chamilo-lms2/main/exercise/calculated_answer.class.php

<?php
/* For licensing terms, see /license.txt */

use Webit\Util\EvalMath\EvalMath;

/**
 *  Class CalculatedAnswer
 *  This class contains calculated answer form and answer processing functions
 *
 *  @author Imanol Losada
 *  @package chamilo.exercise
 **/
class CalculatedAnswer extends Question
{
    public static $typePicture = 'calculated_answer.png';
    public static $explanationLangVar = 'CalculatedAnswer';

    /**
     * Constructor
     */
    public function __construct()
    {
        parent::__construct();
        $this->type = CALCULATED_ANSWER;
        $this->isContent = $this->getIsContent();
    }

    /**
     * @inheritdoc
     */
    public function createAnswersForm($form)
    {
        $defaults = array();
        if (!empty($this->id)) {
            $objAnswer = new Answer($this->id);
            $preArray = explode('@@', $objAnswer->selectAnswer(1));
            $defaults['formula'] = array_pop($preArray);
            $defaults['answer'] = array_shift($preArray);
            $defaults['answer'] = preg_replace("/\[.*\]/", "", $defaults['answer']);
            $defaults['weighting'] = $this->weighting;
        } else {
            $defaults['answer'] = get_lang('DefaultTextInBlanks');
        }
        $lowestValue = "1.00";
        $highestValue = "20.00";

        // javascript //
        echo '<script>
            function parseTextNumber(textNumber, floatValue) {
                if (textNumber.indexOf(".") > -1) {
                    textNumber = parseFloat(textNumber);
                    floatValue.exists = "true";
                } else {
                    textNumber = parseInt(textNumber);
                }
                return textNumber;
            }

            function updateRandomValue(element) {
                // "floatValue" helps to distinguish between an integer (10) and a float with all 0 decimals (10.00)
                var floatValue = { exists: "false" };
                var index = (element.name).match(/\[[^\]]*\]/g);
                var lowestValue = parseTextNumber(document.getElementById("lowestValue"+index).value, floatValue);
                var highestValue = parseTextNumber(document.getElementById("highestValue"+index).value, floatValue);
                var result = Math.random() * (highestValue - lowestValue) + lowestValue;
                if (floatValue.exists == "true") {
                    result = parseFloat(result).toFixed(2);
                } else {
                    result = parseInt(result);
                }
                document.getElementById("randomValue"+index).innerHTML = "'.get_lang("ExampleValue").': " + result;
           }

            CKEDITOR.on("instanceCreated", function(e) {
                if (e.editor.name === "answer") {
                    e.editor.on("change", updateBlanks);
                }
            });

            var firstTime = true;

            function updateBlanks(e) {
                if (firstTime) {
                    field = document.getElementById("answer");
                    var answer = field.value;
                } else {
                    var answer = e.editor.getData();
                }
                var blanks = answer.match(/\[[^\]]*\]/g);
                var fields = "<div class=\"form-group\"><label class=\"col-sm-2\">'.get_lang('VariableRanges').'</label><div class=\"col-sm-8\"><table>";
                if (blanks!=null) {
                    if (typeof updateBlanks.randomValues === "undefined") {
                        updateBlanks.randomValues = [];
                    }
                    for (i=0 ; i<blanks.length ; i++){
                        if (document.getElementById("lowestValue["+i+"]") && document.getElementById("highestValue["+i+"]")) {
                            lowestValue = document.getElementById("lowestValue["+i+"]").value;
                            highestValue = document.getElementById("highestValue["+i+"]").value;
                        } else {
                            lowestValue = '.$lowestValue.'.toFixed(2);
                            highestValue = '.$highestValue.'.toFixed(2);
                            for (j=0; j<blanks.length; j++) {
                                updateBlanks.randomValues[j] = parseFloat(Math.random() * (highestValue - lowestValue) + lowestValue).toFixed(2);
                            }
                        }
                        fields += "<tr><td><label>"+blanks[i]+"</label></td><td><input class=\"span1\" style=\"margin-left: 0em;\" size=\"5\" value=\""+lowestValue+"\" type=\"text\" id=\"lowestValue["+i+"]\" name=\"lowestValue["+i+"]\" onblur=\"updateRandomValue(this)\"/></td><td><input class=\"span1\" style=\"margin-left: 0em; width:80px;\" size=\"5\" value=\""+highestValue+"\" type=\"text\" id=\"highestValue["+i+"]\" name=\"highestValue["+i+"]\" onblur=\"updateRandomValue(this)\"/></td><td><label class=\"span3\" id=\"randomValue["+i+"]\"/>'.get_lang('ExampleValue').': "+updateBlanks.randomValues[i]+"</label></td></tr>";
                    }
                }
                document.getElementById("blanks_weighting").innerHTML = fields + "</table></div></div>";
                if (firstTime) {
                    firstTime = false;
                }
            }

            window.onload = updateBlanks;

        </script>';

        // answer
        $form->addElement('label', null, '<br /><br />'.get_lang('TypeTextBelow').', '.get_lang('And').' '.get_lang('UseTagForBlank'));
        $form->addElement(
            'html_editor',
            'answer',
            Display::return_icon('fill_field.png'),
            array(
                'id' => 'answer',
                'onkeyup' => 'javascript: updateBlanks(this);',
            ),
            array(
                'ToolbarSet' => 'TestQuestionDescription',
                'Width' => '100%',
                'Height' => '350',
            )
        );

