@tisoap/react-flow-smart-edge
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Custom React Flow Edge that never intersects with other nodes
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# React Flow Smart Edge
Custom Edges for React Flow that never intersect with other nodes, using pathfinding.
## Install
With `npm`:
```bash
npm install /react-flow-smart-edge
```
With `yarn`:
```bash
yarn add /react-flow-smart-edge
```
This package is only compatible with [**version 12** of React Flow Edge](https://reactflow.dev/learn/troubleshooting/migrate-to-v12).
## Support
Like this project and want to show your support? Buy me a coffee:
[](https://ko-fi.com/J3J472RAJ)
_Really_ like this project? Sponsor me on GitHub:
[](https://github.com/sponsors/tisoap)
## Usage
This package ships with the following Smart Edges components:
- `SmartBezierEdge`: A smart equivalent to React Flow's [BezierEdge](https://reactflow.dev/docs/api/edges/edge-types/)
- `SmartStraightEdge`: A smart equivalent to React Flow's [StraightEdge](https://reactflow.dev/docs/api/edges/edge-types/)
- `SmartStepEdge`: A smart equivalent to React Flow's [StepEdge](https://reactflow.dev/docs/api/edges/edge-types/)
Each one can be imported individually as a named export.
### Example
```jsx
import React from "react";
import { ReactFlow } from "reactflow";
import { SmartBezierEdge } from "@tisoap/react-flow-smart-edge";
import "@xyflow/react/dist/style.css";
const nodes = [
{
id: "1",
data: { label: "Node 1" },
position: { x: 300, y: 100 },
},
{
id: "2",
data: { label: "Node 2" },
position: { x: 300, y: 200 },
},
];
const edges = [
{
id: "e21",
source: "2",
target: "1",
type: "smart",
},
];
// You can give any name to your edge types
// https://reactflow.dev/docs/api/edges/custom-edges/
const edgeTypes = {
smart: SmartBezierEdge,
};
export const Graph = (props) => {
const { children, ...rest } = props;
return (
<ReactFlow
defaultNodes={nodes}
defaultEdges={edges}
edgeTypes={edgeTypes}
{...rest}
>
{children}
</ReactFlow>
);
};
```
## Edge Options
All smart edges will take the exact same options as a [React Flow Edge](https://reactflow.dev/docs/api/edges/edge-options/).
## Custom Smart Edges
You can have more control over how the edge is rerendered by creating a [custom edge](https://reactflow.dev/docs/api/edges/custom-edges/) and using the provided `getSmartEdge` function. It takes an object with the following keys:
- `sourcePosition`, `targetPosition`, `sourceX`, `sourceY`, `targetX` and `targetY`: The same values your [custom edge](https://reactflow.dev/docs/examples/edges/custom-edge/) will take as props
- `nodes`: An array containing all graph nodes, you can get it from the [`useNodes` hook](https://reactflow.dev/docs/api/hooks/use-nodes/)
### Example
Just like you can use `getBezierPath` from `reactflow` to create a [custom edge with a button](https://reactflow.dev/docs/examples/edges/edge-with-button/), you can do the same with `getSmartEdge`:
```jsx
import React from "react";
import { useNodes, BezierEdge } from "@xyflow/react";
import { getSmartEdge } from "@tisoap/react-flow-smart-edge";
const foreignObjectSize = 200;
export function SmartEdgeWithButtonLabel(props) {
const {
id,
sourcePosition,
targetPosition,
sourceX,
sourceY,
targetX,
targetY,
style,
markerStart,
markerEnd,
} = props;
const nodes = useNodes();
const getSmartEdgeResponse = getSmartEdge({
sourcePosition,
targetPosition,
sourceX,
sourceY,
targetX,
targetY,
nodes,
});
// If the value returned is an Error, it means "getSmartEdge" was unable
// to find a valid path, and you should do something else instead
if (smartResponse instanceof Error) {
return <BezierEdge {...props} />;
}
const { edgeCenterX, edgeCenterY, svgPathString } = getSmartEdgeResponse;
return (
<>
<path
style={style}
className="react-flow__edge-path"
d={svgPathString}
markerEnd={markerEnd}
markerStart={markerStart}
/>
<foreignObject
width={foreignObjectSize}
height={foreignObjectSize}
x={edgeCenterX - foreignObjectSize / 2}
y={edgeCenterY - foreignObjectSize / 2}
requiredExtensions="http://www.w3.org/1999/xhtml"
>
<button
onClick={(event) => {
event.stopPropagation();
alert(`remove ${id}`);
}}
>
X
</button>
</foreignObject>
</>
);
}
```
## Advanced Custom Smart Edges
The `getSmartEdge` function also accepts an optional object `options`, which allows you to configure aspects of the path-finding algorithm. You may use it like so:
```js
const myOptions = {
// your configuration goes here
nodePadding: 20,
gridRatio: 15,
};
// ...
const getSmartEdgeResponse = getSmartEdge({
sourcePosition,
targetPosition,
sourceX,
sourceY,
targetX,
targetY,
nodes,
// Pass down options in the getSmartEdge object
options: myOptions,
});
```
The `options` object accepts the following keys (they're all optional):
- `nodePadding`: How many pixels of padding are added around nodes, or by how much should the edge avoid the walls of a node. Default `10`, minimum `2`.
