resource.class.php

很棒的在线教学系统

<?php // $Id: resource.class.php,v 1.47.2.5 2008/07/10 09:48:47 scyrma Exp $

///////////////////////////////////////////////////////////////////////////
//                                                                       //
// NOTICE OF COPYRIGHT                                                   //
//                                                                       //
// Moodle - Modular Object-Oriented Dynamic Learning Environment         //
//          http://moodle.com                                            //
//                                                                       //
// Copyright (C) 1999 onwards Martin Dougiamas     http://dougiamas.com  //
//           (C) 2001-3001 Eloy Lafuente (stronk7) http://contiento.com  //
//                                                                       //
// 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; either version 2 of the License, or     //
// (at your option) any later version.                                   //
//                                                                       //
// 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:                          //
//                                                                       //
//          http://www.gnu.org/copyleft/gpl.html                         //
//                                                                       //
///////////////////////////////////////////////////////////////////////////

/// Options presented to user :
/// (1) Side navigation menu (navigationmenu)
/// (2) TOC (tableofcontents)
/// (3) Navigation buttons (navigationbuttons)
/// (4) Navigation up button (navigationupbutton)
/// (5) Skip submenu pages (skipsubmenus)
///
/// (1) forces (2), (4) false and (5) true. Forced on setup
/// (2) is a bit silly with (5). Maybe make a rule?
/// (3) false => (5) false. Add graying out on setup.


require_once($CFG->libdir.'/filelib.php');
require_once($CFG->dirroot.'/mod/resource/type/ims/repository_config.php');


/**
* Extend the base resource class for ims resources
*/
class resource_ims extends resource_base {

    var $parameters;  //Attribute of this class where we'll store all the IMS deploy preferences

    function resource_ims($cmid=0) {
    /// super constructor
        parent::resource_base($cmid);

    /// prevent notice
        if (empty($this->resource->alltext)) {
            $this->resource->alltext='';
        }
    /// set own attributes
        $this->parameters = $this->alltext2parameters($this->resource->alltext);

    /// navigation menu forces other settings
        if ($this->parameters->navigationmenu) {
            $this->parameters->tableofcontents = 0;
            $this->parameters->navigationuparrow = 0;
            $this->parameters->skipsubmenus = 1;
        }

    /// Is it in the repository material or not?
        if (isset($this->resource->reference)) {
            $file = $this->resource->reference;
            if ($file[0] == '#') {
                $this->isrepository = true;
                $file = ltrim($file, '#');
                $this->resource->reference = $file;
            } else {
                $this->isrepository = false;
            }
        } else {
            $this->isrepository = false;
        }
    }

    /***
    * This function converts parameters stored in the alltext field to the proper
    * this->parameters object storing the special configuration of this resource type
    */
    function alltext2parameters($alltext) {
        /// set parameter defaults
        $alltextfield = new stdClass();
        $alltextfield->tableofcontents=0;
        $alltextfield->navigationbuttons=0;
        $alltextfield->navigationmenu=1;
        $alltextfield->skipsubmenus=1;
        $alltextfield->navigationupbutton=1;

    /// load up any stored parameters
        if (!empty($alltext)) {
            $parray = explode(',', $alltext);
            foreach ($parray as $key => $fieldstring) {
                $field = explode('=', $fieldstring);
                $alltextfield->$field[0] = $field[1];
            }
        }

        return $alltextfield;
    }

    /***
    * This function converts the this->parameters attribute (object) to the format
    * needed to save them in the alltext field to store all the special configuration
    * of this resource type
    */
    function parameters2alltext($parameters) {
        $optionlist = array();

        $optionlist[] = 'tableofcontents='.$parameters->tableofcontents;
        $optionlist[] = 'navigationbuttons='.$parameters->navigationbuttons;
        $optionlist[] = 'skipsubmenus='.$parameters->skipsubmenus;
        $optionlist[] = 'navigationmenu='.$parameters->navigationmenu;
        $optionlist[] = 'navigationupbutton='.$parameters->navigationupbutton;

        return implode(',', $optionlist);
    }

    /***
    * This function will convert all the parameters configured in the resource form
    * to a this->parameter attribute (object)
    */
    function form2parameters($resource) {
        $parameters = new stdClass;
        $parameters->tableofcontents = isset($resource->param_tableofcontents) ? $resource->param_tableofcontents : 0;
        $parameters->navigationbuttons = $resource->param_navigationbuttons;
        $parameters->skipsubmenus = isset($resource->param_skipsubmenus) ? $resource->param_skipsubmenus : 0;
        $parameters->navigationmenu = $resource->param_navigationmenu;
        $parameters->navigationupbutton = isset($resource->param_navigationupbutton) ? $resource->param_navigationupbutton : 0;

        return $parameters;
    }

    /*** This function checks for errors in the status or deployment of the IMS
    * Content Package returning an error code:
    * 1 = Not a .zip file.
    * 2 = Zip file doesn't exist
    * 3 = Package not deployed.
    * 4 = Package has changed since deployed.
    * If the IMS CP is one from the central repository, then we instead check
    * with the following codes:
    * 5 = Not deployed. Since repository is central must be admin to deploy so terminate
    */
    function check4errors($file, $course, $resource) {
        global $CFG;

        if ($this->isrepository) {
        /// Calculate the path were the IMS package must be deployed
            $deploydir = $CFG->repository . $file;

