Vue Flow 是一个轻量级的 Vue 3 组件库,它允许开发者以简洁直观的方式创建动态流程图。本篇文章记录一下Vue Flow的基本用法
安装
npm add @vue-flow/core
流程图的构成
Nodes、Edges、Handles
主题
默认样式
通过导入样式文件应用
/* these are necessary styles for vue flow */
@import '@vue-flow/core/dist/style.css';
/* this contains the default theme, these are optional styles */
@import '@vue-flow/core/dist/theme-default.css';
对默认主题进行调整
1.可以使用css类名去覆盖
.vue-flow__node-custom {
background: purple;
color: white;
border: 1px solid purple;
border-radius: 4px;
box-shadow: 0 0 0 1px purple;
padding: 8px;
}
2.可以在组件上使用style或者class属性进行替换
<VueFlow
:nodes="nodes"
:edges="edges"
class="my-diagram-class"
:style="{ background: 'red' }"
/>
3.通过在全局的css文件中对组件的样式变量进行覆盖
:root {
--vf-node-bg: #fff;
--vf-node-text: #222;
--vf-connection-path: #b1b1b7;
--vf-handle: #555;
}
具体的css类名和变量名可以通过查阅官方文档确认 Theming | Vue Flow
Nodes
Nodes是流程图中的一个基本组件,可以在图表中可视化任何类型的数据,独立存在并通过edges互连从而创建数据映射
1.展示节点
节点的渲染是通过给VueFlow组件的nodes参数传入一个数组实现的
<script setup>
import { ref, onMounted } from 'vue'
import { VueFlow, Panel } from '@vue-flow/core'
const nodes = ref([
{
id: '1',
position: { x: 50, y: 50 },
data: { label: 'Node 1', },
}
]);
function addNode() {
const id = Date.now().toString()
nodes.value.push({
id,
position: { x: 150, y: 50 },
data: { label: `Node ${id}`, },
})
}
</script>
<template>
<VueFlow :nodes="nodes">
<Panel>
<button type="button" @click="addNode">Add a node</button>
</Panel>
</VueFlow>
</template>
2.节点的增删
对于节点的增加和删除,我们可以通过直接改变nodes参数来实现,也可以使用 useVueFlow 提供的方法addNodes 和removeNodes直接改变组件内部的状态实现
3.节点的更新
节点的更新同样可以使用改变nodes参数来实现,也可以使用useVueFlow得到的实例instance上的updateNodeData,传入对应组件的id和数据对象来更新;
instance.updateNode(nodeId, { selectable: false, draggable: false })
通过对实例的findNode方法拿到的节点实例直接修改组件state同样能够起到更新节点的效果
const node = instance.findNode(nodeId)
node.data = { ...node.data, hello: 'world', }
4.节点的类型
节点的类型通过nodes数组中对应节点项的type属性确定
默认节点(type:'default')
input节点(type:'input')
output节点(type:'output')
自定义节点(type:'custom', type:'special',...)
除了默认的节点类型,用户也可以创建自定义的节点类型
模板插槽模式
<script setup>
import { ref } from 'vue'
import { VueFlow } from '@vue-flow/core'
import CustomNode from './CustomNode.vue'
import SpecialNode from './SpecialNode.vue'
export const nodes = ref([
{
id: '1',
data: { label: 'Node 1' },
// this will create the node-type `custom`
type: 'custom',
position: { x: 50, y: 50 },
},
{
id: '1',
data: { label: 'Node 1' },
// this will create the node-type `special`
type: 'special',
position: { x: 150, y: 50 },
}
])
</script>
<template>
<VueFlow :nodes="nodes">
<template #node-custom="customNodeProps">
<CustomNode v-bind="customNodeProps" />
</template>
<template #node-special="specialNodeProps">
<SpecialNode v-bind="specialNodeProps" />
</template>
</VueFlow>
</template>
<script setup>
import { ref } from 'vue'
import { VueFlow } from '@vue-flow/core'
import CustomNode from './CustomNode.vue'
import SpecialNode from './SpecialNode.vue'
export const nodes = ref([
{
id: '1',
data: { label: 'Node 1' },
// this will create the node-type `custom`
type: 'custom',
position: { x: 50, y: 50 },
},
{
id: '1',
data: { label: 'Node 1' },
// this will create the node-type `special`
type: 'special',
position: { x: 150, y: 50 },
}
])
</script>
<template>
<VueFlow :nodes="nodes">
<template #node-custom="customNodeProps">
<CustomNode v-bind="customNodeProps" />
</template>
<template #node-special="specialNodeProps">
<SpecialNode v-bind="specialNodeProps" />
</template>
</VueFlow>
</template>
