From 425f6250205cc2f76ad5b557307d0868903763e5 Mon Sep 17 00:00:00 2001
From: moklick <info@moritzklack.com>
Date: Mon, 15 May 2023 16:15:42 +0200
Subject: [PATCH] feat(svelte): edge marker support

---
 .../EdgeRenderer/MarkerDefinitions.tsx        | 25 ++--------
 .../lib/components/BaseEdge/BaseEdge.svelte   | 14 +++++-
 .../src/lib/components/BaseEdge/types.ts      |  5 +-
 .../components/EdgeWrapper/EdgeWrapper.svelte | 23 ++++++++--
 .../lib/components/edges/BezierEdge.svelte    | 13 +++++-
 .../components/edges/SmoothStepEdge.svelte    | 12 ++++-
 .../src/lib/components/edges/StepEdge.svelte  | 12 ++++-
 .../lib/components/edges/StraightEdge.svelte  | 13 +++++-
 .../EdgeRenderer/EdgeRenderer.svelte          |  4 ++
 .../MarkerDefinition/Marker.svelte            | 46 +++++++++++++++++++
 .../MarkerDefinition/MarkerDefinition.svelte  | 21 +++++++++
 .../EdgeRenderer/MarkerDefinition/index.ts    |  2 +
 .../container/SvelteFlow/SvelteFlow.svelte    | 12 +++--
 .../src/lib/container/SvelteFlow/types.ts     |  1 +
 .../lib/plugins/Background/Background.svelte  |  4 +-
 packages/svelte/src/lib/store/index.ts        |  9 +++-
 .../svelte/src/lib/store/initial-store.ts     |  9 ++--
 packages/svelte/src/lib/types/edges.ts        |  8 ++++
 packages/system/src/types/edges.ts            |  4 ++
 packages/utils/src/graph.ts                   | 18 --------
 packages/utils/src/index.ts                   |  1 +
 packages/utils/src/marker.ts                  | 40 ++++++++++++++++
 22 files changed, 236 insertions(+), 60 deletions(-)
 create mode 100644 packages/svelte/src/lib/container/EdgeRenderer/MarkerDefinition/Marker.svelte
 create mode 100644 packages/svelte/src/lib/container/EdgeRenderer/MarkerDefinition/MarkerDefinition.svelte
 create mode 100644 packages/svelte/src/lib/container/EdgeRenderer/MarkerDefinition/index.ts
 create mode 100644 packages/utils/src/marker.ts

diff --git a/packages/core/src/container/EdgeRenderer/MarkerDefinitions.tsx b/packages/core/src/container/EdgeRenderer/MarkerDefinitions.tsx
index 1ea6296c..2bfdd15d 100644
--- a/packages/core/src/container/EdgeRenderer/MarkerDefinitions.tsx
+++ b/packages/core/src/container/EdgeRenderer/MarkerDefinitions.tsx
@@ -1,15 +1,11 @@
 import { memo, useCallback } from 'react';
-import type { EdgeMarker } from '@reactflow/system';
-import { getMarkerId } from '@reactflow/utils';
+import type { MarkerProps } from '@reactflow/system';
+import { createMarkerIds } from '@reactflow/utils';
 
 import { useStore } from '../../hooks/useStore';
 import { useMarkerSymbol } from './MarkerSymbols';
 import type { ReactFlowState } from '../../types';
 
-type MarkerProps = EdgeMarker & {
-  id: string;
-};
-
 type MarkerDefinitionsProps = {
   defaultColor: string;
   rfId?: string;
@@ -51,22 +47,9 @@ const Marker = ({
 const markerSelector =
   ({ defaultColor, rfId }: { defaultColor: string; rfId?: string }) =>
   (s: ReactFlowState) => {
-    const ids: string[] = [];
+    const markers = createMarkerIds(s.edges, { id: rfId, defaultColor });
 
-    return s.edges
-      .reduce<MarkerProps[]>((markers, edge) => {
-        [edge.markerStart, edge.markerEnd].forEach((marker) => {
-          if (marker && typeof marker === 'object') {
-            const markerId = getMarkerId(marker, rfId);
-            if (!ids.includes(markerId)) {
-              markers.push({ id: markerId, color: marker.color || defaultColor, ...marker });
-              ids.push(markerId);
-            }
-          }
-        });
-        return markers;
-      }, [])
-      .sort((a, b) => a.id.localeCompare(b.id));
+    return markers;
   };
 
