Eigenverft.NetLib.Configuration.WritebackJson 1.0.0.5-g17613f8942

Eigenverft.NetLib.Configuration.WritebackJson

Manage a typed JSON document with a persisted branch, an initial rollback snapshot, and a separate runtime-only working copy.

✨ At a glance

📦 Installation

dotnet add package Eigenverft.NetLib.Configuration.WritebackJson

🚀 Quick start

The model must be a reference type with a public parameterless constructor:

using Eigenverft.NetLib.Configuration.WritebackJson;

using var store = new WritebackJsonStore<RuntimeSettings>(
    "AppSettings/runtime-settings.json");

store.MutateRuntimeWorkingCopy(settings => settings.Route = "Preview");
store.MutateCurrentAndSave(settings => settings.Route = "Failover");

public sealed class RuntimeSettings
{
    public string Route { get; set; } = "Primary";
}

The runtime copy remains Preview; changing persisted Current does not overwrite it. Call RestoreRuntimeWorkingCopyFromCurrent() when the runtime branch should resynchronize with the file-backed state.

🧭 State and notifications

At construction, the store loads the JSON document or creates one from new T() if the file is absent. It writes the initial document and captures it as InitialSnapshot. The snapshot is a deep copy and remains the rollback baseline for the lifetime of that store.

• Current is the file-backed branch. Use MutateCurrentAndSave(...) to persist changes.
• RuntimeWorkingCopy is detached in-memory state. Use MutateRuntimeWorkingCopy(...); this never writes the backing file.
• CurrentChanged and RuntimeWorkingCopyChanged report changes from store operations. Pass notify: false to suppress an operation's notification.
• GetCurrentSnapshot() returns an independent copy of the current state.

Treat the objects returned by Current and RuntimeWorkingCopy as read-only. Directly changing their properties bypasses persistence and change notifications.

👀 External changes and DI

External-file watching is enabled by default. Successfully reloaded content updates Current; it does not replace InitialSnapshot or RuntimeWorkingCopy. Handle ErrorOccurred for background file-system or reload errors. Dispose the store when its lifetime ends.

To register it in a host's service collection:

using Eigenverft.NetLib.Configuration.WritebackJson;
builder.Services.AddWritebackJsonStore<RuntimeSettings>(
    "AppSettings/runtime-settings.json",
    watchForExternalChanges: true);

The store is not an IConfiguration provider and does not publish configuration reload tokens. It can share a file with a JSON configuration provider or SwitchableJson; configure that provider's reload behavior separately if it should observe writes.

🎯 Target frameworks

• net8.0
• net10.0

A .NET 9 consumer can use the compatible net8.0 asset.

🔗 Project links

• Source project
• Solution documentation
• Repository

📄 License

MIT