<?php
/**
* Quiz Attempt Model
*
* @package LifterLMS/Models/Classes
*
* @since 3.9.0
* @version 4.3.0
*/
defined( 'ABSPATH' ) || exit;
/**
* LLMS_Quiz_Attempt model class
*
* @since 3.9.0
* @since 3.9.2 Added `calculate_point_weight()`, `get_question_order()`, `is_passing()` methods.
* @since 3.16.0 Unknown.
* @since 3.16.7 Unknown.
* @since 3.17.1 Unknown.
* @since 3.19.2 Unknown.
* @since 3.24.0 Unknown.
* @since 3.26.3 Unknown.
* @since 3.29.0 Unknown.
* @since 4.0.0 Remove reliance on deprecated method `LLMS_Quiz::get_passing_percent()` & remove deprecated class method `get_status()`.
* Fix issue encountered when answering a question incorrectly after initially answering it correctly.
* @since 4.2.0 Use strict type comparisons where possible.
* In the `l10n()` method, made sure the status key exists to avoid trying to access to array's undefined index.
* Added the public method `get_siblings()`.
* @since 4.3.0 Added `$type` property declaration.
*/
class LLMS_Quiz_Attempt extends LLMS_Abstract_Database_Store {
/**
* Array of table column name => format
*
* @var array
*/
protected $columns = array(
'student_id' => '%d',
'quiz_id' => '%d',
'lesson_id' => '%d',
'start_date' => '%s',
'update_date' => '%s',
'end_date' => '%s',
'status' => '%s',
'attempt' => '%d',
'grade' => '%f',
'questions' => '%s',
);
protected $date_created = 'start_date';
protected $date_updated = 'update_date';
/**
* Database Table Name
*
* @var string
*/
protected $table = 'quiz_attempts';
/**
* The record type
*
* @var string
*/
protected $type = 'quiz_attempt';
/**
* Constructor
*
* @since 3.9.0
* @since 3.16.0 Unknown.
*
* @param mixed $item Optional. Array/obj of attempt data or int. Default `null`.
* @return void
*/
public function __construct( $item = null ) {
if ( is_numeric( $item ) ) {
$this->id = $item;
} elseif ( is_object( $item ) && isset( $item->id ) ) {
$this->id = $item->id;
} elseif ( is_array( $item ) && isset( $item['id'] ) ) {
$this->id = $item['id'];
}
if ( ! $this->id ) {
if ( is_array( $item ) || is_object( $item ) ) {
$this->setup( $item );
}
parent::__construct();
}
}
/**
* Answer a question
*
* Records the selected option and whether or not the selected option was the correct option.
*
* Automatically updates & saves the attempt to the database
*
* @since 3.9.0
* @since 3.16.0 Updated to accommodate quiz builder improvements.
* @since 4.0.0 Explicitly set earned points to `0` when answering incorrectly.
* Exit the loop as soon as we find our question.
* Use strict comparison for IDs.
*
* @param int $question_id WP_Post ID of the LLMS_Question.
* @param string[] $answer Array of selected choice IDs (for core question types) or an array containing the user-submitted answer(s).
* @return LLMS_Quiz_Attempt Instance of the current attempt.
*/
public function answer_question( $question_id, $answer ) {
$questions = $this->get_questions();
foreach ( $questions as $key => $data ) {
if ( absint( $question_id ) !== absint( $data['id'] ) ) {
continue;
}
$question = llms_get_post( $question_id );
$graded = $question->grade( $answer );
$questions[ $key ]['answer'] = $answer;
$questions[ $key ]['correct'] = $graded;
$questions[ $key ]['earned'] = llms_parse_bool( $graded ) ? $questions[ $key ]['points'] : 0;
break;
}
$this->set_questions( $questions )->save();
return $this;
}
/**
* Calculate and the grade for a completed quiz
*
* @since 3.9.0
* @since 3.24.0 Unknown.
* @since 4.0.0 Remove reliance on deprecated method `LLMS_Quiz::get_passing_percent()`.
*
* @return LLMS_Quiz_Attempt Instance of the current quiz attempt.
