docs: add dagre layout example

2024-02-05 07:51:12 +01:00
parent 0bfb5f4046
commit 3220e20c0e
13 changed files with 192 additions and 40 deletions
@@ -0,0 +1,70 @@
+<script setup>
+import dagre from 'dagre'
+import { nextTick, ref } from 'vue'
+import { Panel, Position, VueFlow, useVueFlow } from '@vue-flow/core'
+
+import { initialEdges, initialNodes } from './initial-elements.js'
+
+const nodes = ref(initialNodes)
+
+const edges = ref(initialEdges)
+
+const { findNode, fitView } = useVueFlow()
+
+function handleLayout(direction) {
+  // we create a new graph instance, in case some nodes/edges were removed, otherwise dagre would act as if they were still there
+  const dagreGraph = new dagre.graphlib.Graph()
+
+  dagreGraph.setDefaultEdgeLabel(() => ({}))
+
+  const isHorizontal = direction === 'LR'
+  dagreGraph.setGraph({ rankdir: direction })
+
+  for (const node of nodes.value) {
+    // if you need width+height of nodes for your layout, you can use the dimensions property of the internal node (`GraphNode` type)
+    const graphNode = findNode(node.id)
+
+    dagreGraph.setNode(node.id, { width: graphNode.dimensions.width || 150, height: graphNode.dimensions.height || 50 })
+  }
+
+  for (const edge of edges.value) {
+    dagreGraph.setEdge(edge.source, edge.target)
+  }
+
+  dagre.layout(dagreGraph)
+
+  // set nodes with updated positions
+  nodes.value = nodes.value.map((node) => {
+    const nodeWithPosition = dagreGraph.node(node.id)
+
+    return {
+      ...node,
+      targetPosition: isHorizontal ? Position.Left : Position.Top,
+      sourcePosition: isHorizontal ? Position.Right : Position.Bottom,
+      position: { x: nodeWithPosition.x, y: nodeWithPosition.y },
+    }
+  })
+
+  nextTick(() => {
+    fitView()
+  })
+}
+</script>
+
+<template>
+  <div class="layoutflow">
+    <VueFlow :nodes="nodes" :edges="edges" @nodes-initialized="handleLayout('TB')">
+      <Panel style="display: flex; gap: 1rem" position="top-right">
+        <button @click="handleLayout('TB')">vertical layout</button>
+        <button @click="handleLayout('LR')">horizontal layout</button>
+      </Panel>
+    </VueFlow>
+  </div>
+</template>
+
+<style>
+.layoutflow {
+  height: 100%;
+  width: 100%;
+}
+</style>
@@ -0,0 +1,2 @@
+export { default as LayoutApp } from './App.vue?raw'
+export { default as LayoutElements } from './initial-elements.js?raw'
@@ -0,0 +1,70 @@
+const position = { x: 0, y: 0 }
+
+export const initialNodes = [
+  {
+    id: '1',
+    type: 'input',
+    label: 'input',
+    position,
+  },
+  {
+    id: '2',
+    label: 'node 2',
+    position,
+  },
+  {
+    id: '2a',
+    label: 'node 2a',
+    position,
+  },
+  {
+    id: '2b',
+    label: 'node 2b',
+    position,
+  },
+  {
+    id: '2c',
+    label: 'node 2c',
+    position,
+  },
+  {
+    id: '2d',
+    label: 'node 2d',
+    position,
+  },
+  {
+    id: '3',
+    label: 'node 3',
+    position,
+  },
+  {
+    id: '4',
+    label: 'node 4',
+    position,
+  },
+  {
+    id: '5',
+    label: 'node 5',
+    position,
+  },
+  {
+    id: '6',
+    type: 'output',
+    label: 'output',
+    position,
+  },
+]
+
+export const initialEdges = [
+  { id: '7', type: 'output', label: 'output', position: { x: 400, y: 450 } },
+  { id: 'e12', source: '1', target: '2', type: 'smoothstep', animated: true },
+  { id: 'e13', source: '1', target: '3', type: 'smoothstep', animated: true },
+  { id: 'e22a', source: '2', target: '2a', type: 'smoothstep', animated: true },
+  { id: 'e22b', source: '2', target: '2b', type: 'smoothstep', animated: true },
+  { id: 'e22c', source: '2', target: '2c', type: 'smoothstep', animated: true },
+  { id: 'e2c2d', source: '2c', target: '2d', type: 'smoothstep', animated: true },
+
+  { id: 'e45', source: '4', target: '5', type: 'smoothstep', animated: true },
+  { id: 'e56', source: '5', target: '6', type: 'smoothstep', animated: true },
+  { id: 'e57', source: '5', target: '7', type: 'smoothstep', animated: true },
+]