WopiHost.FileSystemProvider 6.0.0

WopiHost.FileSystemProvider

Reference implementation of IWopiStorageProvider and IWopiWritableStorageProvider backed by a local directory tree. Identifiers are short opaque strings cached in-memory and mapped to absolute paths.

Suitable for development, validator runs, and single-instance deployments. Storage only — token issuance and ACLs live in WopiHost.Core.

Install

dotnet add package WopiHost.FileSystemProvider

Configure

// appsettings.json
"Wopi": {
  "StorageProviderAssemblyName": "WopiHost.FileSystemProvider",
  "StorageProvider": {
    "RootPath": "./wopi-docs"   // absolute or relative to ContentRootPath
  }
}

RootPath is bound from the Wopi:StorageProvider section (WopiConfigurationSections.STORAGE_OPTIONS).

Register

builder.Services.AddSingleton<InMemoryFileIds>();
builder.Services.AddScoped<IWopiStorageProvider,         WopiFileSystemProvider>();
builder.Services.AddScoped<IWopiWritableStorageProvider, WopiFileSystemProvider>();
builder.Services.AddWopi(o =>
{
    o.ClientUrl                   = new Uri("https://your-office-online-server.com");
    o.StorageProviderAssemblyName = "WopiHost.FileSystemProvider";
});

If you use the sample's assembly-name loader (AddStorageProvider), the two AddScoped lines are not needed — the sample reflectively scans the assembly and registers anything that implements IWopiStorageProvider / IWopiWritableStorageProvider. See sample/WopiHost/Program.cs.

How identifiers work

Identifiers are short tokens generated by InMemoryFileIds on first scan and reused for the lifetime of the process. They are NOT base64-encoded paths; consumers should treat them as opaque strings. Lookup is O(1) in both directions; the cache is rebuilt at startup if RootPath changes.

A consequence of this design: identifiers are stable within a process but not across restarts. Persist your own mapping if you need long-lived URLs.

Customize

To layer behavior — versioning, audit, soft-delete — wrap the provider via composition. The concrete class' interface methods are non-virtual, so a decorator is the cleanest seam:

public class AuditingStorageProvider(IWopiWritableStorageProvider inner, IAuditLog audit)
    : IWopiWritableStorageProvider
{
    public Task<bool> DeleteWopiResource<T>(string id, CancellationToken ct = default)
        where T : class, IWopiResource
    {
        var deleted = inner.DeleteWopiResource<T>(id, ct);
        _ = deleted.ContinueWith(t => { if (t.Result) audit.Log($"deleted {id}"); }, ct);
        return deleted;
    }

    // Forward the rest of IWopiWritableStorageProvider to `inner`.
    public int FileNameMaxLength => inner.FileNameMaxLength;
    // ...
}

License

See the repo README.