 // when you have multiple flows on a page and you hide the first one, the other ones have no markers anymore
diff --git a/packages/svelte/src/lib/components/BaseEdge/BaseEdge.svelte b/packages/svelte/src/lib/components/BaseEdge/BaseEdge.svelte
index 2bf450d1..c684cfc5 100644
--- a/packages/svelte/src/lib/components/BaseEdge/BaseEdge.svelte
+++ b/packages/svelte/src/lib/components/BaseEdge/BaseEdge.svelte
@@ -4,14 +4,26 @@
 
   type $$Props = BaseEdgeProps;
 
+  export let id: $$Props['id'] = undefined;
   export let path: $$Props['path'] = '';
   export let label: $$Props['label'] = undefined;
   export let labelX: $$Props['labelX'] = undefined;
   export let labelY: $$Props['labelY'] = undefined;
+  export let markerStart: $$Props['markerStart'] = undefined;
+  export let markerEnd: $$Props['markerEnd'] = undefined;
+  export let style: $$Props['style'] = undefined;
   export let interactionWidth: $$Props['interactionWidth'] = 20;
 </script>
 
-<path d={path} fill="none" class="svelte-flow__edge-path" />
+<path
+  d={path}
+  id={id}
+  fill="none"
+  class="svelte-flow__edge-path"
+  marker-start={markerStart}
+  marker-end={markerEnd}
+  style={style}
+/>
 
 {#if interactionWidth}
   <path
diff --git a/packages/svelte/src/lib/components/BaseEdge/types.ts b/packages/svelte/src/lib/components/BaseEdge/types.ts
index 199d1edd..0941ccad 100644
--- a/packages/svelte/src/lib/components/BaseEdge/types.ts
+++ b/packages/svelte/src/lib/components/BaseEdge/types.ts
@@ -1,7 +1,10 @@
 import type { EdgeProps } from '$lib/types';
 
-export type BaseEdgeProps = Pick<EdgeProps, 'interactionWidth' | 'label'> & {
+export type BaseEdgeProps = Pick<EdgeProps, 'interactionWidth' | 'label' | 'style'> & {
+  id?: string;
   path: string;
   labelX?: number;
   labelY?: number;
+  markerStart?: string;
+  markerEnd?: string;
 };
diff --git a/packages/svelte/src/lib/components/EdgeWrapper/EdgeWrapper.svelte b/packages/svelte/src/lib/components/EdgeWrapper/EdgeWrapper.svelte
index dae654ca..ba8a0d1b 100644
--- a/packages/svelte/src/lib/components/EdgeWrapper/EdgeWrapper.svelte
+++ b/packages/svelte/src/lib/components/EdgeWrapper/EdgeWrapper.svelte
@@ -1,6 +1,7 @@
 <script lang="ts">
   import { createEventDispatcher, type SvelteComponentTyped } from 'svelte';
   import { Position } from '@reactflow/system';
+  import { getMarkerId } from '@reactflow/utils';
 
   import { useStore } from '$lib/store';
   import BezierEdge from '$lib/components/edges/BezierEdge.svelte';
@@ -16,20 +17,28 @@
   export let sourceY: $$Props['sourceY'] = 0;
   export let targetX: $$Props['targetX'] = 0;
   export let targetY: $$Props['targetY'] = 0;
-  // @ todo: support edge updates
-  // export let sourceHandleId: $$Props['sourceHandleId'] = undefined;
-  // export let targetHandleId: $$Props['targetHandleId'] = undefined;
+  export let data: $$Props['data'] = {};
+  export let style: $$Props['style'] = undefined;
   export let sourcePosition: $$Props['sourcePosition'] = Position.Bottom;
   export let targetPosition: $$Props['targetPosition'] = Position.Top;
   export let animated: $$Props['animated'] = false;
   export let selected: $$Props['selected'] = false;
   export let label: $$Props['label'] = undefined;
+  export let markerStart: $$Props['markerStart'] = undefined;
+  export let markerEnd: $$Props['markerEnd'] = undefined;
+  export let sourceHandleId: $$Props['sourceHandleId'] = undefined;
+  export let targetHandleId: $$Props['targetHandleId'] = undefined;
 