在配置了自定义组件后,VueFlow会将节点类型字段和插槽名字进行动态匹配,从而正确渲染。
Node-types对象模式
直接将引入的组件对象通过VueFlow的nodeTypes参数传入,需要注意的是要去除组件对象的响应式
<script setup>
import { markRaw } from 'vue'
import CustomNode from './CustomNode.vue'
import SpecialNode from './SpecialNode.vue'
const nodeTypes = {
custom: markRaw(CustomNode),
special: markRaw(SpecialNode),
}
const nodes = ref([
{
id: '1',
data: { label: 'Node 1' },
type: 'custom',
},
{
id: '1',
data: { label: 'Node 1' },
type: 'special',
}
])
</script>
<template>
<VueFlow :nodes="nodes" :nodeTypes="nodeTypes" />
</template>
节点事件
Edges
Edges就是节点之间的连线部分,每一条连线都是从一个handle到另一个handle,其拥有独立的id;
展示Edges
Edges的渲染是通过给VueFlow组件的edges参数传入一个数组实现的,需要配合nodes一起确定节点之间的连线关系;
<script setup>
import { ref, onMounted } from 'vue'
import { VueFlow } from '@vue-flow/core'
const nodes = ref([
{
id: '1',
position: { x: 50, y: 50 },
data: { label: 'Node 1', },
},
{
id: '2',
position: { x: 50, y: 250 },
data: { label: 'Node 2', },
}
]);
const edges = ref([
{
id: 'e1->2',
source: '1',
target: '2',
}
]);
</script>
<template>
<VueFlow :nodes="nodes" :edges="edges" />
</template>
增删和更新Edges
和节点的类似,可以通过直接改变edges传参实现,同时useVueFlow也提供了对Edges的操作方法[addEdges
],(vueflow.dev/typedocs/in…)
removeEdges
Edges的更新
同样和节点类型类似,可以通过useVueFlow拿到实例,使用实例的updateEdgeData方法进行更新,也可以使用findEdge拿到的edge直接修改对应的state进行更新
instance.updateEdgeData(edgeId, { hello: 'mona' })
edge.data = { ...edge.data, hello: 'world', }
Edges类型
默认连线(type:'default')
阶梯连线(type:'step')
直线连接(type:'straight')
自定义连接
用法和自定义节点类似,只是插槽名变为edge-开头,参数名由nodeTypes变为edgeTypes
edge事件
Handles
节点边缘上的小圆圈,使用拖拽的方式进行节点之间的连接
使用Handle
Handle是以组件的方式在节点中引入的
<script setup>
import { Handle } from '@vue-flow/core'
defineProps(['id', 'sourcePosition', 'targetPosition', 'data'])
</script>
<template>
<Handle type="source" :position="sourcePosition" />
<span>{{ data.label }}</span>
<Handle type="target" :position="targetPosition" />
</template>
Handle 位置
可以通过Handle组件的position参数来调整其位置
<Handle type="source" :position="Position.Right" />
<Handle type="target" :position="Position.Left" />
多个Handle使用时需要注意组件需要有唯一id
<Handle id="source-a" type="source" :position="Position.Right" /> <Handle id="source-b" type="source" :position="Position.Right" />
多个Handle在同一侧时需要手动调整位置防止重叠
<Handle id="source-a" type="source" :position="Position.Right" style="top: 10px" />
<Handle id="source-b" type="source" :position="Position.Right" style="bottom: 10px; top: auto;" />
Handle的隐藏
需要使用样式opacity,不能使用v-if和v-show
<Handle type="source" :position="Position.Right" style="opacity: 0" />
是否限制连接可以使用Handle组件的connectable参数,传入一个布尔值
<Handle type="source" :position="Position.Right" :connectable="handleConnectable" />
连接模式
<VueFlow :connection-mode="ConnectionMode.Strict" />
配置了ConnectionMode.Strict后只允许在相同类型的Handle之间进行连接
动态位置
在需要动态处理Handle的位置时,需要调用updateNodeInternals方法传入需要更新的节点id数组去应用,防止边缘未对其的情况出现。
import { useVueFlow } from '@vue-flow/core'
const { updateNodeInternals } = useVueFlow()
const onSomeEvent = () => {
updateNodeInternals(['1'])
}
Composables
Vue Flow提供了一些用于获取流程图及其内部组件相关数据的API,可以参考文档 Composables | Vue Flow
Controlled Flow
Vue Flow同样提供了一些API用于对流程图的更新过程进行手动控制并且监听对应事件 受控流量 |Vue 流程 (vueflow.dev)
来看一下官方文档Demo
Layouting | Vue Flow 这个demo较全的使用到了Vue Flow中的一些基本用法:
1.主流程:App.vue:
import "@vue-flow/core/dist/style.css";
import "@vue-flow/core/dist/theme-default.css";
import { nextTick, ref } from "vue";
import { Panel, VueFlow, useVueFlow } from "@vue-flow/core";
import { Background } from "@vue-flow/background";
