); //Remove the operation from the pool
TheOperation = null; //Nullify the Operation
});
ReplyNumber = TheOperation.TaskId;
}
catch {
ReplyNumber = 0;
}
return ReplyNumber;
}
As you can see, the actual UI application, that will refer this DLL, will be sending delegates for progress and completed to the operation(s). Now, the body of the operation itself:
public class UploadFileObjectOperation : BaseOperation, IDisposable {
//Store
public FileSystemObjectUploadCompletedEventHandler onUploadCompleted;
//Constructors
//Disposing stuff
protected override void PerformWork() {
try {
//Init the WebClient
UploadClient.UploadProgressChanged += (UploadProgressChanged_s, UploadProgressChanged_e) => {
//This is my event in base class being raised
ReportProgress(UploadProgressChanged_e.ProgressPercentage, UploadProgressChanged_e);
};
UploadClient.UploadFileCompleted += (UploadFileCompleted_s, UploadFileCompleted_e) => {
if (UploadFileCompleted_e.Error != null) {
throw new ApplicationException("Upload failed. " + UploadFileCompleted_e.Error.Message);
}
JObject JSONLiveObject = JObject.Parse(Encoding.UTF8.GetString(UploadFileCompleted_e.Result));
if (String.Compare((String)JSONLiveObject["status"], Constants._CONST_RESTRESPONSE_STATUS_VALUE_FAIL, false) == 0) {
throw new ApplicationException("Upload response failed. " + (String)JSONLiveObject["result"]["message"]);
}
//Eureka! Success! We have an upload!
//This is my event being raised
UploadTaskCompleted(new UploadFileObjectOperationEventArg {
Error = null,
ResultSource = OperationResultSource.Fresh,
Status = OperationExitStatus.Success,
TaskId = TaskId,
UploadedFileSystemObject = _UploadedFile
});
};
//Start the async upload
UploadClient.UploadFileAsync(AddressOfRESTURI, UploadingMethod, _FileToUpload.FullName);
}
catch (OperationCanceledException exp_Canceled) {
UploadTaskCompleted(new UploadFileObjectOperationEventArg {
Error = exp_Canceled,
ResultSource = OperationResultSource.Fresh,
Status = OperationExitStatus.Canceled,
TaskId = TaskId,
UploadedFileSystemObject = _UploadedFile
});
// To ensure that the calling code knows the task was canceled
//throw;
}
catch (Exception exp) {
UploadTaskCompleted(new UploadFileObjectOperationEventArg {
Error = exp,
ResultSource = OperationResultSource.Fresh,
Status = OperationExitStatus.Error,
TaskId = TaskId,
UploadedFileSystemObject = _UploadedFile
});
// If the calling code also needs to know.
//throw;
}
}
protected void UploadTaskCompleted(UploadFileObjectOperationEventArg arg) {
if (onUploadCompleted == null)
return;
//Sinking into calling UI thread, if possible
if (onUploadCompleted.Target is Control) {
Control targetForm = onUploadCompleted.Target as Control;
targetForm.Invoke(onUploadCompleted, new object[] { arg });
}
else {
onUploadCompleted(arg);
}
Status = OperationRunningStatus.Completed;
}
}
The PerformWork() raises the two events: Progress reporting and completion. Note that while raising an event, I check if can get a route to the calling thread and push the event directly so to avoid invokes at UI.
Now, lets see how I'm using all of the above in a desktop client:
private void UploadFile(FileInfo DraggedFileInfo, FileSystemObject ParentDefination) {
SessionLifetimeStuff.APICore.UploadFile(ParentDefination, DraggedFileInfo,
(PercentageCompleted) => {
#region Progress
this.InvokeEx(f => {
UpdateTaskProgress(newTaskQueue.OID, PercentageCompleted.Progress, PercentageCompleted);
});
#endregion
}, (Result) => {
#region Completion
this.InvokeEx(f => {
switch (Result.Status) {
case OperationExitStatus.Success:
Console.WriteLine(String.Format("File: {0} uploaded to {1}", Result.UploadedFileSystemObject.DocumentFullname, Result.UploadedFileSystemObject.FolderId));
break;
case OperationExitStatus.Canceled:
DialogManager.ShowDialog(DialogTypeEnum.Warning, "Dropbox", "Upload canceled.", null, this);
break;
case OperationExitStatus.Error:
DialogManager.ShowDialog(DialogTypeEnum.Error, "Dropbox", "Upload failed.", Result.Error, this);
break;
}
});
#endregion
});
}
I'm using an extension method I found on Stackoverflow for adding the Invoking functionality:
public static class InvokeExtensions {
public static void InvokeEx<T>(this T #this, Action<T> action) where T : Control {
if (#this.InvokeRequired) {
#this.Invoke(action, new object[] { #this });
}
else {
if (!#this.IsHandleCreated)
return;
if (#this.IsDisposed)
throw new ObjectDisposedException("#this is disposed.");
action(#this);
}
}
public static IAsyncResult BeginInvokeEx<T>(this T #this, Action<T> action)
where T : Control {
return #this.BeginInvoke((Action)(() => #this.InvokeEx(action)));
}
public static void EndInvokeEx<T>(this T #this, IAsyncResult result)
where T : Control {
#this.EndInvoke(result);
}
}
In my code, i have commented out the invokes as I though i don't need then as the events being raised are coming in sinked. However, i realized that my UI was not doing anything at all. So, I added the InvokeEx({ code; }) and my UI started to shoe activity.
Now, why do I need to invoke?
If I attempt different operations from UI, eventually, my UI freezes although the application still behaves as normally functioning.
I found an old article at http://msdn.microsoft.com/en-us/library/ff649143.aspx#scag-ch06_topic4 that described the usage of delegates and I see that there is a IAsyncResult involved.
Could someone point me as to where I'm going wrong here?
Update:
Ok, with the invoking code commented on the UI, I get no activity at all. But upon using the this.InvokeEx or wrapping a work in this.BeginInvokeEx, I get UI updates but after a while, here are the two exceptions occurring (in this order):
Invoke or BeginInvoke cannot be called on a control until the window handle has been created.
A Task's exception(s) were not observed either by Waiting on the Task or accessing its Exception property. As a result, the unobserved exception was rethrown by the finalizer thread.