Dynamically dig into JSON with PHP - php

Question

Okay, so I need to dynamically dig into a JSON structure with PHP and I don't even know if it is possible.
So, let's say that my JSON is stored ad the variable $data:
$data = {
'actions':{
'bla': 'value_actionBla',
'blo': 'value_actionBlo',
}
}
So, to access the value of value_actionsBla, I just do $data['actions']['bla']. Simple enough.
My JSON is dynamically generated, and the next time, it is like this:
$data = {
'actions':{
'bla': 'value_actionBla',
'blo': 'value_actionBlo',
'bli':{
'new': 'value_new'
}
}
}
Once again, to get the new_value, I do: $data['actions']['bli']['new'].
I guess you see the issue.
If I need to dig two levels, then I need to write $data['first_level']['second_level'], with three, it will be $data['first_level']['second_level']['third_level'] and so on ...
Is there any way to perform such actions dynamically? (given I know the keys)
EDIT_0: Here is an example of how I do it so far (in a not dynamic way, with 2 levels)
// For example, assert that 'value_actionsBla' == $data['actions']['bla']
foreach($data as $expected => $value) {
$this->assertEquals($expected, $data[$value[0]][$value[1]]);
}
EDIT_1
I have made a recursive function to do it, based on the solution of #Matei Mihai:
private function _isValueWhereItSupposedToBe($supposedPlace, $value, $data){
foreach ($supposedPlace as $index => $item) {
if(($data = $data[$item]) == $value)
return true;
if(is_array($item))
$this->_isValueWhereItSupposedToBe($item, $value, $data);
}
return false;
}
public function testValue(){
$searched = 'Found';
$data = array(
'actions' => array(
'abort' => '/abort',
'next' => '/next'
),
'form' => array(
'title' => 'Found'
)
);
$this->assertTrue($this->_isValueWhereItSupposedToBe(array('form', 'title'), $searched, $data));
}

Answer 1

You can use a recursive function:
function array_search_by_key_recursive($needle, $haystack)
{
foreach ($haystack as $key => $value) {
if ($key === $needle) {
return $value;
}
if (is_array($value) && ($result = array_search_by_key_recursive($needle, $value)) !== false) {
return $result;
}
}
return false;
}
$arr = ['test' => 'test', 'test1' => ['test2' => 'test2']];
var_dump(array_search_by_key_recursive('test2', $arr));
The result is string(5) "test2"

Answer 2

You could use a function like this to traverse down an array recursively (given you know all the keys for the value you want to access!):
function array_get_nested_value($data, array $keys) {
if (empty($keys)) {
return $data;
}
$current = array_shift($keys);
if (!is_array($data) || !isset($data[$current])) {
// key does not exist or $data does not contain an array
// you could also throw an exception here
return null;
}
return array_get_nested_value($data[$current], $keys);
}
Use it like this:
$array = [
'test1' => [
'foo' => [
'hello' => 123
]
],
'test2' => 'bar'
];
array_get_nested_value($array, ['test1', 'foo', 'hello']); // will return 123