[API Proposal]: Implement IDirectoryContents on PhysicalDirectoryInfo at MS.Extensions.FileProviders.Physical

[vpenades]

Background and motivation

Microsoft.Extensions.FileProviders.Abstractions provides a basic set of interfaces that allow accessing the file system.

The default implementation, Microsoft.Extensions.FileProviders.Physical , wraps FileInfo and DirectoryInfo , and the context is initialized using a PhysicalFileProvider, which, as I understand it, might be used at the directory root, or any directory that can be considered the "local root"

The problem:

PhysicalFileProvider implements IDirectoryContents which gives the list of IFileInfo items contained in the root directory, which are represented by both files and directories , the latter being implemented by a PhysicalDirectoryInfo , which implements IFileInfo, but does not implement IDirectoryContents , and as a consequence of this, it's not possible to traverse the file system tree beyond the 1st directory level provided by PhysicalFileProvider

API Proposal

namespace Microsoft.Extensions.FileProviders.Physical
{
    public class PhysicalDirectoryInfo : IFileInfo, IDirectoryContents  
    {
        // IDirectoryContents implementation
    }

API Usage

class Utils
{
    public static void RecursivelyTraverseTree(IDirectoryContents contents)
    {
        foreach (var entry in contents)
        {
            if (entry.IsDirectory)
            {
                if (entry is IDirectoryContents childContents)
                {
                    RecursivelyTraverseTree(childContents);
                }                
            }
        }           
    }
}

Alternative Designs

Alternatively, PhysicalDirectoryInfo could implement IFileProvider instead of IDirectoryContents because the latter can be retrieved from the former.

Anyway, I am open to proposals to know how to traverse a file system tree based on IFileInfo abstractions, without taking assumptions about the underlaying implementation.

Risks

No response

[ghost]

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Issue Details

---

Background and motivation

Microsoft.Extensions.FileProviders.Abstractions provides a basic set of interfaces that allow accessing the file system.

The default implementation, Microsoft.Extensions.FileProviders.Physical , wraps FileInfo and DirectoryInfo , and the context is initialized using a PhysicalFileProvider, which, as I understand it, might be used at the directory root, or any directory that can be considered the "local root"

The problem:

PhysicalFileProvider implements IDirectoryContents which gives the list of IFileInfo items contained in the root directory, which are represented by both files and directories , the latter being implemented by a PhysicalDirectoryInfo , which implements IFileInfo, but does not implement IDirectoryContents , and as a consequence of this, it's not possible to traverse the file system tree beyond the 1st directory level provided by PhysicalFileProvider

API Proposal

namespace Microsoft.Extensions.FileProviders.Physical
{
    public class PhysicalDirectoryInfo : IFileInfo, IDirectoryContents  
    {
        // IDirectoryContents implementation
    }

API Usage

class Utils
{
    public static void RecursivelyTraverseTree(IDirectoryContents contents)
    {
        foreach (var entry in contents)
        {
            if (entry.IsDirectory)
            {
                if (entry is IDirectoryContents childContents)
                {
                    RecursivelyTraverseTree(childContents);
                }                
            }
        }           
    }
}

Alternative Designs

Alternatively, PhysicalDirectoryInfo could implement IFileProvider instead of IDirectoryContents because the latter can be retrieved from the former.

Anyway, I am open to proposals to know how to traverse a file system tree based on IFileInfo abstractions, without taking assumptions about the underlaying implementation.

Risks

No response

Author:	vpenades
Assignees:	-
Labels:	api-suggestion, area-System.IO
Milestone:	-

[Jozkee]

As a workaround, you could just create a PhysicalDirectoryContents using PhysicalDirectoryInfo.PhysicalPath, no?

[vpenades]

As a workaround, you could just create a PhysicalDirectoryContents using PhysicalDirectoryInfo.PhysicalPath, no?

No, the point of using the interfaces is to have an abstraction layer that does not implicitly assume there's a physical path. In fact I want to create virtualized file systems, or file system from within archives, where PhysicalPath would throw an exception.

[bartonjs]

Video

Looks good as proposed

namespace Microsoft.Extensions.FileProviders.Physical
{
    public partial class PhysicalDirectoryInfo : IFileInfo
+       , IDirectoryContents  
    {
        // IDirectoryContents implementation
    }