Reworked edge rerendering

examples/svelte/src/routes/examples/stress/+page.svelte

@@ -48,7 +48,7 @@
 	}
 
 	let nodes = $state.raw(nodeItems);
-	let edges = $state.raw([]);
+	let edges = $state.raw(edgeItems);
 </script>
 
 <SvelteFlow bind:nodes bind:edges fitView minZoom={0.2}>

packages/svelte/src/lib/actions/drag/index.ts

@@ -1,4 +1,3 @@
-import { get } from 'svelte/store';
 import { XYDrag, type OnDrag } from '@xyflow/system';
 
 import type { SvelteFlowStore } from '$lib/store/types';

packages/svelte/src/lib/components/EdgeWrapper/EdgeWrapper.svelte

@@ -11,51 +11,55 @@
   import type { SvelteFlowStore } from '$lib/store/types';
 
   const {
-    id,
-    type = 'default',
+    edge,
     store,
+    onedgeclick,
+    onedgecontextmenu,
+    onedgemouseenter,
+    onedgemouseleave
+  }: { store: SvelteFlowStore; edge: EdgeLayouted } & EdgeEvents = $props();
+
+  let {
     source,
     target,
-    data = {},
-    style,
-    zIndex,
-    animated = false,
-    selected = false,
-    selectable,
-    deletable,
-    hidden,
-    label,
-    labelStyle,
-    markerStart,
-    markerEnd,
-    sourceHandle,
-    targetHandle,
     sourceX,
     sourceY,
     targetX,
     targetY,
     sourcePosition,
     targetPosition,
-    ariaLabel,
+    animated,
+    selected,
+    label,
+    labelStyle,
+    data = {},
+    style,
     interactionWidth,
+    type = 'default',
+    sourceHandle,
+    targetHandle,
+    markerStart,
+    markerEnd,
+    selectable: edgeSelectable,
+    deletable,
+    hidden,
+    zIndex,
     class: className,
-    onedgeclick,
-    onedgecontextmenu,
-    onedgemouseenter,
-    onedgemouseleave
-  }: { store: SvelteFlowStore } & EdgeLayouted & EdgeEvents = $props();
+    ariaLabel
+  } = $derived(edge);
 
+  const { id } = edge;
   setContext('svelteflow__edge_id', id);
 
-  let edgeType = $derived(type ?? 'default');
-  let EdgeComponent = $derived(store.edgeTypes[edgeType] ?? BezierEdgeInternal);
+  let selectable = $derived(edgeSelectable ?? store.elementsSelectable);
+  let EdgeComponent = $derived(store.edgeTypes[type] ?? BezierEdgeInternal);
+
   let markerStartUrl = $derived(
     markerStart ? `url('#${getMarkerId(markerStart, store.flowId)}')` : undefined
   );
   let markerEndUrl = $derived(
     markerEnd ? `url('#${getMarkerId(markerEnd, store.flowId)}')` : undefined
   );
-  let isSelectable = $derived(selectable ?? store.elementsSelectable);
 
   const handleEdgeSelect = useHandleEdgeSelect();
 
@@ -88,7 +92,7 @@
       class={cc(['svelte-flow__edge', className])}
       class:animated
       class:selected
-      class:selectable={isSelectable}
+      class:selectable
       data-id={id}
       {onclick}
       oncontextmenu={onedgecontextmenu
@@ -130,9 +134,9 @@
         {data}
         {style}
         {interactionWidth}
-        selectable={isSelectable}
+        {selectable}
         deletable={deletable ?? true}
-        type={edgeType}
+        {type}
         sourceHandleId={sourceHandle}
         targetHandleId={targetHandle}
         markerStart={markerStartUrl}

packages/svelte/src/lib/components/NodeWrapper/NodeWrapper.svelte

@@ -4,9 +4,10 @@
   import { errorMessages, nodeHasDimensions, Position } from '@xyflow/system';
 
   import drag from '$lib/actions/drag';
-  import DefaultNode from '$lib/components/nodes/DefaultNode.svelte';
-  import type { ConnectableContext, NodeWrapperProps } from './types';
   import { getNodeInlineStyleDimensions } from './utils';
+  import DefaultNode from '$lib/components/nodes/DefaultNode.svelte';
+
+  import type { ConnectableContext, NodeWrapperProps } from './types';
   import type { Node, NodeEvents } from '$lib/types';
 
   let {
@@ -25,7 +26,6 @@
   }: NodeWrapperProps & NodeEvents = $props();
 
   let {
-    id,
     data = {},
     selected = false,
     draggable: _draggable,
@@ -48,18 +48,16 @@
     dragHandle
   } = $derived(node);
 
