public function test_check_external_forbidden_words()
{
// Remember, this function returns true if the literal is found.
$cases = array(array('sin(ta)', array('ta'), true), array('sin(ta)', array('ta', 'a', 'b'), true), array('sin(ta)', array('sa'), false), array('sin(a)', array('a'), false), array('diff(x^2,x)', array('[[BASIC-CALCULUS]]'), true));
foreach ($cases as $case) {
$cs = new stack_cas_casstring($case[0]);
$this->assertEquals($case[2], $cs->check_external_forbidden_words($case[1]));
}
}
/**
* This is the basic validation of the student's "answer".
* This method is only called if the input is not blank.
*
* Only a few input methods need to modify this method.
* For example, Matrix types have two dimensional contents arrays to loop over.
*
* @param array $contents the content array of the student's input.
* @return array of the validity, errors strings and modified contents.
*/
protected function validate_contents($contents, $forbiddenkeys)
{
$errors = $this->extra_validation($contents);
$valid = !$errors;
// Now validate the input as CAS code.
$modifiedcontents = array();
$allowwords = $this->get_parameter('allowWords', '');
foreach ($contents as $val) {
$answer = new stack_cas_casstring($val);
$answer->get_valid('s', $this->get_parameter('strictSyntax', true), $this->get_parameter('insertStars', 0), $allowwords);
// Ensure student hasn't used a variable name used by the teacher.
if ($forbiddenkeys) {
$answer->check_external_forbidden_words($forbiddenkeys);
}
$forbiddenwords = $this->get_parameter('forbidWords', '');
if ($forbiddenwords) {
$answer->check_external_forbidden_words_literal($forbiddenwords);
}
$modifiedcontents[] = $answer->get_casstring();
$valid = $valid && $answer->get_valid();
$errors .= $answer->get_errors();
}
return array($valid, $errors, $modifiedcontents);
}
