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<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* This file defines the question attempt class, and a few related classes.
*
* @package moodlecore
* @subpackage questionengine
* @copyright 2009 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
/**
* Tracks an attempt at one particular question in a {@link question_usage_by_activity}.
*
* Most calling code should need to access objects of this class. They should be
* able to do everything through the usage interface. This class is an internal
* implementation detail of the question engine.
*
* Instances of this class correspond to rows in the question_attempts table, and
* a collection of {@link question_attempt_steps}. Question inteaction models and
* question types do work with question_attempt objects.
*
* @copyright 2009 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_attempt {
/**
* @var string this is a magic value that question types can return from
* {@link question_definition::get_expected_data()}.
*/
const USE_RAW_DATA = 'use raw data';
/**
* @var string special value used by manual grading because {@link PARAM_NUMBER}
* converts '' to 0.
*/
const PARAM_MARK = 'parammark';
/**
* @var string special value to indicate a response variable that is uploaded
* files.
*/
const PARAM_FILES = 'paramfiles';
/**
* @var string special value to indicate a response variable that is uploaded
* files.
*/
const PARAM_CLEANHTML_FILES = 'paramcleanhtmlfiles';
/** @var integer if this attempts is stored in the question_attempts table, the id of that row. */
protected $id = null;
/** @var integer|string the id of the question_usage_by_activity we belong to. */
protected $usageid;
/** @var integer the number used to identify this question_attempt within the usage. */
protected $slot = null;
/**
* @var question_behaviour the behaviour controlling this attempt.
* null until {@link start()} is called.
*/
protected $behaviour = null;
/** @var question_definition the question this is an attempt at. */
protected $question;
/** @var int which variant of the question to use. */
protected $variant;
/** @var number the maximum mark that can be scored at this question. */
protected $maxmark;
/**
* @var number the minimum fraction that can be scored at this question, so
* the minimum mark is $this->minfraction * $this->maxmark.
*/
protected $minfraction = null;
/**
* @var string plain text summary of the variant of the question the
* student saw. Intended for reporting purposes.
*/
protected $questionsummary = null;
/**
* @var string plain text summary of the response the student gave.
* Intended for reporting purposes.
*/
protected $responsesummary = null;
/**
* @var string plain text summary of the correct response to this question
* variant the student saw. The format should be similar to responsesummary.
* Intended for reporting purposes.
*/
protected $rightanswer = null;
/** @var array of {@link question_attempt_step}s. The steps in this attempt. */
protected $steps = array();
/** @var boolean whether the user has flagged this attempt within the usage. */
protected $flagged = false;
/** @var question_usage_observer tracks changes to the useage this attempt is part of.*/
protected $observer;
/**#@+
* Constants used by the intereaction models to indicate whether the current
* pending step should be kept or discarded.
*/
const KEEP = true;
const DISCARD = false;
/**#@-*/
/**
* Create a new {@link question_attempt}. Normally you should create question_attempts
* indirectly, by calling {@link question_usage_by_activity::add_question()}.
*
* @param question_definition $question the question this is an attempt at.
* @param int|string $usageid The id of the
* {@link question_usage_by_activity} we belong to. Used by {@link get_field_prefix()}.
* @param question_usage_observer $observer tracks changes to the useage this
* attempt is part of. (Optional, a {@link question_usage_null_observer} is
* used if one is not passed.
* @param number $maxmark the maximum grade for this question_attempt. If not
* passed, $question->defaultmark is used.
*/
public function __construct(question_definition $question, $usageid,
question_usage_observer $observer = null, $maxmark = null) {
$this->question = $question;
$this->usageid = $usageid;
if (is_null($observer)) {
$observer = new question_usage_null_observer();
}
$this->observer = $observer;
if (!is_null($maxmark)) {
$this->maxmark = $maxmark;
} else {
$this->maxmark = $question->defaultmark;
}
}
/**
* This method exists so that {@link question_attempt_with_restricted_history}
* can override it. You should not normally need to call it.
* @return question_attempt return ourself.
*/
public function get_full_qa() {
return $this;
}
/** @return question_definition the question this is an attempt at. */
public function get_question() {
return $this->question;
}
/**
* Get the variant of the question being used in a given slot.
* @return int the variant number.
*/
public function get_variant() {
return $this->variant;
}
/**
* Set the number used to identify this question_attempt within the usage.
* For internal use only.
* @param int $slot
*/
public function set_number_in_usage($slot) {
$this->slot = $slot;
}
/** @return int the number used to identify this question_attempt within the usage. */
public function get_slot() {
return $this->slot;
}
/**
* @return int the id of row for this question_attempt, if it is stored in the
* database. null if not.
*/
public function get_database_id() {
return $this->id;
}
/**
* For internal use only. Set the id of the corresponding database row.
* @param int $id the id of row for this question_attempt, if it is
* stored in the database.
