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 library for enableing a drag and drop upload to courses

 *

 * @package    core

 * @subpackage course

 * @copyright  2012 Davo Smith

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

 */

M.course_dndupload = {

    // YUI object.

    Y: null,

    // URL for upload requests

    url: M.cfg.wwwroot + '/course/dndupload.php',

    // maximum size of files allowed in this form

    maxbytes: 0,

    // ID of the course we are on

    courseid: null,

    // Data about the different file/data handlers that are available

    handlers: null,

    // Nasty hack to distinguish between dragenter(first entry),

    // dragenter+dragleave(moving between child elements) and dragleave (leaving element)

    entercount: 0,

    // Used to keep track of the section we are dragging across - to make

    // spotting movement between sections more reliable

    currentsection: null,

    // Used to store the pending uploads whilst the user is being asked for further input

    uploadqueue: null,

    // True if the there is currently a dialog being shown (asking for a name, or giving a

    // choice of file handlers)

    uploaddialog: false,

    // An array containing the last selected file handler for each file type

    lastselected: null,

    // The following are used to identify specific parts of the course page

    // The type of HTML element that is a course section

    sectiontypename: 'li',

    // The classes that an element must have to be identified as a course section

    sectionclasses: ['section', 'main'],

    // The ID of the main content area of the page (for adding the 'status' div)

    pagecontentid: 'page',

    // The selector identifying the list of modules within a section (note changing this may require

    // changes to the get_mods_element function)

    modslistselector: 'ul.section',

    /**

     * Initalise the drag and drop upload interface

     * Note: one and only one of options.filemanager and options.formcallback must be defined

     *

     * @param Y the YUI object

     * @param object options {

     *            courseid: ID of the course we are on

     *            maxbytes: maximum size of files allowed in this form

     *            handlers: Data about the different file/data handlers that are available

     *          }

     */

    init: function(Y, options) {

        this.Y = Y;

        if (!this.browser_supported()) {

            return; // Browser does not support the required functionality

        }

        this.maxbytes = options.maxbytes;

        this.courseid = options.courseid;

        this.handlers = options.handlers;

        this.uploadqueue = new Array();

        this.lastselected = new Array();

        var sectionselector = this.sectiontypename + '.' + this.sectionclasses.join('.');

        var sections = this.Y.all(sectionselector);

        if (sections.isEmpty()) {

            return; // No sections - incompatible course format or front page.

        }

        sections.each( function(el) {

            this.add_preview_element(el);

            this.init_events(el);

        }, this);

        if (options.showstatus) {

            this.add_status_div();

        }

        var self = this;

        require([

            'core_courseformat/courseeditor',

            'core_course/events'

        ], function(

            Editor,

            CourseEvents

        ) {

            // Any change to the course must be applied also to the course state via the courseeditor module.

            self.courseeditor = Editor.getCurrentCourseEditor();

            // Some formats can add sections without reloading the page.

            document.querySelector('#' + self.pagecontentid).addEventListener(

                CourseEvents.sectionRefreshed,

                self.sectionRefreshed.bind(self)

            );

        });

        document.addEventListener('scroll', function() {

            sections.each(function(el) {

                if (el.hasClass('dndupload-dropzone')) {

                    self.rePositionPreviewInfoElement(el);

                }

            }, this);

        }, true);

    },

    /**

     * Setup Drag and Drop in a section.

     * @param {CustomEvent} event The custom event

     */

    sectionRefreshed: function(event) {

        if (event.detail.newSectionElement === undefined) {

            return;

        }

        var element = this.Y.one(event.detail.newSectionElement);

        this.add_preview_element(element);

        this.init_events(element);

    },

    /**

     * Add a div element to tell the user that drag and drop upload

     * is available (or to explain why it is not available)

     */

    add_status_div: function() {

        var Y = this.Y,

            coursecontents = Y.one('#' + this.pagecontentid),

            div,

            handlefile = (this.handlers.filehandlers.length > 0),

            handletext = false,

            handlelink = false,

            i = 0,

            styletop,

            styletopunit;

        if (!coursecontents) {

            return;

        }

        div = Y.Node.create('<div id="dndupload-status"></div>').setStyle('opacity', '0.0');

        coursecontents.insert(div, 0);

        for (i = 0; i < this.handlers.types.length; i++) {

            switch (this.handlers.types[i].identifier) {

                case 'text':

                case 'text/html':

                    handletext = true;

                    break;

                case 'url':

                    handlelink = true;

                    break;

