npm package: @fluid-experimental/last-edited
Description: Tracks the last edited information in the Container.
Author: Microsoft and contributors
Latest version: 2.92.0

# @fluid-experimental/last-edited

LastEditedTracker tracks the last edit to a document, such as the client who last edited the document and the time it happened.

It is created by passing a `SharedSummaryBlock`:

```
constructor(private readonly sharedSummaryBlock: SharedSummaryBlock);
```

It uses the SharedSummaryBlock to store the last edit details.

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**IMPORTANT: This package is experimental.**
**Its APIs may change without notice.**

**Do not use in production scenarios.**

## Using Fluid Framework libraries

When taking a dependency on a Fluid Framework library's public APIs, we recommend using a `^` (caret) version range, such as `^1.3.4`.
While Fluid Framework libraries may use different ranges with interdependencies between other Fluid Framework libraries,
library consumers should always prefer `^`.

If using any of Fluid Framework's unstable APIs (for example, its `beta` APIs), we recommend using a more constrained version range, such as `~`.

## Installation

To get started, install the package by running the following command:

```bash
npm i @fluid-experimental/last-edited
```

## API Documentation

API documentation for **@fluid-experimental/last-edited** is available at <https://fluidframework.com/docs/apis/last-edited>.

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## API

It provides the following APIs to get and update the last edit details:

```
public getLastEditDetails(): ILastEditDetails | undefined;
public updateLastEditDetails(message: ISequencedDocumentMessage);
```

The update should always be called in response to a remote op because:

1. It updates its state from the remote op.
2. It uses a SharedSummaryBlock as storage which must be set in response to a remote op.

The details returned in getLastEditDetails contain the `IUser` object and the `timestamp` of the last edit.

## Last Edited Tracker Data Store

LastEditedTrackerDataObject is a runtime data store built on top of the LastEditedTracker. It creates and manages the SharedSummaryBlock so that the developer doesn't have to know about it or manage it.

It implements IProvideFluidLastEditedTracker and returns an IFluidLastEditedTracker which is an instance of LastEditedTracker above.

## Setup

This package also provides a `setupLastEditedTrackerForContainer` method that can be used to set up a data store that provides IFluidLastEditedTracker to track last edited in a Container:

-   This setup function should be called during container instantiation so that ops are not missed.
-   Registers an "op" listener on the runtime. On each message, it calls the shouldDiscardMessageFn to check if the message should be discarded. It also discards all scheduler message. If a message is not discarded, it passes the last edited information from the message to the last edited tracker in the data store.

Note:

-   By default, message that are not of `"Attach"` and `"Operation"` type are discarded as per the `shouldDiscardMessageDefault` function:

```
function shouldDiscardMessageDefault(message: ISequencedDocumentMessage) {
    if (message.type === MessageType.Attach || message.type === MessageType.Operation) {
        return false;
    }
    return true;
}.
```

-   To discard specific ops, provide the `shouldDiscardMessageFn` funtion that takes in the message and returns a boolean indicating if the message should be discarded.

## Usage

### For tracking the last edit on a Container:

In instantiateRuntime, create a data store that implements IFluidLastEditedTracker. Then call `setupLastEditedTrackerForContainer` with the id of the data store:

```
public async instantiateRuntime(context: IContainerContext): Promise<IRuntime> {
    const dataStoreId = "root";

    // Create the ContainerRuntime
    const runtime = await ContainerRuntime.load(...);

    if (!runtime.existing) {
        // On first boot create the root data store with id `dataStoreId`.
        await runtime.createDataStore(dataStoreId, "lastEditedTracker");
    }

    setupLastEditedTrackerForContainer(dataStoreId, runtime);

    return runtime;
}
```

This will make sure that the root data store loads before any other data store and it tracks every op in the Container.

The IFluidLastEditedTracker can be retrieved from the root data store:

```
const response = await containerRuntime.request({ url: "/" });
const root = response.value;
const lastEditedTracker = root.IFluidLastEditedTracker;
```

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## Minimum Client Requirements

These are the platform requirements for the current version of Fluid Framework Client Packages.
These requirements err on the side of being too strict since within a major version they can be relaxed over time, but not made stricter.
For Long Term Support (LTS) versions this can require supporting these platforms for several years.

It is likely that other configurations will work, but they are not supported: if they stop working, we do not consider that a bug.
If you would benefit from support for something not listed here, file an issue and the product team will evaluate your request.
When making such a request please include if the configuration already works (and thus the request is just that it becomes officially supported), or if changes are required to get it working.