*/
public function set_database_id($id) {
$this->id = $id;
}
/** @return int|string the id of the {@link question_usage_by_activity} we belong to. */
public function get_usage_id() {
return $this->usageid;
}
/**
* Set the id of the {@link question_usage_by_activity} we belong to.
* For internal use only.
* @param int|string the new id.
*/
public function set_usage_id($usageid) {
$this->usageid = $usageid;
}
/** @return string the name of the behaviour that is controlling this attempt. */
public function get_behaviour_name() {
return $this->behaviour->get_name();
}
/**
* For internal use only.
* @return question_behaviour the behaviour that is controlling this attempt.
*/
public function get_behaviour() {
return $this->behaviour;
}
/**
* Set the flagged state of this question.
* @param bool $flagged the new state.
*/
public function set_flagged($flagged) {
$this->flagged = $flagged;
$this->observer->notify_attempt_modified($this);
}
/** @return bool whether this question is currently flagged. */
public function is_flagged() {
return $this->flagged;
}
/**
* Get the name (in the sense a HTML name="" attribute, or a $_POST variable
* name) to use for the field that indicates whether this question is flagged.
*
* @return string The field name to use.
*/
public function get_flag_field_name() {
return $this->get_control_field_name('flagged');
}
/**
* Get the name (in the sense a HTML name="" attribute, or a $_POST variable
* name) to use for a question_type variable belonging to this question_attempt.
*
* See the comment on {@link question_attempt_step} for an explanation of
* question type and behaviour variables.
*
* @param $varname The short form of the variable name.
* @return string The field name to use.
*/
public function get_qt_field_name($varname) {
return $this->get_field_prefix() . $varname;
}
/**
* Get the name (in the sense a HTML name="" attribute, or a $_POST variable
* name) to use for a question_type variable belonging to this question_attempt.
*
* See the comment on {@link question_attempt_step} for an explanation of
* question type and behaviour variables.
*
* @param $varname The short form of the variable name.
* @return string The field name to use.
*/
public function get_behaviour_field_name($varname) {
return $this->get_field_prefix() . '-' . $varname;
}
/**
* Get the name (in the sense a HTML name="" attribute, or a $_POST variable
* name) to use for a control variables belonging to this question_attempt.
*
* Examples are :sequencecheck and :flagged
*
* @param $varname The short form of the variable name.
* @return string The field name to use.
*/
public function get_control_field_name($varname) {
return $this->get_field_prefix() . ':' . $varname;
}
/**
* Get the prefix added to variable names to give field names for this
* question attempt.
*
* You should not use this method directly. This is an implementation detail
* anyway, but if you must access it, use {@link question_usage_by_activity::get_field_prefix()}.
*
* @param $varname The short form of the variable name.
* @return string The field name to use.
*/
public function get_field_prefix() {
return 'q' . $this->usageid . ':' . $this->slot . '_';
}
/**
* Get one of the steps in this attempt.
* For internal/test code use only.
* @param int $i the step number.
* @return question_attempt_step
*/
public function get_step($i) {
if ($i < 0 || $i >= count($this->steps)) {
throw new coding_exception('Index out of bounds in question_attempt::get_step.');
}
return $this->steps[$i];
}
/**
* Get the number of steps in this attempt.
* For internal/test code use only.
* @return int the number of steps we currently have.
*/
public function get_num_steps() {
return count($this->steps);
}
/**
* Return the latest step in this question_attempt.
* For internal/test code use only.
* @return question_attempt_step
*/
public function get_last_step() {
if (count($this->steps) == 0) {
return new question_null_step();
}
return end($this->steps);
}
/**
* @return question_attempt_step_iterator for iterating over the steps in
* this attempt, in order.
*/
public function get_step_iterator() {
return new question_attempt_step_iterator($this);
}
/**
* The same as {@link get_step_iterator()}. However, for a
* {@link question_attempt_with_restricted_history} this returns the full
* list of steps, while {@link get_step_iterator()} returns only the
* limited history.
* @return question_attempt_step_iterator for iterating over the steps in
* this attempt, in order.
*/
public function get_full_step_iterator() {
return $this->get_step_iterator();
}
/**
* @return question_attempt_reverse_step_iterator for iterating over the steps in
* this attempt, in reverse order.
*/
public function get_reverse_step_iterator() {
return new question_attempt_reverse_step_iterator($this);
}
/**
* Get the qt data from the latest step that has any qt data. Return $default
* array if it is no step has qt data.
*
* @param string $name the name of the variable to get.
* @param mixed default the value to return no step has qt data.
* (Optional, defaults to an empty array.)
* @return array|mixed the data, or $default if there is not any.
*/
public function get_last_qt_data($default = array()) {
foreach ($this->get_reverse_step_iterator() as $step) {
$response = $step->get_qt_data();
if (!empty($response)) {
return $response;
}
}
return $default;
}
/**
* Get the last step with a particular question type varialbe set.
* @param string $name the name of the variable to get.
