update(examples): Add layouting example

examples/Layouting/LayoutingExample.vue

@@ -0,0 +1,64 @@
+<script lang="ts" setup>
+import dagre from 'dagre'
+import initialElements from './initial-elements'
+import './layouting.css'
+
+import Flow, { Controls, addEdge, Connection, Edge, Elements, isNode, NodeExtent, Position, removeElements } from '~/index'
+
+const dagreGraph = new dagre.graphlib.Graph()
+dagreGraph.setDefaultEdgeLabel(() => ({}))
+
+const nodeExtent: NodeExtent = [
+  [0, 0],
+  [1000, 1000],
+]
+
+const elements = ref<Elements>(initialElements)
+const onConnect = (params: Connection | Edge) => (elements.value = addEdge(params, elements.value))
+const onElementsRemove = (elementsToRemove: Elements) => (elements.value = removeElements(elementsToRemove, elements.value))
+
+const onLayout = (direction: string) => {
+  const isHorizontal = direction === 'LR'
+  dagreGraph.setGraph({ rankdir: direction })
+
+  elements.value.forEach((el) => {
+    if (isNode(el)) {
+      dagreGraph.setNode(el.id, { width: 150, height: 50 })
+    } else {
+      dagreGraph.setEdge(el.source, el.target)
+    }
+  })
+
+  dagre.layout(dagreGraph)
+
+  elements.value = elements.value.map((el) => {
+    if (isNode(el)) {
+      const nodeWithPosition = dagreGraph.node(el.id)
+      el.targetPosition = isHorizontal ? Position.Left : Position.Top
+      el.sourcePosition = isHorizontal ? Position.Right : Position.Bottom
+      // we need to pass a slighltiy different position in order to notify react flow about the change
+      // @TODO how can we change the position handling so that we dont need this hack?
+      el.position = { x: nodeWithPosition.x + Math.random() / 1000, y: nodeWithPosition.y }
+    }
+
+    return el
+  })
+}
+</script>
+<template>
+  <div class="layoutflow">
+    <Flow
+      :elements="elements"
+      :node-extent="nodeExtent"
+      @connect="onConnect"
+      @clements-remove="onElementsRemove"
+      @load="() => onLayout('TB')"
+    >
+      <Controls />
+    </Flow>
+    <div class="controls">
+      <button :style="{ marginRight: 10 }" @click="() => onLayout('TB')">vertical layout</button>
+      <button @click="() => onLayout('LR')">horizontal layout</button>
+    </div>
+  </div>
+</template>

examples/Layouting/initial-elements.ts

@@ -0,0 +1,71 @@
+import { Elements, XYPosition } from '~/index'
+
+const position: XYPosition = { x: 0, y: 0 }
+
+const elements: Elements = [
+  {
+    id: '1',
+    type: 'input',
+    data: { label: 'input' },
+    position,
+  },
+  {
+    id: '2',
+    data: { label: 'node 2' },
+    position,
+  },
+  {
+    id: '2a',
+    data: { label: 'node 2a' },
+    position,
+  },
+  {
+    id: '2b',
+    data: { label: 'node 2b' },
+    position,
+  },
+  {
+    id: '2c',
+    data: { label: 'node 2c' },
+    position,
+  },
+  {
+    id: '2d',
+    data: { label: 'node 2d' },
+    position,
+  },
+  {
+    id: '3',
+    data: { label: 'node 3' },
+    position,
+  },
+  {
+    id: '4',
+    data: { label: 'node 4' },
+    position,
+  },
+  {
+    id: '5',
+    data: { label: 'node 5' },
+    position,
+  },
+  {
+    id: '6',
+    type: 'output',
+    data: { label: 'output' },
+    position,
+  },
+  { id: '7', type: 'output', data: { label: 'output' }, position: { x: 400, y: 450 } },
+  { id: 'e12', source: '1', target: '2', type: 'smoothstep' },
+  { id: 'e13', source: '1', target: '3', type: 'smoothstep' },
+  { id: 'e22a', source: '2', target: '2a', type: 'smoothstep' },
+  { id: 'e22b', source: '2', target: '2b', type: 'smoothstep' },
+  { id: 'e22c', source: '2', target: '2c', type: 'smoothstep' },
+  { id: 'e2c2d', source: '2c', target: '2d', type: 'smoothstep' },
+
+  { id: 'e45', source: '4', target: '5', type: 'smoothstep' },
+  { id: 'e56', source: '5', target: '6', type: 'smoothstep' },
+  { id: 'e57', source: '5', target: '7', type: 'smoothstep' },
+] as Elements
+
+export default elements

examples/Layouting/layouting.css

@@ -0,0 +1,11 @@
+.layoutflow {
+  flex-grow: 1;
+  position: relative;
+}
+
+.layoutflow .controls {
+  position: absolute;
+  right: 10px;
+  top: 10px;
+  z-index: 10;
+}

examples/router.ts

@@ -45,6 +45,10 @@ export const routes: RouterOptions['routes'] = [
     path: '/interaction',
     component: () => import('./Interaction/InteractionExample.vue'),
   },
+  {
+    path: '/layouting',
+    component: () => import('./Layouting/LayoutingExample.vue'),
+  },
 ]
 
 export const router = createRouter({