Last active
June 20, 2024 18:42
-
-
Save schuchard/a60daa25a1840d9371eae023c5be417a to your computer and use it in GitHub Desktop.
Recursively filter out objects that are infinitely nested and return an immutable object
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
// https://stackblitz.com/edit/recursive-filter-prop?file=index.ts | |
// perf: https://jsbench.me/8cjrlaine7/1 | |
function flatFilter(nestedProp, compareKey, compareId, arr) { | |
return arr.filter(o => { | |
const keep = o[compareKey] != compareId; | |
if (keep && o[nestedProp]) { | |
o[nestedProp] = flatFilter(nestedProp, compareKey, compareId, o[nestedProp]); | |
} | |
return keep; | |
}); | |
} | |
const ARRAY = [ | |
{ | |
id: 1, | |
children: [ | |
{ | |
id: 2, | |
children: [ | |
{ | |
id: 3, | |
}, | |
{ | |
id: 4, | |
}, | |
], | |
}, | |
{ | |
id: 5, | |
children: [ | |
{ | |
id: 3, | |
}, | |
], | |
}, | |
], | |
}, | |
]; | |
console.log(JSON.stringify(flatFilter('children', 'id', 3, ARRAY), null, 2)); | |
/* result | |
[ | |
{ | |
id: 1, | |
children: [ | |
{ | |
id: 2, | |
children: [ | |
{ | |
id: 4, | |
}, | |
], | |
}, | |
{ | |
id: 5, | |
children: [], | |
}, | |
], | |
}, | |
]; | |
*/ | |
BOA MANO VLW
Thanks, it helped us a lot!
Hi, thanks for the snippet, helped me a lot. Just in case someone was confused just as I was.
This block causes the original array to be mutated.
if (keep && o[nestedProp]) {
o[nestedProp] = flatFilter(nestedProp, compareKey, compareId, o[nestedProp]);
}
So if you want to make it immutable, you should do something like this:
function flatFilter(nestedProp, predicate, arr) {
return arr.filter(predicate).map(o => {
if (o[nestedProp]) {
return {
...o,
[nestedProp]: flatFilter(nestedProp, predicate, o[nestedProp]),
};
} else {
return o;
}
});
}
Then use it like this
const flatFiltered = flatFilter(
'children',
child => child.id !== 3,
ARRAY,
);
console.log(flatFiltered)
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
@ayappaP 🙌