* @return question_attempt_step the last step, or a step with no variables
* if there was not a real step.
*/
public function get_last_step_with_qt_var($name) {
foreach ($this->get_reverse_step_iterator() as $step) {
if ($step->has_qt_var($name)) {
return $step;
}
}
return new question_attempt_step_read_only();
}
/**
* Get the last step with a particular behaviour variable set.
* @param string $name the name of the variable to get.
* @return question_attempt_step the last step, or a step with no variables
* if there was not a real step.
*/
public function get_last_step_with_behaviour_var($name) {
foreach ($this->get_reverse_step_iterator() as $step) {
if ($step->has_behaviour_var($name)) {
return $step;
}
}
return new question_attempt_step_read_only();
}
/**
* Get the latest value of a particular question type variable. That is, get
* the value from the latest step that has it set. Return null if it is not
* set in any step.
*
* @param string $name the name of the variable to get.
* @param mixed default the value to return in the variable has never been set.
* (Optional, defaults to null.)
* @return mixed string value, or $default if it has never been set.
*/
public function get_last_qt_var($name, $default = null) {
$step = $this->get_last_step_with_qt_var($name);
if ($step->has_qt_var($name)) {
return $step->get_qt_var($name);
} else {
return $default;
}
}
/**
* Get the latest set of files for a particular question type variable of
* type question_attempt::PARAM_FILES.
*
* @param string $name the name of the associated variable.
* @return array of {@link stored_files}.
*/
public function get_last_qt_files($name, $contextid) {
foreach ($this->get_reverse_step_iterator() as $step) {
if ($step->has_qt_var($name)) {
return $step->get_qt_files($name, $contextid);
}
}
return array();
}
/**
* Get the URL of a file that belongs to a response variable of this
* question_attempt.
* @param stored_file $file the file to link to.
* @return string the URL of that file.
*/
public function get_response_file_url(stored_file $file) {
return file_encode_url(new moodle_url('/pluginfile.php'), '/' . implode('/', array(
$file->get_contextid(),
$file->get_component(),
$file->get_filearea(),
$this->usageid,
$this->slot,
$file->get_itemid())) .
$file->get_filepath() . $file->get_filename(), true);
}
/**
* Prepare a draft file are for the files belonging the a response variable
* of this question attempt. The draft area is populated with the files from
* the most recent step having files.
*
* @param string $name the variable name the files belong to.
* @param int $contextid the id of the context the quba belongs to.
* @return int the draft itemid.
*/
public function prepare_response_files_draft_itemid($name, $contextid) {
foreach ($this->get_reverse_step_iterator() as $step) {
if ($step->has_qt_var($name)) {
return $step->prepare_response_files_draft_itemid($name, $contextid);
}
}
// No files yet.
$draftid = 0; // Will be filled in by file_prepare_draft_area.
file_prepare_draft_area($draftid, $contextid, 'question', 'response_' . $name, null);
return $draftid;
}
/**
* Get the latest value of a particular behaviour variable. That is,
* get the value from the latest step that has it set. Return null if it is
* not set in any step.
*
* @param string $name the name of the variable to get.
* @param mixed default the value to return in the variable has never been set.
* (Optional, defaults to null.)
* @return mixed string value, or $default if it has never been set.
*/
public function get_last_behaviour_var($name, $default = null) {
foreach ($this->get_reverse_step_iterator() as $step) {
if ($step->has_behaviour_var($name)) {
return $step->get_behaviour_var($name);
}
}
return $default;
}
/**
* Get the current state of this question attempt. That is, the state of the
* latest step.
* @return question_state
*/
public function get_state() {
return $this->get_last_step()->get_state();
}
/**
* @param bool $showcorrectness Whether right/partial/wrong states should
* be distinguised.
* @return string A brief textual description of the current state.
*/
public function get_state_string($showcorrectness) {
return $this->behaviour->get_state_string($showcorrectness);
}
/**
* @param bool $showcorrectness Whether right/partial/wrong states should
* be distinguised.
* @return string a CSS class name for the current state.
*/
public function get_state_class($showcorrectness) {
return $this->get_state()->get_state_class($showcorrectness);
}
/**
* @return int the timestamp of the most recent step in this question attempt.
*/
public function get_last_action_time() {
return $this->get_last_step()->get_timecreated();
}
/**
* Get the current fraction of this question attempt. That is, the fraction
* of the latest step, or null if this question has not yet been graded.
* @return number the current fraction.
*/
public function get_fraction() {
return $this->get_last_step()->get_fraction();
}
/** @return bool whether this question attempt has a non-zero maximum mark. */
public function has_marks() {
// Since grades are stored in the database as NUMBER(12,7).
return $this->maxmark >= 0.00000005;
}
/**
* @return number the current mark for this question.
* {@link get_fraction()} * {@link get_max_mark()}.
