Making IAuthorizor or TwitterContext Global / Accessible - twitter

One more follow up to Extract BearerToken from LinqToTwitter IAuthorizer
I am successfully using the Auth / Context / BearerToken with in my application however i wanted to now use the L2T library to Check on Rates. I need TwitterContext to do so, but I am now out of twitterCtx scope.
is it possible to set this up as a public class so I can access it from anywhere without the need to reauthorize?
Thank you in advance.

There are different ways to do this. Here are a couple where you can go the Singleton route or a factory method.
Note: There's debate on whether a Singleton is an appropriate pattern to use or whether a global reference to an object is even
appropriate at all, but that's isn't what you're asking.
public class TwitterContextService
{
static TwitterContext twitterCtx;
public static TwitterContext Instance
{
get
{
if (twitterCtx == null)
twitterCtx = CreateTwitterContext();
return twitterCtx;
}
}
public static TwitterContext CreateTwitterContext()
{
var auth = new ApplicationOnlyAuthorizer()
{
CredentialStore = new InMemoryCredentialStore
{
ConsumerKey = Environment.GetEnvironmentVariable(OAuthKeys.TwitterConsumerKey),
ConsumerSecret = Environment.GetEnvironmentVariable(OAuthKeys.TwitterConsumerSecret)
},
};
return new TwitterContext(auth);
}
}
Then there are two ways you can use this -
as a singleton:
TwitterContext twitterCtx = TwitterContextService.Instance;
or as a factory method:
TwitterContext twitterCtx = TwitterContextService.CreateTwitterContext();
Alternatively, you can use an IoC container (tons of information and available libraries on the Web) and pass the dependencies into the code that uses TwitterContext. I guess there are several different ways to do this.

Related

Auto-registration with a RegistrationSource in Autofac

Here's what I'm doing so far (code simplified):
public class MyRegistrationSource : IRegistrationSource
{
public MyRegistrationSource(ContainerBuilder builder /*,...*/)
{
// ...
this.builder = builder;
}
public IEnumerable<IComponentRegistration> RegistrationsFor(
Service service, Func<Service, IEnumerable<IComponentRegistration>> registrationAccessor)
{
// Some checks here
var interfaceType = serviceWithType.ServiceType;
var implementorType = FindTheRightImplementor(interfaceType);
if (myRegisterConditionSatisfied)
{
return Register(implementorType, interfaceType);
}
return Empty;
}
private IEnumerable<IComponentRegistration> Register(Type concrete, Type #interface)
{
var regBuilder = builder.RegisterType(concrete).As(#interface).IfNotRegistered(#interface);
return new[] { regBuilder.CreateRegistration() };
}
}
Then, at startup I'm doing something like
builder.RegisterSource(
new NonRegisteredServicesRegistrationSource(builder/*, ...*/));
The above is intended to register those matching services only when there's no previous registration. I tried doing the registration without using the ContainerBuilder but couldn't get it to work.
This is working but are there any issues in passing-in the ContainerBuilder instance to the RegistrationSource?
Thanks!
I'd probably argue against passing in a ContainerBuilder.
Every type you register in your source will add a callback to a list of callbacks inside the Container Builder which will never get cleared, potentially creating a memory leak.
I'd suggest calling the static method RegistrationBuilder.ForType instead, which will give you a fluent builder and should let you subsequently call CreateRegistration as you are now.
You can see some pretty good examples of how do this in our Moq integration:
var reg = RegistrationBuilder.ForType(concrete)
.As(#interface)
.CreateRegistration();
Also, I don't believe IfNotRegistered will have any effect when used outside the context of a ContainerBuilder. You should use the provided registrationAccessor parameter to the registration source to look up a TypedService to see if it has already been registered:
var isRegistered = registrationAccessor(new TypedService(#interface)).Any();

AutoMapper: Does Map <A,B> give <B,A>?