        /// Confirm that the IMS package has been deployed. These files must exist if
        /// the package is deployed: moodle_index.ser and moodle_hash.ser
            if (!file_exists($deploydir.'/moodle_inx.ser')) {
                return 5;    //Error
            }
        }
        else {
        /// Check for zip file type
            $mimetype = mimeinfo("type", $file);
            if ($mimetype != "application/zip") {
                return 1;    //Error
            }

        /// Check if the uploaded file exists
            if (!file_exists($CFG->dataroot.'/'.$course->id.'/'.$file)) {
                return 2;    //Error
            }

        /// Calculate the path were the IMS package must be deployed
            $deploydir = $CFG->dataroot.'/'.$course->id.'/'.$CFG->moddata.'/resource/'.$resource->id;


        /// Confirm that the IMS package has been deployed. These files must exist if
        /// the package is deployed: moodle_index.ser and moodle_hash.ser
            if (!file_exists($deploydir.'/moodle_inx.ser') ||
                !file_exists($deploydir.'/moodle_hash.ser')) {
                return 3;    //Error
            }

        /// If teacheredit, make, hash check. It's the md5 of the name of the file
        /// plus its size and modification date
        /// not sure if this capability is suitable
            if (has_capability('moodle/course:manageactivities', get_context_instance(CONTEXT_COURSE, $course->id))) {
                if (!$this->checkpackagehash($file, $course, $resource)) {
                    return 4;
                }
            }
        }

    /// We've arrived here. Everything is ok
        return 0;
    }

    /*** This function will check that the ims package (zip file) uploaded
    * isn't changed since it was deployed.
    */
    function checkpackagehash($file, $course, $resource) {
        global $CFG;

    /// Calculate paths
        $zipfile = $CFG->dataroot.'/'.$course->id.'/'.$file;
        $hashfile= $CFG->dataroot.'/'.$course->id.'/'.$CFG->moddata.'/resource/'.$resource->id.'/moodle_hash.ser';
    /// Get deloyed hash value
        $f = fopen ($hashfile,'r');
        $deployedhash = fread($f, filesize($hashfile));
        fclose ($f);
    /// Unserialize the deployed hash
        $deployedhash = unserialize($deployedhash);
    /// Calculate uploaded file hash value
        $uploadedhash = $this->calculatefilehash($zipfile);

    /// Compare them
        return ($deployedhash == $uploadedhash);
    }

    /*** This function will calculate the hash of any file passes as argument.
    * It's based in a md5 of the filename, filesize and 20 first bytes (it includes
    * the zip CRC at byte 15).
    */
    function calculatefilehash($filefullpath) {

    /// Name and size
        $filename = basename($filefullpath);
        $filesize = filesize($filefullpath);
    /// Read first 20cc
        $f = fopen ($filefullpath,'r');
        $data = fread($f, 20);
        fclose ($f);

        return md5($filename.'-'.$filesize.'-'.$data);
    }

    /**
    * Add new instance of file resource
    *
    * Create alltext field before calling base class function.
    *
    * @param    resource object
    */
    function add_instance($resource) {
        $this->_postprocess($resource);
        return parent::add_instance($resource);
    }


    /**
    * Update instance of file resource
    *
    * Create alltext field before calling base class function.
    *
    * @param    resource object
    */
    function update_instance($resource) {
        $this->_postprocess($resource);
        return parent::update_instance($resource);
    }

    function _postprocess(&$resource) {
        global $RESOURCE_WINDOW_OPTIONS;
        $alloptions = $RESOURCE_WINDOW_OPTIONS;

        if ($resource->windowpopup) {
            $optionlist = array();
            foreach ($alloptions as $option) {
                $optionlist[] = $option."=".$resource->$option;
                unset($resource->$option);
            }
            $resource->popup = implode(',', $optionlist);
            unset($resource->windowpopup);

        } else {
            $resource->popup = '';
        }
    /// Load parameters to this->parameters
        $this->parameters = $this->form2parameters($resource);
    /// Save parameters into the alltext field
        $resource->alltext = $this->parameters2alltext($this->parameters);
    }

    /** Delete instance of IMS-CP resource
     *
     * Delete all the moddata files for the resource
     * @param    resource object
     */
    function delete_instance($resource) {

         global $CFG;

    /// Delete moddata resource dir completely unless repository.
        if (!$this->isrepository) {
            $resource_dir = $CFG->dataroot.'/'.$resource->course.'/'.$CFG->moddata.'/resource/'.$resource->id;
            if (file_exists($resource_dir)) {
                if (!$status = fulldelete($resource_dir)) {
                    return false;
                }
            }
        }