@oat-sa/tao-item-runner-qti/src/scoring/processor/responseRules/processor.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);
 *
 */

/**
 * Single entry point for the response rules processors.
 *
 * @author Bertrand Chevrier <bertrand@taotesting.com>
 */
import _ from 'lodash';
import errorHandler from 'taoQtiItem/scoring/processor/errorHandler';

//keeps the references of processors (this is something we may load dynamically)
var processors = {};

/**
 * Provides you a processor from an rule (definition) and against a state.
 * The Processor must have been registerd previously.
 * See it as a kind of factory.
 *
 * @param {Object} rule - the expression definition
 * @param {String} rule.qtiClass - the expression name that should mastch with the processor name
 * @param {Object} state - the state to give to the processor to lookup for variables like responses
 * @returns {RuleProcessorWrapper} a transparent object that delegates the calls to the processor
 * @throws {Error} by trying to use an unregistered processor
 */
var responseRuleProcessor = function responseRuleProcessor(rule, state) {

    var name = rule.qtiClass;
    var processor = processors[name];

    if (!processor) {
        return errorHandler.throw('scoring', new Error('No processor found for ' + name));
    }

    processor.rule = rule;
    processor.state = state;

    /**
     * Wrap and forward the processing to the enclosed processor
     * @typedef RuleProcessorWrapper
     * @property {Function} process - call's processor's process
     */
    return {
        process: function process() {
            //forward the call to the related expression processor
            return processor.process.apply(processor, [].slice.call(arguments, 1));
        }
    };
};

/**
 * Register a processor
 * @param {String} name - the processor name
 * @param {ResponseRuleProcessor} processor - the processor to register
 * @throws {TypeError} when a parameter isn't valid
 */
responseRuleProcessor.register = function register(name, processor) {

    if (_.isEmpty(name)) {
        return errorHandler.throw('scoring', new TypeError('Please give a valid name to your processor'));
    }
    if (!_.isPlainObject(processor) || !_.isFunction(processor.process)) {
        return errorHandler.throw('scoring', new TypeError('The processor must be an object that contains a process method.'));
    }

    processors[name] = processor;
};

/**
 * @exports taoQtiItem/scoring/processor/responseRule/processor
 */
export default responseRuleProcessor;