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TypeError:无法读取未定义的属性“child”

google-cloud-functions android javascript

LizG · 技术社区 · 7 年前

我一直在研究这个问题,但似乎找不到答案。

exports.newRequest = functions.database.ref('/history/{pushId}').onCreate(event => {
    var requestSnapshot = event.data;
    var distance  = requestSnapshot.child('distance').val();
    var price  = distance * 0.5;
    var pushId = event.params.pushId;
    return requestSnapshot.ref.parent.child(pushId).child('price').set(price);
});

TypeError: Cannot read property 'child' of undefined
at exports.newRequest.functions.database.ref.onCreate.event (/user_code/index.js:17:36)
at cloudFunctionNewSignature (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:105:23)
at cloudFunction (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:135:20)
at /var/tmp/worker/worker.js:733:24
at process._tickDomainCallback (internal/process/next_tick.js:135:7)

索引:17:36

var distance  = requestSnapshot.child('distance').val();

我的第一个想法是,孩子的“距离”是不可用的。在我的代码中,在btnRequest完成之前不会添加子“history”。

有什么想法吗?有没有办法改变密码索引.js使用我应用程序中的代码?

升级API后:

npm install firebase-functions@latest --save
npm install firebase-admin@latest --save-exact

npm install -g firebase-tools

exports.newRequest = functions.database.ref('/history/{pushId}').onCreate(snapshot, context => {
var requestSnapshot = snapshot.val();
var distance  = requestSnapshot.child('distance').val();
var price  = distance * 0.5;
var pushId = snapshot.params.pushId;

return requestSnapshot.ref.parent.child(pushId).child('price').set(price);
});

不确定上述是否正确,但我部署并得到以下响应:

Error: Error occurred while parsing your function triggers.

ReferenceError: snapshot is not defined
    at Object.<anonymous> (/Users/lizg/Desktop/Programs/Android/Google-Play/ryyde_functions/functions/index.js:15:75)
    at Module._compile (module.js:652:30)
    at Object.Module._extensions..js (module.js:663:10)
    at Module.load (module.js:565:32)
    at tryModuleLoad (module.js:505:12)
    at Function.Module._load (module.js:497:3)
    at Module.require (module.js:596:17)
    at require (internal/module.js:11:18)
    at /Users/lizg/.npm-global/lib/node_modules/firebase-tools/lib/triggerParser.js:21:11
    at Object.<anonymous> (/Users/lizg/.npm-global/lib/node_modules/firebase-tools/lib/triggerParser.js:75:3)

编辑#2

更新index.js 代码:

exports.newRequest = functions.database.ref('/history/{pushId}').onCreate((snapshot, context) => {
var requestSnapshot = snapshot.val();
var distance  = requestSnapshot.child('distance').val();
var price  = distance * 0.5;
var pushId = snapshot.params.pushId;

return snapshot.ref.parent.child(pushId).child('price').set(price);

});

在日志中产生错误:

TypeError: requestSnapshot.child is not a function
at exports.newRequest.functions.database.ref.onCreate (/user_code/index.js:17:37)
at cloudFunctionNewSignature (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:105:23)
at cloudFunction (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:135:20)
at /var/tmp/worker/worker.js:733:24
at process._tickDomainCallback (internal/process/next_tick.js:135:7)

1 回复 | 直到 7 年前

Doug Stevenson 7 年前

您正在对Firebase SDK的云函数的更新版本使用旧api。您需要更新到新的api。特别是,您需要注意firebase函数1.0版中的更改。 All the changes are summarized here.

特别地, see what changed in Database triggers . 您正在对数据库触发器的第一个参数使用旧式的“event”参数:

exports.newRequest =
functions.database.ref('/history/{pushId}').onCreate(event => {
    // ...
})

DataSnapshot 和一个 EventContext 对象:

exports.newRequest =
functions.database.ref('/history/{pushId}').onCreate((snapshot, context) => {
    // ...
})

有关更多详细信息,请参阅文档。