I'm new to PostSharp and investigating it's use for our project. I'm trying to apply OnMethodBoundaryAspect on an abstract method and getting the following error: http://screencast.com/t/1LyzIz2M
Able to execute the aspect just fine with regular and virtual methods, am I missing anything or is it not possible w/ abstract members?
Here's my simple aspect:
[Serializable]
public sealed class TraceAttribute : OnMethodBoundaryAspect
{
protected string _strMethodName;
protected static readonly Stopwatch _sw = new Stopwatch();
public TraceAttribute(string pMethodName)
{
_strMethodName = pMethodName;
}
public override void OnEntry(MethodExecutionArgs args)
{
_sw.Start();
string strMsg = string.Format(">> Entering {0}.{1}", args.Method.DeclaringType.Name, args.Method);
Debug.Print(strMsg);
}
public override void OnExit(MethodExecutionArgs args)
{
_sw.Stop();
string strMsg = string.Format("<< Leaving {0}.{1} - EXECTIME: {2} ms", args.Method.DeclaringType.Name,
args.Method, _sw.ElapsedMilliseconds);
Debug.Print(strMsg);
_sw.Reset();
}
}
Related
I have written a custom OnMethodBoundaryAspect called TraceAspect. This aspect checks within the OnEntry, OnExit, and OnException methods whether tracing is enabled or not. I have a central class for reading and writing settings. Both of the two methods Settings.GetLoggingEnabled() and Settings.GetLogLevel() are called from the TraceAspect. They are there, so I reuse them which results in a StackOverflowException.
[assembly: MyCompany.MyProduct.TraceAspect]
[Serializable]
public class TraceAspect : OnMethodBoundaryAspect
{
public override void OnEntry(MethodExecutionArgs args)
{
if (Settings.GetLogginEnabled() && Settings.GetLogLevel() == LogLevel.Trace)
{
// Log the message
}
}
}
Applying the [TraceAspect(AttributeExclude = true)] attribute to the TraceAspect class leads to the same behaviour.
I could write something like this. But this is code duplication.
[assembly: MyCompany.MyProduct.TraceAspect]
[Serializable]
public class TraceAspect : OnMethodBoundaryAspect
{
public override void OnEntry(MethodExecutionArgs args)
{
if (this.GetLogginEnabled() && this.GetLogLevel() == LogLevel.Trace)
{
// Log the message
}
}
private bool GetLoggingEnabled()
{
// copy code from Settings.GetLogginEnabled()
}
private bool GetLogLevel()
{
// copy code from Settings.GetLogLevel()
}
}
How can I tell that the Settings.GetLoggingEnabled() and Settings.GetLogTrace() methods should not be traced, when they are called by the aspect?
You can break the recursion during logging by introducing a thread static flag to indicate that you're currently inside the logging call.
[Serializable]
public class TraceAspect : OnMethodBoundaryAspect
{
[ThreadStatic]
private static bool isLogging;
public override void OnEntry(MethodExecutionArgs args)
{
if (isLogging) return;
isLogging = true;
try
{
if (Settings.GetLogginEnabled() && Settings.GetLogLevel() == LogLevel.Trace)
{
// Log the message
}
}
finally
{
isLogging = false;
}
}
}
I have an MVC4 site that uses both MVC and WebAPI in it. All was going well till I tried to change my classes to have a cross cutting AOP class that would help with caching data. I am now finding that when I call a method that does not have the InterceptAttribute on it, it will crash because Ninject didn't inject with a parameter, and it fails.
