mongodb agregate and filter data - mongodb

Question

I try to filter some results data from mongodb with mongoose in javascript.
This is my json structure:
{
"name": "john",
"firstname": "doe",
"yearold": 22,
"recipes": [
{
"title": "cheesecake",
"data": [
{
"name": "egg",
"label": "Eggs for",
"value": 6,
"unit": "piece"
},
{
"name": "oil",
"label": "Specific oil",
"unit": "oz",
"value": 0.2
},
{
"name": "flour",
"label": "Wholemel flour",
"value": 450,
"unit": "gr"
}
]
},
{
"title": "cake",
"data": [
{
"name": "egg",
"label": "Eggs for",
"value": 6,
"unit": "piece"
},
{
"name": "flour",
"label": "Wholemel flour",
"value": 500,
"unit": "gr"
},
]
}
]
}
In some case i need to return json data with hiding some values. For example I have a list that specifies all the values ​​to hide
hidekeys=["egg"];
and i would like to get this:
{
"name": "john",
"firstname": "doe",
"yearold": 22,
"recipes": [
{
"title": "cheesecake",
"data": [
{
"name": "egg",
"label": "Eggs for",
"value": #######,
"unit": "piece"
},
{
"name": "oil",
"label": "Specific oil",
"unit": "oz",
"value": 0.2
},
{
"name": "flour",
"label": "Wholemel flour",
"value": 450,
"unit": "gr"
}
]
},
{
"title": "cake",
"data": [
{
"name": "egg",
"label": "Eggs for",
"value": #######,
"unit": "piece"
},
{
"name": "flour",
"label": "Wholemel flour",
"value": 500,
"unit": "gr"
},
]
}
]
}
For each recipe i need to hide ingredient value if it is specified in hidekeys.
I tried something with $project and $cond but it doesnt works

Answer 1

Here's a quick way of how to achieve this using $map
const hidekeys = ["egg"];
db.collection.aggregate([
{
$addFields: {
recipes: {
$map: {
input: "$recipes",
as: "recipe",
in: {
$mergeObjects: [
"$$recipe",
{
data: {
$map: {
input: "$$recipe.data",
as: "datum",
in: {
"$mergeObjects": [
"$$datum",
{
$cond: [
{
"$setIsSubset": [
[
"$$datum.name"
],
hidekeys
]
},
{
value: "#####"
},
{
value: "$$datum.value"
}
]
}
]
}
}
}
}
]
}
}
}
}
}
])
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