CODEWITHSUNDEEP
asp.net-mvc
PositiveGuy
PositiveGuy

Reputation: 47783

How to get an instance of the current HttpRequestBase outside of a Controller or View's context

What I'm doing:

I am creating an email mailing engine that takes html templates, replaces tokens with data and then sends off the mail to an SMTP server. Eventually we'll want a CMS UI on top of this to allow them to add/remove file templates or update the content in them via a CMS UI. Anyway I am putting the .htm files for the email templates inside my MVC web project and need to read their contents and get the string of HTML back to work with. If I move all this code out of my MVC project into like a utility C# project layer, the problem is then I have to worry about maintaining physical paths ("C:...\theMVCWebSiteFolder...\Email\Templates\SomeTemplate.htm") and that to me would have to be hard coded I think to keep track if you were to move the site to a different server, different hard drive partition, etc. So I'd like to be able to work with the files using the current application's context unless there's a way to do this agnostic to my MVC app and still not have to worry about having to ever change the location of the physical root every time we move folders.

I've got the following utility method I created in a utility class that sits in a folder somewhere in my ASP.NET MVC web project in just a folder (a folder outside of any view folders:

public static string GetFileData(string filePath)
{
    if (!File.Exists(HttpContext.Current.Request.PhysicalApplicationPath + filePath))
        throw new FileNotFoundException(String.Format("the file {0} was not found", filePath));

    string text;
    FileStream fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.None);

    using(StreamReader read = new StreamReader(fileStream))
        text = read.ReadToEnd();

    return text;
}

I'm trying to figure out why the context is turning up null here. I originally tried HttpContext.Current but current is coming up null so it can't find the current context in my Utility.cs method that sits in my MVC web project.

UPDATE:

Ok so the consensus is to use HttpRequestBase object and not the HttpContext.Current object. I still find it weird that the HttpContext.Current is null. But moving on, if my Utility.cs is outside any context of a controller or view, then how the heck do I get an instance of the current request (HttpRequestBase) to work with and send an instance that implements HttpRequestBase (I do not know what object that would be if I want to do this in the "MVC way" outside a controller or view) to this utility method?

Upvotes: 0

Views: 3533

Answers (3)

to StackOverflow
to StackOverflow

Reputation: 124794

In a utility class I would remove the dependency on any web-related stuff.

For a path relative to the application root I would use:

Path.Combine(System.AppDomain.CurrentDomain.BaseDirectory, fileName)

which will give you what you probably want (a path relative to the web root directory in a web application; relative to the path containing the executable in a WinForms app, ...)

Upvotes: 2

Darin Dimitrov
Darin Dimitrov

Reputation: 1039428

No idea why this returns null but since it is a bad idea to tie your business layers with ASP.NET specifics I'd recommend you the following change to your method:

public static string GetFileData(string filePath)
{
    if (!File.Exists(filePath))
        throw new FileNotFoundException(String.Format("the file {0} was not found", filePath));

    return File.ReadAllText(filePath);
}

and then when you need to consume it from a web application:

public ActionResult Foo()
{
    var result = MyClass.GetFileData(Server.MapPath("~/foo/bar.txt"));
    ...
}

and when you need to consume it in a WinForms application:

protected void Button1_Click(object sender, EventArgs e)
{
    var filePath = Path.Combine(Environment.CurrentDirectory, "bar.txt");
    var result = MyClass.GetFileData(filePath);
    ...
}

Upvotes: 2

archil
archil

Reputation: 39501

If want to rewrite that method in asp.net mvc way, you could rewrite it this way and remove coupling with HttpContext class

public static string GetFileData(HttpRequestBase request, string filePath)
{
    if (!File.Exists(request.PhysicalApplicationPath + filePath))
        throw new FileNotFoundException(String.Format("the file {0} was not found", filePath));

    string text;
    FileStream fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.None);

    using(StreamReader read = new StreamReader(fileStream))
        text = read.ReadToEnd();

    return text;
}

And generally in MVC HttpContext, HttpRequest and HttpResponse are abstracted into HttpContextBase, HttpRequestBase and HttpResponseBase accordingly

Upvotes: 1

Related Questions