Files
xyflow/packages/svelte/src/lib/hooks/useHandleConnections.svelte.ts
T

53 lines
1.6 KiB
TypeScript

import { areConnectionMapsEqual, type HandleConnection, type HandleType } from '@xyflow/system';
import { useStore } from '$lib/store';
import { getContext } from 'svelte';
export type useHandleConnectionsParams = {
type: HandleType;
nodeId?: string;
id?: string | null;
};
const initialConnections: HandleConnection[] = [];
/**
* Hook to check if a <Handle /> is connected to another <Handle /> and get the connections.
*
* @public
* @param param.nodeId
* @param param.type - handle type 'source' or 'target'
* @param param.id - the handle id (this is only needed if the node has multiple handles of the same type)
* @returns an array with connections
*/
export function useHandleConnections({
type,
nodeId: _nodeId,
id = null
}: useHandleConnectionsParams) {
const { edges, connectionLookup } = $derived(useStore());
const contextNodeId = getContext<string>('svelteflow__node_id');
const nodeId = _nodeId ?? contextNodeId;
let prevConnections: Map<string, HandleConnection> | undefined = new Map();
let connectionsArray: HandleConnection[] = initialConnections;
const connections = $derived.by(() => {
// eslint-disable-next-line @typescript-eslint/no-unused-expressions
edges;
const nextConnections = connectionLookup.get(`${nodeId}-${type}-${id || null}`);
if (!areConnectionMapsEqual(nextConnections, prevConnections)) {
prevConnections = nextConnections;
connectionsArray = Array.from(nextConnections?.values() || initialConnections);
}
return connectionsArray;
});
return {
get current() {
return connections;
}
};
}