*/
public function calculate_grade() {
$status = 'pending';
if ( $this->is_auto_gradeable() ) {
$grade = llms()->grades()->round( $this->get_count( 'earned' ) * $this->calculate_point_weight() );
$quiz = $this->get_quiz();
$min_grade = $quiz ? $quiz->get( 'passing_percent' ) : 100;
$this->set( 'grade', $grade );
$status = ( $min_grade <= $grade ) ? 'pass' : 'fail';
}
$this->set_status( $status );
return $this;
}
/**
* Calculate the weight of each point
*
* @since 3.9.2
* @since 3.16.0 Unknown.
*
* @return float
*/
private function calculate_point_weight() {
$available = $this->get_count( 'available_points' );
return ( $available > 0 ) ? ( 100 / $available ) : 0;
}
/**
* Run actions designating quiz completion
*
* @since 3.16.0
* @since 3.17.1 Unknown.
*
* @return void
*/
public function do_completion_actions() {
// Do quiz completion actions.
do_action( 'lifterlms_quiz_completed', $this->get_student()->get_id(), $this->get( 'quiz_id' ), $this );
$passed = false;
switch ( $this->get( 'status' ) ) {
case 'pass':
$passed = true;
do_action( 'lifterlms_quiz_passed', $this->get_student()->get_id(), $this->get( 'quiz_id' ), $this );
break;
case 'fail':
do_action( 'lifterlms_quiz_failed', $this->get_student()->get_id(), $this->get( 'quiz_id' ), $this );
break;
case 'pending':
do_action( 'lifterlms_quiz_pending', $this->get_student()->get_id(), $this->get( 'quiz_id' ), $this );
break;
}
}
/**
* End a quiz attempt
*
* Sets end date, unsets the quiz as the current quiz, and records a grade.
*
* @since 3.9.0
* @since 3.16.0 Unknown.
*
* @param boolean $silent Optional. If `true`, will not trigger actions or mark related lesson as complete. Default `false`.
* @return LLMS_Quiz_Attempt This quiz attempt instance (for chaining).
*/
public function end( $silent = false ) {
$this->set( 'end_date', current_time( 'mysql' ) );
$this->calculate_grade()->save();
if ( ! $silent ) {
$this->do_completion_actions();
}
// Clear "cached" grade so it's recalculated next time it's requested.
$this->get_student()->set( 'overall_grade', '' );
return $this;
}
/**
* Get sibling attempts
*
* @since 4.2.0
*
* @param array $args Optional. List of args to be passed as params of the quiz attempts query. Default empty array.
* See `LLMS_Query_Quiz_Attempt` and `LLMS_Database_Query` for the list of args.
* By default the `per_page` param is set to 1000.
* @param string $return Optional. Type of return [ids|attempts]. Default 'attempts'.
* @return int[]|LLMS_Quiz_Attempt[] Type depends on value of `$return`.
*/
public function get_siblings( $args = array(), $return = 'attempts' ) {
$defaults = array(
'per_page' => 1000,
);
$args = wp_parse_args( $args, $defaults );
$query = new LLMS_Query_Quiz_Attempt(
array_merge(
$args,
array(
'student_id' => $this->get( 'student_id' ),
'quiz_id' => $this->get( 'quiz_id' ),
)
)
);
return 'ids' === $return ? wp_list_pluck( $query->get_results(), 'id' ) : $query->get_attempts();
}
/**
* Retrieve a count for various pieces of information related to the attempt
*
* @since 3.9.0
* @since 3.19.2 Unknown.
* @since 4.2.0 Ensure only one return point.
*
* @param string $key The key of the data to count.
* @return int
*/
public function get_count( $key ) {
$count = 0;
$questions = $this->get_questions();
switch ( $key ) {
case 'available_points':
case 'correct_answers':
case 'earned':
case 'gradeable_questions': // Like "questions" but excludes content questions.
case 'points': // Legacy version of earned.
foreach ( $questions as $data ) {
// Get the total number of correct answers.
if ( 'correct_answers' === $key ) {
if ( 'yes' === $data['correct'] ) {
$count++;
}
} elseif ( 'earned' === $key || 'points' === $key ) {
$count += $data['earned'];
// Get the total number of possible points.
