我在node.js 中使用ES6。长话短说,我现在只关心回调,并想用 promise 替换它们。
我做了一个测试项目,从 api/端点获取 oauth2 token ,刷新它,最后撤销它。目标是向下一个请求提供前一个请求的响应。我的代码如下所示:
const oauth2Adapter = require('./api/adapter/oauth2Adapter')
function test () {
oauth2Adapter.RequestNewAccessToken()
.then(function (response) {
console.log(response)
return oauth2Adapter.RefreshAccessToken(response.body)
})
.then(function (response) {
return oauth2Adapter.RevokeAccessToken(response.body)
})
.then(console.log)
.catch(console.log)
}
test()
第一个 Promise 返回它的响应。现在下一步是将其作为参数传递给第二个 Promise。但第二个 Promise 只收到一个 undefined object 。
我是一名二年级计算机科学学徒,任何评论家都会帮助我并表示赞赏。
编辑:添加“return”关键字并没有改变这种情况。问题是“RefreshAccessToken”“未定义”收到。我也不知道这是否有帮助,但这是“oauth2Adapter.js”代码:
const Promise = require('promise')
const rp = require('request-promise')
const credentials = require('../../misc/credentials/Staging')
function RequestNewAccessToken () {
try {
const response = rp({
method: 'POST',
url: `${credentials.baseUrl}/oauth/token`,
form: {
client_id: credentials.apiKey,
client_secret: credentials.apiSecret,
username: credentials.username,
password: credentials.password,
grant_type: credentials.grantType
},
json: true
})
return Promise.resolve(response)
} catch (error) {
return Promise.reject(error)
}
}
function RefreshAccessToken (token) {
try {
const response = rp({
method: 'POST',
url: `${credentials.baseUrl}/oauth/token`,
form: {
client_id: credentials.apiKey,
client_secret: credentials.apiSecret,
grant_type: 'refresh_token',
refresh_token: token.refresh_token
},
json: true
})
return Promise.resolve(response)
} catch (error) {
return Promise.reject(error)
}
}
function RevokeAccessToken (token) {
try {
const response = rp({
method: 'POST',
url: `${credentials.baseUrl}/oauth/revoke`,
form: {
client_id: credentials.apiKey,
client_secret: credentials.apiSecret,
token: token.access_token
},
json: true
})
return Promise.resolve(response)
} catch (error) {
return Promise.reject(error)
}
}
module.exports = { RequestNewAccessToken, RefreshAccessToken, RevokeAccessToken }
如果我执行代码,我会通过标准输出得到以下文本:
Debugger attached.
{ access_token: '31744bf03a2fb92edb67fcbeead14f4ed8c540843c2439179a54b6439dc94c0e',
token_type: 'Bearer',
expires_in: 660,
refresh_token: 'e53642c69bd0ad954d886dad7a437f88c8c269ecacf2cdcfebc8af1a2d0d9b1e',
created_at: 1538471914 }
TypeError: Cannot read property 'refresh_token' of undefined
at Object.RefreshAccessToken (/Users/quest1onmark/coding_stuff/nodejs/EdgeDeviceAdministration/api/adapter/oauth2Adapter.js:28:28)
at /Users/quest1onmark/coding_stuff/nodejs/EdgeDeviceAdministration/Main.js:7:28
at tryCatcher (/Users/quest1onmark/coding_stuff/nodejs/EdgeDeviceAdministration/node_modules/bluebird/js/release/util.js:16:23)
at Promise._settlePromiseFromHandler (/Users/quest1onmark/coding_stuff/nodejs/EdgeDeviceAdministration/node_modules/bluebird/js/release/promise.js:512:31)
at Promise._settlePromise (/Users/quest1onmark/coding_stuff/nodejs/EdgeDeviceAdministration/node_modules/bluebird/js/release/promise.js:569:18)
at Promise._settlePromise0 (/Users/quest1onmark/coding_stuff/nodejs/EdgeDeviceAdministration/node_modules/bluebird/js/release/promise.js:614:10)
at Promise._settlePromises (/Users/quest1onmark/coding_stuff/nodejs/EdgeDeviceAdministration/node_modules/bluebird/js/release/promise.js:694:18)
at _drainQueueStep (/Users/quest1onmark/coding_stuff/nodejs/EdgeDeviceAdministration/node_modules/bluebird/js/release/async.js:138:12)
at _drainQueue (/Users/quest1onmark/coding_stuff/nodejs/EdgeDeviceAdministration/node_modules/bluebird/js/release/async.js:131:9)
at Async._drainQueues (/Users/quest1onmark/coding_stuff/nodejs/EdgeDeviceAdministration/node_modules/bluebird/js/release/async.js:147:5)
at Immediate.Async.drainQueues (/Users/quest1onmark/coding_stuff/nodejs/EdgeDeviceAdministration/node_modules/bluebird/js/release/async.js:17:14)
at runCallback (timers.js:810:20)
at tryOnImmediate (timers.js:768:5)
at processImmediate [as _immediateCallback] (timers.js:745:5)
Waiting for the debugger to disconnect...
Process finished with exit code 0
最佳答案
通过在 then
block 末尾返回另一个 Promise 来链接 Promise。看来您没有在第一个 then
block 中正确调用 return
。您应该按如下方式更正:
oauth2Adapter.RequestNewAccessToken()
.then(function (requestReponse) {
console.log(response)
return oauth2Adapter.RefreshAccessToken()
})
.then(function (refreshResponse) {
return oauth2Adapter.RevokeAccessToken(JSON.parse(refreshResponse.body))
})
作为旁注,我喜欢在每次 Promise 返回时以不同的方式命名我的回调参数,这将有助于保持简洁!
关于javascript - Promise 链接,使用另一个请求的结果,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/52605072/