My BLL class looks like this:
public class FooBLL
{
#region Private Variables
private readonly IDAL _context;
#endregion
#region Constructor
public Foo(IDAL context)
{
_context = context;
}
#endregion
#region Public Methods
public List<Bar> GetAllBars()
{
return _context.GetAllBars();
}
public List<Bar> GetTwoBars()
{
return _context.GetTwoBars();
}
#endregion
}
My WebApi Controller looks like this:
public class FooController : ApiController
{
#region Private Variables
private readonly FooBLL _fooBll;
#endregion
#region Constructor
public FooController(FooBLL fooBll)
{
_fooBll = fooBll;
}
#endregion
#region Public Methods
#region Estimate Types
#region Get
public List<Bar> GetAllBars()
{
return _fooBll.GetAllBars();
}
public List<Bar> GetTwoBars()
{
return _fooBll.GetTwoBars();
}
#endregion
#endregion
#endregion
}
In my Website, I created the following Ninject classes for resolving the controllers:
public class NinjectRegistrations : NinjectModule
{
public override void Load()
{
Kernel.Bind<IDAL>().To<DAL>().InSingletonScope();
}
}
public class NinjectDependencyResolver : NinjectDependencyScope, IDependencyResolver, System.Web.Mvc.IDependencyResolver
{
private readonly IKernel kernel;
public NinjectDependencyResolver(IKernel kernel)
: base(kernel)
{
this.kernel = kernel;
}
public IDependencyScope BeginScope()
{
return new NinjectDependencyScope(this.kernel.BeginBlock());
}
}
public class NinjectDependencyScope : IDependencyScope
{
private IResolutionRoot resolver;
internal NinjectDependencyScope(IResolutionRoot resolver)
{
Contract.Assert(resolver != null);
this.resolver = resolver;
}
public void Dispose()
{
var disposable = this.resolver as IDisposable;
if (disposable != null)
{
disposable.Dispose();
}
this.resolver = null;
}
public object GetService(Type serviceType)
{
if (this.resolver == null)
{
throw new ObjectDisposedException("this", "This scope has already been disposed");
}
return this.resolver.TryGet(serviceType);
}
public IEnumerable<object> GetServices(Type serviceType)
{
if (this.resolver == null)
{
throw new ObjectDisposedException("this", "This scope has already been disposed");
}
return this.resolver.GetAll(serviceType);
}
}
In Global.asax I then register this resolver:
NinjectHelper.Kernel = new StandardKernel(modules);
var ninjectResolver = new NinjectDependencyResolver(NinjectHelper.Kernel);
DependencyResolver.SetResolver(ninjectResolver); // MVC
GlobalConfiguration.Configuration.DependencyResolver = ninjectResolver; // Web API
//Register Filter Injector
GlobalConfiguration.Configuration.Services.Add(typeof(System.Web.Http.Filters.IFilterProvider), new NinjectWebApiFilterProvider(NinjectHelper.Kernel));
Things were fine till I added the attribute Cache using Ninject.Extensions.Interception.Attributes.InterceptAttribute.
The class now looks like this (note that I added a parameterless constructor and marked one of the methods as virtual, these are both required for the Interception to work):
public class FooBLL
{
#region Private Variables
private readonly IDAL _context;
#endregion
#region Constructor
public Foo(IDAL context)
{
_context = context;
}
public Foo()
{
}
#endregion
#region Public Methods
public List<Bar> GetAllBars()
{
return _context.GetAllBars();
}
[Cache(DefaultTimeoutMinutes = 20)]
public virtual List<Bar> GetTwoBars()
{
return _context.GetTwoBars();
}
#endregion
}
Now on the WebAPI controller, when I call GetToBars(the method with the Intercept Attribute), everything still works fine.
However, when I call GetAllBars(the method that doesn't have the Intercept Attribute), I fail with an exception that _context is null.
Any help would be greatly appreciated.
Ben
I've converted my AsyncTask to an AsyncTaskLoader (mostly to deal with configuration changes). I have a TextView I am using as a progress status and was using onProgressUpdate in the AsyncTask to update it. It doesn't look like AsyncTaskLoader has an equivalent, so during loadInBackground (in the AsyncTaskLoader) I'm using this:
getActivity().runOnUiThread(new Runnable() {
public void run() {
((TextView)getActivity().findViewById(R.id.status)).setText("Updating...");
}
});
I am using this in a Fragment, which is why I'm using getActivity(). This work pretty well, except when a configuration change happens, like changing the screen orientation. My AsyncTaskLoader keeps running (which is why I'm using an AsyncTaskLoader), but the runOnUiThread seems to get skipped.
Not sure why it's being skipped or if this is the best way to update the UI from an AsyncTaskLoader.
UPDATE:
I ended up reverting back to an AsyncTask as it seems better suited for UI updates. Wish they could merge what works with an AsyncTask with an AsyncTaskLoader.
It's actually possible. You essentially need to subclass the AsyncTaskloader and implement a publishMessage() method, which will use a Handler to deliver the progress message to any class that implements the ProgressListener (or whatever you want to call it) interface.
Download this for an example: http://www.2shared.com/file/VW68yhZ1/SampleTaskProgressDialogFragme.html (message me if it goes offline) - this was based of http://habrahabr.ru/post/131560/
Emm... you shouldn't be doing this.
because how an anonymous class access parent class Method or Field is by storing an invisible reference to the parent class.
for example you have a Activity:
public class MyActivity
extends Activity
{
public void someFunction() { /* do some work over here */ }
public void someOtherFunction() {
Runnable r = new Runnable() {
#Override
public void run() {
while (true)
someFunction();
}
};
new Thread(r).start(); // use it, for example here just make a thread to run it.
