feat(connection-line): add status class (valid or invalid) while in connection radius

examples/vite-app/src/examples/Validation/validation.module.css

@@ -31,3 +31,11 @@
 .validationflow :global .valid {
   background: #55dd99;
 }
+
+.validationflow :global .valid .react-flow__connection-path {
+  stroke: #55dd99;
+}
+
+.validationflow :global .invalid .react-flow__connection-path {
+  stroke: #ff6060;
+}

packages/core/src/components/ConnectionLine/index.tsx

@@ -1,12 +1,19 @@
 import { CSSProperties, useCallback } from 'react';
 import { shallow } from 'zustand/shallow';
+import cc from 'classcat';
 
 import { useStore } from '../../hooks/useStore';
 import { getBezierPath } from '../Edges/BezierEdge';
 import { getSmoothStepPath } from '../Edges/SmoothStepEdge';
 import { getSimpleBezierPath } from '../Edges/SimpleBezierEdge';
 import { internalsSymbol } from '../../utils';
-import type { ConnectionLineComponent, HandleType, ReactFlowState, ReactFlowStore } from '../../types';
+import type {
+  ConnectionLineComponent,
+  ConnectionStatus,
+  HandleType,
+  ReactFlowState,
+  ReactFlowStore,
+} from '../../types';
 import { Position, ConnectionLineType, ConnectionMode } from '../../types';
 
 type ConnectionLineProps = {
@@ -15,6 +22,7 @@ type ConnectionLineProps = {
   type: ConnectionLineType;
   style?: CSSProperties;
   CustomComponent?: ConnectionLineComponent;
+  connectionStatus: ConnectionStatus | null;
 };
 
 const oppositePosition = {
@@ -30,6 +38,7 @@ const ConnectionLine = ({
   style,
   type = ConnectionLineType.Bezier,
   CustomComponent,
+  connectionStatus,
 }: ConnectionLineProps) => {
   const { fromNode, handleId, toX, toY, connectionMode } = useStore(
     useCallback(
@@ -80,6 +89,7 @@ const ConnectionLine = ({
         toY={toY}
         fromPosition={fromPosition}
         toPosition={toPosition}
+        connectionStatus={connectionStatus}
       />
     );
   }
@@ -127,12 +137,13 @@ const selector = (s: ReactFlowState) => ({
   nodeId: s.connectionNodeId,
   handleType: s.connectionHandleType,
   nodesConnectable: s.nodesConnectable,
+  connectionStatus: s.connectionStatus,
   width: s.width,
   height: s.height,
 });
 
 function ConnectionLineWrapper({ containerStyle, style, type, component }: ConnectionLineWrapperProps) {
-  const { nodeId, handleType, nodesConnectable, width, height } = useStore(selector, shallow);
+  const { nodeId, handleType, nodesConnectable, width, height, connectionStatus } = useStore(selector, shallow);
   const isValid = !!(nodeId && handleType && width && nodesConnectable);
 
   if (!isValid) {
@@ -146,8 +157,15 @@ function ConnectionLineWrapper({ containerStyle, style, type, component }: Conne
       height={height}
       className="react-flow__edges react-flow__connectionline react-flow__container"
     >
-      <g className="react-flow__connection">
-        <ConnectionLine nodeId={nodeId} handleType={handleType} style={style} type={type} CustomComponent={component} />
+      <g className={cc(['react-flow__connection', connectionStatus])}>
+        <ConnectionLine
+          nodeId={nodeId}
+          handleType={handleType}
+          style={style}
+          type={type}
+          CustomComponent={component}
+          connectionStatus={connectionStatus}
+        />
       </g>
     </svg>
   );

packages/core/src/components/Handle/handler.ts

@@ -2,11 +2,12 @@ import type { MouseEvent as ReactMouseEvent, TouchEvent as ReactTouchEvent } fro
 import { StoreApi } from 'zustand';
 