*/
public function get_mark() {
return $this->fraction_to_mark($this->get_fraction());
}
/**
* This is used by the manual grading code, particularly in association with
* validation. If there is a mark submitted in the request, then use that,
* otherwise use the latest mark for this question.
* @return number the current mark for this question.
* {@link get_fraction()} * {@link get_max_mark()}.
*/
public function get_current_manual_mark() {
$mark = $this->get_submitted_var($this->get_behaviour_field_name('mark'), question_attempt::PARAM_MARK);
if (is_null($mark)) {
return $this->get_mark();
} else {
return $mark;
}
}
/**
* @param number|null $fraction a fraction.
* @return number|null the corresponding mark.
*/
public function fraction_to_mark($fraction) {
if (is_null($fraction)) {
return null;
}
return $fraction * $this->maxmark;
}
/** @return number the maximum mark possible for this question attempt. */
public function get_max_mark() {
return $this->maxmark;
}
/** @return number the maximum mark possible for this question attempt. */
public function get_min_fraction() {
if (is_null($this->minfraction)) {
throw new coding_exception('This question_attempt has not been started yet, the min fraction is not yet konwn.');
}
return $this->minfraction;
}
/**
* The current mark, formatted to the stated number of decimal places. Uses
* {@link format_float()} to format floats according to the current locale.
* @param int $dp number of decimal places.
* @return string formatted mark.
*/
public function format_mark($dp) {
return $this->format_fraction_as_mark($this->get_fraction(), $dp);
}
/**
* The current mark, formatted to the stated number of decimal places. Uses
* {@link format_float()} to format floats according to the current locale.
* @param int $dp number of decimal places.
* @return string formatted mark.
*/
public function format_fraction_as_mark($fraction, $dp) {
return format_float($this->fraction_to_mark($fraction), $dp);
}
/**
* The maximum mark for this question attempt, formatted to the stated number
* of decimal places. Uses {@link format_float()} to format floats according
* to the current locale.
* @param int $dp number of decimal places.
* @return string formatted maximum mark.
*/
public function format_max_mark($dp) {
return format_float($this->maxmark, $dp);
}
/**
* Return the hint that applies to the question in its current state, or null.
* @return question_hint|null
*/
public function get_applicable_hint() {
return $this->behaviour->get_applicable_hint();
}
/**
* Produce a plain-text summary of what the user did during a step.
* @param question_attempt_step $step the step in quetsion.
* @return string a summary of what was done during that step.
*/
public function summarise_action(question_attempt_step $step) {
return $this->behaviour->summarise_action($step);
}
/**
* Helper function used by {@link rewrite_pluginfile_urls()} and
* {@link rewrite_response_pluginfile_urls()}.
* @return array ids that need to go into the file paths.
*/
protected function extra_file_path_components() {
return array($this->get_usage_id(), $this->get_slot());
}
/**
* Calls {@link question_rewrite_question_urls()} with appropriate parameters
* for content belonging to this question.
* @param string $text the content to output.
* @param string $component the component name (normally 'question' or 'qtype_...')
* @param string $filearea the name of the file area.
* @param int $itemid the item id.
* @return srting the content with the URLs rewritten.
*/
public function rewrite_pluginfile_urls($text, $component, $filearea, $itemid) {
return question_rewrite_question_urls($text, 'pluginfile.php',
$this->question->contextid, $component, $filearea,
$this->extra_file_path_components(), $itemid);
}
/**
* Calls {@link question_rewrite_question_urls()} with appropriate parameters
* for content belonging to responses to this question.
*
* @param string $text the text to update the URLs in.
* @param int $contextid the id of the context the quba belongs to.
* @param string $name the variable name the files belong to.
* @param question_attempt_step $step the step the response is coming from.
* @return srting the content with the URLs rewritten.
*/
public function rewrite_response_pluginfile_urls($text, $contextid, $name,
question_attempt_step $step) {
return $step->rewrite_response_pluginfile_urls($text, $contextid, $name,
$this->extra_file_path_components());
}
/**
* Get the {@link core_question_renderer}, in collaboration with appropriate
* {@link qbehaviour_renderer} and {@link qtype_renderer} subclasses, to generate the
* HTML to display this question attempt in its current state.
* @param question_display_options $options controls how the question is rendered.
* @param string|null $number The question number to display.
* @return string HTML fragment representing the question.
*/
public function render($options, $number, $page = null) {
if (is_null($page)) {
global $PAGE;
$page = $PAGE;
}
$qoutput = $page->get_renderer('core', 'question');
$qtoutput = $this->question->get_renderer($page);
return $this->behaviour->render($options, $number, $qoutput, $qtoutput);
}
/**
* Generate any bits of HTML that needs to go in the <head> tag when this question
* attempt is displayed in the body.
* @return string HTML fragment.
*/
public function render_head_html($page = null) {
if (is_null($page)) {
global $PAGE;
$page = $PAGE;
}
// TODO go via behaviour.
return $this->question->get_renderer($page)->head_code($this) .