}
}
the compiler will actually generate something like this:
private static class AnonymousRunnable {
private MyActivity parent;
public AnonymousRunnable(MyActivity parent) {
this.parent = parent;
}
#Override
public void run() {
while (true)
parent.someFunction();
}
}
So, when your parent Activity destroys (due to configuration change, for example), and your anonymous class still exists, the whole activity cannot be gc-ed. (because someone still hold a reference.)
THAT BECOMES A MEMORY LEAK AND MAKE YOUR APP GO LIMBO!!!
If it was me, I would implement the "onProgressUpdate()" for loaders like this:
public class MyLoader extends AsyncTaskLoader<Something> {
private Observable mObservable = new Observable();
synchronized void addObserver(Observer observer) {
mObservable.addObserver(observer);
}
synchronized void deleteObserver(Observer observer) {
mObservable.deleteObserver(observer);
}
#Override
public void loadInBackground(CancellationSignal signal)
{
for (int i = 0;i < 100;++i)
mObservable.notifyObservers(new Integer(i));
}
}
And in your Activity class
public class MyActivity extends Activity {
private Observer mObserver = new Observer() {
#Override
public void update(Observable observable, Object data) {
final Integer progress = (Integer) data;
mTextView.post(new Runnable() {
mTextView.setText(data.toString()); // update your progress....
});
}
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreated(savedInstanceState);
MyLoader loader = (MyLoader) getLoaderManager().initLoader(0, null, this);
loader.addObserver(mObserver);
}
#Override
public void onDestroy() {
MyLoader loader = (MyLoader) getLoaderManager().getLoader(0);
if (loader != null)
loader.deleteObserver(mObserver);
super.onDestroy();
}
}
remember to deleteObserver() during onDestroy() is important, this way the loader don't hold a reference to your activity forever. (the loader will probably be held alive during your Application lifecycle...)
Answering my own question, but from what I can tell, AsyncTaskLoader isn't the best to use if you need to update the UI.
In the class in which you implement LoaderManager.LoaderCallback (presumably your Activity), there is an onLoadFinished() method which you must override. This is what is returned when the AsyncTaskLoader has finished loading.
The best method is to use LiveData, 100% Working
Step 1: Add lifecycle dependency or use androidx artifacts as yes during project creation
implementation "androidx.lifecycle:lifecycle-livedata:2.1.0"
Step 2: Create the loader class as follow, in loader create in public method to set the livedata that can be observed from activity or fragment. see the setLiveCount method in my loader class.
package com.androidcodeshop.asynctaskloaderdemo;
import android.content.Context;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.lifecycle.MutableLiveData;
import androidx.loader.content.AsyncTaskLoader;
import java.util.ArrayList;
public class ContactLoader extends AsyncTaskLoader<ArrayList<String>> {
private MutableLiveData<Integer> countLive = new MutableLiveData<>();
synchronized public void setLiveCount(MutableLiveData<Integer> observer) {
countLive = (observer);
}
public ContactLoader(#NonNull Context context) {
super(context);
}
#Nullable
#Override
public ArrayList<String> loadInBackground() {
return loadNamesFromDB();
}
private ArrayList<String> loadNamesFromDB() {
ArrayList<String> names = new ArrayList<>();
for (int i = 0; i < 10; i++) {
try {
Thread.sleep(1000);
names.add("Name" + i);
countLive.postValue(i);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
return names;
}
#Override
protected void onStartLoading() {
super.onStartLoading();
forceLoad(); // forcing the loading operation everytime it starts loading
}
}
Step 3: Set the live data from activity and observe the change as follows
package com.androidcodeshop.asynctaskloaderdemo;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.lifecycle.MutableLiveData;
import androidx.loader.app.LoaderManager;
import androidx.loader.content.Loader;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity implements
LoaderManager.LoaderCallbacks<ArrayList> {
private ContactAdapter mAdapter;
private ArrayList<String> mNames;
private MutableLiveData<Integer> countLiveData;
private static final String TAG = "MainActivity";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mNames = new ArrayList<>();
mAdapter = new ContactAdapter(this, mNames);
RecyclerView mRecyclerView = findViewById(R.id.recycler_view);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
mRecyclerView.setAdapter(mAdapter);
countLiveData = new MutableLiveData<>();
countLiveData.observe(this, new androidx.lifecycle.Observer<Integer>() {
#Override
public void onChanged(Integer integer) {
Log.d(TAG, "onChanged: " + integer);
Toast.makeText(MainActivity.this, "" +
integer,Toast.LENGTH_SHORT).show();
}
});
// initialize the loader in onCreate of activity
getSupportLoaderManager().initLoader(0, null, this);
// it's deprecated the best way is to use viewmodel and livedata while loading data
}
#NonNull
#Override
public Loader onCreateLoader(int id, #Nullable Bundle args) {
ContactLoader loader = new ContactLoader(this);
loader.setLiveCount(countLiveData);
return loader;
}
#Override
public void onLoadFinished(#NonNull Loader<ArrayList> load, ArrayList data) {
mNames.clear();
mNames.addAll(data);
mAdapter.notifyDataSetChanged();
}
#Override
public void onLoaderReset(#NonNull Loader loader) {
mNames.clear();
}
#Override
protected void onDestroy() {
super.onDestroy();
}
}
Hope this will help you :) happy coding
I am using SignalR in my MVC3 application, and since I have implemented StructureMap Dependency Injection on my controllers I would like to do the same in my hub, but I can't seem to get it working.