-  const { edges, edgeTypes } = useStore();
+   // @ todo: support edge updates
+
+  const { edges, edgeTypes, flowId } = useStore();
   const dispatch = createEventDispatcher();
 
   const edgeComponent: typeof SvelteComponentTyped<EdgeProps> = $edgeTypes[type!] || BezierEdge;
 
+  $: markerStartUrl = markerStart ? `url(#${getMarkerId(markerStart, $flowId)})` : undefined;
+  $: markerEndUrl = markerEnd ? `url(#${getMarkerId(markerEnd, $flowId)})` : undefined;
+
   function onClick() {
     const edge = $edges.find(e => e.id === id);
     dispatch('edge:click', edge);
@@ -57,6 +66,12 @@
     {animated}
     {selected}
     {label}
+    {data}
+    {style}
+    {sourceHandleId}
+    {targetHandleId}
+    markerStart={markerStartUrl}
+    markerEnd={markerEndUrl}
   />
 </g>
 
diff --git a/packages/svelte/src/lib/components/edges/BezierEdge.svelte b/packages/svelte/src/lib/components/edges/BezierEdge.svelte
index 622c3240..780168b1 100644
--- a/packages/svelte/src/lib/components/edges/BezierEdge.svelte
+++ b/packages/svelte/src/lib/components/edges/BezierEdge.svelte
@@ -16,4 +16,15 @@
   });
 </script>
 
-<BaseEdge {path} {labelX} {labelY} {...$$props} />
+<BaseEdge
+  {path}
+  {labelX}
+  {labelY}
+  id={$$props.id}
+  label={$$props.label}
+  markerStart={$$props.markerStart}
+  markerEnd={$$props.markerEnd}
+  interactionWidth={$$props.interactionWidth}
+  style={$$props.style}
+/>
+
diff --git a/packages/svelte/src/lib/components/edges/SmoothStepEdge.svelte b/packages/svelte/src/lib/components/edges/SmoothStepEdge.svelte
index b43dd789..f5093c54 100644
--- a/packages/svelte/src/lib/components/edges/SmoothStepEdge.svelte
+++ b/packages/svelte/src/lib/components/edges/SmoothStepEdge.svelte
@@ -16,4 +16,14 @@
   });
 </script>
 
-<BaseEdge {path} {labelX} {labelY} {...$$props} />
+<BaseEdge
+  {path}
+  {labelX}
+  {labelY}
+  id={$$props.id}
+  label={$$props.label}
+  markerStart={$$props.markerStart}
+  markerEnd={$$props.markerEnd}
+  interactionWidth={$$props.interactionWidth}
+  style={$$props.style}
+/>
diff --git a/packages/svelte/src/lib/components/edges/StepEdge.svelte b/packages/svelte/src/lib/components/edges/StepEdge.svelte
index b765adcc..c51d6bcb 100644
--- a/packages/svelte/src/lib/components/edges/StepEdge.svelte
+++ b/packages/svelte/src/lib/components/edges/StepEdge.svelte
@@ -17,4 +17,14 @@
   });
 </script>
 
-<BaseEdge {path} {labelX} {labelY} {...$$props} />
+<BaseEdge
+  {path}
+  {labelX}
+  {labelY}
+  id={$$props.id}
+  label={$$props.label}
+  markerStart={$$props.markerStart}
+  markerEnd={$$props.markerEnd}
+  interactionWidth={$$props.interactionWidth}
+  style={$$props.style}
+/>
diff --git a/packages/svelte/src/lib/components/edges/StraightEdge.svelte b/packages/svelte/src/lib/components/edges/StraightEdge.svelte
index a0123b67..8b095be9 100644
--- a/packages/svelte/src/lib/components/edges/StraightEdge.svelte
+++ b/packages/svelte/src/lib/components/edges/StraightEdge.svelte
@@ -14,4 +14,15 @@
   });
 </script>
 