$this->behaviour->get_renderer($page)->head_code($this);
}
/**
* Like {@link render_question()} but displays the question at the past step
* indicated by $seq, rather than showing the latest step.
*
* @param int $seq the seq number of the past state to display.
* @param question_display_options $options controls how the question is rendered.
* @param string|null $number The question number to display. 'i' is a special
* value that gets displayed as Information. Null means no number is displayed.
* @return string HTML fragment representing the question.
*/
public function render_at_step($seq, $options, $number, $preferredbehaviour) {
$restrictedqa = new question_attempt_with_restricted_history($this, $seq, $preferredbehaviour);
return $restrictedqa->render($options, $number);
}
/**
* Checks whether the users is allow to be served a particular file.
* @param question_display_options $options the options that control display of the question.
* @param string $component the name of the component we are serving files for.
* @param string $filearea the name of the file area.
* @param array $args the remaining bits of the file path.
* @param bool $forcedownload whether the user must be forced to download the file.
* @return bool true if the user can access this file.
*/
public function check_file_access($options, $component, $filearea, $args, $forcedownload) {
return $this->behaviour->check_file_access($options, $component, $filearea, $args, $forcedownload);
}
/**
* Add a step to this question attempt.
* @param question_attempt_step $step the new step.
*/
protected function add_step(question_attempt_step $step) {
$this->steps[] = $step;
end($this->steps);
$this->observer->notify_step_added($step, $this, key($this->steps));
}
/**
* Use a strategy to pick a variant.
* @param question_variant_selection_strategy $variantstrategy a strategy.
* @return int the selected variant.
*/
public function select_variant(question_variant_selection_strategy $variantstrategy) {
return $variantstrategy->choose_variant($this->get_question()->get_num_variants(),
$this->get_question()->get_variants_selection_seed());
}
/**
* Start this question attempt.
*
* You should not call this method directly. Call
* {@link question_usage_by_activity::start_question()} instead.
*
* @param string|question_behaviour $preferredbehaviour the name of the
* desired archetypal behaviour, or an actual model instance.
* @param int $variant the variant of the question to start. Between 1 and
* $this->get_question()->get_num_variants() inclusive.
* @param array $submitteddata optional, used when re-starting to keep the same initial state.
* @param int $timestamp optional, the timstamp to record for this action. Defaults to now.
* @param int $userid optional, the user to attribute this action to. Defaults to the current user.
*/
public function start($preferredbehaviour, $variant, $submitteddata = array(),
$timestamp = null, $userid = null) {
// Initialise the behaviour.
$this->variant = $variant;
if (is_string($preferredbehaviour)) {
$this->behaviour =
$this->question->make_behaviour($this, $preferredbehaviour);
} else {
$class = get_class($preferredbehaviour);
$this->behaviour = new $class($this, $preferredbehaviour);
}
// Record the minimum fraction.
$this->minfraction = $this->behaviour->get_min_fraction();
// Initialise the first step.
$firststep = new question_attempt_step($submitteddata, $timestamp, $userid);
$firststep->set_state(question_state::$todo);
if ($submitteddata) {
$this->question->apply_attempt_state($firststep);
} else {
$this->behaviour->init_first_step($firststep, $variant);
}
$this->add_step($firststep);
// Record questionline and correct answer.
$this->questionsummary = $this->behaviour->get_question_summary();
$this->rightanswer = $this->behaviour->get_right_answer_summary();
}
/**
* Start this question attempt, starting from the point that the previous
* attempt $oldqa had reached.
*
* You should not call this method directly. Call
* {@link question_usage_by_activity::start_question_based_on()} instead.
*
* @param question_attempt $oldqa a previous attempt at this quetsion that
* defines the starting point.
*/
public function start_based_on(question_attempt $oldqa) {
$this->start($oldqa->behaviour, $oldqa->get_variant(), $oldqa->get_resume_data());
}
/**
* Used by {@link start_based_on()} to get the data needed to start a new
* attempt from the point this attempt has go to.
* @return array name => value pairs.
*/
protected function get_resume_data() {
return $this->behaviour->get_resume_data();
}
/**
* Get a particular parameter from the current request. A wrapper round
* {@link optional_param()}, except that the results is returned without
* slashes.
* @param string $name the paramter name.
* @param int $type one of the standard PARAM_... constants, or one of the
* special extra constands defined by this class.
* @param array $postdata (optional, only inteded for testing use) take the
* data from this array, instead of from $_POST.
* @return mixed the requested value.
*/
public function get_submitted_var($name, $type, $postdata = null) {
switch ($type) {
case self::PARAM_MARK:
// Special case to work around PARAM_NUMBER converting '' to 0.
