useSubscribeToRecord
This Enterprise Edition hook is a specialized version of useSubscribe
that subscribes to events concerning a single record.
Usage
The hook expects a callback function as its only argument, as it guesses the record and resource from the current context. The callback will be executed whenever an event is published on the resource/[resource]/[recordId]
topic.
For instance, the following component displays a dialog when the record is updated by someone else:
import { useState } from 'react';
import { useEditContext, useFormContext } from 'react-admin';
import {
Button,
Dialog,
DialogActions,
DialogContent,
DialogContentText,
DialogTitle,
} from '@mui/material';
import { useSubscribeToRecord } from '@react-admin/ra-realtime';
const WarnWhenUpdatedBySomeoneElse = () => {
const [open, setOpen] = useState(false);
const [author, setAuthor] = useState<string | null>(null);
const handleClose = () => {
setOpen(false);
};
const { refetch } = useEditContext();
const refresh = () => {
refetch();
handleClose();
};
const {
formState: { isDirty },
} = useFormContext();
useSubscribeToRecord((event: Event) => {
if (event.type === 'edited') {
if (isDirty) {
setOpen(true);
setAuthor(event.payload.user);
} else {
refetch();
}
}
});
return (
<Dialog
open={open}
onClose={handleClose}
aria-labelledby="alert-dialog-title"
aria-describedby="alert-dialog-description"
>
<DialogTitle id="alert-dialog-title">
Post Updated by {author}
</DialogTitle>
<DialogContent>
<DialogContentText id="alert-dialog-description">
Your changes and their changes may conflict. What do you
want to do?
</DialogContentText>
</DialogContent>
<DialogActions>
<Button onClick={handleClose}>Keep my changes</Button>
<Button onClick={refresh}>
Get their changes (and lose mine)
</Button>
</DialogActions>
</Dialog>
);
};
const PostEdit = () => (
<Edit>
<SimpleForm>
<TextInput source="id" disabled />
<TextInput source="title" />
<TextInput source="body" multiline />
<WarnWhenUpdatedBySomeoneElse />
</SimpleForm>
</Edit>
);
useSubscribeToRecord
reads the current resource and record from the ResourceContext
and RecordContext
respectively. In the example above, the notification is displayed when the app receives an event on the resource/books/123
topic.
Just like useSubscribe
, useSubscribeToRecord
unsubscribes from the topic when the component unmounts.
Tip: In the example above, <Show>
creates the RecordContext
- thatβs why the useSubscribeToRecord
hook is used in its child component instead of in the <BookShow>
component.
You can provide the resource and record id explicitly if you are not in such contexts:
useSubscribeToRecord(event => { /* ... */ }, 'posts', 123);
Tip: If your reason to subscribe to events on a record is to keep the record up to date, you should use the useGetOneLive
hook instead.
Parameters
Prop | Required | Type | Default | Description |
---|---|---|---|---|
callback |
Required | function |
- | The callback to execute when an event is received. |
resource |
Optional | string |
- | The resource to subscribe to. Defaults to the resource in the ResourceContext . |
recordId |
Optional | string |
- | The record id to subscribe to. Defaults to the id of the record in the RecordContext . |
options |
Optional | object |
- | The subscription options. |
callback
Whenever an event is published on the resource/[resource]/[recordId]
topic, the function passed as the first argument will be called with the event as a parameter.
const [open, setOpen] = useState(false);
const [author, setAuthor] = useState<string | null>(null);
const { refetch } = useEditContext();
const {
formState: { isDirty },
} = useFormContext();
useSubscribeToRecord((event: Event) => {
if (event.type === 'edited') {
if (isDirty) {
setOpen(true);
setAuthor(event.payload.user);
} else {
refetch();
}
}
});
Tip: Memoize the callback using useCallback
to avoid unnecessary subscriptions/unsubscriptions.
const [open, setOpen] = useState(false);
const [author, setAuthor] = useState<string | null>(null);
const { refetch } = useEditContext();
const {
formState: { isDirty },
} = useFormContext();
const handleEvent = useCallback(
(event: Event) => {
if (event.type === 'edited') {
if (isDirty) {
setOpen(true);
setAuthor(event.payload.user);
} else {
refetch();
}
}
},
[isDirty, refetch, setOpen, setAuthor]
);
useSubscribeToRecord(handleEvent);
Just like for useSubscribe
, the callback function receives an unsubscribe
callback as its second argument. You can call it to unsubscribe from the topic after receiving a specific event.
useSubscribeToRecord((event: Event, unsubscribe) => {
if (event.type === 'deleted') {
// do something
unsubscribe();
}
if (event.type === 'edited') {
if (isDirty) {
setOpen(true);
setAuthor(event.payload.user);
} else {
refetch();
}
}
});
options
The options
object can contain the following properties:
enabled
: Whether to subscribe or not. Defaults totrue
once
: Whether to unsubscribe after the first event. Defaults tofalse
.unsubscribeOnUnmount
: Whether to unsubscribe on unmount. Defaults totrue
.
See useSubscribe
for more details.
recordId
The record id to subscribe to. By default, useSubscribeToRecord
builds the topic it subscribes to using the id of the record in the RecordContext
. But you can override this behavior by passing a record id as the third argument.
// will subscribe to the 'resource/posts/123' topic
useSubscribeToRecord(event => { /* ... */ }, 'posts', 123);
Note that if you pass a null record id, the hook will not subscribe to any topic.
resource
The resource to subscribe to. By default, useSubscribeToRecord
builds the topic it subscribes to using the resource in the ResourceContext
. But you can override this behavior by passing a resource name as the second argument.
// will subscribe to the 'resource/posts/123' topic
useSubscribeToRecord(event => { /* ... */ }, 'posts', 123);
Note that if you pass an empty string as the resource name, the hook will not subscribe to any topic.