I'm using Facebook API v5.3 BETA, although have tried the following using v5.2.1 Stable. I am also using the Facebook.Extensions.Tasks library. Upon calling the FBClient.GetTaskAsync() function I get the [net_unknown_prefix] error, any ideas?
public string GetFacebookMe(string access_token)
{
FacebookClient fb = new FacebookClient(access_token);
string _Response = "";
var task = fb.GetTaskAsync("/me");
task.ContinueWith(
t =>
{
if (t.Exception == null)
{
dynamic result = t.Result;
_Response = result.name;
}
else
{
_Response = "Error";
}
});
return _Response;
}
Thanks in advance!
You will need to have the Async CTP SP1 installed inorder to use the Facebook.Extensions.Task library.
Starting from v5.3 beta XTaskAsync methods are already part of the core Facebook.dll. Although for now it is available only for .net 4.0 and .net 4.5.
You can read more about it at http://blog.prabir.me/post/Facebook-CSharp-SDK-What’s-new-in-v5-3.aspx
Related
I have an Angular.js app that I am porting to .NET Core.
It was working fine in the previous version of .NET Core 3 preview; 3.2.
However, after upgrading to latest 3.3 some of the get requests are returning this error:
InvalidOperationException: Synchronous operations are disallowed. Call
WriteAsync or set AllowSynchronousIO to true instead.
I can't see why this is happening with only some requests and not others.
I believe that by default Angular.js does async: xhr.open(method, url, true);
Can anyone shed some light on this?
This problem is described here: https://github.com/aspnet/AspNetCore/issues/8302
The workaround for now is to manually set AllowSynchronous to true in startup.cs;
// Startup.ConfigureServices
services.Configure<IISServerOptions>(options =>
{
options.AllowSynchronousIO = true;
});
It's worth noting that if you host on kestrel directly then your Program.cs should have appropriate ConfigureKestrel call
public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
WebHost.CreateDefaultBuilder(args)
.UseStartup<Startup>()
.ConfigureKestrel((context, options) =>
{
options.AllowSynchronousIO = true;
})
you can disable it for a special method
var syncIOFeature = HttpContext.Features.Get<IHttpBodyControlFeature>();
if (syncIOFeature != null)
{
syncIOFeature.AllowSynchronousIO = true;
}
or disable in all application scope
public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
WebHost.CreateDefaultBuilder(args)
.UseStartup<Startup>()
.ConfigureKestrel((context, options) =>
{
options.AllowSynchronousIO = true;
})
or in service configure startup
services.Configure<IISServerOptions>(options =>
{
options.AllowSynchronousIO = true;
});
If you are using a CustomWebApplicationFactory like me, you can set the flag in its constructor, It makes my test direct from VS2019 works.
public class CustomWebApplicationFactory<TStartup> : WebApplicationFactory<TStartup> where TStartup: class
{
public CustomWebApplicationFactory()
{
Server.AllowSynchronousIO = true;
}
I have built a sencha application using Sencha cmd.
I have integrated it to windows phone using cordova.
Now, when launching the app, after splash screen, a white screen comes and stays for ever.
I trying putting an alert in the launch function (in app.js where view is created) and found out that the launch function does not fire.
What could be the reason of this behaviour?
I found the cause of the issue that I was facing. The sencha app is using a store with SQL proxy. But since SQL proxy is not supported on Windows phone (but supported on other platforms viz. iOS, Android), so the launch function was not getting called.
I had a similar problem with a JSON proxy and I had to modify the following lines of code in cordovalib/XHRHelper.cs file.
var funk = function () {
window.__onXHRLocalCallback = function (responseCode, responseText) {
alias.status = responseCode;
if (responseCode == '200') {
alias.responseText = responseText;
try {
JSON.parse(responseText);
} catch (e) {
Object.defineProperty(alias, 'responseXML', {
get: function () {
return new DOMParser().parseFromString(this.responseText, 'text/xml');
}
});
}
Object.defineProperty(alias, 'responseJSON', {
get: function () {
return new DOMParser().parseFromString(this.responseText, 'text/json');
}
});
}else {
alias.onerror && alias.onerror(responseCode);
}
All, I call a .NET DLL containing a WinForm at run-time from a WinForm C# application. To do this I use the following:
DLL = Assembly.LoadFrom(strDllPath);
classType = DLL.GetType(String.Format("{0}.{1}", strNamespaceName, strClassName));
if (classType != null)
{
if (bDllIsWinForm)
{
classInst = Activator.CreateInstance(classType);
Form dllWinForm = (Form)classInst;
dllWinForm.Show();
// Invoke required method.