import Icon from "./icon.vue";
import ProcessNode from "./processNode.vue";
import AnimationEdge from "./animationEdge.vue";
import { initialEdges, initialNodes } from "./initialElements";
import { useRunProcess } from "./useRunProcess";
import { useShuffle } from "./useShuffle";
import { useLayout } from "./useLayout";
// 节点的初始化数据
const nodes = ref(initialNodes);
// 节点的连接关系
const edges = ref(initialEdges);
// 打乱节点之间的连接关系
const shuffle = useShuffle();
// useLayout 处理节点布局对齐等
const { graph, layout, previousDirection } = useLayout();
const { fitView } = useVueFlow();
// 将节点和连线随机化
async function shuffleGraph() {
await stop();
reset(nodes.value);
edges.value = shuffle(nodes.value);
nextTick(() => {
layoutGraph(previousDirection.value);
});
}
// 进行重新排版
async function layoutGraph(direction) {
await stop();
reset(nodes.value);
nodes.value = layout(nodes.value, edges.value, direction);
nextTick(() => {
fitView();
run(nodes.value);
});
}
<template>
<div class="layout-flow">
<VueFlow :nodes="nodes" :edges="edges" @nodes-initialized="layoutGraph('LR')">
<!-- 以插槽方式传入节点和连线 -->
<template #node-process="props">
<ProcessNode
:data="props.data"
:source-position="props.sourcePosition"
:target-position="props.targetPosition" />
</template>
<template #edge-animation="edgeProps">
<AnimationEdge
:id="edgeProps.id"
:source="edgeProps.source"
:target="edgeProps.target"
:source-x="edgeProps.sourceX"
:source-y="edgeProps.sourceY"
:targetX="edgeProps.targetX"
:targetY="edgeProps.targetY"
:source-position="edgeProps.sourcePosition"
:target-position="edgeProps.targetPosition"
/>
</template>
<Background />
<Panel class="process-panel" position="top-right">
<div class="layout-panel">
<button v-if="isRunning" class="stop-btn" title="stop" @click="stop">
<Icon name="stop" />
<span class="spinner" />
</button>
<button v-else title="start" @click="run(nodes)">
<Icon name="play" />
</button>
<button title="set horizontal layout" @click="layoutGraph('LR')">
<Icon name="horizontal" />
</button>
<button title="set vertical layout" @click="layoutGraph('TB')">
<Icon name="vertical" />
</button>
<button title="shuffle graph" @click="shuffleGraph">
<Icon name="shuffle" />
</button>
</div>
<div class="checkbox-panel">
<label>Cancel on error</label>
<input v-model="cancelOnError" type="checkbox" />
</div>
</Panel>
</VueFlow>
</div>
</template>
.layout-flow {
background-color: #1a192b;
height: 100%;
width: 100%;
}
.process-panel,
.layout-panel {
display: flex;
gap: 10px;
}
.process-panel {
background-color: #2d3748;
padding: 10px;
border-radius: 8px;
box-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
display: flex;
flex-direction: column;
}
.process-panel button {
border: none;
cursor: pointer;
background-color: #4a5568;
border-radius: 8px;
color: white;
box-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
}
.process-panel button {
font-size: 16px;
width: 40px;
height: 40px;
display: flex;
align-items: center;
justify-content: center;
}
.checkbox-panel {
display: flex;
align-items: center;
gap: 10px;
}
.process-panel button:hover,
.layout-panel button:hover {
background-color: #2563eb;
transition: background-color 0.2s;
}
.process-panel label {
color: white;
font-size: 12px;
}
.stop-btn svg {
display: none;
}
.stop-btn:hover svg {
display: block;
}
.stop-btn:hover .spinner {
display: none;
}
.spinner {
border: 3px solid #f3f3f3;
border-top: 3px solid #2563eb;
border-radius: 50%;
width: 10px;
