Recursive Data Filter.php

<?php

/**
* This function recursively searches the JSON API and picks out the
* specified items based on the parameters passed into the function
* 
* @param array $data
* @param string $needle
* @param string $catNeedle
* @return array 
*/
public function RecursiveDataFilter(array $data, $needle, $catNeedle = null)
{
    // Check to make sure $data is passed in as an array
    // if not an array, error string is returned
    if (!is_array($data))
    {
        $result = 'Error! Error retrieving proper stats in an array!';
        return $result;
    }
    
    // Initializing two arrays, one to hold a reduced haystack, the other to hold results
    $results = array();
    $haystack = array();
    
    // Checks to see if a category needle was passed in
    if ($catNeedle)
    {
        // Foreach loop going through each key => value combination of $data
        foreach ($data as $catKey => $catValue)
        {
            // Checks to see if the given index is equivalent to the category needle
            if ($catKey == $catNeedle)
            {
                // Checks to see if the desired needle exists within the category
                if (is_array($catValue) && array_key_exists($needle, $catValue))
                {
                    // Found the key, now assigning and returning the result.
                    echo "Key Found! Assigning results to the return array.<br />";
                    $results = $catValue[$needle];
                    return $results;
                }
                // Breaks out of the foreach loop with or without a result
                break;
            }
            // if it hasn't found the category needle the haystack is reduced
            else
            {
                // Checks to see if its an array
                if(is_array($catValue))
                {
                    // creates a reduced haystack from available, searchable arrays
                    $haystack = array_merge($haystack, $catValue);
                }
            }
        }
        // if $results is empty, prepare to recurse
        if(!$results)
        {
            // Sets $data equal to $haystack to conserve memory
            $data = $haystack;
            // nulls out $haystack to recycle resources
            $haystack = null;
            // intializes the recursion for the next iteration around
            $results = $this->RecursiveDataFilter($data, $needle, $catNeedle);
        }
    }
    // return results whether they're null or not
    return $results;
}