            }

        }

        $msgident = 'dndworking';

        if (handlefile) {

            $msgident += 'file';

        }

        if (handletext) {

            $msgident += 'text';

        }

        if (handlelink) {

            $msgident += 'link';

        }

        div.setContent(M.util.get_string($msgident, 'moodle'));

        styletop = div.getStyle('top') || '0px';

        styletopunit = styletop.replace(/^\d+/, '');

        styletop = parseInt(styletop.replace(/\D*$/, ''), 10);

        var fadein = new Y.Anim({

            node: '#dndupload-status',

            from: {

                opacity: 0.0,

                top: (styletop - 30).toString() + styletopunit

            },

            to: {

                opacity: 1.0,

                top: styletop.toString() + styletopunit

            },

            duration: 0.5

        });

        var fadeout = new Y.Anim({

            node: '#dndupload-status',

            from: {

                opacity: 1.0,

                top: styletop.toString() + styletopunit

            },

            to: {

                opacity: 0.0,

                top: (styletop - 30).toString() + styletopunit

            },

            duration: 0.5

        });

        fadein.run();

        fadein.on('end', function(e) {

            Y.later(3000, this, function() {

                fadeout.run();

            });

        });

        fadeout.on('end', function(e) {

            Y.one('#dndupload-status').remove(true);

        });

    },

    /**

     * Check the browser has the required functionality

     * @return true if browser supports drag/drop upload

     */

    browser_supported: function() {

        if (typeof FileReader == 'undefined') {

            return false;

        }

        if (typeof FormData == 'undefined') {

            return false;

        }

        return true;

    },

    /**

     * Initialise drag events on node container, all events need

     * to be processed for drag and drop to work

     * @param el the element to add events to

     */

    init_events: function(el) {

        this.Y.on('dragenter', this.drag_enter, el, this);

        this.Y.on('dragleave', this.drag_leave, el, this);

        this.Y.on('dragover',  this.drag_over,  el, this);

        this.Y.on('drop',      this.drop,       el, this);

    },

    /**

     * Work out which course section a given element is in

     * @param el the child DOM element within the section

     * @return the DOM element representing the section

     */

    get_section: function(el) {

        var sectionclasses = this.sectionclasses;

        return el.ancestor( function(test) {

            var i;

            for (i=0; i<sectionclasses.length; i++) {

                if (!test.hasClass(sectionclasses[i])) {

                    return false;

                }

                return true;

            }

        }, true);

    },

    /**

     * Work out the number of the section we have been dropped on to, from the section element

     * @param DOMElement section the selected section

     * @return int the section number

     */

    get_section_number: function(section) {

        var sectionid = section.get('id').split('-');

        if (sectionid.length < 2 || sectionid[0] != 'section') {

            return false;

        }

        return parseInt(sectionid[1]);

    },

    /**

     * Check if the event includes data of the given type

     * @param e the event details

     * @param type the data type to check for

     * @return true if the data type is found in the event data

     */

    types_includes: function(e, type) {

        var i;

        var types = e._event.dataTransfer.types;

        type = type.toLowerCase();

        for (i=0; i<types.length; i++) {

            if (!types.hasOwnProperty(i)) {

                continue;

            }

            if (types[i].toLowerCase() === type) {

                return true;

            }

        }

        return false;

    },

    /**

     * Check if the event includes only data of the Files type

     *

     * Chrome drag page images as files. To differentiate a real file from a page

     * image we need to check if all the dataTransfers types are files.

     *

     * @param {Event} e the event details

     * @return true if the data types contains only Files related type

     */

    typesIncludesFilesOnly: function(e) {

        return e._event.dataTransfer.types.every(function(currentType) {

            return (currentType.toLowerCase() != 'text/uri-list'

                && currentType.toLowerCase() != 'text/html'

                && currentType.toLowerCase() != 'text/plain'

            );

        });

    },

    /**

     * Look through the event data, checking it against the registered data types

     * (in order of priority) and return details of the first matching data type

     * @param e the event details

     * @return object|false - false if not found or an object {

     *           realtype: the type as given by the browser

     *           addmessage: the message to show to the user during dragging

     *           namemessage: the message for requesting a name for the resource from the user

     *           type: the identifier of the type (may match several 'realtype's)

     *           }

     */

    drag_type: function(e) {

        // Check there is some data attached.

        if (e._event.dataTransfer === null) {

            return false;

        }

        if (e._event.dataTransfer.types === null) {

            return false;

        }

        if (e._event.dataTransfer.types.length == 0) {

            return false;

        }

        // Check for files first.

        if (this.types_includes(e, 'Files') && this.typesIncludesFilesOnly(e)) {

            if (e.type != 'drop' || e._event.dataTransfer.files.length != 0) {

                if (this.handlers.filehandlers.length == 0) {

                    return false; // No available file handlers - ignore this drag.

