protected function get_choices()
{
if (empty($this->parameters['ddl_values'])) {
return array();
}
$values = stack_utils::list_to_array('[' . trim($this->parameters['ddl_values']) . ']', false);
if (empty($values)) {
return array();
}
$choices = array('' => stack_string('notanswered'));
foreach ($values as $value) {
$choices[$value] = $value;
}
return $choices;
}
public function test_list_to_array()
{
// Do not recurse over lists.
$a = array();
$strin = '';
$this->assertEquals($a, stack_utils::list_to_array($strin, false));
$a = array();
$strin = '[]';
$this->assertEquals($a, stack_utils::list_to_array($strin, false));
$a = array('1');
$strin = '[1]';
$this->assertEquals($a, stack_utils::list_to_array($strin, false));
$a = array('1', '2');
$strin = '[1,2]';
$this->assertEquals($a, stack_utils::list_to_array($strin, false));
$strin = '[x^2, sin(x)]';
$a = array('x^2', ' sin(x)');
$this->assertEquals($a, stack_utils::list_to_array($strin, false));
$a = array('1', 'x+y');
$strin = '[1,x+y]';
$this->assertEquals($a, stack_utils::list_to_array($strin, false));
$a = array('[1,2]');
$strin = '[[1,2]]';
$this->assertEquals($a, stack_utils::list_to_array($strin, false));
$strin = '[[1,2,3], {x^2,x^3}]';
$a = array('[1,2,3]', ' {x^2,x^3}');
$this->assertEquals($a, stack_utils::list_to_array($strin, false));
$a = array('1', '1/sum([1,3])', 'matrix([1],[2])');
$strin = '[1,1/sum([1,3]),matrix([1],[2])]';
$this->assertEquals($a, stack_utils::list_to_array($strin, false));
// Recurse over lists.
$strin = '[[1,2,3], {x^2,x^3}]';
$a = array(array('1', '2', '3'), ' {x^2,x^3}');
$this->assertEquals($a, stack_utils::list_to_array($strin, true));
}
/**
* @return string the teacher's answer, displayed to the student in the general feedback.
*/
public function get_teacher_answer_display($value, $display)
{
$values = stack_utils::list_to_array($value, false);
$values = array_map(function ($ex) {
return '<code>' . $ex . '</code>';
}, $values);
$value = "<br/>" . implode("<br/>", $values);
return stack_string('teacheranswershow', array('value' => $value, 'display' => $display));
}
