👉 Visit the DatoCMS homepage or see What is DatoCMS?

---

datocms-listen

!MIT !MIT 

A lightweight, TypeScript-ready package that offers utilities to work with DatoCMS Real-time Updates API inside a browser.

Installation

``
npm install datocms-listen
`

Example

Import subscribeToQuery from datocms-listen and use it inside your components like this:

`js
import { subscribeToQuery } from "datocms-listen";

const unsubscribe = await subscribeToQuery({
query:
query BlogPosts($first: IntType!) {
allBlogPosts(first: $first) {
title
nonExistingField
}
}
,
variables: { first: 10 },
token: "YOUR_TOKEN",
includeDrafts: true,
onUpdate: (update) => {
// response is the GraphQL response
console.log(update.response.data);
},
onStatusChange: (status) => {
// status can be "connected", "connecting" or "closed"
console.log(status);
},
onChannelError: (error) => {
// error will be something like:
// {
// code: "INVALID_QUERY",
// message: "The query returned an erroneous response. Please consult the response details to understand the cause.",
// response: {
// errors: [
// {
// fields: ["query", "allBlogPosts", "nonExistingField"],
// locations: [{ column: 67, line: 1 }],
// message: "Field 'nonExistingField' doesn't exist on type 'BlogPostRecord'",
// },
// ],
// },
// }
console.error(error);
},
onError: (error) => {
// error will be
// {
// message: "ERROR MESSAGE"
// }
console.log(error.message);
},
onEvent: (event) => {
// event will be
// {
// status: "connected|connected|closed",
// channelUrl: "...",
// message: "MESSAGE",
// }
},
});
`

Initialization options

| prop | type | required | description | default |
| ------------------ | ------------------------------------------------------------------------------------------ | ------------------ | ------------------------------------------------------------------------------------------------ | ------------------------------------ |
| query | string \| TypedDocumentNode | :white_check_mark: | The GraphQL query to subscribe | |
| token | string | :white_check_mark: | DatoCMS API token to use | |
| onUpdate | function | :white_check_mark: | Callback function to receive query update events | |
| onChannelError | function | :x: | Callback function to receive channelError events | |
| onStatusChange | function | :x: | Callback function to receive status change events | |
| onError | function | :x: | Callback function to receive error events | |
| onEvent | function | :x: | Callback function to receive other events | |
| variables | Object | :x: | GraphQL variables for the query | |
| includeDrafts | boolean | :x: | If true, draft records will be returned | |
| excludeInvalid | boolean | :x: | If true, invalid records will be filtered out | |
| environment | string | :x: | The name of the DatoCMS environment where to perform the query (defaults to primary environment) | |
| contentLink | 'vercel-1' or undefined | :x: | If true, embed metadata that enable Content Link | |
| baseEditingUrl | string | :x: | The base URL of the DatoCMS project | |
| cacheTags | boolean | :x: | If true, receive the Cache Tags associated with the query | |
| reconnectionPeriod | number | :x: | In case of network errors, the period (in ms) to wait to reconnect | 1000 |
| fetcher | a fetch-like function | :x: | The fetch function to use to perform the registration query | window.fetch |
| eventSourceClass | an EventSource-like class | :x: | The EventSource class to use to open up the SSE connection | window.EventSource |
| baseUrl | string | :x: | The base URL to use to perform the query | https://graphql-listen.datocms.com |

Events

$3

This function will be called everytime the channel sends an updated query result. The updateData argument has the following properties:

| prop | type | description |
| -------- | ------ | ---------------------------- |
| response | Object | The GraphQL updated response |

$3

The status argument represents the state of the server-sent events connection. It can be one of the following:

- connecting: the subscription channel is trying to connect
- connected: the channel is open, we're receiving live updates
- closed: the channel has been permanently closed due to a fatal error (ie. an invalid query)

$3

The errorData argument has the following properties:

| prop | type | description |
| -------- | ------ | ------------------------------------------------------- |
| code | string | The code of the error (ie. INVALID_QUERY) |
| message | string | An human friendly message explaining the error |
| response | Object | The raw response returned by the endpoint, if available |

$3

This function is called when connection errors occur.

The error argument has the following properties:

| prop | type | description |
| ------- | ------ | ---------------------------------------------- |
| message | string | An human friendly message explaining the error |

$3

This function is called then other events occur.

The event argument has the following properties:

| prop | type | description |
| ---------- | ------ | ---------------------------------------------- |
| status | string | The current connection status (see above) |
| channelUrl | string | The current channel URL |
| message | string | An human friendly message explaining the event |

Return value

The function returns a Promise<() => void>`. You can call the function to gracefully close the SSE channel.

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What is DatoCMS?

DatoCMS is the REST & GraphQL Headless CMS for the modern web.

Trusted by over 25,000 enterprise businesses, agency partners, and individuals across the world, DatoCMS users create online content at scale from a central hub and distribute it via API. We ❤️ our developers, content editors and marketers!

Quick links:

- ⚡️ Get started with a free DatoCMS account
- 🔖 Go through the docs
- ⚙️ Get support from us and the community
- 🆕 Stay up to date on new features and fixes on the changelog

Our featured repos:
- datocms/react-datocms: React helper components for images, Structured Text rendering, and more
- datocms/js-rest-api-clients: Node and browser JavaScript clients for updating and administering your content. For frontend fetches, we recommend using our GraphQL Content Delivery API instead.
- datocms/cli: Command-line interface that includes our Contentful importer and Wordpress importer
- datocms/plugins: Example plugins we've made that extend the editor/admin dashboard
- DatoCMS Starters has examples for various Javascript frontend frameworks

Or see all our public repos