$mark = $this->get_submitted_var($name, PARAM_RAW_TRIMMED, $postdata);
if ($mark === '') {
return $mark;
} else {
return $this->get_submitted_var($name, PARAM_NUMBER, $postdata);
}
case self::PARAM_FILES:
return $this->process_response_files($name, $name, $postdata);
case self::PARAM_CLEANHTML_FILES:
$var = $this->get_submitted_var($name, PARAM_CLEANHTML, $postdata);
return $this->process_response_files($name, $name . ':itemid', $postdata, $var);
default:
if (is_null($postdata)) {
$var = optional_param($name, null, $type);
} else if (array_key_exists($name, $postdata)) {
$var = clean_param($postdata[$name], $type);
} else {
$var = null;
}
return $var;
}
}
/**
* Handle a submitted variable representing uploaded files.
* @param string $name the field name.
* @param string $draftidname the field name holding the draft file area id.
* @param array $postdata (optional, only inteded for testing use) take the
* data from this array, instead of from $_POST. At the moment, this
* behaves as if there were no files.
* @param string $text optional reponse text.
* @return question_file_saver that can be used to save the files later.
*/
protected function process_response_files($name, $draftidname, $postdata = null, $text = null) {
if ($postdata) {
// There can be no files with test data (at the moment).
return null;
}
$draftitemid = file_get_submitted_draft_itemid($draftidname);
if (!$draftitemid) {
return null;
}
return new question_file_saver($draftitemid, 'question', 'response_' .
str_replace($this->get_field_prefix(), '', $name), $text);
}
/**
* Get any data from the request that matches the list of expected params.
* @param array $expected variable name => PARAM_... constant.
* @param string $extraprefix '-' or ''.
* @return array name => value.
*/
protected function get_expected_data($expected, $postdata, $extraprefix) {
$submitteddata = array();
foreach ($expected as $name => $type) {
$value = $this->get_submitted_var(
$this->get_field_prefix() . $extraprefix . $name, $type, $postdata);
if (!is_null($value)) {
$submitteddata[$extraprefix . $name] = $value;
}
}
return $submitteddata;
}
/**
* Get all the submitted question type data for this question, whithout checking
* that it is valid or cleaning it in any way.
* @return array name => value.
*/
protected function get_all_submitted_qt_vars($postdata) {
if (is_null($postdata)) {
$postdata = $_POST;
}
$pattern = '/^' . preg_quote($this->get_field_prefix()) . '[^-:]/';
$prefixlen = strlen($this->get_field_prefix());
$submitteddata = array();
foreach ($_POST as $name => $value) {
if (preg_match($pattern, $name)) {
$submitteddata[substr($name, $prefixlen)] = $value;
}
}
return $submitteddata;
}
/**
* Get all the sumbitted data belonging to this question attempt from the
* current request.
* @param array $postdata (optional, only inteded for testing use) take the
* data from this array, instead of from $_POST.
* @return array name => value pairs that could be passed to {@link process_action()}.
*/
public function get_submitted_data($postdata = null) {
$submitteddata = $this->get_expected_data(
$this->behaviour->get_expected_data(), $postdata, '-');
$expected = $this->behaviour->get_expected_qt_data();
if ($expected === self::USE_RAW_DATA) {
$submitteddata += $this->get_all_submitted_qt_vars($postdata);
} else {
$submitteddata += $this->get_expected_data($expected, $postdata, '');
}
return $submitteddata;
}
/**
* Get a set of response data for this question attempt that would get the
* best possible mark. If it is not possible to compute a correct
* response, this method should return null.
* @return array|null name => value pairs that could be passed to {@link process_action()}.
*/
public function get_correct_response() {
$response = $this->question->get_correct_response();
if (is_null($response)) {
return null;
}
$imvars = $this->behaviour->get_correct_response();
foreach ($imvars as $name => $value) {
$response['-' . $name] = $value;
}
return $response;
}
/**
* Change the quetsion summary. Note, that this is almost never necessary.
* This method was only added to work around a limitation of the Opaque
* protocol, which only sends questionLine at the end of an attempt.
* @param $questionsummary the new summary to set.
*/
public function set_question_summary($questionsummary) {
$this->questionsummary = $questionsummary;
$this->observer->notify_attempt_modified($this);
}
/**
* @return string a simple textual summary of the question that was asked.
*/
public function get_question_summary() {
return $this->questionsummary;
}
/**
* @return string a simple textual summary of response given.
*/
public function get_response_summary() {
return $this->responsesummary;
}
/**
* @return string a simple textual summary of the correct resonse.
*/
public function get_right_answer_summary() {
return $this->rightanswer;
}
/**
* Perform the action described by $submitteddata.
* @param array $submitteddata the submitted data the determines the action.
* @param int $timestamp the time to record for the action. (If not given, use now.)
* @param int $userid the user to attribute the aciton to. (If not given, use the current user.)