-<BaseEdge {path} {labelX} {labelY} {...$$props} />
+<BaseEdge
+  {path}
+  {labelX}
+  {labelY}
+  id={$$props.id}
+  label={$$props.label}
+  markerStart={$$props.markerStart}
+  markerEnd={$$props.markerEnd}
+  interactionWidth={$$props.interactionWidth}
+  style={$$props.style}
+/>
+
diff --git a/packages/svelte/src/lib/container/EdgeRenderer/EdgeRenderer.svelte b/packages/svelte/src/lib/container/EdgeRenderer/EdgeRenderer.svelte
index a60efbb8..6c495dd9 100644
--- a/packages/svelte/src/lib/container/EdgeRenderer/EdgeRenderer.svelte
+++ b/packages/svelte/src/lib/container/EdgeRenderer/EdgeRenderer.svelte
@@ -1,5 +1,6 @@
 <script lang="ts">
   import { EdgeWrapper } from '$lib/components/EdgeWrapper';
+  import { MarkerDefinition } from '$lib/container/EdgeRenderer/MarkerDefinition';
   import { useStore } from '$lib/store';
 
   const { edgesLayouted, width, height } = useStore();
@@ -9,8 +10,11 @@
   {#each $edgesLayouted as edge (edge.id)}
     <EdgeWrapper {...edge} on:edge:click />
   {/each}
+
+  <MarkerDefinition />
 </svg>
 
+
 <style>
   .svelte-flow__edges {
     width: 100%;
diff --git a/packages/svelte/src/lib/container/EdgeRenderer/MarkerDefinition/Marker.svelte b/packages/svelte/src/lib/container/EdgeRenderer/MarkerDefinition/Marker.svelte
new file mode 100644
index 00000000..82c9a787
--- /dev/null
+++ b/packages/svelte/src/lib/container/EdgeRenderer/MarkerDefinition/Marker.svelte
@@ -0,0 +1,46 @@
+<script lang="ts">
+  import { type MarkerProps, MarkerType } from '@reactflow/system';
+
+  type $$Props = MarkerProps;
+
+  export let id: $$Props['id'];
+  export let type: $$Props['type'];
+  export let width: $$Props['width'] = 12.5;
+  export let height: $$Props['height'] = 12.5;
+  export let markerUnits: $$Props['markerUnits'] = 'strokeWidth';
+  export let orient: $$Props['orient']= 'auto-start-reverse';
+  export let color: $$Props['color'] = undefined;
+  export let strokeWidth: $$Props['strokeWidth'] = undefined;
+</script>
+
+<marker
+  class="svelte-flow__arrowhead"
+  id={id}
+  markerWidth={`${width}`}
+  markerHeight={`${height}`}
+  viewBox="-10 -10 20 20"
+  markerUnits={markerUnits}
+  orient={orient}
+  refX="0"
+  refY="0"
+>
+  {#if type === MarkerType.Arrow}
+    <polyline
+      stroke={color}
+      stroke-linecap="round"
+      stroke-linejoin="round"
+      stroke-width={strokeWidth}
+      fill="none"
+      points="-5,-4 0,0 -5,4"
+    />
+  {:else if type === MarkerType.ArrowClosed}
+    <polyline
+      stroke={color}
+      stroke-linecap="round"
+      stroke-linejoin="round"
+      stroke-width={strokeWidth}
+      fill={color}
+      points="-5,-4 0,0 -5,4 -5,-4"
+    />
+  {/if}
+</marker>
\ No newline at end of file
diff --git a/packages/svelte/src/lib/container/EdgeRenderer/MarkerDefinition/MarkerDefinition.svelte b/packages/svelte/src/lib/container/EdgeRenderer/MarkerDefinition/MarkerDefinition.svelte
new file mode 100644
index 00000000..602d6b57
--- /dev/null
+++ b/packages/svelte/src/lib/container/EdgeRenderer/MarkerDefinition/MarkerDefinition.svelte
@@ -0,0 +1,21 @@
+<script lang="ts">
+  import { useStore } from '$lib/store';
+  import { Marker } from '$lib/container/EdgeRenderer/MarkerDefinition';
+
+  const { markers } = useStore();
+</script>
+
+<defs>
+  {#each $markers as marker(marker.id)}
+    <Marker
+      id={marker.id}
+      type={marker.type}
+      color={marker.color}
+      width={marker.width}
+      height={marker.height}
+      markerUnits={marker.markerUnits}
+      strokeWidth={marker.strokeWidth}
+      orient={marker.orient}
+    />
+  {/each}
+</defs>
\ No newline at end of file
diff --git a/packages/svelte/src/lib/container/EdgeRenderer/MarkerDefinition/index.ts b/packages/svelte/src/lib/container/EdgeRenderer/MarkerDefinition/index.ts
new file mode 100644
index 00000000..9e2cc390
--- /dev/null
+++ b/packages/svelte/src/lib/container/EdgeRenderer/MarkerDefinition/index.ts
@@ -0,0 +1,2 @@
+export { default as MarkerDefinition } from './MarkerDefinition.svelte';
+export { default as Marker } from './Marker.svelte';
diff --git a/packages/svelte/src/lib/container/SvelteFlow/SvelteFlow.svelte b/packages/svelte/src/lib/container/SvelteFlow/SvelteFlow.svelte
index e1cc77a9..35eb0247 100644
--- a/packages/svelte/src/lib/container/SvelteFlow/SvelteFlow.svelte
+++ b/packages/svelte/src/lib/container/SvelteFlow/SvelteFlow.svelte
@@ -17,7 +17,7 @@
 
