@oat-sa/tao-item-runner-qti/src/qtiCommonRenderer/helpers/PciResponse.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 (original work) Open Assessment Technologies SA ;
 */
import _ from 'lodash';
import pciPrettyPrint from 'taoQtiItem/qtiCommonRenderer/helpers/PciPrettyPrint';

var _qtiModelPciResponseCardinalities = {
    single: 'base',
    multiple: 'list',
    ordered: 'list',
    record: 'record'
};

export default {
    /**
     * Parse a response variable formatted according to IMS PCI: http://www.imsglobal.org/assessment/pciv1p0cf/imsPCIv1p0cf.html#_Toc353965343
     *
     * @see serialize
     * @param {Object} response
     * @param {Object} interaction
     * @returns {Array}
     */
    unserialize: function(response, interaction) {
        var ret = [],
            responseDeclaration = interaction.getResponseDeclaration(),
            baseType = responseDeclaration.attr('baseType'),
            cardinality = responseDeclaration.attr('cardinality'),
            mappedCardinality;

        if (_qtiModelPciResponseCardinalities[cardinality]) {
            mappedCardinality = _qtiModelPciResponseCardinalities[cardinality];
            var responseValues = response[mappedCardinality];

            if (responseValues === null) {
                ret = [];
            } else if (_.isObject(responseValues)) {
                if (responseValues[baseType] !== undefined) {
                    ret = responseValues[baseType];
                    ret = _.isArray(ret) ? ret : [ret];
                } else {
                    throw 'invalid response baseType';
                }
            } else {
                throw 'invalid response cardinality, expected ' + cardinality + ' (' + mappedCardinality + ')';
            }
        } else {
            throw 'unknown cardinality in the responseDeclaration of the interaction';
        }

        return ret;
    },
    /**
     * Serialize the input response array into the format to be send to result server according to IMS PCI recommendation :
     * http://www.imsglobal.org/assessment/pciv1p0cf/imsPCIv1p0cf.html#_Toc353965343
     * With the only exception for empty response, which is represented by a javascript "null" value
     *
     * @see http://www.imsglobal.org/assessment/pciv1p0cf/imsPCIv1p0cf.html#_Toc353965343
     * @param {Array} responseValues
     * @param {Object} interaction
     * @returns {Object|null}
     */
    serialize: function(responseValues, interaction) {
        if (!_.isArray(responseValues)) {
            throw 'invalid argument : responseValues must be an Array';
        }

        var response = {},
            responseDeclaration = interaction.getResponseDeclaration(),
            baseType = responseDeclaration.attr('baseType'),
            cardinality = responseDeclaration.attr('cardinality'),
            mappedCardinality;

        responseValues = _.map(responseValues || [], function(v) {
            return baseType === 'boolean' ? v === true || v === 'true' : v;
        });

        if (_qtiModelPciResponseCardinalities[cardinality]) {
            mappedCardinality = _qtiModelPciResponseCardinalities[cardinality];
            if (mappedCardinality === 'base') {
                if (responseValues.length === 0) {
                    //return empty response:
                    response.base = null;
                } else {
                    response.base = {};
                    response.base[baseType] = responseValues[0];
                }
            } else {
                response[mappedCardinality] = {};
                response[mappedCardinality][baseType] = responseValues;
            }
        } else {
            throw 'unknown cardinality in the responseDeclaration of the interaction';
        }

        return response;
    },
    isEmpty: function(response) {
        return (
            response === null ||
            _.isEmpty(response) ||
            response.base === null ||
            (_.isArray(response.list) && _.isEmpty(response.list)) ||
            (_.isArray(response.record) && _.isEmpty(response.record))
        );
    },

    /**
     * Print a PCI JSON response into a human-readable string.
     *
     * @param {Object} response A response in PCI JSON representation.
     * @returns {String} A human-readable version of the PCI JSON representation.
     */
    prettyPrint: function(response) {
        var print = '';

        if (typeof response.base !== 'undefined') {
            // -- BaseType.
            print += pciPrettyPrint.printBase(response, true);
        } else if (typeof response.list !== 'undefined') {
            // -- ListType
            print += pciPrettyPrint.printList(response, true);
        } else if (typeof response.record !== 'undefined') {
            // -- RecordType
            print += pciPrettyPrint.printRecord(response, true);
        } else {
            throw 'Not a valid PCI JSON Response';
        }

        return print;
    }
};