+  let { id } = node;
+
   let draggable = $derived(_draggable ?? store.nodesDraggable);
   let selectable = $derived(_selectable ?? store.elementsSelectable);
   let connectable = $derived(_connectable ?? store.nodesConnectable);
   let initialized = $derived(nodeHasDimensions(node));
 
-  // TODO: does this make sense
-  let flipFlop = false;
-  let shouldRerenderSignal = $derived.by(() =>
-    store.adoptNodes.has(id) ? (flipFlop = !flipFlop) : flipFlop
-  );
-
-  function getInternalNode(node: Node, shouldRerender: boolean = false) {
+  // we also pass store.nodes to this function to rerender when a node changes
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
+  function getInternalNode(node: Node, nodes: Node[]) {
     return { ...store.nodeLookup.get(node.id)! };
   }
 
@@ -68,7 +66,7 @@
       z: zIndex = 0,
       positionAbsolute: { x: positionX, y: positionY }
     }
-  } = $derived(getInternalNode(node, shouldRerenderSignal));
+  } = $derived(getInternalNode(node, store.nodes));
 
   function isInParentLookup(id: string) {
     return store.parentLookup.has(id);

packages/svelte/src/lib/components/NodeWrapper/types.ts

@@ -1,45 +1,13 @@
 import type { SvelteFlowStore } from '$lib/store/types';
-import type { InternalNode, Node } from '$lib/types';
+import type { Node } from '$lib/types';
 
 export type ConnectableContext = {
   value: boolean;
 };
 
 export type NodeWrapperProps = {
-  // Pick<
-  //   Node,
-  //   | 'id'
-  //   | 'class'
-  //   | 'connectable'
-  //   | 'data'
-  //   | 'draggable'
-  //   | 'dragging'
-  //   | 'selected'
-  //   | 'selectable'
-  //   | 'deletable'
-  //   | 'style'
-  //   | 'type'
-  //   | 'sourcePosition'
-  //   | 'targetPosition'
-  //   | 'dragHandle'
-  //   | 'hidden'
-  //   | 'width'
-  //   | 'height'
-  //   | 'initialWidth'
-  //   | 'initialHeight'
-  //   | 'parentId'
-  // > & {
-  //   measuredWidth?: number;
-  //   measuredHeight?: number;
-  //   type: string;
-  //   positionX: number;
-  //   positionY: number;
-  //   'on:nodeclick'?: (event: MouseEvent) => void;
-  //   isParent?: boolean;
-  //   zIndex: number;
-  // initialized: boolean;
   node: Node;
+  store: SvelteFlowStore;
   nodeClickDistance?: number;
   resizeObserver?: ResizeObserver | null;
-  store: SvelteFlowStore;
 };

packages/svelte/src/lib/container/EdgeRenderer/EdgeRenderer.svelte

@@ -14,16 +14,26 @@
     onedgemouseleave
   }: { store: SvelteFlowStore } & EdgeEvents = $props();
 
-  // const { edges, nodes } = store;
-
+  let previousLayoutedEdges = new Map<string, EdgeLayouted>();
   let layoutedEdges = $derived.by(() => {
     store.nodes;
-    const layoutedEdges = store.edges.reduce<EdgeLayouted[]>((res, edge) => {
+
+    const layoutedEdges = new Map<string, EdgeLayouted>();
+
+    for (let edge of store.edges) {
       const sourceNode = store.nodeLookup.get(edge.source);
       const targetNode = store.nodeLookup.get(edge.target);
 
       if (!sourceNode || !targetNode) {
-        return res;
+        continue;
+      }
+
+      // we reuse the previous edge object if the source and target node are the same as before
+      // references to internalNodes that haven't changed stay the same
+      const previous = previousLayoutedEdges.get(edge.id);
+      if (previous && sourceNode == previous.sourceNode && targetNode == previous.targetNode) {
+        layoutedEdges.set(edge.id, previous);
+        continue;
       }
 
       const edgePosition = getEdgePosition({
@@ -37,7 +47,7 @@
       });
 
       if (edgePosition) {
-        res.push({
+        layoutedEdges.set(edge.id, {
           ...edge,
           zIndex: getElevatedEdgeZIndex({
             selected: edge.selected,
@@ -46,13 +56,14 @@
             targetNode,
             elevateOnSelect: false
           }),
-          ...edgePosition
+          ...edgePosition,
+          sourceNode,
+          targetNode
         });
       }
+    }
 
