Get data from a compound query in firestore with cloud function? - firebase

Question

First I search a specific document with a document. In this function I use different filters for getting specific values from the data. The result of this filters is an array that will use it form a "foreach". The result is concatenated in elementosaux and next is equal to elementos. The problem is that i print o get the value elementos the result is undefined
This is the code. Thanks for your help.
exports.autentifyday = functions.https.onRequest((req, res) => {
cors(req, res, () => {
var db = admin.firestore();
const key=req.query.key;
const dia=req.query.dia;
db.collection("/servicios_disponibles/").doc(key).get().then(function(doc){
var Ddr;
var Str;
var horario;
var horas;
var horasaux;
var horasselected;
var elementos: any[] = [];
var elementosaux: any[] = [];
var elementoselement;
if( doc.exists){
var diaselected;
Ddr = JSON.parse(JSON.stringify(doc.data()));
horario=Ddr.horario;
horario.filter((dias: { dia: any; disponibilidad: boolean; })=>{
if(dias.dia==dia){
if(dias.disponibilidad==true){
diaselected=dias;
}
}
});
horas=JSON.parse(JSON.stringify(diaselected));
horasaux=horas.horas;
horasselected=horasaux.filter((hora: { disponibilidad: boolean; })=>hora.disponibilidad==true);
horasselected.forEach(function(hora: { hora: any; }){
db.collection("pedidos_servicios").where("key","==",key)
.where("horas","array-contains",hora.hora).get().then(snapshot=>{
snapshot.forEach(doc3=>{
elementoselement = {
"horas": doc3.data().horas
}
elementosaux = elementosaux.concat(elementoselement);
console.log(elementosaux)//return an array with the answer query
});
elementos=[];
elementos=elementosaux;
console.log(elementos)//is undefined in this point
}).catch((e)=>console.log(e))
})
}
console.log(elementosaux)//is undefined in this point
res.send(Str);
return Str;
}).catch(reason => {
res.send(reason);
console.log(reason);
return reason;
});
});
});

Answer 1

This might be metter of asynchronous code. I took part of your code and created simple example:
const db = new Firestore()
var elementos: any[] = [];
var elementosaux: any[] = [];
var elementoselement;
let colRef = db.collection("collection1");
if (true) {
console.log("start")
colRef.get().then((snapshot) => {
snapshot.forEach(doc3=>{
elementoselement = {
"horas": doc3.data().horas
}
console.log("elementoselement",elementoselement)
elementosaux = elementosaux.concat(elementoselement);
console.log("elementosaux inside snapshot", elementosaux)//return an array with the answer query
});
elementos=[];
elementos=elementosaux;
console.log("elementos inside snapshot", elementos)//is undefined in this point
});
console.log("elementosaux outside snapshot", elementosaux)
console.log("elementos outside snapshot", elementos)
}
console.log("elementosaux outside if", elementosaux)//is undefined in this point
console.log("end")
I added to my firestore collection collection1 with one document containing field horas: horas_value - to make it working.
The example contains more log information about which part of code particular log is. When you run it like ts-node test_main.ts you get following result:
start
elementosaux outside snapshot []
elementos outside snapshot []
elementosaux outside if []
end
elementoselement { horas: 'horas_value' }
elementosaux inside snapshot [ { horas: 'horas_value' } ]
elementos inside snapshot [ { horas: 'horas_value' } ]
As get is asynchronous you can see that logs inside it are at the end.
There is a lot of possibilities to deal with that. For example you can put whole if in 'async' function and add 'await' to get:
async function main() {
if (true) {
....
await colRef.get().then((snapshot) => {
....
}
main()
and then result is:
start
elementoselement { horas: 'horas_value' }
elementosaux inside snapshot [ { horas: 'horas_value' } ]
elementos inside snapshot [ { horas: 'horas_value' } ]
elementosaux outside snapshot [ { horas: 'horas_value' } ]
elementos outside snapshot [ { horas: 'horas_value' } ]
elementosaux outside if [ { horas: 'horas_value' } ]
end
Only I don't know why you say this is undefined, it shouldn't be...
I have empty arrays... Maybe it's a matter of way how to run the code.
I hope it will help!