firebase firestore get object/array from document - js

Question

My firestore database currently looks like this: firestore db

how can I get the value of, say, DEVICES/ID. currently my code returns undefined when i try to get the value.

var userDeviceRef = db.collection("USERS").doc(data.uid);
userDeviceRef.get().then(function(doc){
    if (doc.exists) {
        console.log("Document data:", doc.data());
        console.log("document customdata foo: " + doc.data().DEVICES.ID);
    }
}

data.uid returns a proper value. the value of the document ID. doc.data() returns all the fields and its children in what appears to be string format. however when I add DEVICES.ID, it returns undefined. how can i get the nested data as shown in the image?

Doug Stevenson · Accepted Answer · 2018-07-07 02:31:07Z

6

Your field called DEVICES is actually an array. As far as I can tell, it has at least one element in it. If you want the value of the ID field of the first element of that array, you'll have to index into that array:

doc.data().DEVICES[0].ID

answered Jul 7, 2018 at 2:31

Doug Stevenson

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5 Comments

Muaaz Kasker Over a year ago

YES! thank you so much. it works. can't believe I didn't see that

Muaaz Kasker Over a year ago

is there a way to get all the nodes/children of the devices array

Doug Stevenson Over a year ago

It's just like any other JavaScript array.

SVG Over a year ago

Wow you are genius man @DougStevenson!! I was struggling the whole day to extract the values in the array. It worked liked a charm. Thank you very much

SVG Over a year ago

@MuaazKasker thanks for posting such a valuable question in this forum :) :).

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