change value in json by path in array - php

Question

I have an array like:
$arr = ["pages","homepage","welcomeText"];
$newWelcomeText = "Hello there";
and JSON which looks like:
{
lang: "en",
something: [0, 1, 33],
pages: {
homepage: {
welcomeText: "Hello!",
subHeaiding: "have a nice day"
}
}
}
and I want to find a way how to replace the "welcomeText" with a new value.
I tried something like:
public function findAndReplace ($path, $obj, $data, $index = 0) {
if($index + 1 == sizeof($path)) {
if(!is_array($obj)) {
$obj = json_decode(json_encode($obj), true);
}
$obj[$path[$index]] = $data;
return $obj;
}
return $this->findAndReplace($path, $obj, $data, $index + 1);
}
I never know how the path will look like so I need some kind of function that receives an array and this object as a parameter and returns a modified object.

Answer 1

You could utilize the array_walk_recursive function with some extra bells and whistles to allow referential access to array values.
Create some function array_walk_recursive_referential which will allow referential access to each key/value and pass it to your own function that you send in($function):
function array_walk_recursive_referential(&$array, $function, $parameters = []) {
$reference_function = function(&$value, $key, $userdata) {
$parameters = array_merge([$value], [$key], $userdata[1]);
$value = call_user_func_array($userdata[0], $parameters);
};
array_walk_recursive($array, $reference_function, [$function, $parameters]);
}
And use it with your $arr data:
array_walk_recursive_referential($arr, function($value, $key) {
if(is_string($key))
{
if($key === 'welcomeText')
{
$value = 'My New Welcome Text'
}
}
return $value;
});
Your $arr variable is passed in with a reference so you don't need to re-assign it after function call.

Answer 2

If I want to replace a value in an JSON onbject by path given in an array, I ended up with this:
$json = '{
lang: "en",
something: [0, 1, 33],
pages: {
homepage: {
welcomeText: "Hello!",
subHeaiding: "have a nice day"
}
}
}'
$obj = json_decode($json, true);
$path = ["pages","homepage","welcomeText"]
Function below takes the object and a path to the key in an array and returns a modified object.
function findAndReplace ($obj, $path, $data, $index = 0) {
if($index + 1 == sizeof($path)) {
if(!is_array($obj)) {
$obj = json_decode(json_encode($obj), true);
}
$obj[$path[$index]] = $data;
return $obj;
}
$obj[$path[$index]] = findAndReplaceAndDo($obj[$path[$index]], $path, $data, $index + 1);
return $obj;
}