### Supported Runtimes

-   NodeJs ^20.10.0 except that we will drop support for it [when NodeJs 20 loses its upstream support on 2026-04-30](https://github.com/nodejs/release#release-schedule), and will support a newer LTS version of NodeJS (22) at least 1 year before 20 is end-of-life. This same policy applies to NodeJS 22 when it is end of life (2027-04-30).
    -   Running Fluid in a Node.js environment with the `--no-experimental-fetch` flag is not supported.
-   Modern browsers supporting the es2022 standard library: in response to asks we can add explicit support for using babel to polyfill to target specific standards or runtimes (meaning we can avoid/remove use of things that don't polyfill robustly, but otherwise target modern standards).

### Supported Tools

-   TypeScript 5.4:
    -   All [`strict`](https://www.typescriptlang.org/tsconfig) options are supported.
    -   [`strictNullChecks`](https://www.typescriptlang.org/tsconfig) is required.
    -   [Configuration options deprecated in 5.0](https://github.com/microsoft/TypeScript/issues/51909) are not supported.
    -   `exactOptionalPropertyTypes` is currently not fully supported.
        If used, narrowing members of Fluid Framework types types using `in`, `Reflect.has`, `Object.hasOwn` or `Object.prototype.hasOwnProperty` should be avoided as they may incorrectly exclude `undefined` from the possible values in some cases.
-   [webpack](https://webpack.js.org/) 5
    -   We are not intending to be prescriptive about what bundler to use.
        Other bundlers which can handle ES Modules should work, but webpack is the only one we actively test.

### Module Resolution

[`Node16`, `NodeNext`, or `Bundler`](https://www.typescriptlang.org/tsconfig#moduleResolution) resolution should be used with TypeScript compilerOptions to follow the [Node.js v12+ ESM Resolution and Loading algorithm](https://nodejs.github.io/nodejs.dev/en/api/v20/esm/#resolution-and-loading-algorithm).
Node10 resolution is not supported as it does not support Fluid Framework's API structuring pattern that is used to distinguish stable APIs from those that are in development.

### Module Formats

-   ES Modules:
    ES Modules are the preferred way to consume our client packages (including in NodeJs) and consuming our client packages from ES Modules is fully supported.
-   CommonJs:
    Consuming our client packages as CommonJs is supported only in NodeJS and only for the cases listed below.
    This is done to accommodate some workflows without good ES Module support.
    If you have a workflow you would like included in this list, file an issue.
    Once this list of workflows motivating CommonJS support is empty, we may drop support for CommonJS one year after notice of the change is posted here.

    -   Testing with Jest (which lacks [stable ESM support](https://jestjs.io/docs/ecmascript-modules) due to [unstable APIs in NodeJs](https://github.com/nodejs/node/issues/37648))

## Contribution Guidelines

There are many ways to [contribute](https://github.com/microsoft/FluidFramework/blob/main/CONTRIBUTING.md) to Fluid.

-   Participate in Q&A in our [GitHub Discussions](https://github.com/microsoft/FluidFramework/discussions).
-   [Submit bugs](https://github.com/microsoft/FluidFramework/issues) and help us verify fixes as they are checked in.
-   Review the [source code changes](https://github.com/microsoft/FluidFramework/pulls).
-   [Contribute bug fixes](https://github.com/microsoft/FluidFramework/blob/main/CONTRIBUTING.md).

Detailed instructions for working in the repo can be found in the [Wiki](https://github.com/microsoft/FluidFramework/wiki).

This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/).
For more information see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or contact [opencode@microsoft.com](mailto:opencode@microsoft.com) with any additional questions or comments.

This project may contain Microsoft trademarks or logos for Microsoft projects, products, or services.
Use of these trademarks or logos must follow Microsoft’s [Trademark & Brand Guidelines](https://www.microsoft.com/trademarks).
Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship.

## Help

Not finding what you're looking for in this README? Check out [fluidframework.com](https://fluidframework.com/docs/).

Still not finding what you're looking for? Please [file an issue](https://github.com/microsoft/FluidFramework/wiki/Submitting-Bugs-and-Feature-Requests).

Thank you!

## Trademark

This project may contain Microsoft trademarks or logos for Microsoft projects, products, or services.

Use of these trademarks or logos must follow Microsoft's [Trademark & Brand Guidelines](https://www.microsoft.com/en-us/legal/intellectualproperty/trademarks/usage/general).

Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship.

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