I have an array:
[
{ id: 1,
name: "parent1",
children: [
{ id: 10,
name: "first_child_of_id_1",
children: [
{ id: 100, name: "child_of_id_10", children: []},
{ id: 141, name: "child_of_id_10", children: []},
{ id: 155, name: "child_of_id_10", children: []}
]
},
{ id: 42,
name: "second_child_of_id_1",
children: [
{ id: 122, name: "child_of_id_42", children: []},
{ id: 133, name: "child_of_id_42", children: []},
{ id: 177, name: "child_of_id_42", children: []}
]
}
]
},
{ id: 7,
name: "parent7",
children: [
{ id: 74,
name: "first_child_of_id_7",
children: [
{ id: 700, name: "child_of_id_74", children: []},
{ id: 732, name: "child_of_id_74", children: []},
{ id: 755, name: "child_of_id_74", children: []}
]
},
{ id: 80,
name: "second_child_of_id_7",
children: [
{ id: 22, name: "child_of_id_80", children: []},
{ id: 33, name: "child_of_id_80", children: []},
{ id: 77, name: "child_of_id_80", children: []}
]
}
]
}
]
What I need is an array of arrays like this:
[
[ "id", "name", "parent_id", "parent_name" ],
[ 1, "parent1", null, "" ],
[ 10, "first_child_of_id_1", 1, "parent1"],
[ 42, "second_child_of_id_1", 1, "parent1"],
[100, "child_of_id_10", 10, "first_child_of_id_1"]
]
and so on for all nested objects for me to convert them into CSV rows. I've checked many answers and found a similar problem here: How to convert array of nested objects to CSV? But it produces too long rows for many nested objects and I am not experienced enough with JavaScript to modify map function.
const categories = [
{ id: 1,
name: "parent1",
children: [
{ id: 10,
name: "first_child_of_id_1",
children: [
{ id: 100, name: "child_of_id_10", children: []},
{ id: 141, name: "child_of_id_10", children: []},
{ id: 155, name: "child_of_id_10", children: []}
]
},
{ id: 42,
name: "second_child_of_id_1",
children: [
{ id: 122, name: "child_of_id_42", children: []},
{ id: 133, name: "child_of_id_42", children: []},
{ id: 177, name: "child_of_id_42", children: []}
]
}
]
},
{ id: 7,
name: "parent7",
children: [
{ id: 74,
name: "first_child_of_id_7",
children: [
{ id: 700, name: "child_of_id_74", children: []},
{ id: 732, name: "child_of_id_74", children: []},
{ id: 755, name: "child_of_id_74", children: []}
]
},
{ id: 80,
name: "second_child_of_id_7",
children: [
{ id: 22, name: "child_of_id_80", children: []},
{ id: 33, name: "child_of_id_80", children: []},
{ id: 77, name: "child_of_id_80", children: []}
]
}
]
}
]
function pivot(arr) {
var mp = new Map();
function setValue(a, path, val) {
if (Object(val) !== val) { // primitive value
var pathStr = path.join('.');
var i = (mp.has(pathStr) ? mp : mp.set(pathStr, mp.size)).get(pathStr);
a[i] = val;
} else {
for (var key in val) {
setValue(a, key == '0' ? path : path.concat(key), val[key]);
}
}
return a;
}
var result = arr.map(obj => setValue([], [], obj));
return [[...mp.keys()], ...result];
}
function toCsv(arr) {
return arr.map(row =>
row.map(val => isNaN(val) ? JSON.stringify(val) : +val).join(',')
).join('\n');
}<button onclick="console.log(toCsv(pivot(categories)))">Output</button>