 import { getHostForElement, calcAutoPan, getEventPosition } from '../../utils';
-import type { OnConnect, HandleType, ReactFlowState, Connection } from '../../types';
+import type { OnConnect, HandleType, ReactFlowState, Connection, ConnectionStatus } from '../../types';
 import { pointToRendererPoint, rendererPointToPoint } from '../../utils/graph';
 import {
   ConnectionHandle,
   getClosestHandle,
+  getConnectionStatus,
   getHandleLookup,
   getHandleType,
   isValidHandle,
@@ -91,6 +92,7 @@ export function handlePointerDown({
     connectionNodeId: nodeId,
     connectionHandleId: handleId,
     connectionHandleType: handleType,
+    connectionStatus: null,
   });
 
   onConnectStart?.(event, { nodeId, handleId, handleType });
@@ -123,7 +125,7 @@ export function handlePointerDown({
 
     setState({
       connectionPosition:
-        prevClosestHandle && isValid
+        prevClosestHandle && result.isValid
           ? rendererPointToPoint(
               {
                 x: prevClosestHandle.x,
@@ -132,6 +134,7 @@ export function handlePointerDown({
               transform
             )
           : connectionPosition,
+      connectionStatus: getConnectionStatus(!!prevClosestHandle, result.isValid),
     });
 
     if (!prevClosestHandle) {

packages/core/src/components/Handle/utils.ts

@@ -1,6 +1,6 @@
 import { MouseEvent as ReactMouseEvent, TouchEvent as ReactTouchEvent } from 'react';
 
-import { ConnectionMode } from '../../types';
+import { ConnectionMode, ConnectionStatus } from '../../types';
 import { getEventPosition, internalsSymbol } from '../../utils';
 import type { Connection, HandleType, XYPosition, Node, NodeHandleBounds } from '../../types';
 
@@ -167,3 +167,15 @@ export function getHandleType(
 export function resetRecentHandle(handleDomNode: Element): void {
   handleDomNode?.classList.remove('valid', 'connecting', 'react-flow__handle-valid', 'react-flow__handle-connecting');
 }
+
+export function getConnectionStatus(isInsideConnectionRadius: boolean, isHandleValid: boolean) {
+  let connectionStatus = null;
+
+  if (isHandleValid) {
+    connectionStatus = 'valid';
+  } else if (isInsideConnectionRadius && !isHandleValid) {
+    connectionStatus = 'invalid';
+  }
+
+  return connectionStatus as ConnectionStatus;
+}

packages/core/src/store/index.ts

@@ -274,6 +274,7 @@ const createRFStore = () =>
         connectionNodeId: initialState.connectionNodeId,
         connectionHandleId: initialState.connectionHandleId,
         connectionHandleType: initialState.connectionHandleType,
+        connectionStatus: initialState.connectionStatus,
       }),
     reset: () => set({ ...initialState }),
   }));

packages/core/src/store/initialState.ts

@@ -32,6 +32,7 @@ const initialState: ReactFlowStore = {
   connectionHandleId: null,
   connectionHandleType: 'source',
   connectionPosition: { x: 0, y: 0 },
+  connectionStatus: null,
   connectionMode: ConnectionMode.Strict,
   domNode: null,
   paneDragging: false,

packages/core/src/types/edges.ts

@@ -1,7 +1,7 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
 import type { CSSProperties, ComponentType, HTMLAttributes, ReactNode, MouseEvent as ReactMouseEvent } from 'react';
 
-import { Position } from '.';
+import { ConnectionStatus, Position } from '.';
 import type { Connection, HandleElement, HandleType, Node } from '.';
 
 type EdgeLabelOptions = {
@@ -155,6 +155,7 @@ export type ConnectionLineComponentProps = {
   toY: number;
   fromPosition: Position;
   toPosition: Position;
+  connectionStatus: ConnectionStatus | null;
 };
 
 export type ConnectionLineComponent = ComponentType<ConnectionLineComponentProps>;

packages/core/src/types/general.ts

@@ -61,6 +61,8 @@ export interface Connection {
   targetHandle: string | null;
 }
 
+export type ConnectionStatus = 'valid' | 'invalid';
+
 export enum ConnectionMode {
   Strict = 'strict',
   Loose = 'loose',
@@ -166,6 +168,7 @@ export type ReactFlowStore = {
   connectionHandleId: string | null;
   connectionHandleType: HandleType | null;
   connectionPosition: XYPosition;
+  connectionStatus: ConnectionStatus | null;
   connectionMode: ConnectionMode;
 
   snapToGrid: boolean;