Using Automapper I create a simple map:
Mapper.CreateMap<MyCustomerDTO, YourCustomerDTO>()
I often need to go the other way too. Do I need to also create the mapping the other way, or will Automapper infer it based on the above mapping?
Mapper.CreateMap<YourCustomerDTO, MyCustomerDTO>() //Needed?
This is a duplicate to Do i need to create automapper createmap both ways?
Note the answer regarding .ReverseMap() here.
Note that .ReverseMap() is for basic mapping. If you need to use options (such as specific ForMember mappings), you will need to create a custom reverse map.
No. you must create two way mapping. A good helper method for two way mapping could be :
protected virtual void ViceVersa<T1, T2>()
{
Mapper.CreateMap<T1, T2>();
Mapper.CreateMap<T2, T1>();
}
then use it like this :
ViceVersa<T1, T2>();
you need to create second mapping as well. A simple test trying to run your app without second mapping will give you a runtime error
I've come across the same issue when working with AutoMapper, and #Behnam-Esmaili is a good answer but it could be improved.
You could implement a extension method for IMapperConfigurationExpression which would do this two way mapping and also expecting two optional parameter (Action<IMappingExpression<T, Y>>) which would be used when trying to configure the Mappings for both types.
public static class ModelMapper
{
private static readonly IMapper _mapper;
static ModelMapper()
{
var mapperConfiguration = new MapperConfiguration(config =>
{
config.CreateTwoWayMap<CustomerViewModel, Customer>(
secondExpression: (exp) => exp.ForMember((source) => source.CustomerEmail, opt => opt.MapFrom(src => src.Email)));
});
_mapper = mapperConfiguration.CreateMapper();
}
public static void CreateTwoWayMap<T, Y>(this IMapperConfigurationExpression config,
Action<IMappingExpression<T, Y>> firstExpression = null,
Action<IMappingExpression<Y, T>> secondExpression = null)
{
var mapT = config.CreateMap<T, Y>();
var mapY = config.CreateMap<Y, T>();
firstExpression?.Invoke(mapT);
secondExpression?.Invoke(mapY);
}
public static T Map<T>(object model)
{
return _mapper.Map<T>(model);
}
}
The implementation above is a one way of achieving it, however it can be design differently.

Orchard CMS : Creating module for OpenRasta, problems with dependency injection

I'm trying to create an Orchard CMS module that enables a RESTful web service using OpenRasta for a given route (/openrasta/* for example).
I need to get to the Orchard ContentManager to get the content for the service to return, so my OpenRasta handler (ContentHandler) uses a ContentService, which implements IContentService, which inherits IDependency. Normally this would work because Orchard will inject a ContentManager into the constructor:
public class ContentService : IContentService {
public IContentManager content;
public ContentService(IContentManager content) {
this.content = content;
}
public IEnumerable<string> GetContentTypeDefinitionNames() {
return content.GetContentTypeDefinitions().Select(d => d.Name);
}
}
But when I run it I get an error because OpenRasta doesn't know anything about the Orchard dependencies and it's trying to create ContentService, not Orchard, which is fair enough:
OpenRasta.DI.DependencyResolutionException: Could not resolve type
ContentService because its dependencies couldn't be fullfilled
Constructor: Orchard.ContentManagement.IContentManager
Is there a way to achieve this, can I go to an Orchard class somewhere and say "give me an instance of the ContentManager"?
Update: See my comments on #rfcdejong's answer for updates on my progress.
Are u using a ServiceRoute, added in a class implementing IRouteProvider
Look at the ServiceRoute summary, it says "Enables the creation of service routes over HTTP in support of REST scenarios."
public class Routes : IRouteProvider
{
public void GetRoutes(ICollection<RouteDescriptor> routes)
{
foreach (var routeDescriptor in GetRoutes())
routes.Add(routeDescriptor);
}
private static ServiceRoute _rastaService = new ServiceRoute(
"openrasta",
new MyServiceHostFactory<IOpenRastaService>(),
typeof(IOpenRastaService));
public IEnumerable<RouteDescriptor> GetRoutes()
{
return new[]
{
new RouteDescriptor
{
Priority = -1,
Route = _rastaService
}
};
}
}
And want to resolve ContentService? U might have to resolve the interface.
i guess u want the following to work:
var contentService = LifetimeScope.ResolveNew<IContentService>();
I have used HostContainer.Resolve directly and had issues as well. I will describe the solution i'm using at the moment in my own ServiceHostFactory
Do u have a own ServiceHostFactory deriven from OrchardServiceHostFactory?
In that case u can implement the following code to help u resolve instances
private ILifetimeScope _lifetimeScope = null;
private ILifetimeScope LifetimeScope
{
get
{
if (_lifetimeScope == null)
{
IHttpContextAccessor accessor = HostContainer.Resolve<IHttpContextAccessor>();
IRunningShellTable runningShellTable = HostContainer.Resolve<IRunningShellTable>();
ShellSettings shellSettings = runningShellTable.Match(accessor.Current());
IOrchardHost orchardHost = HostContainer.Resolve<IOrchardHost>();
ShellContext shellContext = orchardHost.GetShellContext(shellSettings);
_lifetimeScope = shellContext.LifetimeScope;
}
return _lifetimeScope;
}
}
I also created LifetimeScopeExtensions that has the following code
public static class LifetimeScopeExtensions
{
public static T ResolveNew<T>(this ILifetimeScope scope)
{
IWorkContextAccessor workContextAccessor = scope.Resolve<IWorkContextAccessor>();
WorkContext workContext = workContextAccessor.GetContext();
if (workContext == null)
{
using (IWorkContextScope workContextScope = workContextAccessor.CreateWorkContextScope())
{
ILifetimeScope lifetimeScope = workContextScope.Resolve<ILifetimeScope>();
return lifetimeScope.Resolve<T>();
}
}
else
{
ILifetimeScope lifetimeScope = workContext.Resolve<ILifetimeScope>();
return lifetimeScope.Resolve<T>();
}
}
public static object ResolveNew(this ILifetimeScope scope, Type type)
{
IWorkContextAccessor workContextAccessor = scope.Resolve<IWorkContextAccessor>();
WorkContext workContext = workContextAccessor.GetContext();
if (workContext == null)
{
using (IWorkContextScope workContextScope = workContextAccessor.CreateWorkContextScope())
{
ILifetimeScope lifetimeScope = workContextScope.Resolve<ILifetimeScope>();
return lifetimeScope.Resolve(type);
}
}
else
{
ILifetimeScope lifetimeScope = workContext.Resolve<ILifetimeScope>();
return lifetimeScope.Resolve(type);
}
}
}
var settingsService = LifetimeScope.ResolveNew<ITokenServiceSettingsService>();
So the issue is that your CMS uses its own IoC container. By default OpenRasta does that too.
This means that services that are present in Orchard won't be visible to OpenRasta.
For all other IoC containers, the answer is damn right simple: You use the IoC adaptation layer that lets OpenRasta live in whatever ioc container you want. We support unity, structuremap, castle and ninject. That said, autofac is not supported as no one ever built it.
The cleanest way for you to solve this problem (and any other you may encounter in the future for those issues) would be to build your own autofac ioc adaptation layer for openrasta. If you need help doing that, you can join the openeverything mailing list where the devs would be happy to help you.

