MDL-66609 core_h5p: Player and embed.php implementation

h5p/embed.php

@@ -0,0 +1,93 @@
+<?php
+// 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/>.
+
+/**
+ * Render H5P content from an H5P file.
+ *
+ * @package    core_h5p
+ * @copyright  2019 Sara Arjona <sara@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+require_once(__DIR__ . '/../config.php');
+
+// The login check is done inside the player when getting the file from the url param.
+
+$url = required_param('url', PARAM_LOCALURL);
+
+$config = new stdClass();
+$config->frame = optional_param('frame', 0, PARAM_INT);
+$config->export = optional_param('export', 0, PARAM_INT);
+$config->embed = optional_param('embed', 0, PARAM_INT);
+$config->copyright = optional_param('copyright', 0, PARAM_INT);
+
+$PAGE->set_url(new \moodle_url('/h5p/embed.php', array('url' => $url)));
+try {
+    $h5pplayer = new \core_h5p\player($url, $config);
+    $messages = $h5pplayer->get_messages();
+
+} catch (\Exception $e) {
+    $messages = (object) [
+        'exception' => $e->getMessage(),
+    ];
+}
+
+if (empty($messages->error) && empty($messages->exception)) {
+    // Configure page.
+    $PAGE->set_context($h5pplayer->get_context());
+    $PAGE->set_title($h5pplayer->get_title());
+    $PAGE->set_heading($h5pplayer->get_title());
+
+    // Embed specific page setup.
+    $PAGE->add_body_class('h5p-embed');
+    $PAGE->set_pagelayout('embedded');
+
+    // Load the embed.js to allow communication with the parent window.
+    $PAGE->requires->js(new moodle_url('/h5p/js/embed.js'));
+
+    // Add H5P assets to the page.
+    $h5pplayer->add_assets_to_page();
+
+    // Check if there is some error when adding assets to the page.
+    $messages = $h5pplayer->get_messages();
+    if (empty($messages->error) && empty($messages->exception)) {
+
+        // Print page HTML.
+        echo $OUTPUT->header();
+
+        echo $h5pplayer->output();
+    }
+} else {
+    // If there is any error or exception when creating the player, it should be displayed.
+    $PAGE->set_context(context_system::instance());
+    $title = get_string('h5p', 'core_h5p');
+    $PAGE->set_title($title);
+    $PAGE->set_heading($title);
+
+    $PAGE->add_body_class('h5p-embed');
+    $PAGE->set_pagelayout('embedded');
+
+    // Errors can't be printed yet, because some more errors might been added while preparing the output
+}
+
+if (!empty($messages->error) || !empty($messages->exception)) {
+    // Print all the errors.
+    echo $OUTPUT->header();
+    $messages->h5picon = new \moodle_url('/h5p/pix/icon.svg');
+    echo $OUTPUT->render_from_template('core_h5p/h5perror', $messages);
+}
+
+echo $OUTPUT->footer();

h5p/js/embed.js

@@ -0,0 +1,155 @@
+// 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/>.
+
+/* global H5PEmbedCommunicator:true */
+/**
+ * When embedded the communicator helps talk to the parent page.
+ * This is a copy of the H5P.communicator, which we need to communicate in this context
+ *
+ * @type {H5PEmbedCommunicator}
+ * @module     core_h5p
+ * @copyright  2019 Joubel AS <contact@joubel.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+H5PEmbedCommunicator = (function() {
+    /**
+     * @class
+     * @private
+     */
+    function Communicator() {
+        var self = this;
+
+        // Maps actions to functions.
+        var actionHandlers = {};
+
+        // Register message listener.
+        window.addEventListener('message', function receiveMessage(event) {
+            if (window.parent !== event.source || event.data.context !== 'h5p') {
+                return; // Only handle messages from parent and in the correct context.
+            }
+
+            if (actionHandlers[event.data.action] !== undefined) {
+                actionHandlers[event.data.action](event.data);
+            }
+        }, false);
+
+        /**
+         * Register action listener.
+         *
+         * @param {string} action What you are waiting for
+         * @param {function} handler What you want done
+         */
+        self.on = function(action, handler) {
+            actionHandlers[action] = handler;
+        };
+
+        /**
+         * Send a message to the all mighty father.
+         *
+         * @param {string} action
+         * @param {Object} [data] payload
+         */
+        self.send = function(action, data) {
+            if (data === undefined) {
+                data = {};
+            }
+            data.context = 'h5p';
+            data.action = action;
+
+            // Parent origin can be anything.
+            window.parent.postMessage(data, '*');
+        };
+    }
+
+    return (window.postMessage && window.addEventListener ? new Communicator() : undefined);
+})();
+
+document.onreadystatechange = function() {
+    // Wait for instances to be initialize.
+    if (document.readyState !== 'complete') {
+        return;
+    }
+
+    // Check for H5P iFrame.
+    var iFrame = document.querySelector('.h5p-iframe');
+    if (!iFrame || !iFrame.contentWindow) {
+        return;
+    }
+    var H5P = iFrame.contentWindow.H5P;
+
+    // Check for H5P instances.
+    if (!H5P || !H5P.instances || !H5P.instances[0]) {
+        return;
+    }
+
+    var resizeDelay;
+    var instance = H5P.instances[0];
+    var parentIsFriendly = false;
+
+    // Handle that the resizer is loaded after the iframe.
+    H5PEmbedCommunicator.on('ready', function() {
+        H5PEmbedCommunicator.send('hello');
+    });
+
+    // Handle hello message from our parent window.
+    H5PEmbedCommunicator.on('hello', function() {
+        // Initial setup/handshake is done.
+        parentIsFriendly = true;
+
+        // Hide scrollbars for correct size.
+        iFrame.contentDocument.body.style.overflow = 'hidden';
+
+        document.body.classList.add('h5p-resizing');
+
+        // Content need to be resized to fit the new iframe size.
+        H5P.trigger(instance, 'resize');
+    });
+
+    // When resize has been prepared tell parent window to resize.
+    H5PEmbedCommunicator.on('resizePrepared', function() {
+        H5PEmbedCommunicator.send('resize', {
+            scrollHeight: iFrame.contentDocument.body.scrollHeight
+        });
+    });
+
+    H5PEmbedCommunicator.on('resize', function() {
+        H5P.trigger(instance, 'resize');
+    });
+
+    H5P.on(instance, 'resize', function() {
+        if (H5P.isFullscreen) {
+            return; // Skip iframe resize.
+        }
+
+        // Use a delay to make sure iframe is resized to the correct size.
+        clearTimeout(resizeDelay);
+        resizeDelay = setTimeout(function() {
+            // Only resize if the iframe can be resized.
+            if (parentIsFriendly) {
+                H5PEmbedCommunicator.send('prepareResize',
+                    {
+                        scrollHeight: iFrame.contentDocument.body.scrollHeight,
+                        clientHeight: iFrame.contentDocument.body.clientHeight
+                    }
+                );
+            } else {
+                H5PEmbedCommunicator.send('hello');
+            }
+        }, 0);
+    });
+
+    // Trigger initial resize for instance.
+    H5P.trigger(instance, 'resize');
+};