                }

                return {

                    realtype: 'Files',

                    addmessage: M.util.get_string('addfilehere', 'moodle'),

                    namemessage: null, // Should not be asked for anyway

                    type: 'Files'

                };

            }

        }

        // Check each of the registered types.

        var types = this.handlers.types;

        for (var i=0; i<types.length; i++) {

            // Check each of the different identifiers for this type

            var dttypes = types[i].datatransfertypes;

            for (var j=0; j<dttypes.length; j++) {

                if (this.types_includes(e, dttypes[j])) {

                    return {

                        realtype: dttypes[j],

                        addmessage: types[i].addmessage,

                        namemessage: types[i].namemessage,

                        handlermessage: types[i].handlermessage,

                        type: types[i].identifier,

                        handlers: types[i].handlers

                    };

                }

            }

        }

        return false; // No types we can handle

    },

    /**

     * Check the content of the drag/drop includes a type we can handle, then, if

     * it is, notify the browser that we want to handle it

     * @param event e

     * @return string type of the event or false

     */

    check_drag: function(e) {

        var type = this.drag_type(e);

        if (type) {

            // Notify browser that we will handle this drag/drop

            e.stopPropagation();

            e.preventDefault();

        }

        return type;

    },

    /**

     * Handle a dragenter event: add a suitable 'add here' message

     * when a drag event occurs, containing a registered data type

     * @param e event data

     * @return false to prevent the event from continuing to be processed

     */

    drag_enter: function(e) {

        if (!(type = this.check_drag(e))) {

            return false;

        }

        var section = this.get_section(e.currentTarget);

        if (!section) {

            return false;

        }

        if (this.currentsection && this.currentsection != section) {

            this.currentsection = section;

            this.entercount = 1;

        } else {

            this.entercount++;

            if (this.entercount > 2) {

                this.entercount = 2;

                return false;

            }

        }

        this.showPreviewInfoElement(section);

        return false;

    },

    /**

     * Handle a dragleave event: remove the 'add here' message (if present)

     * @param e event data

     * @return false to prevent the event from continuing to be processed

     */

    drag_leave: function(e) {

        if (!this.check_drag(e)) {

            return false;

        }

        this.entercount--;

        if (this.entercount == 1) {

            return false;

        }

        this.entercount = 0;

        this.currentsection = null;

        this.hide_preview_element();

        return false;

    },

    /**

     * Handle a dragover event: just prevent the browser default (necessary

     * to allow drag and drop handling to work)

     * @param e event data

     * @return false to prevent the event from continuing to be processed

     */

    drag_over: function(e) {

        this.check_drag(e);

        return false;

    },

    /**

     * Handle a drop event: hide the 'add here' message, check the attached

     * data type and start the upload process

     * @param e event data

     * @return false to prevent the event from continuing to be processed

     */

    drop: function(e) {

        this.hide_preview_element();

        if (!(type = this.check_drag(e))) {

            return false;

        }

        // Work out the number of the section we are on (from its id)

        var section = this.get_section(e.currentTarget);

        var sectionnumber = this.get_section_number(section);

        // Process the file or the included data

        if (type.type == 'Files') {

            var files = e._event.dataTransfer.files;

            for (var i=0, f; f=files[i]; i++) {

                this.handle_file(f, section, sectionnumber);

            }

        } else {

            var contents = e._event.dataTransfer.getData(type.realtype);

            if (contents) {

                this.handle_item(type, contents, section, sectionnumber);

            }

        }

        return false;

