问题描述
function getNode(subjectId, nodeId){request(`http://hr.amiaodaifu.com:50000/1610/questions/${subjectId}/get-children/${nodeId}`, (err, res, body) => {console.log(body)if(err){ return console.log('err: ',err)} else { const content = JSON.parse(body); console.log(content) return content.length == 0 ? Promise.resolve(content) : Promise.resolve({id: nodeId,children: JSON.parse(body) })} })}function getTree(subjectId, nodeId){ getNode(subjectId, nodeId).then(items => { return Promise.map(items.children, item => (getTree(item)))})// .then((children) => ({// id: nodeId,// children// }))}
调用getTree的时候，提示的错误是:
Cannot read property ’then’ of undefined
是我的思路有问题吗？
问题解答
回答1：首先，request返回值不是Promise。其次，你的getNode方法里也没有返回request的结果。
可以这么改下：
function getNode(subjectId, nodeId){return new Promise((resolve, reject) => { request(`http://hr.amiaodaifu.com:50000/1610/questions/${subjectId}/get-children/${nodeId}`, (err, res, body) => { if(err){return reject('err: ',err) } else {const content = JSON.parse(body); return content.length == 0 ? resolve(content) : resolve({ id: nodeId, children: JSON.parse(body)}) }}) });}回答2：
楼上正解, promise用错地方了
回答3：return Promise.map(items.children, item => (getTree(item)))
有 Promise.map这个函数吗?怎么用?