} elseif ( 'available_points' === $key ) {
$count += $data['points'];
} elseif ( 'gradeable_questions' === $key ) {
if ( $data['points'] ) {
$count++;
}
}
}
break;
case 'questions':
$count = count( $questions );
break;
}
return $count;
}
/**
* Retrieve a formatted date
*
* @since 3.9.0
* @since 3.16.0 Unknown.
*
* @param string $key 'start' or 'end'.
* @param string $format Optional. Output date format (PHP), uses WordPress format options if none provided.
* If not provided defaults to WP date format options.
* @return string
*/
public function get_date( $key, $format = null ) {
$date = strtotime( $this->get( $key . '_date' ) );
$format = ! $format ? get_option( 'date_format' ) . ' ' . get_option( 'time_format' ) : $format;
return date_i18n( $format, $date );
}
/**
* Retrieve the first question for the attempt
*
* @since 3.9.0
* @since 3.16.0 Unknown.
*
* @return int|false
*/
public function get_first_question() {
$questions = $this->get_questions();
if ( $questions ) {
$first = array_shift( $questions );
return $first['id'];
}
return false;
}
/**
* Get the numeric order of a question in a given quiz
*
* @since 3.9.2
* @since 3.16.0 Unknown.
* @since 4.2.0 Use strict type comparison.
*
* @param int $question_id WP Post ID of the LLMS_Question.
* @return int
*/
public function get_question_order( $question_id ) {
foreach ( $this->get_questions() as $order => $data ) {
if ( absint( $data['id'] ) === $question_id ) {
return $order + 1;
}
}
return 0;
}
/**
* Get an encoded attempt key that can be passed in URLs and the like
*
* @since 3.9.0
* @since 3.16.7 Unknown.
*
* @return string
*/
public function get_key() {
return LLMS_Hasher::hash( $this->get( 'id' ) );
}
/**
* Retrieve an array of blank questions for insertion into a new attempt during initialization
*
* @since 3.9.0
* @since 3.16.0 Unknown.
*
* @return array
*/
private function get_new_questions() {
$quiz = llms_get_post( $this->get( 'quiz_id' ) );
$questions = array();
if ( $quiz ) {
$randomize = llms_parse_bool( $quiz->get( 'random_questions' ) );
// Array of indexes that will be locked during shuffling.
$locks = array();
foreach ( $quiz->get_questions() as $index => $question ) {
// If randomization is enabled, store the questions index so we can lock it during randomization.
if ( $randomize && $question->supports( 'random_lock' ) ) {
$locks[] = $index;
}
$questions[] = array(
'id' => $question->get( 'id' ),
'earned' => 0,
'points' => $question->supports( 'points' ) ? $question->get( 'points' ) : 0,
'answer' => null,
'correct' => null,
);
}
if ( $randomize ) {
// Lifted from https://stackoverflow.com/a/28491007/400568.
// I generally comprehend this code but also in a truer way i have no idea...
$inc = array();
$i = 0;
$j = 0;
$l = count( $questions );
$le = count( $locks );
while ( $i < $l ) {
if ( $j >= $le || $i < $locks[ $j ] ) {
$inc[] = $i;
} else {
$j++;
}
$i++;
}
// Fisher-yates-knuth shuffle variation O(n).
$num = count( $inc );
while ( $num-- ) {
$perm = rand( 0, $num );
$swap = $questions[ $inc[ $num ] ];
$questions[ $inc[ $num ] ] = $questions[ $inc[ $perm ] ];
$questions[ $inc[ $perm ] ] = $swap;
}
}
}
return $questions;
}
/**
* Retrieve the next unanswered question in the attempt
*
* @since 3.9.0
* @since 3.16.0 Unknown.
* @since 4.2.0 Use strict type comparison.
*
* @param int $last_question Optional. WP Post ID of the current LLMS_Question the "next" refers to. Default `null`.
* @return int|false
*/
public function get_next_question( $last_question = null ) {
$next = false;
foreach ( $this->get_questions() as $question ) {
if ( $next || is_null( $question['answer'] ) ) {
return $question['id'];
// When rewinding and moving back through we don't want to skip questions.