    },

    /**

     * Find or create the 'ul' element that contains all of the module

     * instances in this section

     * @param section the DOM element representing the section

     * @return false to prevent the event from continuing to be processed

     */

    get_mods_element: function(section) {

        // Find the 'ul' containing the list of mods

        var modsel = section.one(this.modslistselector);

        if (!modsel) {

            // Create the above 'ul' if it doesn't exist

            modsel = document.createElement('ul');

            modsel.className = 'section img-text';

            var contentel = section.get('children').pop();

            var brel = contentel.get('children').pop();

            contentel.insertBefore(modsel, brel);

            modsel = this.Y.one(modsel);

        }

        return modsel;

    },

    /**

     * Add a new dummy item to the list of mods, to be replaced by a real

     * item & link once the AJAX upload call has completed

     * @param name the label to show in the element

     * @param section the DOM element reperesenting the course section

     * @return DOM element containing the new item

     */

    add_resource_element: function(name, section, module) {

        var modsel = this.get_mods_element(section);

        var resel = {

            parent: modsel,

            li: document.createElement('li'),

            div: document.createElement('div'),

            indentdiv: document.createElement('div'),

            a: document.createElement('a'),

            icon: document.createElement('img'),

            namespan: document.createElement('span'),

            groupingspan: document.createElement('span'),

            progressouter: document.createElement('span'),

            progress: document.createElement('span')

        };

        resel.li.className = 'activity ' + module + ' modtype_' + module;

        resel.indentdiv.className = 'mod-indent';

        resel.li.appendChild(resel.indentdiv);

        resel.div.className = 'activityinstance';

        resel.indentdiv.appendChild(resel.div);

        resel.a.href = '#';

        resel.div.appendChild(resel.a);

        resel.icon.src = M.util.image_url('i/ajaxloader');

        resel.icon.className = 'activityicon iconlarge';

        resel.a.appendChild(resel.icon);

        resel.namespan.className = 'instancename';

        resel.namespan.innerHTML = name;

        resel.a.appendChild(resel.namespan);

        resel.groupingspan.className = 'groupinglabel';

        resel.div.appendChild(resel.groupingspan);

        resel.progressouter.className = 'dndupload-progress-outer';

        resel.progress.className = 'dndupload-progress-inner';

        resel.progress.innerHTML = ' ';

        resel.progressouter.appendChild(resel.progress);

        resel.div.appendChild(resel.progressouter);

        modsel.insertBefore(resel.li, modsel.get('children')); // Leave the 'preview element' at the bottom

        return resel;

    },

    /**

     * Hide any visible dndupload-preview elements on the page

     */

    hide_preview_element: function() {

        this.Y.all('.dndupload-preview-wrapper').addClass('dndupload-hidden');

        this.Y.all('.dndupload-over').removeClass('dndupload-over');

        this.Y.all('.dndupload-dropzone').removeClass('dndupload-dropzone');

    },

    /**

     * Unhide the preview element for the given section and set it to display

     * the correct message

     * @param section the YUI node representing the selected course section

     * @param type the details of the data type detected in the drag (including the message to display)

     * @deprecated Since Moodle 4.0. Please use showPreviewInfoElement() instead.

     */

    show_preview_element: function(section, type) {

        this.hide_preview_element();

        var preview = section.one('li.dndupload-preview').removeClass('dndupload-hidden');

        section.addClass('dndupload-over');

        // Horrible work-around to allow the 'Add X here' text to be a drop target in Firefox.

        var node = preview.one('span').getDOMNode();

        node.firstChild.nodeValue = type.addmessage;

    },

    /**

     * Unhide the preview information element for the given section and set it to display

     * the correct message

     * @param {Object} section the YUI node representing the selected course section

     */

    showPreviewInfoElement: function(section) {

        this.hide_preview_element();

        section.one('.dndupload-preview-wrapper').removeClass('dndupload-hidden');

        section.addClass('dndupload-dropzone');

        this.rePositionPreviewInfoElement(section);

    },

    /**

     * Add the preview element to a course section. Note: this needs to be done before 'addEventListener'

     * is called, otherwise Firefox will ignore events generated when the mouse is over the preview

     * element (instead of passing them up to the parent element)

     * @param {Object} section the YUI node representing the selected course section

     */

    add_preview_element: function(section) {

        const modsEl = this.get_mods_element(section);

        // Create overlay div.

        const overlay = document.createElement('div');

        overlay.className = 'dndupload-preview-overlay';

        modsEl.get('parentNode').appendChild(overlay);

        // Create preview div.

