cytoscape js dijkstra 方法在回调中抛出 TypeError

Question

当我运行以下代码时出现以下错误：

TypeError: Cannot read property 'data' of undefined

const elementsList = [
            {data: {id: 'a'}},
            {data: {id: 'b'}},
            {data: {id: 'c'}},
            {data: {id: 'ab', source: 'a', target: 'b', weight: 4}},
            {data: {id: 'as', source: 'a', target: 'c', weight: 3}}
        ];
        const testGraph = cytoscape({elements: elementsList});
        const dijkstra = testGraph.elements().dijkstra('#a', () => {
            return this.data('weight');
        }, false);

这与 cytoscape 文档中描述的代码几乎完全相同，所以我不确定哪里出错了。当我运行 dijkstra 没有回调时，我没有收到任何错误，我什至能够对返回的结果执行 pathTo() 和 distanceTo()。 FIDDLE

Answer 1

Arrow functions 没有 this 绑定。但是边缘被传递给那个权重函数，如果您将代码更改为：

可能会更好读

const dijkstra = testGraph.elements().dijkstra('#a', (edge) => {
  return edge.data('weight');
}, false);

var distanceToC = dijkstra.distanceTo(testGraph.$('#c')); // 3

Fiddle

cytoscape js dijkstra 方法在回调中抛出 TypeError

cytoscape js dijkstra method throwing TypeError on the callback

javascript

graph-theory

dijkstra

cytoscape