Get all from a Firestore collection in Flutter

Question

I set up Firestore in my project. I created new collection named categories. In this collection I created three documents with uniq id. Now I want to get this c

Answer 1

Here is the code if you just want to read it once

   QuerySnapshot querySnapshot = await Firestore.instance.collection("collection").getDocuments();
    var list = querySnapshot.documents;

Answer 2

I was able to figure out a solution:

Future getDocs() async {
  QuerySnapshot querySnapshot = await Firestore.instance.collection("collection").getDocuments();
  for (int i = 0; i < querySnapshot.documents.length; i++) {
    var a = querySnapshot.documents[i];
    print(a.documentID);
  }
}

Call the getDocs() function, I used build function, and it printed all the document IDs in the console.

Answer 3

QuerySnapshot snap = await 
    Firestore.instance.collection('collection').getDocuments();

snap.documents.forEach((document) {
    print(document.documentID);
  });

Answer 4

Using StreamBuilder

import 'package:flutter/material.dart';
import 'package:firebase_firestore/firebase_firestore.dart';

class ExpenseList extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new StreamBuilder<QuerySnapshot>(
        stream: Firestore.instance.collection("expenses").snapshots,
        builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
          if (!snapshot.hasData) return new Text("There is no expense");
          return new ListView(children: getExpenseItems(snapshot));
        });
  }

  getExpenseItems(AsyncSnapshot<QuerySnapshot> snapshot) {
    return snapshot.data.documents
        .map((doc) => new ListTile(title: new Text(doc["name"]), subtitle: new Text(doc["amount"].toString())))
        .toList();
  }
}