Getting Object in PHP by key value - php

Question

I have a very large object that I have to loop through to get a specific object.
I tried foreach($obj as $item), foreach($obj as $item => $value) and for in various configurations.
I want to get all the objects where the class is "table-responsive"
My Element looks like this (in JSON):
{
"dummy":"dummytext",
"children": [
{
"tag":null
},
{
"tag":"body",
"children": [
{
"class":"not_the_one"
},
{
"class":"table-responsive",
"html":"Gotcha!"
}
]
}
]
}
What I want to get as a result is:
{
"class":"table-responsive",
"html":"Gotcha!"
}
There could be more than one object that has the class of "table-responsive", so if there are multiple ones:
[
{
"class":"table-responsive",
"html":"Gotcha!"
},
{
"class":"table-responsive",
"html":"Gotcha!"
}
]
I was trying to accomplish a function that goes through all the elements and checks where the key of class equals "table-responsive" if so, push the object to an array. (array_push($result, $obj);) If the current element is an array, loop through it too. There can be a lot of dimensions so ideally the function calls itself. (recursive)

Answer 1

What you're after is a recursive reduce operation. Something that can
Iterate your elements
Capture any with the matching property, and
Perform the same operation on any children
// decode your JSON into an associative array
$data = json_decode($json, true);
// setup search parameters
$findKey = 'class';
$findValue = 'table-responsive';
// create a recursive reducer
$reducer = function($carry, $item) use (&$reducer, $findKey, $findValue) {
if (array_key_exists($findKey, $item) && $item[$findKey] === $findValue) {
// if this $item matches, add it to the $carry array
$carry[] = $item;
}
if (!empty($item['children'])) {
// this $item has children so dive deeper
return array_reduce($item['children'], $reducer, $carry);
}
// no children in this one so on to the next iteration
return $carry;
};
// Run the reducer at the top level.
// Note I've wrapped the root object in an array so the reducer can iterate it
$found = array_reduce([ $data ], $reducer, []);
// and display
echo json_encode($found, JSON_PRETTY_PRINT);
Demo ~ https://3v4l.org/6mWmC