@oat-sa/tao-test-runner-qti/src/plugins/tools/answerMasking/answerMasking.js

TAO Test Runner QTI implementation

/**
 * 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) 2017 (original work) Open Assessment Technologies SA;
 */
/**
 * @author Christophe Noël <christophe@taotesting.com>
 */
import _ from 'lodash';
import $ from 'jquery';
import statifier from 'core/statifier';
import componentFactory from 'ui/component';
import maskTpl from 'taoQtiTest/runner/plugins/tools/answerMasking/tpl/mask';

var ns = '.answerMasking';

/**
 * @param {jQuery} $contentArea - DOM element containing the rendered item
 */
export default function answerMaskingFactory($contentArea) {
    var answerMasking,
        allMasks = [],
        maskApi = {
            /**
             * Toggle mask visibility
             * @returns {component}
             */
            toggle: function toggle() {
                if (this.is('masked')) {
                    return this.reveal();
                } else {
                    return this.mask();
                }
            },

            /**
             * Show the choice under the current mask
             * @returns {component}
             */
            reveal: function reveal() {
                var $container = this.getContainer();
                $container.removeClass('masked');
                $container.find('input').removeAttr('disabled');

                this.setState('masked', false);

                return this;
            },

            /**
             * Cover the whole choice with the mask
             * @returns {component}
             */
            mask: function mask() {
                var $container = this.getContainer();
                $container.addClass('masked');
                $container.find('input').attr('disabled', 'disabled');

                this.setState('masked', true);

                return this;
            }
        };

    /**
     * Creates a ui/component to serve as a mask over a QTI Choice
     * @param {jQuery} $container - the qti-choice element
     * @returns {component}
     */
    function createMask($container) {
        return componentFactory(maskApi)
            .setTemplate(maskTpl)
            .on('render', function() {
                var self = this,
                    $component = this.getElement();

                $component.on(`click${ns}`, function(e) {
                    e.stopPropagation();
                    e.preventDefault();

                    self.toggle();
                });
            })
            .on('destroy', function() {
                var $component = this.getElement();
                $component.off(ns);
            })
            .init()
            .render($container)
            .mask();
    }

    /**
     * The answer masking helper
     */
    answerMasking = {
        /**
         * Enable the answer masking functionality by creating masks over the Qti Choices
         */
        enable: function enable() {
            var $choiceInteractions = $contentArea.find('.qti-choiceInteraction'),
                $qtiChoices = $contentArea.find('.qti-choice');

            allMasks = [];

            $choiceInteractions.addClass('maskable');

            $qtiChoices.each(function() {
                var $choice = $(this);
                allMasks.push(createMask($choice));
            });

            this.setState('enabled', true);
        },

        /**
         * Remove any answerMasking-related markup from the rendered item
         */
        disable: function disable() {
            var $choiceInteractions = $contentArea.find('.qti-choiceInteraction');
            $choiceInteractions.removeClass('maskable');

            allMasks.forEach(function(mask) {
                mask.reveal(); // remove class on container
                mask.destroy();
            });

            allMasks = [];

            this.setState('enabled', false);
        },

        /**
         * Return the current state of the masks
         * @returns {Boolean[]} - true if the choice is masked, false if the choice is revealed
         */
        getMasksState: function getMasksState() {
            var state = allMasks.map(function(mask) {
                return mask.is('masked');
            });
            return state;
        },

        /**
         * Restore a previously saved state for the masked choices
         * @param {Boolean[]} state - array of boolean, most probably given by the getMasksState method
         */
        setMasksState: function setMasksState(state) {
            state = state || [];

            state.forEach(function(masked, index) {
                var mask = allMasks[index];

                if (_.isObject(mask) && _.isFunction(mask.reveal) && !masked) {
                    mask.reveal();
                }
            });
        }
    };

    statifier(answerMasking);

    return answerMasking;
}