lib/paintweb/ext/moodle/imagesave.php

   1 <?php
   2 /*
   3  * Copyright (C) 2009 Mihai Şucan
   4  *
   5  * This file is part of PaintWeb.
   6  *
   7  * PaintWeb is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * PaintWeb is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with PaintWeb.  If not, see <http://www.gnu.org/licenses/>.
  19  *
  20  * $URL: http://code.google.com/p/paintweb $
  21  * $Date: 2009-07-30 22:31:47 +0300 $
  22  */
  23
  24 // This script performs asynchronous image save in PaintWeb. This is used by the
  25 // Moodle extension of PaintWeb, to save image edits.
  26
  27 require_once('../../../../config.php');
  28
  29 function paintwebSaveDone ($successful, $errorMessage = null) {
  30   global $imgUrl, $imgUrlNew;
  31
  32   $output = array(
  33     'successful' => $successful,
  34     'url' => $imgUrl,
  35     'urlNew' => $imgUrlNew,
  36     'errorMessage' => $errorMessage
  37   );
  38
  39   echo json_encode($output);
  40   exit;
  41 }
  42
  43 function prepareImgUrl () {
  44   global $CFG, $imgUrl, $imgUrlNew, $imgDest, $imgProxies, $myProxy, $imgDataURL, $imgAllowedTypes, $imgInfo;
  45
  46   // check if the image URL points to a proxy.
  47   foreach ($imgProxies as $proxy => $type) {
  48     if (strpos($imgUrl, $proxy) !== 0) {
  49       continue;
  50     }
  51
  52     $relpath = substr($imgUrl, strlen($proxy));
  53     if ($relpath{0} === '?') {
  54       $relpath = substr($relpath, 1);
  55       $pathvars = array();
  56       parse_str($relpath, $pathvars);
  57       if (isset($pathvars['file'])) {
  58         $relpath = $pathvars['file'];
  59       } else {
  60         $relpath = false;
  61       }
  62       unset($pathvars);
  63
  64     } else if (strpos($relpath, '?')) {
  65       $relpath = substr($relpath, 0, strpos($relpath, '?'));
  66     }
  67
  68     if (!$relpath) {
  69         continue;
  70     }
  71
  72     $relpath = trim($relpath, '/');
  73     $tmpDest = $CFG->dataroot . '/' . $relpath;
  74
  75     if (!file_exists($tmpDest) || !is_writeable($tmpDest) || is_dir($tmpDest)) {
  76       continue;
  77     }
  78
  79     $fname = basename($tmpDest);
  80     $ext = substr($fname, strrpos($fname, '.') + 1);
  81     $ftype = array_search(strtolower($ext), $imgAllowedTypes);
  82
  83     if (!$ftype || $ftype !== $imgInfo[0]) {
  84       continue;
  85     }
  86
  87     // check permissions, if the image proxy is for a course file.
  88     if ($type === 'course') {
  89       $arrpath = explode('/', $relpath);
  90       if (count($arrpath) < 2) {
  91         continue;
  92       }
  93
  94       $course = get_record('course', 'id', $arrpath[0]);
  95       require_login($course);
  96       require_capability('moodle/course:managefiles', get_context_instance(CONTEXT_COURSE, $course->id));
  97     }
  98
  99     $imgDest = $tmpDest;
 100     return;
 101   }
 102
 103   $imgDest = $CFG->dataroot . '/' . $CFG->paintwebImagesFolder;
 104
 105   if (!is_dir($imgDest) || !make_upload_directory($imgDest, false)) {
 106     paintwebSaveDone(false, 'failed to mkdir ' . $imgDest);
 107   }
 108
 109   // simply create a new file in the PainWeb images folder.
 110   $fname = sha1($imgDataURL) . '.' . $imgAllowedTypes[$imgInfo[0]];
 111   $imgDest .=  '/' . $fname;
 112   $imgUrlNew = $CFG->wwwroot . '/' . $myProxy . '?img=' . $fname;
 113 }
 114
 115 // The list of allowed image MIME types associated to file extensions.
 116 $imgAllowedTypes = array('image/png' => 'png', 'image/jpeg' => 'jpg');
 117
 118 // The list of file serving proxies recognized from Moodle. For example, course
 119 // images are served by /file.php. So, when you add an image in TinyMCE, the
 120 // path will be like /file.php/course_id/dir/file.ext.
 121 $imgProxies = array(
 122   $CFG->wwwroot . '/file.php' => 'course',     // course files
 123   $CFG->httpswwwroot . '/file.php' => 'course' // course files
 124 );
 125
 126 if ($CFG->paintwebDisallowImageUpdates) {
 127   $imgProxies = array();
 128 }
 129
 130 $myProxy = dirname(__FILE__) . '/imageview.php';
 131 if (strpos($myProxy, $CFG->dirroot) === 0) {
 132   $myProxy = trim(substr($myProxy, strlen($CFG->dirroot)), '/');
 133 } else {
 134   paintwebSaveDone(false, 'failed to find my image file proxy!');
 135 }
 136
 137 $imgUrl = $_POST['url'];
 138 $imgUrlNew = null;
 139
 140 $imgDataURL = &$_POST['dataURL'];
 141
 142 if (empty($imgUrl)) {
 143   paintwebSaveDone(false, 'empty url');
 144 }
 145
 146 if (empty($imgDataURL)) {
 147   paintwebSaveDone(false, 'empty data URL');
 148 }
 149
 150 // A data URL starts like this:
 151 // data:[<MIME-type>][;charset="<encoding>"][;base64],<data>
 152
 153 // Here we find the comma delimiter.
 154 $comma = strpos($imgDataURL, ',');
 155 $imgInfo = substr($imgDataURL, 0, $comma);
 156 if (empty($imgInfo) || !isset($imgDataURL{($comma+2)})) {
 157   paintwebSaveDone(false, 'malformed data URL');
 158 }
 159
 160 // Split by ':' to find the 'data' prefix and the rest of the info.
 161 $imgInfo = explode(':', $imgInfo);
 162
 163 // The array must have exactly two elements and the second element must not be
 164 // empty.
 165 if (count($imgInfo) !== 2 || $imgInfo[0] !== 'data' || empty($imgInfo[1])) {
 166   paintwebSaveDone(false, 'malformed data URL');
 167 }
 168
 169 // The MIME type must be given and it must be base64-encoded.
 170 $imgInfo = explode(';', $imgInfo[1]);
 171
 172 if (count($imgInfo) < 2 || !array_key_exists($imgInfo[0], $imgAllowedTypes) ||
 173     ($imgInfo[1] !== 'base64' && $imgInfo[2] !== 'base64')) {
 174   paintwebSaveDone(false, 'malformed data URL');
 175 }
 176
 177 prepareImgUrl();
 178
 179 $imgDataURL = substr($imgDataURL, $comma + 1);
 180
 181 if (!file_put_contents($imgDest, base64_decode($imgDataURL))) {
 182   paintwebSaveDone(false, 'failed to save file');
 183 }
 184
 185 paintwebSaveDone(true);
 186
 187 // vim:set spell spl=en fo=anl1qrowcb tw=80 ts=2 sw=2 sts=2 sta et noai nocin fenc=utf-8 ff=unix:
 188