Array Unflatten with PHP

array_unflatten.php

<?php

if ( ! function_exists( 'array_unflatten' ) )
{   
    /**
     * Convert flatten collection (with dot notation) to multiple dimmensionals array
     * @param  Collection $collection Collection to be flatten
     * @return Array
     */
    function array_unflatten( $collection )
    {
        $collection = (array) $collection;

        $output = array();

        foreach ( $collection as $key => $value )
        {
            array_set( $output, $key, $value );

            if ( is_array( $value ) && ! strpos( $key, '.' ) )
            {
                $nested = array_unflatten( $value );
                
                $output[$key] = $nested;
            }
        }

        return $output;
    }
}


// From Laravel
if ( ! function_exists( 'array_set' ) )
{
    function array_set( &$array, $key, $value )
    {
        if ( is_null( $key ) ) 
            return $array = $value;

        $keys = explode( '.', $key );

        while ( count( $keys ) > 1 )
        {
            $key = array_shift( $keys );

            // If the key doesn't exist at this depth, we will just create an empty array
            // to hold the next value, allowing us to create the arrays to hold final
            // values at the correct depth. Then we'll keep digging into the array.
            if ( ! isset( $array[$key] ) || ! is_array( $array[$key] ) )
            {
                $array[$key] = array();
            }

            $array =& $array[$key];
        }

        $array[array_shift( $keys )] = $value;

        return $array;
    }
}