<Handle />
The <Handle />
component is used in your custom nodes
to define connection points.
import { Handle, Position } from '@xyflow/react';
export CustomNode = ({ data }) => {
return (
<>
<div style={{ padding: '10px 20px' }}>
{data.label}
</div>
<Handle type="target" position={Position.Left} />
<Handle type="source" position={Position.Right} />
</>
);
};
Props
For TypeScript users, the props type for the <Handle />
component is exported
as HandleProps
.
Name | Type | Default |
---|---|---|
# id? | string |
|
# type | "source" | "target" |
|
# position | Position The position of the handle relative to the node. In a horizontal
flow source handles are typically Position.Right and in a vertical flow they
are typically Position.Top. |
|
# isConnectable? | boolean |
|
# isConnectableStart? | boolean Dictates whether a connection can start from this handle. |
|
# isConnectableEnd? | boolean Dictates whether a connection can end on this handle. |
|
# onConnect? | (connection: Connection) => void |
|
# isValidConnection? | (connection: Connection) => boolean Called when a connection is dragged to this handle. You can
use this callback to perform some custom validation logic based on the
connection target and source, for example. Where possible, we recommend you
move this logic to the isValidConnection prop on the main ReactFlow component
for performance reasons. |
|
Examples
Custom handle with validation
You can create your own custom handles by wrapping the <Handle />
component.
This example shows a custom handle that only allows connections when the
connection source matches a given id.
import { Handle, Position } from '@xyflow/react';
export const TargetHandleWithValidation = ({ position, source }) => (
<Handle
type="target"
position={position}
isValidConnection={(connection) => connection.source === source}
onConnect={(params) => console.log('handle onConnect', params)}
style={{ background: '#fff' }}
/>
);
Style handles when connecting
The handle receives the additional class names connecting
when the connection
line is above the handle and valid
if the connection is valid. You can find an
example which uses these classes here.
Multiple handles
If you need multiple source or target handles you can achieve this by creating a
custom node. Normally you just use the id of a node for the source
or target
of an edge. If you have multiple source or target handles you need to pass an id
to these handles. These ids can be used by an edge with the sourceHandle
and
targetHandle
options, so that you can connect a specific handle. If you have a
node with an id = 1
and a handle with an id = a
you can connect this handle
by using the node source=1
and the sourceHandle=a
.
Dynamic handles
If you are programmatically changing the position or number of handles in your
custom node, you need to update the node internals with the
useUpdateNodeInternals
hook.
You can find an example of how to implement a custom node with multiple handles in the custom node guide or in the custom node example.
Custom handle styles
Since the handle is a div, you can use CSS to style it or pass a style prop to customize a Handle. You can see this in the Add Node On Edge Drop and Simple Floating Edges examples.
Notes
- If you need to hide a handle for some reason, you must use
visibility: hidden
oropacity: 0
instead ofdisplay: none
. This is important because React Flow needs to calculate the dimensions of the handle to work properly and usingdisplay: none
will report a width and height of 0!