} elseif ( $last_question && absint( $last_question ) === absint( $question['id'] ) ) {
$next = true;
}
}
return false;
}
/**
* Retrieve a permalink for the attempt
*
* @since 3.9.0
*
* @return string
*/
public function get_permalink() {
if ( ! $this->get_quiz() ) {
return '';
}
return add_query_arg( 'attempt_key', $this->get_key(), get_permalink( $this->get_quiz()->get( 'id' ) ) );
}
/**
* Get array of serialized questions
*
* @since 3.16.0
*
* @param boolean $cache Optional. If `true`, save data to to the object for future gets. Default `true`.
* @return array
*/
public function get_questions( $cache = true ) {
$questions = $this->get( 'questions', $cache );
if ( $questions ) {
return unserialize( $questions );
}
return array();
}
/**
* Retrieve an array of attempt question objects
*
* @since 3.16.0
* @since 5.3.0 Add a parameter to filter out removed questions.
*
* @param boolean $cache Optional. If `true`, save data to to the object for future gets. Default `true`.
* Cached questions won't take into account the `$filte_removed` parameter.
* @param boolean $filter_removed Optional. If `true`, removed questions will be filtered out. Default `false`.
* @return array
*/
public function get_question_objects( $cache = true, $filter_removed = false ) {
$questions = array();
foreach ( $this->get_questions( $cache ) as $qdata ) {
$question = new LLMS_Quiz_Attempt_Question( $qdata );
if ( ! $filter_removed || $question->get_question() instanceof LLMS_Question ) {
$questions[] = $question;
}
}
return $questions;
}
/**
* Get an instance of the LLMS_Quiz for the attempt
*
* @since 3.9.0
*
* @return LLMS_Quiz
*/
public function get_quiz() {
return llms_get_post( $this->get( 'quiz_id' ) );
}
/**
* Get an LLMS_Student for the quiz
*
* @since 3.9.0
*
* @return LLMS_Student
*/
public function get_student() {
return llms_get_student( $this->get( 'student_id' ) );
}
/**
* Get the time spent on the quiz from start to end
*
* @since 3.9.0
*
* @param integer $precision Precision passed to `llms_get_date_diff()`.
* @return string
*/
public function get_time( $precision = 2 ) {
return llms_get_date_diff( $this->get_date( 'start', 'U' ), $this->get_date( 'end', 'U' ), $precision );
}
/**
* Retrieve a title-like string
*
* @since 3.16.0
* @since 3.26.3 Unknown.
*
* @return string
*/
public function get_title() {
$student = $this->get_student();
$name = $student ? $this->get_student()->get_name() : apply_filters( 'llms_quiz_attempt_deleted_student_name', __( '[Deleted]', 'lifterlms' ) );
return sprintf( __( 'Quiz Attempt #%1$d by %2$s', 'lifterlms' ), $this->get( 'attempt' ), $name );
}
/**
* Initialize a new quiz attempt by quiz and lesson for a user
*
* If no user found throws an Exception.
*
* @since 3.9.0
* @version 3.16.0
*
* @throws Exception When the user is not logged in.
*
* @param int $quiz_id WP Post ID of the quiz.
* @param int $lesson_id WP Post ID of the lesson.
* @param mixed $student Optional. Accepts anything that can be passed to llms_get_student.
* If no user is passed the current user will be used. Default `null`.
*
* @return obj
*/
public static function init( $quiz_id, $lesson_id, $student = null ) {
$student = llms_get_student( $student );
if ( ! $student ) {
throw new Exception( __( 'You must be logged in to take a quiz!', 'lifterlms' ) );
}
// Initialize a new attempt.
