Warning: Invalid argument supplied for foreach()

If you get this error it means that the “array” you’ve passed to the foreach loop is actually not an array. To check if a variable is an array use the is_array($var) function. But if your variable turns out to be an array, it means then that it is null or has null elements. To clear an array from null (or empty) elements use the array_filter($array) function. You may need to use array_filter(array($array)) .

Warning: array_filter() [function.array-filter]: The first argument should be an array

Even if my variable $kwds was an array, and the function is_array returned true i don’t know why it still threw a warning. To overpass it, instead of
$kwds=array_filter($kwds);
i wrote
$kwds=array_filter(array($kwds));
Now it works I Hope it will help somebody.