Reading a file in MVC 6

Question

I want to access my create.sql file in the main folder of my server. It contains queries to set up my database. I have a problem to access this file at all.

1) I cannot really get there through Configuration. I can only use AddJsonFile, AddXmlFile, and AddIniFile. And I guess this is not the best idea to put a big sql file into any of those.

2) Mvc source on github seems to be missing MapPath. So no possibility of using Server.MapPath("~/create.sql").

How to achieve this then?

Answer 1

As already noticed and mentioned in the comments it seems that there is no MapPath in ASP.NET VNext (MVC 6). I found the workaround here:

http://forums.asp.net/t/2005166.aspx?HostingEnvironment+Equivalent+For+MapPath

Basically you need to get the ApplicationBasePath from IApplicationEnvironment interface, which currently is implemented as a service, following below the solution:

    private readonly IApplicationEnvironment _appEnvironment;

    public HomeController(IApplicationEnvironment appEnvironment)
    {
        _appEnvironment = appEnvironment;
    }

    public IActionResult Index()
    {
        var rootPath = _appEnvironment.ApplicationBasePath;
        return View();
    }

Answer 2

And also, instead of injecting IApplicationEnvironment you may use PlatformServices.Default.Application.ApplicationBasePath.

EDIT: Here's a possible implementation of MapPath/UnmapPath as extensions to PlatformServices:

removed (see EDIT2)

EDIT2: Slightly modified, IsPathMapped() added as well as some checks to see if path mapping/unmapping is really needed.

public static class PlatformServicesExtensions
{
    public static string MapPath(this PlatformServices services, string path)
    {
        var result = path ?? string.Empty;
        if (services.IsPathMapped(path) == false)
        {
            var wwwroot = services.WwwRoot();
            if (result.StartsWith("~", StringComparison.Ordinal))
            { 
                result = result.Substring(1); 
            }
            if (result.StartsWith("/", StringComparison.Ordinal))
            { 
                result = result.Substring(1);
            }
            result = Path.Combine(wwwroot, result.Replace('/', '\\'));
        }

        return result;
    }

    public static string UnmapPath(this PlatformServices services, string path)
    {
        var result = path ?? string.Empty;
        if (services.IsPathMapped(path))
        {
            var wwwroot = services.WwwRoot();
            result = result.Remove(0, wwwroot.Length);
            result = result.Replace('\\', '/');

            var prefix = (result.StartsWith("/", StringComparison.Ordinal) ? "~" : "~/");
            result = prefix + result;
        }

        return result;
    }

    public static bool IsPathMapped(this PlatformServices services, string path)
    {
        var result = path ?? string.Empty;
        return result.StartsWith(services.Application.ApplicationBasePath,
            StringComparison.Ordinal);
    }

    public static string WwwRoot(this PlatformServices services)
    {
        // todo: take it from project.json!!!
        var result = Path.Combine(services.Application.ApplicationBasePath, "wwwroot");
        return result;
    }
}

EDIT3: PlatformServices.WwwRoot() return the actual execution path and in .net core 2.0, DEBUG mode it is xxx\bin\Debug\netcoreapp2.0, which, obviously is not what is required. Instead, replace PlatformServices with IHostingEnvironment and use environment.WebRootPath.