Custom file system providers

The CMS.IO library allows you to customize Xperience to support a file system of your choice. As described in Files API and CMS.IO, you can achieve this by developing a custom provider based on the classes contained within CMS.IO.

Preparation

To implement a custom file system provider, you need to add a new assembly to the Xperience solution:

1. Open your solution in Visual Studio.
2. Add a new Class Library project.

Implementation

To create a file system provider, implement the following classes:

1. Create two separate classes that inherit from the following abstract classes:

   • CMS.IO.AbstractDirectory
   • CMS.IO.AbstractFile

2. Implement all methods defined in the abstract classes.

3. Create three other classes that inherit from the following classes:

   • CMS.IO.DirectoryInfo
   • CMS.IO.FileInfo
   • CMS.IO.FileStream

4. Override all methods and properties from those classes.

5. Create constructors for the classes listed in step 3 according to the following table:

   Inherits from	Constructors
   CMS.IO.DirectoryInfo	public DirectoryInfo(string path)
   CMS.IO.FileInfo	public FileInfo(string filename)
   CMS.IO.FileStream	public FileStream(string path, CMS.IO.FileMode mode) public FileStream(string path, CMS.IO.FileMode mode, CMS.IO.FileAccess access) public FileStream(string path, CMS.IO.FileMode mode, CMS.IO.FileAccess access, CMS.IO.FileShare share) public FileStream(string path, CMS.IO.FileMode mode, CMS.IO.FileAccess access, CMS.IO.FileShare share, int bSize)

Configuration

Perform the following configuration steps to start using your custom file system provider:

1. Add the CMSStorageProviderAssembly application setting to your project. Set the key’s value to the assembly name of your custom provider.
2. Create a custom module that reads from the storage path registry and maps registered paths to your custom provider.

Example

The following code registers a module that maps all SharedPersistent paths to a custom storage provider:

using CMS;
using CMS.DataEngine;
using CMS.IO;

using Microsoft.Extensions.DependencyInjection;

// Registers the custom module into the system
[assembly: RegisterModule(typeof(CustomInitializationModule))]

public class CustomInitializationModule : Module
{
    // Module class constructor, the system registers the module under the name "CustomInit"
    public CustomInitializationModule()
        : base("CustomInit")
    {
    }

    // Contains initialization code that is executed when the application starts
    protected override void OnInit(ModuleInitParameters parameters)
    {
        base.OnInit(parameters);

        var pathRegistry = parameters.Services.GetRequiredService<IStoragePathRegistry>();

        foreach (var registration in pathRegistry.GetRegistrations(PathType.SharedPersistent))
        {
            // Creates a new StorageProvider instance using the custom 'CustomFileSystemProvider' assembly
            var provider = new StorageProvider("custom", "CustomFileSystemProvider");

            // Maps the registered path to the provider
            StorageHelper.MapStoragePath(registration.MappedPath, provider);
        }
    }
}