        $form->addRule('answer', get_lang('GiveText'), 'required');
        $form->addRule('answer', get_lang('DefineBlanks'), 'regex', '/\[.*\]/');

        $form->addElement('label', null, get_lang('IfYouWantOnlyIntegerValuesWriteBothLimitsWithoutDecimals'));
        $form->addElement('html', '<div id="blanks_weighting"></div>');

        $notationListButton = Display::url(
            get_lang('NotationList'),
            api_get_path(WEB_CODE_PATH).'exercise/evalmathnotation.php',
            array(
                'class' => 'btn btn-info ajax',
                'data-title' => get_lang('NotationList'),
                '_target' => '_blank'
            )
        );
        $form->addElement(
            'label',
            null,
            $notationListButton
        );

        $form->addElement('label', null, get_lang('FormulaExample'));
        $form->addElement('text', 'formula', get_lang('Formula'), array('id' => 'formula'));
        $form->addRule('formula', get_lang('GiveFormula'), 'required');

        $form->addElement('text', 'weighting', get_lang('Weighting'), array('id' => 'weighting'));
        $form->setDefaults(array('weighting' => '10'));

        $form->addElement('text', 'answerVariations', get_lang('AnswerVariations'));
        $form->addRule(
            'answerVariations',
            get_lang('GiveAnswerVariations'),
            'required'
        );
        $form->setDefaults(array('answerVariations' => '1'));

        global $text;
        // setting the save button here and not in the question class.php
        $form->addButtonSave($text, 'submitQuestion');

        if (!empty($this->id)) {
            $form -> setDefaults($defaults);
        } else {
            if ($this->isContent == 1) {
                $form->setDefaults($defaults);
            }
        }
    }

    /**
     * @inheritdoc
     */
    public function processAnswersCreation($form, $exercise)
    {
        if (!self::isAnswered()) {
            $table = Database::get_course_table(TABLE_QUIZ_ANSWER);
            Database::delete(
                $table,
                array(
                    'c_id = ? AND question_id = ?' => array(
                        $this->course['real_id'],
                        $this->id
                    )
                )
            );
            $answer = $form->getSubmitValue('answer');
            $formula = $form->getSubmitValue('formula');
            $lowestValues = $form->getSubmitValue('lowestValue');
            $highestValues = $form->getSubmitValue('highestValue');
            $answerVariations = $form->getSubmitValue('answerVariations');
            $this->weighting = $form->getSubmitValue('weighting');

            // Create as many answers as $answerVariations
            for ($j = 0; $j < $answerVariations; $j++) {
                $auxAnswer = $answer;
                $auxFormula = $formula;
                $nb = preg_match_all('/\[[^\]]*\]/', $auxAnswer, $blanks);
                if ($nb > 0) {
                    for ($i = 0; $i < $nb; ++$i) {
                        $blankItem = $blanks[0][$i];
                        $replace = array("[", "]");
                        $newBlankItem = str_replace($replace, "", $blankItem);
                        $newBlankItem = "[".trim($newBlankItem)."]";
                        // take random float values when one or both edge values have a decimal point
                        $randomValue =
                            (strpos($lowestValues[$i], '.') !== false ||
                            strpos($highestValues[$i], '.') !== false) ?
                            mt_rand($lowestValues[$i] * 100, $highestValues[$i] * 100) / 100 : mt_rand($lowestValues[$i], $highestValues[$i]);
                        $auxAnswer = str_replace($blankItem, $randomValue, $auxAnswer);
                        $auxFormula = str_replace($blankItem, $randomValue, $auxFormula);
                    }
                    $math = new EvalMath();
                    $result = $math->evaluate($auxFormula);
                    $result = number_format($result, 2, ".", "");
                    // Remove decimal trailing zeros
                    $result = rtrim($result, "0");
                    // If it is an integer (ends in .00) remove the decimal point
                    if (mb_substr($result, -1) === ".") {
                        $result = str_replace(".", "", $result);
                    }
                    // Attach formula
                    $auxAnswer .= " [".$result."]@@".$formula;
                }
                $this->save();
                $objAnswer = new Answer($this->id);
                $objAnswer->createAnswer($auxAnswer, 1, '', $this->weighting, '');
                $objAnswer->position = array();
                $objAnswer->save();
            }
        }
    }

    /**
     * @inheritdoc
     */
    public function return_header($exercise, $counter = null, $score = null)
    {
        $header = parent::return_header($exercise, $counter, $score);
        $header .= '<table class="'.$this->question_table_class.'">
            <tr>
                <th>'.get_lang('Answer').'</th>
                <th>'.get_lang('YourChoice').'</th>
                <th>'.get_lang('ExpectedChoice').'</th>
                <th>'.get_lang('Status').'</th>
            </tr>';
        return $header;
    }

    /**
     * Returns true if the current question has been attempted to be answered
     * @return boolean
     */
    public function isAnswered()
    {
        $table = Database::get_main_table(TABLE_STATISTIC_TRACK_E_ATTEMPT);
        $result = Database::select(
            'question_id',
            $table,
            array(
                'where' => array(
                    'question_id = ? AND c_id = ?' => array(
                        $this->id,
                        $this->course['real_id']
                    )
                )
            )
        );

        return empty($result) ? false : true;
    }
}