*/
public function process_action($submitteddata, $timestamp = null, $userid = null) {
$pendingstep = new question_attempt_pending_step($submitteddata, $timestamp, $userid);
if ($this->behaviour->process_action($pendingstep) == self::KEEP) {
$this->add_step($pendingstep);
if ($pendingstep->response_summary_changed()) {
$this->responsesummary = $pendingstep->get_new_response_summary();
}
}
}
/**
* Perform a finish action on this question attempt. This corresponds to an
* external finish action, for example the user pressing Submit all and finish
* in the quiz, rather than using one of the controls that is part of the
* question.
*
* @param int $timestamp the time to record for the action. (If not given, use now.)
* @param int $userid the user to attribute the aciton to. (If not given, use the current user.)
*/
public function finish($timestamp = null, $userid = null) {
$this->process_action(array('-finish' => 1), $timestamp, $userid);
}
/**
* Perform a regrade. This replays all the actions from $oldqa into this
* attempt.
* @param question_attempt $oldqa the attempt to regrade.
* @param bool $finished whether the question attempt should be forced to be finished
* after the regrade, or whether it may still be in progress (default false).
*/
public function regrade(question_attempt $oldqa, $finished) {
$first = true;
foreach ($oldqa->get_step_iterator() as $step) {
if ($first) {
$first = false;
$this->start($oldqa->behaviour, $oldqa->get_variant(), $step->get_all_data(),
$step->get_timecreated(), $step->get_user_id());
} else {
$this->process_action($step->get_submitted_data(),
$step->get_timecreated(), $step->get_user_id());
}
}
if ($finished) {
$this->finish();
}
}
/**
* Perform a manual grading action on this attempt.
* @param $comment the comment being added.
* @param $mark the new mark. (Optional, if not given, then only a comment is added.)
* @param int $timestamp the time to record for the action. (If not given, use now.)
* @param int $userid the user to attribute the aciton to. (If not given, use the current user.)
* @return unknown_type
*/
public function manual_grade($comment, $mark, $timestamp = null, $userid = null) {
$submitteddata = array('-comment' => $comment);
if (!is_null($mark)) {
$submitteddata['-mark'] = $mark;
$submitteddata['-maxmark'] = $this->maxmark;
}
$this->process_action($submitteddata, $timestamp, $userid);
}
/** @return bool Whether this question attempt has had a manual comment added. */
public function has_manual_comment() {
foreach ($this->steps as $step) {
if ($step->has_behaviour_var('comment')) {
return true;
}
}
return false;
}
/**
* @return array(string, int) the most recent manual comment that was added
* to this question, and the FORMAT_... it is.
*/
public function get_manual_comment() {
foreach ($this->get_reverse_step_iterator() as $step) {
if ($step->has_behaviour_var('comment')) {
return array($step->get_behaviour_var('comment'),
$step->get_behaviour_var('commentformat'));
}
}
return array(null, null);
}
/**
* @return array subpartid => object with fields
* ->responseclassid matches one of the values returned from quetion_type::get_possible_responses.
* ->response the actual response the student gave to this part, as a string.
* ->fraction the credit awarded for this subpart, may be null.
* returns an empty array if no analysis is possible.
*/
public function classify_response() {
return $this->behaviour->classify_response();
}
/**
* Create a question_attempt_step from records loaded from the database.
*
* For internal use only.
*
* @param Iterator $records Raw records loaded from the database.
* @param int $questionattemptid The id of the question_attempt to extract.
* @return question_attempt The newly constructed question_attempt_step.
*/
public static function load_from_records($records, $questionattemptid,
question_usage_observer $observer, $preferredbehaviour) {
$record = $records->current();
while ($record->questionattemptid != $questionattemptid) {
$record = $records->next();
if (!$records->valid()) {
throw new coding_exception("Question attempt $questionattemptid not found in the database.");
}
$record = $records->current();
}
try {
$question = question_bank::load_question($record->questionid);
} catch (Exception $e) {
// The question must have been deleted somehow. Create a missing
// question to use in its place.
$question = question_bank::get_qtype('missingtype')->make_deleted_instance(
$record->questionid, $record->maxmark + 0);
}
$qa = new question_attempt($question, $record->questionusageid,
null, $record->maxmark + 0);
$qa->set_database_id($record->questionattemptid);
$qa->set_number_in_usage($record->slot);
$qa->variant = $record->variant + 0;
$qa->minfraction = $record->minfraction + 0;
$qa->set_flagged($record->flagged);
$qa->questionsummary = $record->questionsummary;
$qa->rightanswer = $record->rightanswer;
$qa->responsesummary = $record->responsesummary;
$qa->timemodified = $record->timemodified;
$qa->behaviour = question_engine::make_behaviour(
$record->behaviour, $qa, $preferredbehaviour);
$i = 0;
while ($record && $record->questionattemptid == $questionattemptid && !is_null($record->attemptstepid)) {
$qa->steps[$i] = question_attempt_step::load_from_records($records, $record->attemptstepid);
if ($i == 0) {
$question->apply_attempt_state($qa->steps[0]);
}
$i++;
if ($records->valid()) {
$record = $records->current();
} else {
$record = false;
}
}
$qa->observer = $observer;
return $qa;
}
}
/**
* This subclass of question_attempt pretends that only part of the step history
* exists. It is used for rendering the question in past states.