        const preview = {

            wrapper: document.createElement('div'),

            div: document.createElement('div'),

            iconSpan: document.createElement('span'),

            nameSpan: document.createElement('span')

        };

        preview.wrapper.className = 'dndupload-preview-wrapper dndupload-hidden';

        preview.wrapper.appendChild(preview.div);

        preview.div.className = 'dndupload-preview';

        preview.div.appendChild(document.createTextNode(' '));

        preview.iconSpan.className = 'fa fa-arrow-circle-o-down';

        preview.nameSpan.className = 'instancename';

        preview.nameSpan.innerHTML = M.util.get_string('addfilehere', 'moodle');

        preview.div.appendChild(preview.iconSpan);

        preview.div.appendChild(preview.nameSpan);

        modsEl.get('parentNode').appendChild(preview.wrapper);

    },

    /**

     * Re-position the preview information element by calculating the section position.

     *

     * @param {Object} section the YUI node representing the selected course section

     */

    rePositionPreviewInfoElement: function(section) {

        const sectionElement = document.getElementById(section.get('id'));

        const rect = sectionElement.getBoundingClientRect();

        const sectionHeight = parseInt(window.getComputedStyle(sectionElement).height, 10);

        const sectionOffset = rect.top;

        const preview = sectionElement.querySelector('.dndupload-preview-wrapper');

        const previewHeight = parseInt(window.getComputedStyle(preview).height, 10) +

            (2 * parseInt(window.getComputedStyle(preview).padding, 10));

        let top, bottom;

        if (sectionOffset < 0) {

            if (sectionHeight + sectionOffset >= previewHeight) {

                // We have enough space here, just stick the preview to the top.

                let offSetTop = 0 - sectionOffset;

                const navBar = document.querySelector('nav.navbar.fixed-top');

                if (navBar) {

                    offSetTop = offSetTop + navBar.offsetHeight;

                }

                top = offSetTop + 'px';

                bottom = 'unset';

            } else {

                // We do not have enough space here, just stick the preview to the bottom.

                top = 'unset';

                bottom = 0;

            }

        } else {

            top = 0;

            bottom = 'unset';

        }

        preview.style.top = top

        preview.style.bottom = bottom;

    },

    /**

     * Find the registered handler for the given file type. If there is more than one, ask the

     * user which one to use. Then upload the file to the server

     * @param file the details of the file, taken from the FileList in the drop event

     * @param section the DOM element representing the selected course section

     * @param sectionnumber the number of the selected course section

     */

    handle_file: function(file, section, sectionnumber) {

        var handlers = new Array();

        var filehandlers = this.handlers.filehandlers;

        var extension = '';

        var dotpos = file.name.lastIndexOf('.');

        if (dotpos != -1) {

            extension = file.name.substr(dotpos+1, file.name.length).toLowerCase();

        }

        for (var i=0; i<filehandlers.length; i++) {

            if (filehandlers[i].extension == '*' || filehandlers[i].extension == extension) {

                handlers.push(filehandlers[i]);

            }

        }

        if (handlers.length == 0) {

            // No handlers at all (not even 'resource'?)

            return;

        }

        if (handlers.length == 1) {

            this.upload_file(file, section, sectionnumber, handlers[0].module);

            return;

        }

        this.file_handler_dialog(handlers, extension, file, section, sectionnumber);

    },

    /**

     * Show a dialog box, allowing the user to choose what to do with the file they are uploading

     * @param handlers the available handlers to choose between

     * @param extension the extension of the file being uploaded

     * @param file the File object being uploaded

     * @param section the DOM element of the section being uploaded to

     * @param sectionnumber the number of the selected course section

     */

    file_handler_dialog: function(handlers, extension, file, section, sectionnumber) {

        if (this.uploaddialog) {

            var details = new Object();

            details.isfile = true;

            details.handlers = handlers;

            details.extension = extension;

            details.file = file;

            details.section = section;

            details.sectionnumber = sectionnumber;

            this.uploadqueue.push(details);

            return;

        }

        this.uploaddialog = true;

        var timestamp = new Date().getTime();

        var uploadid = Math.round(Math.random()*100000)+'-'+timestamp;

        var content = '';

        var sel;

        if (extension in this.lastselected) {

            sel = this.lastselected[extension];

        } else {

            sel = handlers[0].module;

