Umbraco-CMS/src/Umbraco.Core/Hosting/IHostingEnvironment.cs

using System;

namespace Umbraco.Core.Hosting
{
    public interface IHostingEnvironment
    {
        string SiteName { get; }

        string ApplicationId { get; }

        /// <summary>
        /// Will return the physical path to the root of the application
        /// </summary>
        string ApplicationPhysicalPath { get; }

        string LocalTempPath { get; }

        /// <summary>
        /// The web application's hosted path
        /// </summary>
        /// <remarks>
        /// In most cases this will return "/" but if the site is hosted in a virtual directory then this will return the virtual directory's path such as "/mysite".
        /// This value must begin with a "/" and cannot end with "/".
        /// </remarks>
        string ApplicationVirtualPath { get; }

        bool IsDebugMode { get; }

        /// <summary>
        /// Gets a value indicating whether Umbraco is hosted.
        /// </summary>
        bool IsHosted { get; }

        /// <summary>
        /// Maps a virtual path to a physical path to the application's web root
        /// </summary>
        /// <remarks>
        /// Depending on the runtime 'web root', this result can vary. For example in Net Framework the web root and the content root are the same, however
        /// in netcore the web root is /www therefore this will Map to a physical path within www.
        /// </remarks>
        string MapPathWebRoot(string path);

        /// <summary>
        /// Maps a virtual path to a physical path to the application's root (not always equal to the web root)
        /// </summary>
        /// <remarks>
        /// Depending on the runtime 'web root', this result can vary. For example in Net Framework the web root and the content root are the same, however
        /// in netcore the web root is /www therefore this will Map to a physical path within www.
        /// </remarks>
        string MapPathContentRoot(string path);

        /// <summary>
        /// Converts a virtual path to an absolute URL path based on the application's web root
        /// </summary>
        /// <param name="virtualPath">The virtual path. Must start with either ~/ or / else an exception is thrown.</param>
        /// <remarks>
        /// This maps the virtual path syntax to the web root. For example when hosting in a virtual directory called "site" and the value "~/pages/test" is passed in, it will
        /// map to "/site/pages/test" where "/site" is the value of <see cref="ApplicationVirtualPath"/>.
        /// </remarks>
        /// <exception cref="InvalidOperationException">
        /// If virtualPath does not start with ~/ or /
        /// </exception>
        string ToAbsolute(string virtualPath);
    }
}