MethodInfo methodInfo = classType.GetMethod(strMethodName);
if (methodInfo != null)
{
object result = null;
result = methodInfo.Invoke(classInst, new object[] { dllParams });
return result == null ? String.Empty : result.ToString();
}
}
}
This is invoking the WinForm DLL and the required method fine for serial methods within the DLL. However, I am now invoking a multi-threaded DLL, and calling the following method:
public async void ExecuteTest(object[] args)
{
Result result = new Result();
if (!BuildParameterObjects(args[0].ToString(), args[1].ToString()))
return;
IProgress<ProgressInfo> progressIndicator = new Progress<ProgressInfo>(ReportProgress);
List<Enum> enumList = new List<Enum>()
{
Method.TestSqlConnection,
Method.ImportReferenceTables
};
Task task = Task.Factory.StartNew(() =>
{
foreach (Method method in enumList)
{
result = Process.ProcessStrategyFactory.Execute(Parameters.Instance, progressIndicator,
Process.ProcessStrategyFactory.GetProcessType(method));
if (!result.Succeeded)
{
// Display error.
return;
}
}
});
await task;
Utilities.InfoMsg("VCDC run executed successfully.");
}
But this is returning control to the caller right away due to the await (which is expected). However, the return causes the calling method to exit which closes the DLL WinForm.
What is the best method to keep the DLL WinForm active/open?
Thanks for your time.
Edit. Following the suggestion by Stephen below I have decided to turn my DLL intery method type to Task<object> and set up a continuation as follows
if (classType != null)
{
if (bDllIsWinForm)
{
// To pass object array to constructor use the following.
// classInst = Activator.CreateInstance(classType, new object[] {dllParams});
classInst = Activator.CreateInstance(classType);
dllWinForm = (Form)classInst;
dllWinForm.Show();
// Invoke required method.
MethodInfo methodInfo = classType.GetMethod(strMethodName);
if (methodInfo != null)
{
object result = null;
result = methodInfo.Invoke(classInst, new object[] { dllParams });
if (result != null)
{
if (result.GetType() == typeof(Task<object>))
{
Task<object> task = (Task<object>)result;
task.ContinueWith(ant =>
{
object innerResult = task.Result;
return innerResult == null ? String.Empty : innerResult.ToString();
});
}
return result.ToString();
}
return String.Empty;
}
}
}
I decided to set up the continuation instead of the await to avoid the chaining that would occur with the await keyword - that is making the calling method (that calling the DLL of type Task<String> etc. up the call stack.
The DLL entry method now becomes:
public Task<object> ExecuteTest(object[] args)
{
Task<object> task = null;
Result result = new Result();
if (!BuildParameterObjects(args[0].ToString(), args[1].ToString()))
return task;
IProgress<ProgressInfo> progressIndicator = new Progress<ProgressInfo>(ReportProgress);
List<Enum> enumList = new List<Enum>()
{
Method.TestSqlConnection,
Method.ImportReferenceTables
};
task = Task.Factory.StartNew<object>(() =>
{
foreach (Method method in enumList)
{
result = Process.ProcessStrategyFactory.Execute(Parameters.Instance, progressIndicator,
Process.ProcessStrategyFactory.GetProcessType(method));
if (!result.Succeeded)
{
// Display error.
}
task.Wait(5000); // Wait to prevent the method returning too quickly for testing only.
}
return null;
});
return task;
}
But this causes the DLL WinForm to be show for a split second and then disapear. i even attempted to make the Form dllWinForm global to keep the refernce to the object active, but this also has not worked. I want to note that the call to the DLL (N.B. the calling method is already running on a background thread-pool thread).
Any further helps is appreciated.
Change the return type of Execute to Task and await it.
It's difficult to guess what you have in dll but eventually your dll code + exposed in your question:
dllWinForm.Show();
should eventually have been after juxtaposing:
new Thread
(
() => new Form().ShowDialog()
)
.Start();
Probably, you should change dllWinForm.Show(); by dllWinForm.ShowDialog().Start();
ShowDialog(), in contrast with Show(), starts its own message pumping and returns only when explicitly closed.
Update (in respnse to comment):
It is not absolutely necessary to launch a form from UI.
Since you are on .NET 4.5, it is probably simpler to use WPF (instead of Windows Form) form.
Here is the code for WPF form which, in order to adjust for Windows Form, you should change Dispatcher parts by initializing WindowsFormsSynchronizationContext
Though, IMO, WinForms code will be much more complex.
I have downloaded the sample 'Breeze 0.83.5' applications from http://www.breezejs.com/documentation/download
The Angular 'ToDo' sample does not work with IE8.
I have included the following script references above my Breeze script reference.
Any idea why this doesn't work?
Breeze's Angular support makes use of the 'backingStoreAdapter' which in turn depends on the ES5 Javascript 'defineProperty' method being implemented by the browser. This was not implemented in IE8, and unfortunately, cannot be supplemented via the use of a shim.
This is the only adapter that has this limitation, the breeze knockout and backbone adapters, both work with IE8 with the use of ES5 shims.
Sorry!
It will not work on IE8 in the future versions of Breeze neither.
