@oat-sa/tao-item-runner-qti/src/scoring/processor/expressions/randomFloat.js

TAO QTI Item Runner modules

/*
 * This program 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; under version 2
 * of the License (non-upgradable).
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright (c) 2015-2019 (original work) Open Assessment Technlogies SA (under the project TAO-PRODUCT);
 *
 */

/**
 * The randomFloat expression processor.
 *
 * @see http://www.imsglobal.org/question/qtiv2p1/imsqti_infov2p1.html#element10588
 *
 * @author Bertrand Chevrier <bertrand@taotesting.com>
 */
import _ from 'lodash';
import errorHandler from 'taoQtiItem/scoring/processor/errorHandler';

/**
 * Correct expression
 * @type {ExpressionProcesssor}
 * @exports taoQtiItem/scoring/processor/expressions/randomFloat
 */
var randomFloatProcessor = {

    /**
     * Process the expression
     * @returns {ProcessingValue} the value from the expression
     */
    process: function() {

        var min = this.preProcessor.parseValue(this.expression.attributes.min, 'floatOrVariableRef');
        var max = this.preProcessor.parseValue(this.expression.attributes.max, 'floatOrVariableRef');

        var result = {
            cardinality: 'single',
            baseType: 'float'
        };

        //verfiy attributes
        if (_.isNaN(min) || !_.isFinite(min)) {
            min = 0;
        }
        if (_.isNaN(max) || !_.isFinite(max)) {
            return errorHandler.throw('scoring', new Error('The max value of a randomFloat expresssion should be a finite integer.'));
        }

        if (min > max) {
            return errorHandler.throw('scoring', new Error('Come on! How am I supposed to generate a random number from a negative range : min > max'));
        }

        //get the random value
        result.value = _.random(min, max, true);

        return result;
    }
};

export default randomFloatProcessor;