Using Sessions in my Project - asp.net

Question

I am new to .NET programming and I am trying to implement sessions in my already screwed sample. So here are the details of my sample i had done till now.
I have types of solutions in my project. A Class library, web application and console application.
I created a static class which has a bunch of get/properties and using these properties as global variables to use in my Class library. These get/set properties have a mixed set of data structures like list and dictionaries.
My Web app has only one page with a bunch of list boxes and button. I am using all the get set properties from my class library in to my Web application for some data storing and retrieving purposes. Now when the web page is opened in two different browsers then the data is over written from one user to the other as I am using all static variables and storing data in those static variables.
My best solution to this is using sessions but I am a little confused of using them in my project. Can any one please help me in this regard.
Here is a small sample of my explanation:
a XMLData Class in Class Library has a bunch of these get/set properties.
public Dictionary<string, List<string>> Content
{
get { return _testContent; }
set { _testContent = value;}
}
Now how do I use HttpContext Sessions to use in my Class Library to move these static properties to sessions so that every user who uses my site have their set of data. FYI. The web project is basically used for call in methods to the class library and do a little selection on the list box of the UI which are kind of inputs to my test.
Thanks In Advance.

Answer 1

The simple way is that you can access the current context in a class in your class library using
HttpContext.Current
this has Session available on it.
There are more complex ways that your application could be architected, but we'll start with the simplest :)
To elaborate, your class library may declare an interface for a component that is able to access session
public interface ISessionStore
{
object Get(string key);
void Save(string key, object value);
}
now, define a concrete implementation of ISessionStore
public class HttpContextSessionStore : ISessionStore
{
public object Get(string key)
{
var context = HttpContext.Current;
if (context == null)
throw new InvalidOperationException("this class is intended to work only within web applications");
return context.Session(key);
}
public void Save(string key, object value)
{
var context = HttpContext.Current;
if (context == null)
throw new InvalidOperationException("this class is intended to work only within web applications");
// note that this will overwrite anything already set
// against this key in session
context.Session[key] = value;
}
}
Now you can program against the interface ISessionStore and use the HttpContextSessionStore in your application.
I'd recommend looking at the MVP pattern if you're working with web forms or alternatively, take a look at the MVC framework.

Answer 2

In addition to Russ Cam's comments above, you should also check that HttpContext.Current != null in methods in your class library. It's guaranteed to bite you in the ass if you start writing unit tests, or for any code which isn't being executed within ASP.Net