$attempt = new self();
$attempt->set( 'quiz_id', $quiz_id );
$attempt->set( 'lesson_id', $lesson_id );
$attempt->set( 'student_id', $student->get_id() );
$attempt->set_status( 'incomplete' );
$attempt->set_questions( $attempt->get_new_questions() );
$number = 1;
$last_attempt = $student->quizzes()->get_last_attempt( $quiz_id );
if ( $last_attempt ) {
$number = absint( $last_attempt->get( 'attempt' ) ) + 1;
}
$attempt->set( 'attempt', $number );
return $attempt;
}
/**
* Determine if the attempt can be autograded
*
* @since 3.16.0
*
* @return bool
*/
private function is_auto_gradeable() {
foreach ( $this->get_question_objects() as $question ) {
if ( 'waiting' === $question->get_status() ) {
return false;
}
}
return true;
}
/**
* Determine if the attempt was passing
*
* @since 3.9.2
* @since 3.16.0 Unknown.
*
* @return boolean
*/
public function is_passing() {
return ( 'pass' === $this->get( 'status' ) );
}
/**
* Translate attempt related strings
*
* @since 3.9.0
* @since 3.16.0 Unknown.
* @since 4.2.0 Made sure the status key exists to avoid trying to access to array's undefined index.
*
* @param string $key Key to translate.
* @return string
*/
public function l10n( $key ) {
$tkey = '';
switch ( $key ) {
case 'passed': // Deprecated.
case 'status':
$statuses = llms_get_quiz_attempt_statuses();
$status = $this->get( 'status' );
$tkey = ( $status && isset( $statuses[ $status ] ) ) ? $statuses[ $status ] : $tkey;
break;
}
return $tkey;
}
/**
* Setter for serialized questions array
*
* @since 3.16.0
*
* @param array $questions Question data.
* @param boolean $save Optional. If `true`, immediately persists to database. Default `false`.
* @return LLMS_Quiz_Attempt This quiz attempt instance (for chaining).
*/
public function set_questions( $questions = array(), $save = false ) {
return $this->set( 'questions', serialize( $questions ), $save );
}
/**
* Set the status of the attempt
*
* @since 3.16.0
* @since 4.0.0 Use strict comparisons.
*
* @param string $status Status value.
* @param boolean $save If `true`, immediately persists to database.
* @return false|LLMS_Quiz_Attempt
*/
public function set_status( $status, $save = false ) {
$statuses = array_keys( llms_get_quiz_attempt_statuses() );
if ( ! in_array( $status, $statuses, true ) ) {
return false;
}
return $this->set( 'status', $status );
}
/**
* Record the attempt as started
*
* @since 3.9.0
*
* @return LLMS_Quiz_Attempt Instance of the current quiz attempt object.
*/
public function start() {
$this->set( 'start_date', current_time( 'mysql' ) );
$this->save();
return $this;
}
/**
* Retrieve the private data array
*
* @since 3.9.0
*
* @return array
*/
public function to_array() {
return $this->data;
}
/**
* Delete the object from the database
*
* Overrides the parent method to perform other actions before deletion.
*
* @since 4.2.0
*
* @return bool `true` on success, `false` otherwise.
*/
public function delete() {
if ( ! $this->id ) {
return false;
}
$lesson = llms_get_post( $this->get( 'lesson_id' ) );
// No lesson, or lesson incomplete, nothing special to do here.
if ( ! $lesson || ! ( $lesson instanceof LLMS_Lesson ) || ! llms_is_complete( $this->get( 'student_id' ), $this->get( 'lesson_id' ), 'lesson' ) ) {
return parent::delete();
}
/**
* Prepare the query args to retrieve at least another sibling attempt,
* excluding the current one.
*/
$sibling_query_args = array(
'exclude' => $this->get_id( 'id' ),
'per_page' => 1,
);
/**
* If this lesson requires a passing grade, then retrieve only the possible passed sibling
* that might have been triggered the lesson completion.
*/
if ( llms_parse_bool( $lesson->get( 'require_passing_grade' ) ) ) {
$sibling_query_args['status'] = array(
'pass',
);
}
$sibling_attempts = $this->get_siblings( $sibling_query_args, 'ids' );
// If this is the only one relevant left attempt.
if ( empty( $sibling_attempts ) ) {
llms_mark_incomplete(
$this->get( 'student_id' ),
$this->get( 'lesson_id' ),
'lesson',
'quiz_' . $this->get( 'quiz_id' )
);
}
return parent::delete();
}
}