create global non-cached variable

How can i create a global variable in Symfony, but one that will never be cached?
I basically want to be able to get BaseForm token key anywhere in my app without the need to create a new instance of it every time..
Thanks!
You should create a static method and store the token you need in a static variable.
// /lib/form/BaseForm.class.php
protected static $token = null;
public static getToken(){
if(is_null(self::$token)){
$form = new BaseForm();
self::$token = $form->getCSRFToken();
}
return self::$token;
}
public static setToken($){
self::$token =
}
You use it then
BaseForm::getToken();

Session variables in ASP.NET MVC

I am writing a web application that will allow a user to browse to multiple web pages within the website making certain requests. All information that the user inputs will be stored in an object that I created. The problem is that I need this object to be accessed from any part of the website and I don't really know the best way to accomplish this. I know that one solution is to use session variables but I don't know how to use them in asp .net MVC. And where would I declare a session variable? Is there any other way?
I would think you'll want to think about if things really belong in a session state. This is something I find myself doing every now and then and it's a nice strongly typed approach to the whole thing but you should be careful when putting things in the session context. Not everything should be there just because it belongs to some user.
in global.asax hook the OnSessionStart event
void OnSessionStart(...)
{
HttpContext.Current.Session.Add("__MySessionObject", new MySessionObject());
}
From anywhere in code where the HttpContext.Current property != null you can retrive that object. I do this with an extension method.
public static MySessionObject GetMySessionObject(this HttpContext current)
{
return current != null ? (MySessionObject)current.Session["__MySessionObject"] : null;
}
This way you can in code
void OnLoad(...)
{
var sessionObj = HttpContext.Current.GetMySessionObject();
// do something with 'sessionObj'
}
The answer here is correct, I however struggled to implement it in an ASP.NET MVC 3 app. I wanted to access a Session object in a controller and couldn't figure out why I kept on getting a "Instance not set to an instance of an Object error". What I noticed is that in a controller when I tried to access the session by doing the following, I kept on getting that error. This is due to the fact that this.HttpContext is part of the Controller object.
this.Session["blah"]
// or
this.HttpContext.Session["blah"]
However, what I wanted was the HttpContext that's part of the System.Web namespace because this is the one the Answer above suggests to use in Global.asax.cs. So I had to explicitly do the following:
System.Web.HttpContext.Current.Session["blah"]
this helped me, not sure if I did anything that isn't M.O. around here, but I hope it helps someone!
Because I dislike seeing "HTTPContext.Current.Session" about the place, I use a singleton pattern to access session variables, it gives you an easy to access strongly typed bag of data.
[Serializable]
public sealed class SessionSingleton
{
#region Singleton
private const string SESSION_SINGLETON_NAME = "Singleton_502E69E5-668B-E011-951F-00155DF26207";
private SessionSingleton()
{
}
public static SessionSingleton Current
{
get
{
if ( HttpContext.Current.Session[SESSION_SINGLETON_NAME] == null )
{
HttpContext.Current.Session[SESSION_SINGLETON_NAME] = new SessionSingleton();
}
return HttpContext.Current.Session[SESSION_SINGLETON_NAME] as SessionSingleton;
}
}
#endregion
public string SessionVariable { get; set; }
public string SessionVariable2 { get; set; }
// ...
then you can access your data from anywhere:
SessionSingleton.Current.SessionVariable = "Hello, World!";
Well, IMHO..
never reference a Session inside your view/master page
minimize your useage of Session. MVC provides TempData obj for this, which is basically a Session that lives for a single trip to the server.
With regards to #1, I have a strongly typed Master View which has a property to access whatever the Session object represents....in my instance the stongly typed Master View is generic which gives me some flexibility with regards to strongly typed View Pages
ViewMasterPage<AdminViewModel>
AdminViewModel
{
SomeImportantObjectThatWasInSession ImportantObject
}
