php change value of multidimensional array - php

Question

I got a problem.
I make a function to update my config.json file.
The problem is, my config.json is a multdimensional array. To get a value of a key i use this function:
public function read($key)
{
$read = explode('.', $key);
$config = $this->config;
foreach ($read as $key) {
if (array_key_exists($key, $config)) {
$config = $config[$key];
}
}
return $config;
}
I also made a function to update a key. But the problem is if i make update('database.host', 'new value'); it dont updates only that key but it overrides the whole array.
This is my update function
public function update($key, $value)
{
$read = explode('.', $key);
$config = $this->config;
foreach ($read as $key) {
if (array_key_exists($key, $config)) {
if ($key === end($read)) {
$config[$key] = $value;
}
$config = $config[$key];
}
}
print_r( $config );
}
my config.json looks like this:
{
"database": {
"host": "want to update with new value",
"user": "root",
"pass": "1234",
"name": "dev"
},
some more content...
}
I have a working function but thats not really good. I know that the max of the indexes only can be three, so I count the exploded $key and update the value:
public function update($key, $value)
{
$read = explode('.', $key);
$count = count($read);
if ($count === 1) {
$this->config[$read[0]] = $value;
} elseif ($count === 2) {
$this->config[$read[0]][$read[1]] = $value;
} elseif ($count === 3) {
$this->config[$read[0]][$read[1]][$read[3]] = $value;
}
print_r($this->config);
}
Just to know: the variable $this->config is my config.json parsed to an php array, so nothing wrong with this :)

Answer 1

After I had read your question better I now understand what you want, and your read function, though not very clear, works fine.
Your update can be improved though by using assign by reference & to loop over your indexes and assign the new value to the correct element of the array.
What the below code does is assign the complete config object to a temporary variable newconfig using call by reference, this means that whenever we change the newconfig variable we also change the this->config variable.
Using this "trick" multiple times we can in the end assign the new value to the newconfig variable and because of the call by reference assignments the correct element of the this->config object should be updated.
public function update($key, $value)
{
$read = explode('.', $key);
$count = count($read);
$newconfig = &$this->config; //assign a temp config variable to work with
foreach($read as $key){
//update the newconfig variable by reference to a part of the original object till we have the part of the config object we want to change.
$newconfig = &$newconfig[$key];
}
$newconfig = $value;
print_r($this->config);
}

Answer 2

You can try something like this:
public function update($path, $value)
{
array_replace_recursive(
$this->config,
$this->pathToArray("$path.$value")
);
var_dump($this->config);
}
protected function pathToArray($path)
{
$pos = strpos($path, '.');
if ($pos === false) {
return $path;
}
$key = substr($path, 0, $pos);
$path = substr($path, $pos + 1);
return array(
$key => $this->pathToArray($path),
);
}
Please note that you can improve it to accept all data types for value, not only scalar ones