   type $$Props = SvelteFlowProps;
 
-  export let id: $$Props['id'] = '1';
+  export let id = '1';
   export let fitView: $$Props['fitView'] = undefined;
   export let minZoom: $$Props['minZoom'] = undefined;
   export let maxZoom: $$Props['maxZoom'] = undefined;
@@ -31,13 +31,14 @@
   export let connectionRadius: $$Props['connectionRadius'] = undefined;
   export let connectionLineType: $$Props['connectionLineType'] = undefined;
   export let isValidConnection: $$Props['isValidConnection'] = undefined;
+  export let defaultMarkerColor = '#b1b1b7';
 
   export let style: $$Props['style'] = undefined;
   let className: $$Props['class'] = undefined;
   export { className as class };
-
   let domNode: HTMLDivElement;
-
+  
+  $: flowId = id;
   const store = useStore();
 
   onMount(() => {
@@ -53,12 +54,13 @@
 
   $: {
     const updatableProps = {
-      id,
+      flowId,
       connectionLineType,
       connectionRadius,
       selectionMode,
       snapGrid,
-      isValidConnection
+      isValidConnection,
+      defaultMarkerColor
     };
 
     Object.keys(updatableProps).forEach(prop => {
diff --git a/packages/svelte/src/lib/container/SvelteFlow/types.ts b/packages/svelte/src/lib/container/SvelteFlow/types.ts
index 6526bd5d..539de845 100644
--- a/packages/svelte/src/lib/container/SvelteFlow/types.ts
+++ b/packages/svelte/src/lib/container/SvelteFlow/types.ts
@@ -32,6 +32,7 @@ export type SvelteFlowProps = DOMAttributes<HTMLDivElement> & {
   connectionRadius?: number;
   selectionMode?: SelectionMode;
   snapGrid?: SnapGrid;
+  defaultMarkerColor?: string;
 
   class?: string;
   style?: string;
diff --git a/packages/svelte/src/lib/plugins/Background/Background.svelte b/packages/svelte/src/lib/plugins/Background/Background.svelte
index 908d3f6d..4ef0c66b 100644
--- a/packages/svelte/src/lib/plugins/Background/Background.svelte
+++ b/packages/svelte/src/lib/plugins/Background/Background.svelte
@@ -31,14 +31,14 @@
   let className: $$Props['class'] = '';
   export { className as class };
 
-  const { transform, id } = useStore();
+  const { transform, flowId } = useStore();
   const patternColor = color || defaultColor[variant!];
   const patternSize = size || defaultSize[variant!];
   const isDots = variant === BackgroundVariant.Dots;
   const isCross = variant === BackgroundVariant.Cross;
   const gapXY: number[] = Array.isArray(gap!) ? gap! : [gap!, gap!];
 