-      return res;
-    }, []);
-
+    previousLayoutedEdges = layoutedEdges;
     return layoutedEdges;
   });
 </script>
@@ -62,36 +73,10 @@
     <MarkerDefinition />
   </svg>
 
-  {#each layoutedEdges as edge (edge.id)}
+  {#each layoutedEdges.values() as edge (edge.id)}
     <EdgeWrapper
       {store}
-      id={edge.id}
-      source={edge.source}
-      target={edge.target}
-      data={edge.data}
-      style={edge.style}
-      animated={edge.animated}
-      selected={edge.selected}
-      selectable={edge.selectable ?? store.elementsSelectable}
-      deletable={edge.deletable}
-      hidden={edge.hidden}
-      label={edge.label}
-      labelStyle={edge.labelStyle}
-      markerStart={edge.markerStart}
-      markerEnd={edge.markerEnd}
-      sourceHandle={edge.sourceHandle}
-      targetHandle={edge.targetHandle}
-      sourceX={edge.sourceX}
-      sourceY={edge.sourceY}
-      targetX={edge.targetX}
-      targetY={edge.targetY}
-      sourcePosition={edge.sourcePosition}
-      targetPosition={edge.targetPosition}
-      ariaLabel={edge.ariaLabel}
-      interactionWidth={edge.interactionWidth}
-      class={edge.class}
-      type={edge.type || 'default'}
-      zIndex={edge.zIndex}
+      {edge}
       {onedgeclick}
       {onedgecontextmenu}
       {onedgemouseenter}
@@ -99,7 +84,7 @@
     />
   {/each}
 
-  {#if layoutedEdges.length > 0}
+  {#if layoutedEdges.size > 0}
     <CallOnMount
       onMount={() => {
         store.edgesInitialized = true;

packages/svelte/src/lib/container/NodeRenderer/NodeRenderer.svelte

@@ -2,6 +2,7 @@
   import { onDestroy } from 'svelte';
 
   import { NodeWrapper } from '$lib/components/NodeWrapper';
+
   import type { NodeEvents } from '$lib/types';
   import type { SvelteFlowStore } from '$lib/store/types';
 

packages/system/src/utils/store.ts

@@ -93,7 +93,6 @@ export function adoptUserNodes<NodeType extends NodeBase>(
   nodeLookup.clear();
   parentLookup.clear();
 
-  const updatedChildNodes = new Set<string>();
   for (const userNode of nodes) {
     let internalNode = tmpLookup.get(userNode.id);
 
@@ -124,10 +123,9 @@ export function adoptUserNodes<NodeType extends NodeBase>(
     }
 
     if (userNode.parentId) {
-      updateChildNode(internalNode, nodeLookup, parentLookup, options, updatedChildNodes);
+      updateChildNode(internalNode, nodeLookup, parentLookup, options);
     }
   }
-  return updatedChildNodes;
 }
 
 function updateParentLookup<NodeType extends NodeBase>(
@@ -154,8 +152,7 @@ function updateChildNode<NodeType extends NodeBase>(
   node: InternalNodeBase<NodeType>,
   nodeLookup: NodeLookup<InternalNodeBase<NodeType>>,
   parentLookup: ParentLookup<InternalNodeBase<NodeType>>,
-  options?: UpdateNodesOptions<NodeType>,
-  updatedChildNodes?: Set<string>
+  options?: UpdateNodesOptions<NodeType>
 ) {
   const { elevateNodesOnSelect, nodeOrigin, nodeExtent } = mergeObjects(defaultOptions, options);
   const parentId = node.parentId!;
@@ -176,12 +173,15 @@ function updateChildNode<NodeType extends NodeBase>(
   const positionChanged = x !== positionAbsolute.x || y !== positionAbsolute.y;
 
   if (positionChanged || z !== node.internals.z) {
-    node.internals = {
-      ...node.internals,
-      positionAbsolute: positionChanged ? { x, y } : positionAbsolute,
-      z,
-    };
-    updatedChildNodes?.add(node.id);
+    // we create a new object to mark the node as updated
+    nodeLookup.set(node.id, {
+      ...node,
+      internals: {
+        ...node.internals,
+        positionAbsolute: positionChanged ? { x, y } : positionAbsolute,
+        z,
+      },
+    });
   }
 }