Firebase未找到云功能？

Question

我想用云功能进行一些测试，以实现更大的目标。作为一名Android开发人员，我的知识在JavaScript方面有点受限。

我正在尝试使用Cloud功能从firebase访问此数据库。

我的代码访问此数据库以在浏览器中获取JSON响应。

    const functions = require('firebase-functions');
    const admin = require('firebase-admin');
    admin.initializeApp(functions.config().firebase);
    const cors = require('cors')({origin: true});
    
    // Take the text parameter passed to this HTTP endpoint and insert it into the
    // Realtime Database under the path /messages/:pushId/original
    exports.addMessage = functions.https.onRequest((req, res) => {
      // Grab the text parameter.
      const original = req.query.text;
      // Push the new message into the Realtime Database using the Firebase Admin SDK.
      admin.database().ref('/messages').push({original: original}).then(snapshot => {
        // Redirect with 303 SEE OTHER to the URL of the pushed object in the Firebase console.
        res.redirect(303, snapshot.ref);
      });
    });
    
    // Listens for new messages added to /messages/:pushId/original and creates an
    // uppercase version of the message to /messages/:pushId/uppercase
    exports.makeUppercase = functions.database.ref('/messages/{pushId}/original')
        .onWrite(event => {
          // Grab the current value of what was written to the Realtime Database.
          const original = event.data.val();
          console.log('Uppercasing', event.params.pushId, original);
          const uppercase = original.toUpperCase();
          // You must return a Promise when performing asynchronous tasks inside a Functions such as
          // writing to the Firebase Realtime Database.
          // Setting an "uppercase" sibling in the Realtime Database returns a Promise.
          return event.data.ref.parent.child('uppercase').set(uppercase);
        });
    
    var db = admin.database();
    exports.getUserMessage = functions.https.onRequest((req, res) => {
    var query = firebase.database().ref("messages").orderByKey();
    query.once("value")
      .then(function(snapshot) {
        snapshot.forEach(function(childSnapshot) {
          // key will be "ada" the first time and "alan" the second time
          var key = childSnapshot.key;
          // childData will be the actual contents of the child
          var childData = childSnapshot.val();
      });
    });  
    });

但我收到错误：

  

错误：无法处理请求

这些是来自Firebase的日志错误：

ReferenceError: firebase is not defined
    at exports.getUserMessage.functions.https.onRequest (/user_code/index.js:34:49)
    at cloudFunction (/user_code/node_modules/firebase-functions/lib/providers/https.js:26:47)
    at /var/tmp/worker/worker.js:635:7
    at /var/tmp/worker/worker.js:619:9
    at _combinedTickCallback (internal/process/next_tick.js:73:7)
    at process._tickDomainCallback (internal/process/next_tick.js:128:9)

package.json脚本

{
  "name": "functions",
  "description": "Cloud Functions for Firebase",
  "dependencies": {
    "cors": "^2.8.1",
    "firebase-admin": "~4.2.1",
    "firebase-functions": "^0.5.7"

  },
  "private": true
}

Answer 1

这里的问题是：

var query = firebase.database().ref("messages").orderByKey();

应该是

db.ref("messages").orderByKey();

您在该行中使用的firebase未在Cloud Functions for Firebase中定义。如果要查询数据库，则已使用Admin SDK对其进行了引用：

var db = admin.database();