-  $: patternId = `background-pattern-${$id}`;
+  $: patternId = `background-pattern-${$flowId}`;
   $: scaledGap = [gapXY[0] * $transform[2] || 1, gapXY[1] * $transform[2] || 1];
   $: scaledSize = patternSize * $transform[2];
   $: patternDimensions = (isCross ? [scaledSize, scaledSize] : scaledGap) as [number, number];
diff --git a/packages/svelte/src/lib/store/index.ts b/packages/svelte/src/lib/store/index.ts
index 273b6ffc..3693a518 100644
--- a/packages/svelte/src/lib/store/index.ts
+++ b/packages/svelte/src/lib/store/index.ts
@@ -1,5 +1,5 @@
 import { getContext } from 'svelte';
-import { get } from 'svelte/store';
+import { derived, get } from 'svelte/store';
 import { zoomIdentity } from 'd3-zoom';
 import {
   type NodeDragItem,
@@ -11,6 +11,7 @@ import {
   type CoordinateExtent
 } from '@reactflow/system';
 import {
+  createMarkerIds,
   fitView as fitViewUtil,
   getD3Transition,
   getDimensions,
@@ -314,6 +315,12 @@ export function createStore(params: CreateStoreParams): SvelteFlowStore {
     // derived state
     edgesLayouted: getEdgesLayouted(store),
     connectionPath: getConnectionPath(store),
+    markers: derived(
+      [store.edges, store.defaultMarkerColor, store.flowId],
+      ([edges, defaultColor, id]) => {
+        return createMarkerIds(edges, { defaultColor, id });
+      }
+    ),
 
     // actions
     setNodeTypes,
diff --git a/packages/svelte/src/lib/store/initial-store.ts b/packages/svelte/src/lib/store/initial-store.ts
index 31e37833..a11d2a29 100644
--- a/packages/svelte/src/lib/store/initial-store.ts
+++ b/packages/svelte/src/lib/store/initial-store.ts
@@ -7,7 +7,8 @@ import {
   ConnectionLineType,
   type SelectionRect,
   type Transform,
-  type SnapGrid
+  type SnapGrid,
+  type MarkerProps
 } from '@reactflow/system';
 
 import DefaultNode from '$lib/components/nodes/DefaultNode.svelte';
@@ -49,7 +50,7 @@ export const initialEdgeTypes = {
 };
 
 export const initialStoreState = {
-  id: writable<string | null>(null),
+  flowId: writable<string | null>(null),
   nodes: writable<Node[]>([]),
   edges: writable<Edge[]>([]),
   edgesLayouted: readable<EdgeLayouted[]>([]),
@@ -80,5 +81,7 @@ export const initialStoreState = {
   connection: writable<ConnectionData>(initConnectionData),
   connectionRadius: writable<number>(25),
   connectionLineType: writable<ConnectionLineType>(ConnectionLineType.Bezier),
-  isValidConnection: writable<IsValidConnection>(() => true)
+  isValidConnection: writable<IsValidConnection>(() => true),
+  markers: readable<MarkerProps[]>([]),
+  defaultMarkerColor: writable<string>('#b1b1b7')
 };
diff --git a/packages/svelte/src/lib/types/edges.ts b/packages/svelte/src/lib/types/edges.ts
index a60f5f76..24f8af72 100644
--- a/packages/svelte/src/lib/types/edges.ts
+++ b/packages/svelte/src/lib/types/edges.ts
@@ -47,11 +47,15 @@ export type EdgeLayouted = Omit<Edge, 'sourceHandle' | 'targetHandle'> & {
   targetPosition: Position;
   sourceHandleId?: string;
   targetHandleId?: string;
+  markerStart?: string;
+  markerEnd?: string;
 };
 
 export type EdgeProps = Pick<
   EdgeLayouted,
   | 'id'
+  | 'data'
+  | 'style'
   | 'source'
   | 'target'
   | 'sourceX'
@@ -64,6 +68,10 @@ export type EdgeProps = Pick<
   | 'selected'
   | 'label'
   | 'interactionWidth'
+  | 'markerStart'
+  | 'markerEnd'
+  | 'sourceHandleId'
+  | 'targetHandleId'
 >;
 
