Guzzle path-enabled json response visitor.

JsonResponseVisitor.php

<?php
namespace Guzzle\Service\Command\LocationVisitor\Response;

use Guzzle\Http\Message\Response;
use Guzzle\Service\Command\CommandInterface;
use Guzzle\Service\Description\Parameter;

class JsonPathVisitor extends JsonVisitor
{
    public function visit(
        CommandInterface $command,
        Response $response,
        Parameter $param,
        &$value,
        $context = null
    ){
        $name = $param->getName();
        $path = $param->getWireName();

        if (!strstr($path, '/')) {
            return parent::visit($command, $response, $param, $value, $context);
        } elseif ($param->getData('jsonFlattened')) {
            if (is_array($value)) {
                $this->recursiveProcess($param, $value);
                $value = array(
                    $name => $value
                );
            }
        } elseif (self::issetPath($value, $path)) {
            $this->recursiveProcess($param, self::getValueAtPath($value, $path));
            $value[$name] = self::getValueAtPath($value, $path);
            self::unsetPath($value, $path);
        }
    }

    protected static function issetPath(&$array, $path)
    {
        $path = explode('/', $path);
        $pointer = & $array;
        foreach ($path as $segment) {
            if (!isset($pointer[$segment])) {
                return false;
            }
            $pointer = & $pointer[$segment];
        }

        return true;
    }

    protected static function & getValueAtPath(&$array, $path)
    {
        $path = explode('/', $path);
        $pointer = & $array;
        foreach ($path as $segment) {
            $pointer = & $pointer[$segment];
        }

        return $pointer;
    }

    protected static function unsetPath(&$array, $path)
    {
        $path = explode('/', $path);
        $pointer = & $array;

        // First, remove the desired value at the top
        $count = count($path);
        for ($x = 0; $x < $count - 1; $x++) {
            if (!isset($pointer[$path[$x]])) {
                return; // path not found
            }
            $pointer = & $pointer[$path[$x]];
        }
        unset($pointer[$path[$x]]);

        // Now walk downwards from the path and remove any redundant empty elements
        for ($x = $count - 2; $x >= 0; $x--) {
            $pointer = & $array;
            for ($y = 0; $y <= $x - 1; $y++) {
                $pointer = & $pointer[$path[$y]];
            }

            // remove the element if it's empty
            if (empty($pointer[$path[$y]])) {
                unset($pointer[$path[$y]]);
            } else {
                break; // nothing more to remove as parent elements contain this one
            }
        }
    }
}