# @truffle/dashboard-message-bus-client > Client library for accessing the truffle dashboard's message bus Latest version **0.1.12** (published 2023-09-07) · MIT license · 0 weekly downloads > **Deprecated.** This package is deprecated. ## Install ```sh npm install @truffle/dashboard-message-bus-client pnpm add @truffle/dashboard-message-bus-client yarn add @truffle/dashboard-message-bus-client bun add @truffle/dashboard-message-bus-client ``` ## Health **Score 10/100 (F)** — status: deprecated. Negative: deprecated. ## Facts | | | |---|---| | Version | 0.1.12 | | Published | 2023-09-07 | | First published | 2022-06-23 | | Weekly downloads | 0 | | License | MIT | | TypeScript types | bundled | | Module format | CommonJS | | Node | ^16.20 \|\| ^18.16 \|\| >=20 | | Dependencies | 9 | | Unpacked size | 56.1 KB | | Known vulnerabilities | 0 (+30 in 1 direct dependencies) | | Install scripts | no | | GitHub stars | 13915 | | Maintainers | rizedr, joshuafernandes, cliffoo, kevinbluer, gnidan, haltman, eggplantzzz, fainashalts, cds-amal | | Keywords | ethereum, etherscan, ipfs, solidity, verify-source, sourcify, compile | ## Links - npm: https://www.npmjs.com/package/@truffle/dashboard-message-bus-client - Repository: https://github.com/trufflesuite/truffle - Homepage: https://github.com/trufflesuite/truffle/tree/master/packages/dashboard-message-bus-client#readme - Issues: https://github.com/trufflesuite/truffle/issues - npm.io page: https://npm.io/package/@truffle/dashboard-message-bus-client ## Dependencies (9) - [ws](https://npm.io/package/ws.md) ^7.2.0 - [axios](https://npm.io/package/axios.md) 1.5.0 - [debug](https://npm.io/package/debug.md) ^4.3.1 - [delay](https://npm.io/package/delay.md) ^5.0.0 - [isomorphic-ws](https://npm.io/package/isomorphic-ws.md) ^4.0.1 - [tiny-typed-emitter](https://npm.io/package/tiny-typed-emitter.md) ^2.1.0 - [node-abort-controller](https://npm.io/package/node-abort-controller.md) ^3.0.1 - [@truffle/promise-tracker](https://npm.io/package/@truffle/promise-tracker.md) ^0.1.7 - [@truffle/dashboard-message-bus-common](https://npm.io/package/@truffle/dashboard-message-bus-common.md) ^0.1.7 ## Recent versions - 0.1.12 (latest) — 2023-09-07 - 0.1.7-hardhat-error.0 (hardhat-error) — 2022-08-25 - 0.1.3-typescript-migrations.0 (typescript-migrations) — 2022-07-21 - 0.1.0-alpha.2 (signTypedData_v4) — 2022-06-24 - 0.1.11 — 2023-06-06 - 0.1.10 — 2023-01-27 - 0.1.9 — 2022-11-23 - 0.1.8 — 2022-10-26 - 0.1.7 — 2022-10-12 - 0.1.6 — 2022-08-24 - 0.1.6-hardhat-error.1 — 2022-08-22 - 0.1.6-hardhat-error.0 — 2022-08-20 - 0.1.5 — 2022-08-17 - 0.1.4 — 2022-08-10 - 0.1.3 — 2022-07-21 - … 4 more at https://npm.io/package/@truffle/dashboard-message-bus-client/versions ## README # `@truffle/dashboard-message-bus-client` This library is used for connecting with the message bus that powers the Truffle dashboard. ## Usage ### Connecting to the message bus and producing a message ```ts import { DashboardMessageBusClient } from "@truffle/dashboard-message-bus-client"; const client = new DashboardMessageBusClient({ port, host }); const message = { type: "helloWorld", id: new DateTime().getTime(), payload: { hello: "world" } }; const messageLifecycle = await client.publish(message); ``` #### The lifecycle of published messages Publishing a message creates a lifecycle for that message. The lifecycle is tracked by the publisher as an object of type `PublishedMessageLifecycle`. Publish message lifecycles terminate in one of three ways: 1. Receipt of a corresponding response message 2. Invalidation of the message 3. Abandonment of the message ##### Waiting for a response to a message To enable request/response messaging (e.g. proxied JSON-RPC messages), publish lifecycles contain a promise that resolves when a response to the originally published message is received. ```ts const response = await publishLifecycle.response; ``` ##### Abandoning messages To allow for fire-and-forget messages (e.g. event data), simply call the `abandon` method on the lifecycle object. **Important**: If the `abandon` method of the publish lifecycle is not called, the process will hang forever on exit, as it will forever be waiting for a response that will never arive. ```ts await messageLifecycle.abandon(); ``` ##### Invalidating messages (aka message cancellation) The consumer of a published message often will need to perform some longer running operation as a result of that message. To cancel that work, or to communicate to the consumer that the message is no longer valid, simply call `cancel` on the publish lifecycle. ```ts await messageLifecycle.invalidate(); ``` ### Consuming and responding to messages Messages can be consumed by calling the `subscribe` method of the client. The `subscribe` method returns a `DashboardMessageSubscription` object. This object emits `message` events whenever messages are received that match the subscription's filter. Received messages are wrapped up in a lifecycle object similar to the one used for publishing messages, however there's only a single `respond` method. ```ts import { DashboardMessageBusClient } from "@truffle/dashboard-message-bus-client"; const client = new DashboardMessageBusClient({ port, host }); // omitting the type string in the options object will return a subscription // for all messages const subscription = client.subscribe({ type: "helloWorld" }); subscription.on("message", receivedMessageLifecycle => { const helloTarget = receivedMessageLifecycle.message.payload.hello; if (helloTarget.toLowerCase() === "world") { // respond by passing your response payload directly to the response await receivedMessageLifecycle.respond({ someArbitraryResponse: "Why hello there. Pleased to make your acquaintance" }); } else { await receivedMessageLifecycle.respond({ error: `I'm sorry, you have the wrong number. This is world, not "${helloTarget}"` }); } }); ``` --- _Source: https://npm.io/package/@truffle/dashboard-message-bus-client · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._