[AngularFire2] Build a Custom Node Backend Using Firebase Queue

In this lesson we are going to learn how to build a custom Node process for batch processing of Firebase data using the Firebase queue library.

From UI, we create a request to add 'queue/tasks' node in database which contains the data to be deleted by queue later.

Controller:

  requestLessonDeletion() {

    this.courseService.deleteLEssonById(

      this.lesson.$key,

      this.lesson.courseId

    )

      .then(() => alert("lesson delete successfully"))

      .catch((err) => console.error(err));

  }

Service:

this.rootDb = fb.database().ref()  

...

deleteLEssonById(lessonId: string, courseId) {

    return this.rootDb.child('queue/tasks')

      .push({

        lessonId,

        courseId

      })

  }

Then we will build a node server to do the deletion:

package.json:

"batch-server": "./node_modules/.bin/ts-node ./batch-server.ts",

Install:

npm install --save-dev ts-promise firebase-queue

import {firebaseConfig} from "./src/environments/firebase.config";

import {initializeApp, auth,database} from 'firebase';

const Queue = require('firebase-queue');

import Promise from "ts-promise";

console.log('Running batch server ...');

initializeApp(firebaseConfig);

auth()

  .signInWithEmailAndPassword('o@you.com', 'youdon'tknow')

  .then(runConsumer)

  .catch(onError);

function onError(err) {

  console.error("Could not login", err);

  process.exit();

}

function runConsumer() {

  console.log("Running consumer ...");

  const lessonsRef = database().ref("lessons");

  const lessonsPerCourseRef = database().ref("lessonsPerCourse");

  const queueRef = database().ref('queue');

  const queue = new Queue(queueRef, function(data, progress, resolve, reject) {

    console.log('received delete request ...',data);

    const deleteLessonPromise = lessonsRef.child(data.lessonId).remove();

    const deleteLessonPerCoursePromise =

      lessonsPerCourseRef.child(`${data.courseId}/${data.lessonId}`).remove();

    Promise.all([deleteLessonPromise, deleteLessonPerCoursePromise])

      .then(

        () => {

          console.log("lesson deleted");

          resolve();

        }

      )

      .catch(() => {

        console.log("lesson deletion in error");

        reject();

      });

  });

}

Run 'npm run batch-server', then the data inside "lessons" & "lessonsPreCourse" & "queue/tasks" will all be deleted.

{

  "rules": {

    ".read": "auth != null",

    ".write": "auth != null",

      "courses": {

        ".indexOn": ["url"]

       },

    "lessons": {

      ".indexOn": ["url"]

    },

      "queue": {

        "tasks": {

          ".indexOn": ["_state"]

        }

      }

  }

}

Need to add "queue" to the firebase ruels to get rid of error message.

Github

巴特西

[AngularFire2] Build a Custom Node Backend Using Firebase Queue

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