- `gridRatio`: The size in pixels of each square grid cell used for path-finding. Smaller values for a more accurate path, bigger for faster path-finding. Default `10`, minimum `2`.
- `drawEdge`: Allows you to change the function responsible to draw the SVG line, by default it's the same used by `SmartBezierEdge` ([more below](#drawedge))
- `generatePath`: Allows you to change the function for the path-finding, by default it's the same used by `SmartBezierEdge` ([more below](#generatepath))
### `drawEdge`
With the `drawEdge` option, you can change the function used to generate the final [SVG path string](https://developer.mozilla.org/en-US/docs/Web/SVG/Tutorial/Paths), used to draw the line. By default it's the `svgDrawSmoothLinePath` function (same as used by the `SmartBezierEdge`), but the package also includes `svgDrawStraightLinePath` (same as used by the `SmartStraightEdge` and `SmartStepEdge`), or you can provide your own.
```jsx
import {
getSmartEdge,
// Available built-in SVG draw functions
svgDrawSmoothLinePath,
svgDrawStraightLinePath,
} from "@tisoap/react-flow-smart-edge";
// Using provided SVG draw functions:
const result = getSmartEdge({
// ...
options: {
drawEdge: svgDrawSmoothLinePath,
},
});
// ...or using your own custom function
const result = getSmartEdge({
// ...
options: {
drawEdge: (source, target, path) => {
// your code goes here
// ...
return svgPath;
},
},
});
```
The function you provided must comply with this signature:
```ts
type SVGDrawFunction = (
source: XYPosition, // The starting {x, y} point
target: XYPosition, // The ending {x, y} point
path: number[][], // The sequence of points [x, y] the line must follow
) => string; // A string to be used in the "d" property of the SVG line
```
For inspiration on how to implement your own, you can check the [`drawSvgPath.ts` source code](https://github.com/tisoap/react-flow-smart-edge/blob/main/src/functions/drawSvgPath.ts).
### `generatePath`
With the `generatePath` option, you can change the function used to do [Pathfinding](https://en.wikipedia.org/wiki/Pathfinding). By default, it's the `pathfindingAStarDiagonal` function (same as used by the `SmartBezierEdge`), but the package also includes `pathfindingAStarNoDiagonal` (used by `SmartStraightEdge` and `SmartStepEdge`), or your can provide your own.
```jsx
import {
getSmartEdge,
// Available built-in pathfinding functions
pathfindingAStarDiagonal,
pathfindingAStarNoDiagonal,
} from "@tisoap/react-flow-smart-edge";
// Using provided pathfinding functions:
const result = getSmartEdge({
// ...
options: {
generatePath: pathfindingAStarDiagonal,
},
});
// ...or using your own custom function
const result = getSmartEdge({
// ...
options: {
generatePath: (grid, start, end) => {
// your code goes here
// ...
return { fullPath, smoothedPath };
},
},
});
```
The function you provide must comply with this signature:
```ts
type PathFindingFunction = (
grid: Grid, // Grid representation of the graph
start: XYPosition, // The starting {x, y} point
end: XYPosition, // The ending {x, y} point
) => number[][]; // Array of points [x, y] representing the full path with all points
```
For inspiration on how to implement your own, you can check the [`generatePath.ts` source code](https://github.com/tisoap/react-flow-smart-edge/blob/main/src/functions/generatePath.ts).
### Advanced Examples
```jsx
import {
getSmartEdge,
svgDrawSmoothLinePath,
svgDrawStraightLinePath
pathfindingAStarDiagonal,
pathfindingAStarNoDiagonal,
} from '/react-flow-smart-edge'
// ...
// Same as importing "SmartBezierEdge" directly
const bezierResult = getSmartEdge({
// ...
options: {
drawEdge: svgDrawSmoothLinePath,
generatePath: pathfindingAStarDiagonal,
}
})
// Same as importing "SmartStepEdge" directly
const stepResult = getSmartEdge({
// ...
options: {
drawEdge: svgDrawStraightLinePath,
generatePath: pathfindingAStarNoDiagonal,
}
})
// Same as importing "SmartStraightEdge" directly
const straightResult = getSmartEdge({
// ...
options: {
drawEdge: svgDrawStraightLinePath,
generatePath: pathfindingAStarNoDiagonal,
}
})
```
## Storybook
You can see live Storybook examples by visiting [this page](https://tisoap.github.io/react-flow-smart-edge/), and see their source code [here](https://github.com/tisoap/react-flow-smart-edge/blob/main/src/stories/SmartEdge.stories.tsx).
## License
This project is [MIT](https://github.com/tisoap/react-flow-smart-edge/blob/main/LICENSE) licensed.