@fluidframework/map

@fluidframework/map

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 ~.

Importing from this package

This package leverages package.json exports to separate its APIs by support level. For more information on the related support guarantees, see API Support Levels.

To access the public (SemVer) APIs, import via @fluidframework/map like normal.

To access the legacy APIs, import via @fluidframework/map/legacy.

SharedMap

The SharedMap distributed data structure can be used to store key-value pairs. It provides the same API for setting and retrieving values that JavaScript developers are accustomed to with the Map built-in object.

Creation

To create a SharedMap, call the static create method:

const myMap = SharedMap.create(this.runtime, id);

Usage

Unlike the JavaScript Map, a SharedMap's keys must be strings. The value must only be plain JS objects or handles (e.g. to another DDS or Fluid objects).

In collaborative scenarios, the value is settled with a policy of last write wins.

Eventing

SharedMap is an EventEmitter, and will emit events when other clients make modifications. You should register for these events and respond appropriately as the data is modified. valueChanged will be emitted in response to a set or delete, and provide the key and previous value that was stored at that key. clear will be emitted in response to a clear.

SharedDirectory and IDirectory

A SharedDirectory is a map-like DDS that additionally supports storing key/value pairs within a tree of subdirectories. This subdirectory tree can be used to give hierarchical structure to stored key/value pairs rather than storing them on a flat map. Both the SharedDirectory and any subdirectories are IDirectories.

Creation

To create a SharedDirectory, call the static create method:

const myDirectory = SharedDirectory.create(this.runtime, id);

Usage

The map operations on an IDirectory refer to the key/value pairs stored in that IDirectory, and function just like SharedMap including the same extra functionality and restrictions on keys and values. To operate on the subdirectory structure, use the corresponding subdirectory methods.

getWorkingDirectory()

To "navigate" the subdirectory structure, IDirectory provides a getWorkingDirectory method which takes a relative path and returns the IDirectory located at that path if it exists.

Eventing

valueChanged events additionally provide the absolute path to the subdirectory storing the value that changed.

dispose events are fired on sub directory which is deleted. Any access to this sub directory will throw an error once it is disposed.

API Documentation

API documentation for @fluidframework/map is available at https://fluidframework.com/docs/apis/map.

Contribution Guidelines

There are many ways to contribute to Fluid.

• Participate in Q&A in our GitHub Discussions.
• Submit bugs and help us verify fixes as they are checked in.
• Review the source code changes.
• Contribute bug fixes.

Detailed instructions for working in the repo can be found in the Wiki.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact [e-mail] 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. 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.

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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.

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