height: 10px;
animation: spin 1s linear infinite;
}
@keyframes spin {
0% {
transform: rotate(0deg);
}
100% {
transform: rotate(360deg);
}
}
2.useShuffle.js
该文件提供的方法主要是用来随机打乱节点以及连线的关系
// 打乱数组的顺序
function shuffleArray(array) {
for (let i = array.length - 1; i > 0; i--) {
const j = Math.floor(Math.random() * (i + 1));
[array[i], array[j]] = [array[j], array[i]];
}
}
// 根据节点数组生成一个可能的节点之间的映射关系
function generatePossibleEdges(nodes) {
const possibleEdges = [];
for (const sourceNode of nodes) {
for (const targetNode of nodes) {
if (sourceNode.id !== targetNode.id) {
const edgeId = `e${sourceNode.id}-${targetNode.id}`;
possibleEdges.push({
id: edgeId,
source: sourceNode.id,
target: targetNode.id,
type: "animation",
animated: true
});
}
}
}
return possibleEdges;
}
// 返回新的节点连接关系;
export function useShuffle() {
return nodes => {
const possibleEdges = generatePossibleEdges(nodes);
shuffleArray(possibleEdges);
const usedNodes = new Set();
const newEdges = [];
for (const edge of possibleEdges) {
if (
!usedNodes.has(edge.target) &&
(usedNodes.size === 0 || usedNodes.has(edge.source))
) {
newEdges.push(edge);
usedNodes.add(edge.source);
usedNodes.add(edge.target);
}
}
return newEdges;
};
}
3.useLayout.js
使用dagre对节点进行排版,返回排版后的图数据;
import dagre from "dagre";
import { ref } from "vue";
import { Position, useVueFlow } from "@vue-flow/core";
export function useLayout() {
const { findNode } = useVueFlow();
const graph = ref(new dagre.graphlib.Graph());
const previousDirection = ref("LR");
function layout(nodes, edges, direction) {
const dagreGraph = new dagre.graphlib.Graph();
graph.value = dagreGraph;
// 设置默认的边标签
dagreGraph.setDefaultEdgeLabel(() => ({}));
const isHorizontal = direction === "LR";
// 设置图布局
dagreGraph.setGraph({ rankdir: direction });
previousDirection.value = direction;
for (const node of nodes) {
// 查找到节点的信息
const graphNode = findNode(node.id);
// 设置节点
dagreGraph.setNode(node.id, {
width: graphNode.dimensions.width || 150,
height: graphNode.dimensions.height || 50
});
}
// 设置边
for (const edge of edges) {
dagreGraph.setEdge(edge.source, edge.target);
}
// 排版
dagre.layout(dagreGraph);
// 排版结束后返回新的节点状态
return nodes.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 }
};
});
}
return { graph, layout, previousDirection };
}
4.useRunProcess.js
用于模拟流程运行过程中的各种状态
import { ref, toRef, toValue } from "vue";
import { useVueFlow } from "@vue-flow/core";
export function useRunProcess({ graph: dagreGraph, cancelOnError = true }) {
const { updateNodeData, getConnectedEdges } = useVueFlow();
const graph = toRef(() => toValue(dagreGraph));
// 是否正在运行
const isRunning = ref(false);
//已执行的节点
const executedNodes = new Set();
// 当前正在执行的节点
const runningTasks = new Map();
// 即将执行的节点
const upcomingTasks = new Set();
async function runNode(node, isStart = false) {
if (executedNodes.has(node.id)) {
return;
}
// 加入到即将执行的节点
upcomingTasks.add(node.id);
// 过滤出指向当前节点的连线
const incomers = getConnectedEdges(node.id).filter(
connection => connection.target === node.id
);
// 等待进入动画全部执行完成
await Promise.all(
incomers.map(incomer => until(() => !incomer.data.isAnimating))
);
// 清空
upcomingTasks.clear();
if (!isRunning.value) {
return;
}
// 节点加入到已经执行的节点
executedNodes.add(node.id);
// 更新节点的状态
updateNodeData(node.id, {
isRunning: true,
isFinished: false,
hasError: false,
isCancelled: false
});
const delay = Math.floor(Math.random() * 2000) + 1000;
return new Promise(resolve => {
const timeout = setTimeout(
