Copy a document into a new collection in firestore using cloud function

Question

Path 1 - Match_Creator/cricket/matchList; Path 2 - Match_Creator/cricket/completedMatchList; I have a collection called matchList (Path 1) In which i am having a doc called c434108. Now I want to move this doc(c434108) to Path 2;

/* eslint-disable promise/catch-or-return */
const functions = require("firebase-functions");
const admin = require("firebase-admin");

const { db } = require("./db/index");

const createCompletedMatchListDoc = (request, response) => {
  completedMatchDocsData();
};

function completedMatchDocsData() {
  createNewCompletedMatchDocs()
 }

function getOldCompletedMatchDocs(){

  var completedMatchesRef = db
  .collection("Match_Creator")
  .doc("cricket")
  .collection("matchList");

  var completedMatchDocData;
  var completedMatchDataArr = [];

return new Promise(resolve => {
    let query = completedMatchesRef
      .where("status", "==", "live")
      .get()
      .then(snapshot => {
        // eslint-disable-next-line promise/always-return
        if (snapshot.empty) {
          console.log("No matching documents.");
          return;
        }

        snapshot.forEach(doc => {
          completedMatchDocData = doc.data();     
          completedMatchDataArr.push(completedMatchDocData);
          resolve(completedMatchDataArr);
        });
        console.log("sarang", completedMatchDataArr[2]);
      })
      .catch(err => {
        console.log("Error getting documents", err);
      });
    });
}

const createNewCompletedMatchDocs = (async(change, context) => {
  let completedMatchData = await getOldCompletedMatchDocs();

  console.log('aman', completedMatchData[1]);

  const newValue = change.after.data();
  const previousValue = change.before.data();

  const st1 =newValue.status;
  const st2 = previousValue.status;
  console.log('I am a log entry' + st1 + ' ' + st2);

  var data = completedMatchData[0];

  return db.collection('Match_Creator').doc('cricket').collection('completedMatchList').add(data)
  .catch(error => {
    console.log('Error writting document: ' + error);
    return false;
  });
})

module.exports = createCompletedMatchListDoc;

And After copy this doc(c434108) i want to delete this doc(c434108) from path 1.

And My index.js file is:

const functions = require("firebase-functions");
const admin = require("firebase-admin");
const storeMatchData = require("./liveScoring");
const createCompletedMatchListDoc = require("./completedMatchList");

var http = require("https");

module.exports = {
  liveScoring: functions.https.onRequest(storeMatchData),
  createCompletedMatchListDoc: functions.https.onRequest(
    createCompletedMatchListDoc
  )
};

Answer 1

I am able to solve my problem.

This is my completeMatchList.js file

/* eslint-disable promise/catch-or-return */
const functions = require("firebase-functions");
const admin = require("firebase-admin");

const { db } = require("./db/index");

const createCompletedMatchListDoc = (request, response) => {
  completedMatchDocsData();
};

function completedMatchDocsData() {
  setNewCompletedMatchDocs()
 }

function getOldCompletedMatchDocs(){

  var completedMatchesRef = db
  .collection("Match_Creator")
  .doc("cricket")
  .collection("matchList");

  var completedMatchDocData;
  var completedMatchDataArr = [];

return new Promise(resolve => {
    let query = completedMatchesRef
      .where("status", "==", "live")
      .get()
      .then(snapshot => {
        // eslint-disable-next-line promise/always-return
        if (snapshot.empty) {
          console.log("No matching documents.");
          return;
        }

        snapshot.forEach(doc => {
          // completedMatchDocData = doc.data();
          completedMatchDocData = {
            docId: "",
            docData: ""
          } 
          completedMatchDocData.docId = doc.id;
          completedMatchDocData.docData = doc.data();

          completedMatchDataArr.push(completedMatchDocData);
          resolve(completedMatchDataArr); // Here i am getting the data and pushing it in array
        });
        console.log("sarang", completedMatchDataArr);
      })
      .catch(err => {
        console.log("Error getting documents", err);
      });
    });
}

const setNewCompletedMatchDocs = (async () => {
  let getCompletedMatchData = await getOldCompletedMatchDocs();
  // console.log("balram", getCompletedMatchData[0].docId);
  let newCompletedMatchDocRef = db.collection("Match_Creator").doc("cricket").collection("completedMatchList").doc(getCompletedMatchData[0].docId);
  return newCompletedMatchDocRef.set(getCompletedMatchData[0].docData); //set/copy the data to new path.
})

This is my main index.js file

const functions = require("firebase-functions");
const admin = require("firebase-admin");
const storeMatchData = require("./liveScoring");
const createCompletedMatchListDoc = require("./completedMatchList");

const { db } = require("./db/index");

var http = require("https");

module.exports = {
  liveScoring: functions.https.onRequest(storeMatchData),
  createCompletedMatchListDoc: functions.https.onRequest(
    createCompletedMatchListDoc
  )
};

Now after copy document data to a new path i will delete the previous document. For deleting the document i have not written the function.

Answer 2

I'm not seeing anything that would allow you to move a document between collections(someone correct me if I'm wrong). You have to copy from the old collection to the new one and then remove the old one.

This is another post on StackOverflow that is running into this same issue and someone provided Java code on how to implement it.

EDIT: Updated link.

Hope this helps.