Proyectos de Subversion Moodle

// This file is part of Moodle - http://moodle.org/

//

// Moodle 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, either version 3 of the License, or

// (at your option) any later version.

//

// Moodle 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 Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * JavaScript for the random_question_form_preview of the

 * add_random_form class.

 *

 * @module    mod_quiz/random_question_form_preview

 * @copyright 2018 Ryan Wyllie <ryan@moodle.com>

 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

define(

    [

        'jquery',

        'core/ajax',

        'core/str',

        'core/notification',

        'core/templates',

        'core/paged_content_factory'

    ],

    function(

        $,

        Ajax,

        Str,

        Notification,

        Templates,

        PagedContentFactory

    ) {

    var ITEMS_PER_PAGE = 5;

    var TEMPLATE_NAME = 'mod_quiz/random_question_form_preview_question_list';

    var SELECTORS = {

        LOADING_ICON_CONTAINER: '[data-region="overlay-icon-container"]',

        QUESTION_COUNT_CONTAINER: '[data-region="question-count-container"]',

        QUESTION_LIST_CONTAINER: '[data-region="question-list-container"]'

    };

    /**

     * Show the loading spinner over the preview section.

     *

     * @param  {jquery} root The root element.

     */

    var showLoadingIcon = function(root) {

        root.find(SELECTORS.LOADING_ICON_CONTAINER).removeClass('hidden');

    };

    /**

     * Hide the loading spinner.

     *

     * @param  {jquery} root The root element.

     */

    var hideLoadingIcon = function(root) {

        root.find(SELECTORS.LOADING_ICON_CONTAINER).addClass('hidden');

    };

    /**

     * Render the section of text to show the question count.

     *

     * @param  {jquery} root The root element.

     * @param  {int} questionCount The number of questions.

     */

    var renderQuestionCount = function(root, questionCount) {

        Str.get_string('questionsmatchingfilter', 'mod_quiz', questionCount)

            .then(function(string) {

                root.find(SELECTORS.QUESTION_COUNT_CONTAINER).html(string);

                return;

            })

            .fail(Notification.exception);

    };

    /**

     * Send a request to the server for more questions.

     *

     * @param  {int} categoryId A question category id.

     * @param  {bool} includeSubcategories If the results should include subcategory questions

     * @param  {int[]} tagIds The list of tag ids that each question must have.

     * @param  {int} contextId The context where the questions will be added.

     * @param  {int} limit How many questions to retrieve.

     * @param  {int} offset How many questions to skip from the start of the result set.

     * @return {promise} Resolved when the preview section has rendered.

     */

    var requestQuestions = function(

        categoryId,

        includeSubcategories,

        tagIds,

        contextId,

        limit,

        offset

    ) {

        var request = {

            methodname: 'core_question_get_random_question_summaries',

            args: {

                categoryid: categoryId,

                includesubcategories: includeSubcategories,

                tagids: tagIds,

                contextid: contextId,

                limit: limit,

                offset: offset

            }

        };

        return Ajax.call([request])[0];

    };

    /**

     * Build a paged content widget for questions with the given criteria. The

     * criteria is used to fetch more questions from the server as the user

     * requests new pages.

     *

     * @param  {int} categoryId A question category id.

     * @param  {bool} includeSubcategories If the results should include subcategory questions

     * @param  {int[]} tagIds The list of tag ids that each question must have.

     * @param  {int} contextId The context where the questions will be added.

     * @param  {int} totalQuestionCount How many questions match the criteria above.

     * @param  {object[]} firstPageQuestions List of questions for the first page.

     * @return {promise} A promise resolved with the HTML and JS for the paged content.

     */

    var renderQuestionsAsPagedContent = function(

        categoryId,

        includeSubcategories,

        tagIds,

        contextId,

        totalQuestionCount,

        firstPageQuestions

    ) {

        // Provide a callback, renderQuestionsPages,

        // to control how the questions on each page are rendered.

        return PagedContentFactory.createFromAjax(

            totalQuestionCount,

            ITEMS_PER_PAGE,

            // Callback function to render the requested pages.

            function(pagesData) {

                return pagesData.map(function(pageData) {

                    var limit = pageData.limit;

                    var offset = pageData.offset;

                    if (offset == 0) {

                        // The first page is being requested and we've already got

                        // that data so we can just render it immediately.

                        return Templates.render(TEMPLATE_NAME, {questions: firstPageQuestions});

                    } else {

                        // Otherwise we need to ask the server for the data.

                        return requestQuestions(

                            categoryId,

                            includeSubcategories,

                            tagIds,

                            contextId,

                            limit,

                            offset

                        )

                        .then(function(response) {

                            var questions = response.questions;

                            return Templates.render(TEMPLATE_NAME, {questions: questions});

                        })

                        .fail(Notification.exception);

                    }

                });

            }

        );

    };

    /**

     * Re-render the preview section based on the provided filter criteria.

     *

     * @param  {jquery} root The root element.

     * @param  {int} categoryId A question category id.

     * @param  {bool} includeSubcategories If the results should include subcategory questions

     * @param  {int[]} tagIds The list of tag ids that each question must have.

     * @param  {int} contextId The context where the questions will be added.

     * @return {promise} Resolved when the preview section has rendered.

     */

    var reload = function(root, categoryId, includeSubcategories, tagIds, contextId) {

        // Show the loading spinner to tell the user that something is happening.

        showLoadingIcon(root);

        // Load the first set of questions.

        return requestQuestions(categoryId, includeSubcategories, tagIds, contextId, ITEMS_PER_PAGE, 0)

            .then(function(response) {

                var totalCount = response.totalcount;

                // Show the help message for the user to indicate how many questions

                // match their filter criteria.

                renderQuestionCount(root, totalCount);

                return response;

            })

            .then(function(response) {

                var totalQuestionCount = response.totalcount;

                var questions = response.questions;

                if (questions.length) {

                    // We received some questions so render them as paged content

                    // with a paging bar.

                    return renderQuestionsAsPagedContent(

                        categoryId,

                        includeSubcategories,

                        tagIds,

                        contextId,

                        totalQuestionCount,

                        questions

                    );

                } else {

                    // If we didn't receive any questions then we can return empty

                    // HTML and JS to clear the preview section.

                    return $.Deferred().resolve('', '');

                }

            })

            .then(function(html, js) {

                // Show the user the question set.

                var container = root.find(SELECTORS.QUESTION_LIST_CONTAINER);

                Templates.replaceNodeContents(container, html, js);

                return;

            })

            .always(function() {

                hideLoadingIcon(root);

            })

            .fail(Notification.exception);

    };

    return {

        reload: reload,

        showLoadingIcon: showLoadingIcon,

        hideLoadingIcon: hideLoadingIcon

    };

});