*
* All methods that try to modify the question_attempt throw exceptions.
*
* @copyright 2010 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_attempt_with_restricted_history extends question_attempt {
/**
* @var question_attempt the underlying question_attempt.
*/
protected $baseqa;
/**
* Create a question_attempt_with_restricted_history
* @param question_attempt $baseqa The question_attempt to make a restricted version of.
* @param int $lastseq the index of the last step to include.
* @param string $preferredbehaviour the preferred behaviour. It is slightly
* annoyting that this needs to be passed, but unavoidable for now.
*/
public function __construct(question_attempt $baseqa, $lastseq, $preferredbehaviour) {
$this->baseqa = $baseqa->get_full_qa();
if ($lastseq < 0 || $lastseq >= $this->baseqa->get_num_steps()) {
throw new coding_exception('$lastseq out of range', $lastseq);
}
$this->steps = array_slice($this->baseqa->steps, 0, $lastseq + 1);
$this->observer = new question_usage_null_observer();
// This should be a straight copy of all the remaining fields.
$this->id = $this->baseqa->id;
$this->usageid = $this->baseqa->usageid;
$this->slot = $this->baseqa->slot;
$this->question = $this->baseqa->question;
$this->maxmark = $this->baseqa->maxmark;
$this->minfraction = $this->baseqa->minfraction;
$this->questionsummary = $this->baseqa->questionsummary;
$this->responsesummary = $this->baseqa->responsesummary;
$this->rightanswer = $this->baseqa->rightanswer;
$this->flagged = $this->baseqa->flagged;
// Except behaviour, where we need to create a new one.
$this->behaviour = question_engine::make_behaviour(
$this->baseqa->get_behaviour_name(), $this, $preferredbehaviour);
}
public function get_full_qa() {
return $this->baseqa;
}
public function get_full_step_iterator() {
return $this->baseqa->get_step_iterator();
}
protected function add_step(question_attempt_step $step) {
coding_exception('Cannot modify a question_attempt_with_restricted_history.');
}
public function process_action($submitteddata, $timestamp = null, $userid = null) {
coding_exception('Cannot modify a question_attempt_with_restricted_history.');
}
public function start($preferredbehaviour, $variant, $submitteddata = array(), $timestamp = null, $userid = null) {
coding_exception('Cannot modify a question_attempt_with_restricted_history.');
}
public function set_database_id($id) {
coding_exception('Cannot modify a question_attempt_with_restricted_history.');
}
public function set_flagged($flagged) {
coding_exception('Cannot modify a question_attempt_with_restricted_history.');
}
public function set_number_in_usage($slot) {
coding_exception('Cannot modify a question_attempt_with_restricted_history.');
}
public function set_question_summary($questionsummary) {
coding_exception('Cannot modify a question_attempt_with_restricted_history.');
}
public function set_usage_id($usageid) {
coding_exception('Cannot modify a question_attempt_with_restricted_history.');
}
}
/**
* A class abstracting access to the {@link question_attempt::$states} array.
*
* This is actively linked to question_attempt. If you add an new step
* mid-iteration, then it will be included.
*
* @copyright 2009 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_attempt_step_iterator implements Iterator, ArrayAccess {
/** @var question_attempt the question_attempt being iterated over. */
protected $qa;
/** @var integer records the current position in the iteration. */
protected $i;
/**
* Do not call this constructor directly.
* Use {@link question_attempt::get_step_iterator()}.
* @param question_attempt $qa the attempt to iterate over.
*/
public function __construct(question_attempt $qa) {
$this->qa = $qa;
$this->rewind();
}
/** @return question_attempt_step */
public function current() {
return $this->offsetGet($this->i);
}
/** @return int */
public function key() {
return $this->i;
}
public function next() {
++$this->i;
}
public function rewind() {
$this->i = 0;
}
/** @return bool */
public function valid() {
return $this->offsetExists($this->i);
}
/** @return bool */
public function offsetExists($i) {
return $i >= 0 && $i < $this->qa->get_num_steps();
}
/** @return question_attempt_step */
public function offsetGet($i) {
return $this->qa->get_step($i);
}
public function offsetSet($offset, $value) {
throw new coding_exception('You are only allowed read-only access to question_attempt::states through a question_attempt_step_iterator. Cannot set.');
}
public function offsetUnset($offset) {
throw new coding_exception('You are only allowed read-only access to question_attempt::states through a question_attempt_step_iterator. Cannot unset.');
}
}
/**
* A variant of {@link question_attempt_step_iterator} that iterates through the
* steps in reverse order.
*
* @copyright 2009 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_attempt_reverse_step_iterator extends question_attempt_step_iterator {
public function next() {
--$this->i;
}
public function rewind() {
$this->i = $this->qa->get_num_steps() - 1;
}
}
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