['foo' => ['bar' => ['baz' => 'some_value']]]
*
* and you wanted to insert or extract an element. Usually, you would use:
*
* $array['foo']['bar']['baz'] = 'new_value';
*
* but sometimes you do not have access to the variable - so a string representation is needed. Using
* XPath-like syntax, this class allows you to do this:
*
* $jsonPath = new JsonPath($array);
* $jsonPath->set('foo.bar.baz', 'new_value');
* $val = $jsonPath->get('foo.bar.baz');
*
*/
class JsonPath
{
/** @var array */
private $jsonStructure;
/**
* @param $structure The initial data structure to extract from and insert into. Typically this will be a
* multidimensional associative array; but well-formed JSON strings are also acceptable.
*/
public function __construct($structure)
{
$this->jsonStructure = is_string($structure) ? json_decode($structure, true) : $structure;
}
/**
* Set a node in the structure.
*
* @param $path The XPath to use
* @param $value The new value of the node
*/
public function set(string $path, $value)
{
$this->jsonStructure = $this->setPath($path, $value, $this->jsonStructure);
}
/**
* Internal method for recursive calls.
*
* @param $path
* @param $value
* @param $json
*
* @return mixed
*/
private function setPath(string $path, $value, array $json): array
{
$nodes = explode('.', $path);
$point = array_shift($nodes);
if (!isset($json[$point])) {
$json[$point] = [];
}
if (!empty($nodes)) {
$json[$point] = $this->setPath(implode('.', $nodes), $value, $json[$point]);
} else {
$json[$point] = $value;
}
return $json;
}
/**
* Return the updated structure.
*
* @return mixed
*/
public function getStructure()
{
return $this->jsonStructure;
}
/**
* Get a path's value. If no path can be matched, NULL is returned.
*
* @param $path
*
* @return mixed|null
*/
public function get(string $path)
{
return $this->getPath($path, $this->jsonStructure);
}
/**
* Internal method for recursion.
*
* @param $path
* @param $json
*/
private function getPath(string $path, $json)
{
$nodes = explode('.', $path);
$point = array_shift($nodes);
if (!isset($json[$point])) {
return null;
}
if (empty($nodes)) {
return $json[$point];
} else {
return $this->getPath(implode('.', $nodes), $json[$point]);
}
}
}