[英]Custom nodes with REACTFLOW; saving additional data to a node once the node is created
這是我對react-flow
的第一次介紹。 我希望創建一個自定義節點,創建后,用戶可以在節點中輸入信息並保存/顯示它。 從自定義節點上的react-flow
文檔中,他們有一個類似的示例,他們創建了一個TextUpdaterNode
,該console.logs
用戶輸入。
我沒有通過控制台記錄它,而是在尋找一種將信息保存到節點本身並將其顯示在節點上的方法。 例如,如果用戶在輸入中輸入24, male並按下enter
,我希望使用下面的信息更新節點。
go 有什么方法可以做到這一點?
你想要做的還不止這些:
你可以在這里看到活生生的例子:https://codesandbox.io/s/dank-waterfall-8jfcf4?file=/src/App.js
基本上,您需要:
useNodesState
;const [nodes, setNodes, onNodesChange] = useNodesState(initialNodes);
const onAdd = useCallback(() => {
const newNode = {
id: getNodeId(),
data: { label: `${state.name} (${state.age})` },
position: {
x: 0,
y: 0 + (nodes.length + 1) * 20
}
};
setNodes((nds) => nds.concat(newNode));
}, [nodes, setNodes, state.name, state.age]);
const onEdit = () => {
setNodes((nds) =>
nds.map((node) => {
if (node.id === editState.id) {
node.data = {
...node.data,
label: `${node.id} - ${editState.name} (${editState.age})`
};
}
return node;
})
);
};
<ReactFlow nodes={nodes} edges={edges} onNodesChange={onNodesChange} />
整個代碼如下所示:
import React, { useState, useCallback } from "react";
import ReactFlow, {
ReactFlowProvider,
useNodesState,
useEdgesState
} from "react-flow-renderer";
import "./styles.css";
const getNodeId = () => `randomnode_${+new Date()}`;
const initialNodes = [
{ id: "1", data: { label: "Node 1" }, position: { x: 100, y: 100 } },
{ id: "2", data: { label: "Node 2" }, position: { x: 100, y: 200 } }
];
const initialEdges = [{ id: "e1-2", source: "1", target: "2" }];
const FlowExample = () => {
const [nodes, setNodes, onNodesChange] = useNodesState(initialNodes);
const [edges] = useEdgesState(initialEdges);
const [state, setState] = useState({ name: "", age: "" });
const onAdd = useCallback(() => {
const newNode = {
id: getNodeId(),
data: { label: `${state.name} (${state.age})` },
position: {
x: 0,
y: 0 + (nodes.length + 1) * 20
}
};
setNodes((nds) => nds.concat(newNode));
}, [nodes, setNodes, state.name, state.age]);
return (
<div>
Name:{" "}
<input
type="text"
onChange={(e) => {
setState((prev) => ({ ...prev, name: e.target.value }));
}}
/>
Age:{" "}
<input
type="text"
onChange={(e) => {
setState((prev) => ({ ...prev, age: e.target.value }));
}}
/>
<button onClick={onAdd}>add node</button>
<div style={{ width: "500px", height: "500px" }}>
<ReactFlow nodes={nodes} edges={edges} onNodesChange={onNodesChange} />
</div>
</div>
);
};
export default () => (
<ReactFlowProvider>
<FlowExample />
</ReactFlowProvider>
);
此外,通過編輯:
import React, { useState, useCallback } from "react";
import ReactFlow, {
ReactFlowProvider,
useNodesState,
useEdgesState
} from "react-flow-renderer";
import "./styles.css";
const getNodeId = () => `${String(+new Date()).slice(6)}`;
const initialNodes = [
{ id: "1", data: { label: "Node 1" }, position: { x: 100, y: 100 } },
{ id: "2", data: { label: "Node 2" }, position: { x: 100, y: 200 } }
];
const initialEdges = [{ id: "e1-2", source: "1", target: "2" }];
const FlowExample = () => {
const [nodes, setNodes, onNodesChange] = useNodesState(initialNodes);
const [edges] = useEdgesState(initialEdges);
const [state, setState] = useState({ name: "", age: "" });
const [editState, setEditState] = useState({ id: "", name: "", age: "" });
const onEdit = () => {
setNodes((nds) =>
nds.map((node) => {
if (node.id === editState.id) {
node.data = {
...node.data,
label: `${node.id} - ${editState.name} (${editState.age})`
};
}
return node;
})
);
};
const onAdd = () => {
const id = getNodeId();
const newNode = {
id,
