CODEWITHSUNDEEP
javascriptjsonfirebasefirebase-realtime-databasegoogle-cloud-functions
Jean
Jean

Reputation: 201

Firebase - Update specific fields simultaneously without replacing all of the data

I would like to be able to publish simultaneously in two directories of my Firebase database. I created a function for this, according to the example proposed in the "Update specific fields" section of the Firebase Javascript documentation:

  function linkTwoUsers(user1, user2) {

    // The two users are "connected".

    var user1Data = {
        userLink: user2
    };
    var user2Data = {
        userLink: user1
    };

    var updates = {};
    updates["/users/" + user1] = user1Data;
    updates["/users/" + user2] = user2Data;

    return database
      .ref()
      .update(updates)
      .then(() => {
        return res.status(200).end();
      })
      .catch(error => {
        return res.status(500).send("Error: " + error.message);
      });
  }

The problem is that when I run the function, instead of uploading the directories, it replaces all the data present in it.

Here are the user directories before the function:

enter image description here

And then:

enter image description here

How do we make sure the data doesn't overwrite the others? Thank you for your help.

Upvotes: 1

Views: 1480

Answers (2)

Stradosphere
Stradosphere

Reputation: 1285

Try to narrow your path to just the property you are trying to update:

updates["/users/" + user1 + "/userLink/"] = user1;
updates["/users/" + user2 + "/userLink/"] = user2;

Upvotes: 4

spierce
spierce

Reputation: 141

It seems as though you're creating an entirely new object when you set:

 var userData = { someThing: stuff }

When you pass that in, it will override the original object. One way you might solve this (there might be a more efficient way) is to grab the objects from Firebase, add the new property and value to the object, then send the entire object back into Firebase.

In some javascript frameworks, you should be able to use the spread operator to set all of an object's props to another object like this:

 var newObject = { ...originalObject }
 newObject.userData = "something"
 // then save newObject to firebase

Upvotes: 2

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