Please tell me what's wrong with my codes below:
SignalRSmDependencyResolver.cs
public class SignalRSmDependencyResolver : DefaultDependencyResolver
{
private IContainer _container;
public SignalRSmDependencyResolver(IContainer container)
{
_container = container;
}
public override object GetService(Type serviceType)
{
object service = null;
if (!serviceType.IsAbstract && !serviceType.IsInterface && serviceType.IsClass)
{
// Concrete type resolution
service = _container.GetInstance(serviceType);
}
else
{
// Other type resolution with base fallback
service = _container.TryGetInstance(serviceType) ?? base.GetService(serviceType);
}
return service;
}
public override IEnumerable<object> GetServices(Type serviceType)
{
var objects = _container.GetAllInstances(serviceType).Cast<object>();
objects.Concat(base.GetServices(serviceType));
return objects;
}
}
SignalRExtensionsRegistry.cs
public class SignalRExtensionsRegistry : Registry
{
public SignalRExtensionsRegistry()
{
For<IDependencyResolver>().Add<SignalRSmDependencyResolver>();
}
}
IoC.cs
public static class IoC {
public static IContainer Initialize() {
var container = BootStrapper.Initialize();
container.Configure(x =>
{
x.For<IControllerActivator>().Singleton().Use<StructureMapControllerActivator>();
});
return container;
}
}
public class StructureMapControllerActivator : IControllerActivator {
public StructureMapControllerActivator(IContainer container) {
_container = container;
}
private IContainer _container;
public IController Create(RequestContext requestContext, Type controllerType) {
IController controller = DependencyResolver.Current.GetService(controllerType) as IController;
return controller;
}
}
AppStart_Structuremap.cs
[assembly: WebActivator.PreApplicationStartMethod(typeof(StoreUI.AppStart_Structuremap), "Start")]
namespace MyNameSpace {
public static class AppStart_Structuremap {
public static void Start() {
var container = (IContainer) IoC.Initialize();
DependencyResolver.SetResolver(new StructureMapDependenceyResolver(container));
AspNetHost.SetResolver(new StructureMapDependencyResolver(container));
}
}
}
NotificationsHub.cs
[HubName("notificationsHub")]
public class NotificationsHub : Hub
{
#region Declarations
private readonly IUserService userService;
#endregion
#region Constructor
public NotificationsHub(IUserService userService)
{
this.userService = userService;
}
#endregion
public void updateServer(string message)
{
Clients.updateClient(message);
}
}
Thanks
Getting Structuremap into SignalR is actually pretty easy. First you want to create your own resolver:
StructureMap Resolver
Usings:
using SignalR.Infrastructure;
using StructureMap;
Class:
public class StructureMapResolver : DefaultDependencyResolver
{
private IContainer _container;
public StructureMapResolver(IContainer container)
{
_container = container;
}
public override object GetService(Type serviceType)
{
object service = null;
if (!serviceType.IsAbstract && !serviceType.IsInterface && serviceType.IsClass)
{
// Concrete type resolution
service = _container.GetInstance(serviceType);
}
else
{
// Other type resolution with base fallback
service = _container.TryGetInstance(serviceType) ?? base.GetService(serviceType);
}
return service;
}
public override IEnumerable<object> GetServices(Type serviceType)
{
var objects = _container.GetAllInstances(serviceType).Cast<object>();
return objects.Concat(base.GetServices(serviceType));
}
}
The idea here is to try and use your container to resolve the dependencies, if you do not have the dependency wired up, pass it through to the default resolver. This way you don't have to worry about all of the other dependencies in SignalR and can focus only on the stuff you want to inject into (Hubs, ConnectionIdFactory, MessageBus, etc.).