Todo-Angular runs in modern browsers such as IE9, IE10, and recent
Chrome, Safari, Firefox, and WebKit browsers. Breeze does not support
AngularJS apps running in older browsers that lack ECMAScript 5
property getters and setters.
Breeze uses the ViewModel of the hosting MVVM framework. That’s generally a good decision. Additionally, change tracking on entities is a fundamental concept of breeze.js (same for Entity Framework). It’s an easy task to track changes if the MVVM framework uses Observables with real getter and setters (e.g. Knockout). AngularJS on the other hands works with plain JavaScript objects. This makes change tracking difficulty. The only two reliable ways are ES5-properties (simple, but not supported by IE8) or a very deep integration in the $digest cycle. The breeze-team took the first-choice - what a pity for projects that have to support IE8!
Ok, let's analyze the root cause of the problem: change tracking
Do you really need that feature? At least in our project we decided for breeze.js/OData for reading and for a more "restful" approach when it comes to writing. If you don’t need those advanced features, than the following script should solve the issue:
/********************************************************
* A replacement for the "backingStore" modelLibrary
*
* This is a bare version of the original backingStore,
* without ANY change tracking - that's why it will work in IE8!
* (Object.defineProperty not required any more)
*
* This adapter is a "drop in" replacement for the "backingStore" adapter in Breeze core.
* It has the same adapter name so it will silently replace the original "backingStore" adapter
* when you load this script AFTER the breeze library.
* WARNING: For obvious reasons a lot of breeze magic will be lost!
*
* Author: Johannes Hoppe / haushoppe-its.de
*
* Copyright 2014 IdeaBlade, Inc. All Rights Reserved.
* Use, reproduction, distribution, and modification of this code is subject to the terms and
* conditions of the IdeaBlade Breeze license, available at http://www.breezejs.com/license
******************************************************/
(function (definition, window) {
if (window.breeze) {
definition(window.breeze);
} else if (typeof require === "function" && typeof exports === "object" && typeof module === "object") {
// CommonJS or Node
var b = require('breeze');
definition(b);
} else if (typeof define === "function" && define["amd"] && !window.breeze) {
// Requirejs / AMD
define(['breeze'], definition);
} else {
throw new Error("Can't find breeze");
}
}(function (breeze) {
"use strict";
var core = breeze.core;
var ctor = function () {
this.name = "backingStore";
this.A_BIG_FAT_WARNING = "This is a bare version of the backingStore! Change tracking won't work!";
};
var protoFn = ctor.prototype;
protoFn.initialize = function() {
};
protoFn.getTrackablePropertyNames = function (entity) {
var names = [];
for (var p in entity) {
if (p === "entityType") continue;
if (p === "_$typeName") continue;
var val = entity[p];
if (!core.isFunction(val)) {
names.push(p);
}
}
return names;
};
protoFn.initializeEntityPrototype = function (proto) {
proto.getProperty = function (propertyName) {
return this[propertyName];
};
proto.setProperty = function (propertyName, value) {
this[propertyName] = value;
return this;
};
};
// This method is called when an EntityAspect is first created - this will occur as part of the entityType.createEntity call.
// which can be called either directly or via standard query materialization
// entity is either an entity or a complexObject
protoFn.startTracking = function (entity, proto) {
// assign default values to the entity
var stype = entity.entityType || entity.complexType;
stype.getProperties().forEach(function (prop) {
var propName = prop.name;
var val = entity[propName];
if (prop.isDataProperty) {
if (prop.isComplexProperty) {
if (prop.isScalar) {
val = prop.dataType._createInstanceCore(entity, prop);
} else {
val = breeze.makeComplexArray([], entity, prop);
}
} else if (!prop.isScalar) {
val = breeze.makePrimitiveArray([], entity, prop);
} else if (val === undefined) {
val = prop.defaultValue;
}
} else if (prop.isNavigationProperty) {
if (val !== undefined) {
throw new Error("Cannot assign a navigation property in an entity ctor.: " + prop.Name);
}
if (prop.isScalar) {
// TODO: change this to nullstob later.
val = null;
} else {
val = breeze.makeRelationArray([], entity, prop);
}
} else {
throw new Error("unknown property: " + propName);
}
entity[propName] = val;
});
};
breeze.config.registerAdapter("modelLibrary", ctor);
}, this));
Download at: https://gist.github.com/JohannesHoppe/72d7916aeb08897bd256
This is a bare version of the original backingStore, without ANY change tracking - that's why it will work in IE8! (Object.defineProperty not required any more) This adapter is a "drop in" replacement for the "backingStore" adapter in Breeze core. It has the same adapter name so it will silently replace the original "backingStore" adapter when you load the script AFTER the breeze library.
Here is a demo to proof the functionality:
http://jsfiddle.net/Johannes_Hoppe/bcav9hzL/5/
JsFiddle does not support IE8, please use this direct link:
http://jsfiddle.net/Johannes_Hoppe/bcav9hzL/5/embedded/result/
Cheers!
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