CODEWITHSUNDEEP
javascriptfirebasevue.jsgoogle-cloud-firestore
Yaroslav Saenko
Yaroslav Saenko

Reputation: 587

How to recursively fetch collection with all subcollections?

I have a collection in firestore called 'steps' and inside steps collection I have lots of documents and subcollections called 'substeps' in each steps document. I need to create array which will have all the steps and substeps inside that I could use this component, so the array should look like this

let steps = [
  {
    step: 1,
    id: '1'
    substeps: [
      {
        step: '1.1'
        substeps: [
          {
            step: '1.1.2'
          }
        ]
      }
    ]
  }
]

Now I want to crate recursive functions with will fetch all the substeps if they are exists

I tried to create function which should fetch all the subcollections, but I don't know how to finish it, so below example of what I tried, but notice function not finished and it is only first steps Here is documentation

fetchAllStepsDeep (request) {
    //this.steps = array of objects with step data
    let result = []
    let requestLocal = this.$firebaseFirestore.collection('steps_for_classes')

    for (let i in this.steps) {
        result.push(this.steps[i])
        requestLocal.doc(this.steps[i].id).get().then((doc) => {
            if (doc.exists) {
                console.log('Document data:', doc.data())
            } else {
                // doc.data() will be undefined in this case
                console.log('No such document!')
            }
        }).catch((error) => {
            console.log('Error getting document:', error)
        })
    }
}

Can someone help me to retrieve all the subcollections inside collection and create one big array with other child arrays of objects? I use vue framework, so maybe this can be helpful

Thanks

Upvotes: 1

Views: 1438

Answers (2)

Marcin Żmigrodzki
Marcin Żmigrodzki

Reputation: 393

If interested in Firestore 9 you can do it by array of strings:

let pathSegment: string[] = [parentKey, "comments"] 
doc(db, "channels", channelKey, "comments", ...pathSegments, commentKey)

Upvotes: 0

Frank van Puffelen
Frank van Puffelen

Reputation: 598688

If the subcollection is always called substeps, you can create a helper function to handle the recursion

function getSubstepsOf(docRef, path, result) {
  docRef.collection("substeps").get((querySnapshot) => {
    querySnapshot.forEach((doc) => {
      result.push({ path, doc });
      getSubstepsOf(doc.ref, `${path}/substeps/${doc.id}`, result);
    });
  });
}

And then call it with this from your existing code:

getSubstepsOf(doc.ref, doc.id, result);

Upvotes: 1

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