async () => {
// 获取当前节点的所有后续子节点
const children = graph.value.successors(node.id);
// 随机抛出错误
const willThrowError = Math.random() < 0.15;
// 模拟错误的情况
if (!isStart && willThrowError) {
updateNodeData(node.id, { isRunning: false, hasError: true });
if (toValue(cancelOnError)) {
// 跳过错误节点后续子节点的处理
await skipDescendants(node.id);
// 删除节点对应正在执行的任务
runningTasks.delete(node.id);
// @ts-expect-error
resolve();
return;
}
}
// 更新节点的状态未结束
updateNodeData(node.id, { isRunning: false, isFinished: true });
runningTasks.delete(node.id);
// 递归执行后续节点
if (children.length > 0) {
await Promise.all(children.map(id => runNode({ id })));
}
resolve();
},
isStart ? 0 : delay
);
// 将当前任务加入到运行任务
runningTasks.set(node.id, timeout);
});
}
// 从起始节点开始执行的情况
async function run(nodes) {
if (isRunning.value) {
return;
}
reset(nodes);
isRunning.value = true;
// 过滤出起始节点
const startingNodes = nodes.filter(
node => graph.value.predecessors(node.id)?.length === 0
);
// 调用runNode从起始节点执行
await Promise.all(startingNodes.map(node => runNode(node, true)));
clear();
}
//重置
function reset(nodes) {
clear();
for (const node of nodes) {
updateNodeData(node.id, {
isRunning: false,
isFinished: false,
hasError: false,
isSkipped: false,
isCancelled: false
});
}
}
async function skipDescendants(nodeId) {
const children = graph.value.successors(nodeId);
for (const child of children) {
updateNodeData(child, { isRunning: false, isSkipped: true });
await skipDescendants(child);
}
}
// 暂停运行
async function stop() {
isRunning.value = false;
for (const nodeId of upcomingTasks) {
clearTimeout(runningTasks.get(nodeId));
runningTasks.delete(nodeId);
updateNodeData(nodeId, {
isRunning: false,
isFinished: false,
hasError: false,
isSkipped: false,
isCancelled: true
});
await skipDescendants(nodeId);
}
for (const [nodeId, task] of runningTasks) {
clearTimeout(task);
runningTasks.delete(nodeId);
updateNodeData(nodeId, {
isRunning: false,
isFinished: false,
hasError: false,
isSkipped: false,
isCancelled: true
});
await skipDescendants(nodeId);
}
executedNodes.clear();
upcomingTasks.clear();
}
function clear() {
isRunning.value = false;
executedNodes.clear();
runningTasks.clear();
}
return { run, stop, reset, isRunning };
}
// 等待直到condition为true
async function until(condition) {
return new Promise(resolve => {
const interval = setInterval(() => {
if (condition()) {
clearInterval(interval);
resolve();
}
}, 100);
});
}
5.processNode.js
流程图节点组件,根据节点状态显示不同的样式
import { computed, toRef } from 'vue'
import { Handle, useHandleConnections } from '@vue-flow/core'
const props = defineProps({
data: {
type: Object,
required: true,
},
sourcePosition: {
type: String,
},
targetPosition: {
type: String,
},
})
const sourceConnections = useHandleConnections({
type: 'target',
})
const targetConnections = useHandleConnections({
type: 'source',
})
// 判断是发送节点还是接收节点
const isSender = toRef(() => sourceConnections.value.length <= 0)
const isReceiver = toRef(() => targetConnections.value.length <= 0)
// 根据节点的数据参数来确定节点的背景颜色
const bgColor = computed(() => {
if (isSender.value) {
return '#2563eb'
}
if (props.data.hasError) {
return '#f87171'
}
if (props.data.isFinished) {
return '#42B983'
}
if (props.data.isCancelled) {
return '#fbbf24'
}
return '#4b5563'
})
const processLabel = computed(() => {
if (props.data.hasError) {
return '❌'
}
if (props.data.isSkipped) {
return '
标签:Vue,const,Flow,value,id,vue,Vue3,import,节点
From: https://blog.51cto.com/u_16802720/12101013