Remove all array elements except what I want?

Question

I have controller that takes post parameters from HTML form, it will then send them to model that will insert the array into Cassandra database.

It is SQLInjection proof

Answer 1

This is called white listing, your example is misleading as the $_POST is an association array.

$post = [
    'parent_id' => 'val',
    'type' => 'val',
    'title' => 'val',
    'body' => 'val',
    'tags' => 'val',
    'one' => 'val',
    'two' => 'val',
    'three'=>'val',
];

$whitelist = ['parent_id', 'type', 'title', 'body', 'tags'];

$sanitized_post = array_whitelist_assoc($post, $whitelist);

This is a whitelisting function I created for associative arrays.

if(!function_exists('array_whitelist_assoc')){

    /**
     * Returns an associative array containing all the entries of array1 which have keys that are present in all the arguments when using their values as keys.
     *
     * @param array $array The array with master keys to check.
     * @param array $array2 An array to compare keys against its values.
     * @return array $array2,... A variable list of arrays to compare.
     * 
     */

    function array_whitelist_assoc(Array $array1, Array $array2) {

        if(func_num_args() > 2){
            $args = func_get_args();
            array_shift($args);
            $array2 = call_user_func_array('array_merge', $args);
        } 
        return array_intersect_key($array1, array_flip($array2)); 
    }
}