        }

        content += '<p>'+M.util.get_string('actionchoice', 'moodle', file.name)+'</p>';

        content += '<div id="dndupload_handlers'+uploadid+'">';

        for (var i=0; i<handlers.length; i++) {

            var id = 'dndupload_handler'+uploadid+handlers[i].module;

            var checked = (handlers[i].module == sel) ? 'checked="checked" ' : '';

            content += '<input type="radio" name="handler" value="'+handlers[i].module+'" id="'+id+'" '+checked+'/>';

            content += ' <label for="'+id+'">';

            content += handlers[i].message;

            content += '</label><br/>';

        }

        content += '</div>';

        var Y = this.Y;

        var self = this;

        var panel = new M.core.dialogue({

            bodyContent: content,

            width: '350px',

            modal: true,

            visible: false,

            render: true,

            align: {

                node: null,

                points: [Y.WidgetPositionAlign.CC, Y.WidgetPositionAlign.CC]

            }

        });

        panel.show();

        // When the panel is hidden - destroy it and then check for other pending uploads

        panel.after("visibleChange", function(e) {

            if (!panel.get('visible')) {

                panel.destroy(true);

                self.check_upload_queue();

            }

        });

        // Add the submit/cancel buttons to the bottom of the dialog.

        panel.addButton({

            label: M.util.get_string('upload', 'moodle'),

            action: function(e) {

                e.preventDefault();

                // Find out which module was selected

                var module = false;

                var div = Y.one('#dndupload_handlers'+uploadid);

                div.all('input').each(function(input) {

                    if (input.get('checked')) {

                        module = input.get('value');

                    }

                });

                if (!module) {

                    return;

                }

                panel.hide();

                // Remember this selection for next time

                self.lastselected[extension] = module;

                // Do the upload

                self.upload_file(file, section, sectionnumber, module);

            },

            section: Y.WidgetStdMod.FOOTER

        });

        panel.addButton({

            label: M.util.get_string('cancel', 'moodle'),

            action: function(e) {

                e.preventDefault();

                panel.hide();

            },

            section: Y.WidgetStdMod.FOOTER

        });

    },

    /**

     * Check to see if there are any other dialog boxes to show, now that the current one has

     * been dealt with

     */

    check_upload_queue: function() {

        this.uploaddialog = false;

        if (this.uploadqueue.length == 0) {

            return;

        }

        var details = this.uploadqueue.shift();

        if (details.isfile) {

            this.file_handler_dialog(details.handlers, details.extension, details.file, details.section, details.sectionnumber);

        } else {

            this.handle_item(details.type, details.contents, details.section, details.sectionnumber);

        }

    },

    /**

     * Do the file upload: show the dummy element, use an AJAX call to send the data

     * to the server, update the progress bar for the file, then replace the dummy

     * element with the real information once the AJAX call completes

     * @param file the details of the file, taken from the FileList in the drop event

     * @param section the DOM element representing the selected course section

     * @param sectionnumber the number of the selected course section

     */

    upload_file: function(file, section, sectionnumber, module) {

        // This would be an ideal place to use the Y.io function

        // however, this does not support data encoded using the

        // FormData object, which is needed to transfer data from

        // the DataTransfer object into an XMLHTTPRequest

        // This can be converted when the YUI issue has been integrated:

        // http://yuilibrary.com/projects/yui3/ticket/2531274

        var xhr = new XMLHttpRequest();

        var self = this;

        if (this.maxbytes > 0 && file.size > this.maxbytes) {

            new M.core.alert({message: M.util.get_string('namedfiletoolarge', 'moodle', {filename: file.name})});

            return;

        }

        // Add the file to the display

        var resel = this.add_resource_element(file.name, section, module);

        // Update the progress bar as the file is uploaded

        xhr.upload.addEventListener('progress', function(e) {

            if (e.lengthComputable) {

                var percentage = Math.round((e.loaded * 100) / e.total);

                resel.progress.style.width = percentage + '%';

            }

        }, false);

        // Wait for the AJAX call to complete, then update the

        // dummy element with the returned details

        xhr.onreadystatechange = function() {

            if (xhr.readyState == 1) {

                this.originalUnloadEvent = window.onbeforeunload;

                // Trigger form upload start events.

                require(['core_form/events'], function(FormEvent) {

                    FormEvent.notifyUploadStarted(section.get('id'));

                });

            }

            if (xhr.readyState == 4) {

                if (xhr.status == 200) {

                    var result = JSON.parse(xhr.responseText);

                    if (result) {

                        if (result.error == 0) {

                            // All OK - replace the dummy element.