AdminViewModel<TModel> : AdminViewModel where TModel : class
{
TModel Content
}
and then...
ViewPage<AdminViewModel<U>>
If you are using asp.net mvc, here is a simple way to access the session.
From a Controller:
{Controller}.ControllerContext.HttpContext.Session["{name}"]
From a View:
<%=Session["{name}"] %>
This is definitely not the best way to access your session variables, but it is a direct route. So use it with caution (preferably during rapid prototyping), and use a Wrapper/Container and OnSessionStart when it becomes appropriate.
HTH
Although I don't know about asp.net mvc, but this is what we should do in a normal .net website. It should work for asp.net mvc also.
YourSessionClass obj=Session["key"] as YourSessionClass;
if(obj==null){
obj=new YourSessionClass();
Session["key"]=obj;
}
You would put this inside a method for easy access.
HTH
There are 3 ways to do it.
You can directly access HttpContext.Current.Session
You can Mock HttpContextBase
Create a extension method for HttpContextBase
I prefer 3rd way.This link is good reference.
Get/Set HttpContext Session Methods in BaseController vs Mocking HttpContextBase to create Get/Set methods
My way of accessing sessions is to write a helper class which encapsulates the various field names and their types. I hope this example helps:
using System;
using System.Collections.Generic;
using System.Web;
using System.Web.SessionState;
namespace dmkp
{
/// <summary>
/// Encapsulates the session state
/// </summary>
public sealed class LoginInfo
{
private HttpSessionState _session;
public LoginInfo(HttpSessionState session)
{
this._session = session;
}
public string Username
{
get { return (this._session["Username"] ?? string.Empty).ToString(); }
set { this._session["Username"] = value; }
}
public string FullName
{
get { return (this._session["FullName"] ?? string.Empty).ToString(); }
set { this._session["FullName"] = value; }
}
public int ID
{
get { return Convert.ToInt32((this._session["UID"] ?? -1)); }
set { this._session["UID"] = value; }
}
public UserAccess AccessLevel
{
get { return (UserAccess)(this._session["AccessLevel"]); }
set { this._session["AccessLevel"] = value; }
}
}
}
Great answers from the guys but I would caution you against always relying on the Session. It is quick and easy to do so, and of course would work but would not be great in all cicrumstances.
For example if you run into a scenario where your hosting doesn't allow session use, or if you are on a web farm, or in the example of a shared SharePoint application.
If you wanted a different solution you could look at using an IOC Container such as Castle Windsor, creating a provider class as a wrapper and then keeping one instance of your class using the per request or session lifestyle depending on your requirements.
The IOC would ensure that the same instance is returned each time.
More complicated yes, if you need a simple solution just use the session.
Here are some implementation examples below out of interest.
Using this method you could create a provider class along the lines of:
public class CustomClassProvider : ICustomClassProvider
{
public CustomClassProvider(CustomClass customClass)
{
CustomClass = customClass;
}
public string CustomClass { get; private set; }
}
And register it something like:
public void Install(IWindsorContainer container, IConfigurationStore store)
{
container.Register(
Component.For<ICustomClassProvider>().UsingFactoryMethod(
() => new CustomClassProvider(new CustomClass())).LifestylePerWebRequest());
}
You can use ViewModelBase as base class for all models , this class will take care of pulling data from session
class ViewModelBase
{
public User CurrentUser
{
get { return System.Web.HttpContext.Current.Session["user"] as User };
set
{
System.Web.HttpContext.Current.Session["user"]=value;
}
}
}
You can write a extention method on HttpContextBase to deal with session data
T FromSession<T>(this HttpContextBase context ,string key,Action<T> getFromSource=null)
{
if(context.Session[key]!=null)
{
return (T) context.Session[key];
}
else if(getFromSource!=null)
{
var value = getFromSource();
context.Session[key]=value;
return value;
}
else
return null;
}
Use this like below in controller
User userData = HttpContext.FromSession<User>("userdata",()=> { return user object from service/db });
The second argument is optional it will be used fill session data for that key when value is not present in session.

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