Bindings for Resolver and Hub
Next you will want to register this in your container (i like using registries):
Usings:
using SignalR.Infrastructure;
using StructureMap.Configuration.DSL;
Class:
public class ExtensionsRegistry : Registry
{
public ExtensionsRegistry()
{
For<IDependencyResolver>().Add<StructureMapResolver>();
}
}
Resolver Replacement
Finally you will want to tell SignalR to use your resolver instead of the default:
Global::Application_Start or WebActivator::Pre_Start
Usings:
using SignalR.Hosting.AspNet;
using SignalR.Infrastructure;
Application_Start:
// Make sure you build up the container first
AspNetHost.SetResolver(StructureMap.ObjectFactory.GetInstance<IDependencyResolver>());
Silly Hub with injected dependencies
Now you can just inject any dependencies your container knows about into the hubs themselves:
[HubName("defaultHub")]
public class DefaultHub : Hub, IDisconnect
{
private readonly IRepository _repo;
public DefaultHub(IRepository repo)
{
_repo = repo;
}
public void Connect()
{
Caller.setUser(Context.ConnectionId);
Clients.addMessage(string.Format("{0} has connected", Context.ConnectionId));
}
public void MessageSender(string message)
{
Caller.addMessage(_repo.RepositoryMessage());
Clients.addMessage(message);
}
public Task Disconnect()
{
var clientId = this.Context.ConnectionId;
return Task.Factory.StartNew(() => { Clients.addMessage(string.Format("{0} has disconnected", clientId)); });
}
}
Have you followed the instructions here:- https://github.com/SignalR/SignalR/wiki/Extensibility ?
You'll need to use AspNetHost.SetResolver.
I know this is an old thread, but for those who are wondering where is the AspNetHost.SetResolver in the newer version of signalR, you can use this in the App_Start StructuremapMvc.cs:
public static void Start() {
IContainer container = IoC.Initialize();
GlobalHost.DependencyResolver = new SignalRSmDependencyResolver(container); // for signalR
DependencyResolver.SetResolver(new StructureMapDependencyResolver(container));
GlobalConfiguration.Configuration.DependencyResolver = new StructureMapDependencyResolver(container);
}
Add something like this to a file in your App_Start folder. This code snippet is for Ninject, so just replace AspNetHost.SetResolver()
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.Mvc;
using Ninject;
using SignalR.Hosting.AspNet;
using SignalR.Infrastructure;
using SignalR.Ninject;
using Web.Models;
[assembly: WebActivator.PreApplicationStartMethod(typeof(Web.App_Start.NinjectSignalR), "Start")]
namespace Web.App_Start
{
public static class NinjectSignalR
{
public static void Start()
{
IKernel kernel = CreateKernel();
// switch this line to the structuremap resolver
AspNetHost.SetResolver(new NinjectDependencyResolver(kernel));
}
private static IKernel CreateKernel()
{
var kernel = new StandardKernel();
RegisterServices(kernel);
return kernel;
}
private static void RegisterServices(IKernel kernel)
{
// add your services here
//kernel.Bind<IRepository>().To<Repository>();
}
}
}
in the ModelStateDictionary class there are only AddModelError and Add function , i want extention the class, add the method like AddModeSuccess，AddModelWarning.
i have a look at the MVC3 source code and found there a lot of thing need add. i don't want to modify the MVC3 code, i just want to add a extention. how could i do?
public void Add(KeyValuePair<string, ModelState> item) {
((IDictionary<string, ModelState>)_innerDictionary).Add(item);
}
public void Add(string key, ModelState value) {
_innerDictionary.Add(key, value);
}
public void AddModelError(string key, Exception exception) {
GetModelStateForKey(key).Errors.Add(exception);
}
public void AddModelError(string key, string errorMessage) {
GetModelStateForKey(key).Errors.Add(errorMessage);
}
You could add them as extension methods to the ModelStateDictionary class:
public static class ModelStateExtensions
{
public static void AddModelSuccess(this ModelStateDictionary modelState, ... some parameters)
{
...
}
public static void AddModelWarning(this ModelStateDictionary modelState, ... some parameters)
{
...
}
}