                            resel.li.outerHTML = result.fullcontent;

                            if (self.Y.UA.gecko > 0) {

                                // Fix a Firefox bug which makes sites with a '~' in their wwwroot

                                // log the user out when clicking on the link (before refreshing the page).

                                resel.li.outerHTML = unescape(resel.li.outerHTML);

                            }

                            self.add_editing(result.elementid);

                            // Once done, send any new course module id to the courseeditor to update de course state.

                            self.courseeditor.dispatch('cmState', [result.cmid]);

                            // Fire the content updated event.

                            require(['core/event', 'jquery'], function(event, $) {

                                event.notifyFilterContentUpdated($(result.fullcontent));

                            });

                        } else {

                            // Error - remove the dummy element

                            resel.parent.removeChild(resel.li);

                            new M.core.alert({message: result.error});

                        }

                    }

                } else {

                    new M.core.alert({message: M.util.get_string('servererror', 'moodle')});

                }

                // Trigger form upload complete events.

                require(['core_form/events'], function(FormEvent) {

                    FormEvent.notifyUploadCompleted(section.get('id'));

                });

            }

        };

        // Prepare the data to send

        var formData = new FormData();

        try {

            formData.append('repo_upload_file', file);

        } catch (e) {

            // Edge throws an error at this point if we try to upload a folder.

            resel.parent.removeChild(resel.li);

            new M.core.alert({message: M.util.get_string('filereaderror', 'moodle', file.name)});

            return;

        }

        formData.append('sesskey', M.cfg.sesskey);

        formData.append('course', this.courseid);

        formData.append('section', sectionnumber);

        formData.append('module', module);

        formData.append('type', 'Files');

        // Try reading the file to check it is not a folder, before sending it to the server.

        var reader = new FileReader();

        reader.onload = function() {

            // File was read OK - send it to the server.

            xhr.open("POST", self.url, true);

            xhr.send(formData);

        };

        reader.onerror = function() {

            // Unable to read the file (it is probably a folder) - display an error message.

            resel.parent.removeChild(resel.li);

            new M.core.alert({message: M.util.get_string('filereaderror', 'moodle', file.name)});

        };

        if (file.size > 0) {

            // If this is a non-empty file, try reading the first few bytes.

            // This will trigger reader.onerror() for folders and reader.onload() for ordinary, readable files.

            reader.readAsText(file.slice(0, 5));

        } else {

            // If you call slice() on a 0-byte folder, before calling readAsText, then Firefox triggers reader.onload(),

            // instead of reader.onerror().

            // So, for 0-byte files, just call readAsText on the whole file (and it will trigger load/error functions as expected).

            reader.readAsText(file);

        }

    },

    /**

     * Show a dialog box to gather the name of the resource / activity to be created

     * from the uploaded content

     * @param type the details of the type of content

     * @param contents the contents to be uploaded

     * @section the DOM element for the section being uploaded to

     * @sectionnumber the number of the section being uploaded to

     */

    handle_item: function(type, contents, section, sectionnumber) {

        if (type.handlers.length == 0) {

            // Nothing to handle this - should not have got here

            return;

        }

        if (type.handlers.length == 1 && type.handlers[0].noname) {

            // Only one handler and it doesn't need a name (i.e. a label).

            this.upload_item('', type.type, contents, section, sectionnumber, type.handlers[0].module);

            this.check_upload_queue();

            return;

        }

        if (this.uploaddialog) {

            var details = new Object();

            details.isfile = false;

            details.type = type;

            details.contents = contents;

            details.section = section;

            details.setcionnumber = sectionnumber;

            this.uploadqueue.push(details);

            return;

        }

        this.uploaddialog = true;

        var timestamp = new Date().getTime();

        var uploadid = Math.round(Math.random()*100000)+'-'+timestamp;

        var nameid = 'dndupload_handler_name'+uploadid;

        var content = '';

        if (type.handlers.length > 1) {

            content += '<p>'+type.handlermessage+'</p>';

            content += '<div id="dndupload_handlers'+uploadid+'">';

            var sel = type.handlers[0].module;

            for (var i=0; i<type.handlers.length; i++) {

                var id = 'dndupload_handler'+uploadid+type.handlers[i].module;