 export type EdgeTypes = Record<string, typeof SvelteComponentTyped<EdgeProps>>;
diff --git a/packages/system/src/types/edges.ts b/packages/system/src/types/edges.ts
index 6698ca52..3b9e4e29 100644
--- a/packages/system/src/types/edges.ts
+++ b/packages/system/src/types/edges.ts
@@ -57,3 +57,7 @@ export enum MarkerType {
   Arrow = 'arrow',
   ArrowClosed = 'arrowclosed',
 }
+
+export type MarkerProps = EdgeMarker & {
+  id: string;
+};
diff --git a/packages/utils/src/graph.ts b/packages/utils/src/graph.ts
index c8f608e6..9f2bc2c7 100644
--- a/packages/utils/src/graph.ts
+++ b/packages/utils/src/graph.ts
@@ -5,7 +5,6 @@ import { boxToRect, clamp, devWarn, getBoundsOfBoxes, getOverlappingArea, rectTo
 import {
   errorMessages,
   type Connection,
-  type EdgeMarkerType,
   type Transform,
   type XYPosition,
   type Rect,
@@ -54,23 +53,6 @@ export const getIncomersBase = <NodeType extends BaseNode = BaseNode, EdgeType e
 const getEdgeId = ({ source, sourceHandle, target, targetHandle }: Connection | BaseEdge): string =>
   `reactflow__edge-${source}${sourceHandle || ''}-${target}${targetHandle || ''}`;
 
-export const getMarkerId = (marker: EdgeMarkerType | undefined, rfId?: string): string => {
-  if (typeof marker === 'undefined') {
-    return '';
-  }
-
-  if (typeof marker === 'string') {
-    return marker;
-  }
-
-  const idPrefix = rfId ? `${rfId}__` : '';
-
-  return `${idPrefix}${Object.keys(marker)
-    .sort()
-    .map((key: string) => `${key}=${(marker as any)[key]}`)
-    .join('&')}`;
-};
-
 const connectionExists = (edge: BaseEdge, edges: BaseEdge[]) => {
   return edges.some(
     (el) =>
diff --git a/packages/utils/src/index.ts b/packages/utils/src/index.ts
index 60a93bf6..d4a84150 100644
--- a/packages/utils/src/index.ts
+++ b/packages/utils/src/index.ts
@@ -1,2 +1,3 @@
 export * from './graph';
 export * from './utils';
+export * from './marker';
diff --git a/packages/utils/src/marker.ts b/packages/utils/src/marker.ts
new file mode 100644
index 00000000..cc13bf48
--- /dev/null
+++ b/packages/utils/src/marker.ts
@@ -0,0 +1,40 @@
+import type { BaseEdge, EdgeMarker, EdgeMarkerType, MarkerProps } from '@reactflow/system';
+
+export function getMarkerId(marker: EdgeMarkerType | undefined, id?: string | null): string {
+  if (!marker) {
+    return '';
+  }
+
+  if (typeof marker === 'string') {
+    return marker;
+  }
+
+  const idPrefix = id ? `${id}__` : '';
+
+  return `${idPrefix}${Object.keys(marker)
+    .sort()
+    .map((key) => `${key}=${marker[key as keyof EdgeMarker]}`)
+    .join('&')}`;
+}
+
+export function createMarkerIds(
+  edges: BaseEdge[],
+  { id, defaultColor }: { id?: string | null; defaultColor?: string }
+) {
+  const ids: string[] = [];
+
+  return edges
+    .reduce<MarkerProps[]>((markers, edge) => {
+      [edge.markerStart, edge.markerEnd].forEach((marker) => {
+        if (marker && typeof marker === 'object') {
+          const markerId = getMarkerId(marker, id);
+          if (!ids.includes(markerId)) {
+            markers.push({ id: markerId, color: marker.color || defaultColor, ...marker });
+            ids.push(markerId);
+          }
+        }
+      });
+      return markers;
+    }, [])
+    .sort((a, b) => a.id.localeCompare(b.id));
+}