How to transform a Laravel collection by keys? - php

Question

I have a Laravel collection where I have data for users (their posts, comments and reputation). I would like to transform this collection where each item becomes one of the three properties (posts, comments and reputation).
So the result would be like - for field: 'posts' and user_id: 46 we have 1542 posts. And for field: 'comments' the same user has 2. etc.
I tried to create multiple loops over the collection to get to this result but it is not working as I don't know how may loops I need. Is there a better and more clean way to do this?
Here is my original collection
"data": [
{
"user_id": 46,
"username": "johnive",
"posts": 1542,
"comments": 2,
"reputation": 48.5,
},
{
"user_id": 30,
"username": "zacky13",
"posts": 54,
"comments": 16,
"reputation": 14.3,
},
{
"user_id": 107,
"username": "lil_elf4",
"posts": 564,
"comments": 60,
"reputation": 67.5,
},
],
Here is the result I would like to achieve
"data": [
{
"user_id": 46,
"username": "johnive",
"field": "posts",
"value": 1542
},
{
"user_id": 46,
"username": "johnive",
"field": "comments",
"value": 2
},
{
"user_id": 46,
"username": "johnive",
"field": "reputation",
"value": 48.5
},
{
"user_id": 30,
"username": "zacky13",
"field": "posts",
"value": 54
},
{
"user_id": 30,
"username": "zacky13",
"field": "comments",
"value": 16
},
...
],
I tried using multiple loops seems like a dirty way to do it and I don't know how many loops I would need.
foreach ($collection as $item)
{
$new_item = new stdClass;
$new_item->user_id = $item->user_id;
$new_item->username = $item->username;
$new_item->field = 'posts';
$new_item->value = $item->posts;
}
foreach ($collection as $item)
{
$new_item = new stdClass;
$new_item->user_id = $item->user_id;
$new_item->username = $item->username;
$new_item->field = 'comments';
$new_item->value = $item->comments;
}
foreach ($collection as $item)
{
$new_item = new stdClass;
$new_item->user_id = $item->user_id;
$new_item->username = $item->username;
$new_item->field = 'reputation';
$new_item->value = $item->reputation;
}

Answer 1

You could do it e.g. like this:
$result = collect();
foreach ($collection as $item)
{
foreach(['posts', 'comments', 'reputations'] as $type) {
$new_item = new stdClass;
$new_item->user_id = $item->user_id;
$new_item->username = $item->username;
$new_item->field = $type;
$new_item->value = $item->$type;
$result->push($new_item);
}
}