data: { label: `${id} - ${state.name} (${state.age})` },
position: {
x: 0,
y: 0 + (nodes.length + 1) * 20
}
};
setNodes((nds) => nds.concat(newNode));
};
return (
<div>
Name:{" "}
<input
type="text"
onChange={(e) => {
setState((prev) => ({ ...prev, name: e.target.value }));
}}
/>
Age:{" "}
<input
type="text"
onChange={(e) => {
setState((prev) => ({ ...prev, age: e.target.value }));
}}
/>
<button onClick={onAdd}>add node</button>
<br />
Id:{" "}
<input
type="text"
onChange={(e) => {
setEditState((prev) => ({ ...prev, id: e.target.value }));
}}
/>
Name:{" "}
<input
type="text"
onChange={(e) => {
setEditState((prev) => ({ ...prev, name: e.target.value }));
}}
/>
Age:{" "}
<input
type="text"
onChange={(e) => {
setEditState((prev) => ({ ...prev, age: e.target.value }));
}}
/>
<button onClick={onEdit}>Edit node</button>
<div style={{ width: "500px", height: "500px" }}>
<ReactFlow nodes={nodes} edges={edges} onNodesChange={onNodesChange} />
</div>
</div>
);
};
export default () => (
<ReactFlowProvider>
<FlowExample />
</ReactFlowProvider>
);
文檔中一個更有幫助的例子是:
但是您必須刪除所有額外的信息(另外,您可以使用它來更深入地了解 go!)
我設法想出了一個解決方案來創建這樣一個允許您輸入、保存和顯示信息的自定義節點。 我試圖包括相關信息和我在下面使用的代碼塊。
自定義節點
import { useCallback } from 'react';
import { Handle, Position} from 'react-flow-renderer';
const handleStyle = { left: 10 };
//Custom node requires props of data to be passed to it.
function CustomNode({ data }) {
let serviceType = "offered";
//This handles pressing enter inside the description
const handleKeyDown = (evt) => {
if (evt.key === "Enter") {
//Check if empty string
if (evt.target.value.length !== 0) {
//This code is because services are either offered or borrowed.
if (serviceType === "offered") {
data.serviceOffered.push(evt.target.value);
} else if (serviceType === "borrowed") {
data.serviceBorrowed.push(evt.target.value);
}
//Clearing input after pressing enter
evt.currentTarget.value = "";
}
}
};
const onChange = useCallback((evt) => {
//Update service type without pressing enter
serviceType = evt.target.value;
});
return (
<div className="text-updater-node">
<Handle type="target" position={Position.Top} />
<div>
<p>Entity</p>
<label htmlFor="text"><p className='nodeTitle'>{data.label}</p></label>
<input id="text" name="text" onKeyDown={handleKeyDown} />
<select name="type" onChange={onChange}>
<option value="offered" >Offered </option>
<option value="borrowed">Borrowed</option>
</select>
<div className="info">
{/* This is where the description information is displayed. It checks if it is empty, if not it loops through and displays it. */}
<h2>Service Borrowed</h2>
<ul>
{data.serviceBorrowed.length? data.serviceBorrowed.map(service => (<li key={service}>{service}</li>)) : <span></span>}
</ul>
<h2>Service Offered</h2>
<ul>
{data.serviceOffered.length? data.serviceOffered.map(service => (<li key={service}>{service}</li>)) : <span></span>}
</ul>
</div>
</div>
<Handle type="source" position={Position.Bottom} id="a" style={handleStyle} />
<Handle type="source" position={Position.Bottom} id="b" />
</div>
);
}
export default CustomNode;
我有一個帶有以下代碼塊的父reactFlow
組件。 重要的是設置react flow
的自定義節點類型並傳入一個object
包含有關要渲染的節點和邊緣的信息。
import { Fragment, useCallback, useState } from "react";
import ReactFlow, {
addEdge,
applyEdgeChanges,
applyNodeChanges,
} from "react-flow-renderer";
import initialNodes from "../data/nodes"; //This both ended up being empty file
import initialEdges from "../data/edges"; //This both ended up being empty file
import CustomNode from "./customNode";
import "./customNode.css";
//Set nodetype as Custom node, IMPORTANT!
