1、找到节点相交的边

/**
   * 
   * 将节点拖入两节点之间自动插入【找相交的边】
   * date 2023-07-29
   */
   export const findIntersectsEdge = (graph, node) => {
  const edges = graph.getEdges();
  const bbox = node.getBBox();
  const lines = [bbox.leftLine, bbox.rightLine, bbox.topLine, bbox.bottomLine];  
  let res = null;
  edges.forEach((edge) => {    
    const view = graph.findViewByCell(edge);
    lines.forEach((line) => {      
      if (view) {
        if (view.path.intersectsWithLine(line)) {
          res = edge;
        }
      }
    });
  });
  return res;
};

2、对插入的节点进行判断、克隆、设置、插入

 graph.on("node:added", ({ node }) => {
    const e = findIntersectsEdge(graph, node);
    if (e) {
      if (e.store.data.source.cell) {
        let newNode = graph.getCellById(node.id);
        const sourceNode = e.getSourceNode();
        const targetNode = e.getTargetNode();     
        let isInsertFlag = false; //是否插入标志位
        if (
          newNode.shape == "flow-chart-rect-end" ||
          newNode.shape == "flow-chart-rect-start" ||       
        ) {
          isInsertFlag = false;
        } else { 
          isInsertFlag = true;
        }
        if (sourceNode && targetNode && isInsertFlag) {
          e.clone()
            .setSource({
              cell: sourceNode.id,
              connectionPoint: {
                name: "boundary",
                args: {
                  sticky: true,
                },
              },
            })
            .setTarget({
              cell: node.id,
              connectionPoint: {
                name: "boundary",
                args: {
                  sticky: true,
                },
              },
              })
            .addTo(graph);
          e.clone()
            .setSource({
              cell: node.id,
              connectionPoint: {
                name: "boundary",
                args: {
                  sticky: true,
                },
              },
              })
            .setTarget({
              cell: targetNode.id,
              connectionPoint: {
                name: "boundary",
                args: {
                  sticky: true,
                },
              },        
            })
            .addTo(graph);  
          graph.removeEdge(e);
        }
      }
    }
  });

效果图：

参考：https://blog.csdn.net/ZCJSGSZ/article/details/126545542