Solo necesita agregar un filtro en su segundo $addFields
etapa en la que está filtrando roomTypes
y el resto de las etapas serían las mismas, simplemente resalte el nuevo código a continuación desde el comentario de inicio y el comentario final,
$reduce
para iterar el ciclo deroomDetails.description
matriz $cond para hacer coincidir local y devolver el resultado de la coincidencia al valor, el mismo proceso pararoomDetails.title
array, y combine estos 2 campos actualizados con el objeto actual usando$mergeObjects
{
$addFields: {
roomTypes: {
$map: {
input: "$roomTypes",
in: {
$mergeObjects: [
"$$this",
{
Inicio:
roomDetails: {
$mergeObjects: [
"$$this.roomDetails",
{
description: {
$reduce: {
input: "$$this.roomDetails.description",
initialValue: "",
in: {
$cond: [
{ $eq: ["$$this.locale", "pl"] },
"$$this.value",
"$$value"
]
}
}
},
title: {
$reduce: {
input: "$$this.roomDetails.title",
initialValue: "",
in: {
$cond: [
{ $eq: ["$$this.locale", "pl"] },
"$$this.value",
"$$value"
]
}
}
}
}
]
},
~Fin~
available: {
$reduce: {
input: "$$this.capacity",
initialValue: 0,
in: {
$cond: [
{ $eq: ["$$this.cruiseID", "$cruiseID"] },
"$$this.available",
"$$value"
]
}
}
}
}
]
}
}
}
}
}
En la opción genérica he respondido en su pregunta de referencia puedes usar la misma función como,
function languageFilter(inputField, locale) {
return {
$reduce: {
input: inputField,
initialValue: "",
in: {
$cond: [{ $eq: ["$$this.locale", locale] }, "$$this.value", "$$value"]
}
}
};
}
Su consulta final sería:
let locale = "pl";
db.cs.aggregate([
{ $match: { cID: "00001" } },
{
$lookup: {
from: "rooms",
localField: "roomTypes.roomID",
foreignField: "roomID",
as: "roomTypes"
}
},
{
$addFields: {
title: languageFilter("$title", locale),
description: languageFilter("$description", locale),
roomTypes: {
$map: {
input: "$roomTypes",
in: {
$mergeObjects: [
"$$this",
{
roomDetails: {
$mergeObjects: [
"$$this.roomDetails",
{
description: languageFilter("$$this.roomDetails.description", locale),
title: languageFilter("$$this.roomDetails.title", locale)
}
]
},
available: {
$reduce: {
input: "$$this.capacity",
initialValue: 0,
in: {
$cond: [
{ $eq: ["$$this.cruiseID", "$cruiseID"] },
"$$this.available",
"$$value"
]
}
}
}
}
]
}
}
}
}
},
{
$project: {
_id: 0,
"roomTypes": { _id: 0 },
"roomTypes.capacity": 0
}
}
]);