h5p/lib.php

@@ -0,0 +1,112 @@
+<?php
+// 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/>.
+
+/**
+ * Callbacks.
+ *
+ * @package    core_h5p
+ * @copyright  2019 Bas Brands <bas@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * Serve the files from the core_h5p file areas.
+ *
+ * @package core_h5p
+ * @category files
+ *
+ * @param  stdClass $course the course object
+ * @param  stdClass $cm the course module object
+ * @param  stdClass $context the newmodule's context
+ * @param  string $filearea the name of the file area
+ * @param  array $args extra arguments (itemid, path)
+ * @param  bool $forcedownload whether or not force download
+ * @param  array $options additional options affecting the file serving
+ *
+ * @return bool Returns false if we don't find a file.
+ */
+function core_h5p_pluginfile($course, $cm, $context, string $filearea, array $args, bool $forcedownload,
+    array $options = []) : bool {
+    global $DB;
+
+    $filesettingsset = false;
+
+    switch ($filearea) {
+        default:
+            return false; // Invalid file area.
+
+        case \core_h5p\file_storage::LIBRARY_FILEAREA:
+            if ($context->contextlevel != CONTEXT_SYSTEM) {
+                 return false; // Invalid context because the libraries are loaded always in the context system.
+            }
+
+            $itemid = null;
+
+            // The files that can be delivered to this function are unfortunately out of our control. Some of the
+            // references are embedded into the JavaScript of the files and we have no ability to inject an item id.
+            // We also don't know the location of the item id when we do include it, so we look for the first numeric
+            // value and try to serve that file.
+            foreach ($args as $key => $value) {
+                if (is_numeric($value)) {
+                    $itemid = $value;
+                    unset($args[$key]);
+                    break;
+                }
+            }
+
+            if (!isset($itemid)) {
+                // We didn't find an item id to use, so we fall back to retrieving the record using all the other
+                // fields. The combination of component, filearea, filepath, and filename is enough for a unique
+                // record.
+                $filename = array_pop($args);
+                $filepath = '/' . implode('/', $args) . '/';
+                $itemid = $DB->get_field('files', 'itemid', [
+                    'component' => \core_h5p\file_storage::COMPONENT,
+                    'filearea' => \core_h5p\file_storage::LIBRARY_FILEAREA,
+                    'filepath' => $filepath,
+                    'filename' => $filename
+                ]);
+                $filesettingsset = true;
+            }
+            break;
+        case \core_h5p\file_storage::CONTENT_FILEAREA:
+            if ($context->contextlevel != CONTEXT_SYSTEM) {
+                return false; // Invalid context because the content files are loaded always in the context system.
+            }
+            $itemid = array_shift($args);
+            break;
+        case \core_h5p\file_storage::CACHED_ASSETS_FILEAREA:
+        case \core_h5p\file_storage::EXPORT_FILEAREA:
+            $itemid = 0;
+            break;
+    }
+
+    if (!$filesettingsset) {
+        $filename = array_pop($args);
+        $filepath = (!$args ? '/' : '/' . implode('/', $args) . '/');
+    }
+
+    $fs = get_file_storage();
+    $file = $fs->get_file($context->id, \core_h5p\file_storage::COMPONENT, $filearea, $itemid, $filepath, $filename);
+    if (!$file) {
+        return false; // No such file.
+    }
+
+    send_stored_file($file, null, 0, $forcedownload, $options);
+
+    return true;
+}