const nodeTypes = { customNode: CustomNode };
function Flow() {
const defaultEdgeOptions = { animated: true };
//Input Elements
const [name, setName] = useState("");
const addNode = () => {
setNodes((e) =>
e.concat({
id: (e.length + 1).toString(),
data: { label: `${name}`, serviceOffered: [], serviceBorrowed: [] },
position: { x: 0, y: 0 },
type: "customNode",
})
);
};
//Nodes and edges containing information of the nodes and edges
const [nodes, setNodes] = useState(initialNodes);
const [edges, setEdges] = useState(initialEdges);
//Boiler plate code for reactFlow
const onNodesChange = useCallback(
(changes) => setNodes((nds) => applyNodeChanges(changes, nds)),
[setNodes]
);
const onEdgesChange = useCallback(
(changes) => setEdges((eds) => applyEdgeChanges(changes, eds)),
[setEdges]
);
const onConnect = useCallback(
(connection) => setEdges((eds) => addEdge(connection, eds)),
[setEdges]
);
return (
<Fragment>
<Row>
<Col lg={9}>
<ReactFlow
className="Canvas mt-1 border border-secondary rounded"
nodes={nodes} //Node information is passed here
edges={edges} //Edges information is passed here
onNodesChange={onNodesChange}
onEdgesChange={onEdgesChange}
onConnect={onConnect}
defaultEdgeOptions={defaultEdgeOptions}
style={{ width: "100%", height: "80vh" }}
fitView
nodeTypes={nodeTypes}
/>
</Col>
</Row>
</Fragment>
);
}
export default Flow;
我在node.js
的data
屬性中添加了更多信息。 它最終被初始化為空,但這個模板應該有助於理解我如何保存node
的信息。 edge
遵循react-flow
文檔中顯示的標准格式。
export default [
// {
// id: '1',
// type: 'customNode',
// data: { label: 'Input Node', info: [{id:1, action:"Everything is burning"}, {id:2, action:"I'm fine"}], noOfActions:2 },
// position: { x: 250, y: 25 },
// },
];
我希望這很有用!
接受的答案是關於修改組件的屬性,這不是 React 方式。 該代碼可能很容易損壞。 還有其他方法可以為自定義節點帶來回調。
這來自 React 流程文檔: https://reactflow.dev/docs/examples/nodes/custom-node/
setNodes([
...
{
id: '2',
type: 'selectorNode',
data: { onChange: onChange, color: initBgColor },
...
缺點:動態修改或創建新節點時需要格外注意
在這種方法中,您將節點數據和行為問題分開。
我使用 TypeScript 來顯示我們一路操作的數據類型。
首先,使用回調擴展自定義節點屬性:
import {NodeProps} from "react-flow-renderer/dist/esm/types/nodes";
// by default, custom node is provisioned with NodeProps<T>
// we extend it with additional property
export type CustomNodeProps = NodeProps<CustomData> & {
onClick: (id: string) => void
}
function CustomNode(props: CustomNodeProps) {
return <button onClick={() => props.onClick(props.id)}>Do it</button>
}
然后創建提供回調的新構造函數,並使用記憶化將其放入自定義節點映射中:
function Flow() {
const [graph, dispatchAction] = useReducer(...);
...
// useMemo is neccessary https://reactflow.dev/docs/guides/troubleshooting/#it-looks-like-you-have-created-a-new-nodetypes-or-edgetypes-object-if-this-wasnt-on-purpose-please-define-the-nodetypesedgetypes-outside-of-the-component-or-memoize-them
const nodeTypes = useMemo(() => {
return {
custom: (props: NodeProps<CustomData>) => {
return CustomNode({...props, onClick: (id: string) => {
dispatchAction({
type: 'customNodeButtonClicked',
nodeId: id,
})
}})
}
}
}, [])
return (
<>
<ReactFlow nodeTypes={nodeTypes} ... />
</>
);
}
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