[Summary view]

Differences Between: [Versions 310 and 402] [Versions 311 and 402] [Versions 39 and 402] [Versions 400 and 402]

   1  <?php
   2  // This file is part of Moodle - http://moodle.org/
   3  //
   4  // Moodle is free software: you can redistribute it and/or modify
   5  // it under the terms of the GNU General Public License as published by
   6  // the Free Software Foundation, either version 3 of the License, or
   7  // (at your option) any later version.
   8  //
   9  // Moodle is distributed in the hope that it will be useful,
  10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  // GNU General Public License for more details.
  13  //
  14  // You should have received a copy of the GNU General Public License
  15  // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16  /**
  17   * Contains the remote_resource class definition.
  18   *
  19   * @package tool_moodlenet
  20   * @copyright 2020 Jake Dallimore <jrhdallimore@gmail.com>
  21   * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  22   */
  23  namespace tool_moodlenet\local;
  24  
  25  /**
  26   * The remote_resource class.
  27   *
  28   * Objects of type remote_resource provide a means of interacting with resources over HTTP.
  29   *
  30   * @copyright 2020 Jake Dallimore <jrhdallimore@gmail.com>
  31   * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  32   */
  33  class remote_resource {
  34  
  35      /** @var \curl $curl the curl http helper.*/
  36      protected $curl;
  37  
  38      /** @var url $url the url to the remote resource.*/
  39      protected $url;
  40  
  41      /** @var string $filename the name of this remote file.*/
  42      protected $filename;
  43  
  44      /** @var string $extension the file extension of this remote file.*/
  45      protected $extension;
  46  
  47      /** @var array $headinfo the array of information for the most recent HEAD request.*/
  48      protected $headinfo = [];
  49  
  50      /** @var \stdClass $metadata information about the resource. */
  51      protected $metadata;
  52  
  53      /**
  54       * The remote_resource constructor.
  55       *
  56       * @param \curl $curl a curl object for HTTP requests.
  57       * @param url $url the URL of the remote resource.
  58       * @param \stdClass $metadata resource metadata such as name, summary, license, etc.
  59       */
  60      public function __construct(\curl $curl, url $url, \stdClass $metadata) {
  61          $this->curl = $curl;
  62          $this->url = $url;
  63          $this->filename = pathinfo($this->url->get_path() ?? '', PATHINFO_FILENAME);
  64          $this->extension = pathinfo($this->url->get_path() ?? '', PATHINFO_EXTENSION);
  65          $this->metadata = $metadata;
  66      }
  67  
  68      /**
  69       * Return the URL for this remote resource.
  70       *
  71       * @return url the url object.
  72       */
  73      public function get_url(): url {
  74          return $this->url;
  75      }
  76  
  77      /**
  78       * Get the name of the file as taken from the metadata.
  79       */
  80      public function get_name(): string {
  81          return $this->metadata->name ?? '';
  82      }
  83  
  84      /**
  85       * Get the resource metadata.
  86       *
  87       * @return \stdClass the metadata.
  88       */
  89      public function get_metadata(): \stdClass {
  90          return$this->metadata;
  91      }
  92  
  93      /**
  94       * Get the description of the resource as taken from the metadata.
  95       *
  96       * @return string
  97       */
  98      public function get_description(): string {
  99          return $this->metadata->description ?? '';
 100      }
 101  
 102      /**
 103       * Return the extension of the file, if found.
 104       *
 105       * @return string the extension of the file, if found.
 106       */
 107      public function get_extension(): string {
 108          return $this->extension;
 109      }
 110  
 111      /**
 112       * Returns the file size of the remote file, in bytes, or null if it cannot be determined.
 113       *
 114       * @return int|null the content length, if able to be determined, otherwise null.
 115       */
 116      public function get_download_size(): ?int {
 117          $this->get_resource_info();
 118          return $this->headinfo['download_content_length'] ?? null;
 119      }
 120  
 121      /**
 122       * Download the remote resource to a local requestdir, returning the path and name of the resulting file.
 123       *
 124       * @return array an array containing filepath adn filename, e.g. [filepath, filename].
 125       * @throws \moodle_exception if the file cannot be downloaded.
 126       */
 127      public function download_to_requestdir(): array {
 128          $filename = sprintf('%s.%s', $this->filename, $this->get_extension());
 129          $path = make_request_directory();
 130          $fullpathwithname = sprintf('%s/%s', $path, $filename);
 131  
 132          // In future, use a timeout (download and/or connection) controlled by a tool_moodlenet setting.
 133          $downloadtimeout = 30;
 134  
 135          $result = $this->curl->download_one($this->url->get_value(), null, ['filepath' => $fullpathwithname,
 136              'timeout' => $downloadtimeout]);
 137          if ($result !== true) {
 138              throw new \moodle_exception('errorduringdownload', 'tool_moodlenet', '', $result);
 139          }
 140  
 141          return [$path, $filename];
 142      }
 143  
 144      /**
 145       * Fetches information about the remote resource via a HEAD request.
 146       *
 147       * @throws \coding_exception if any connection problems occur.
 148       */
 149      protected function get_resource_info() {
 150          if (!empty($this->headinfo)) {
 151              return;
 152          }
 153          $options['CURLOPT_RETURNTRANSFER'] = 1;
 154          $options['CURLOPT_FOLLOWLOCATION'] = 1;
 155          $options['CURLOPT_MAXREDIRS'] = 5;
 156          $options['CURLOPT_FAILONERROR'] = 1; // We want to consider http error codes as errors to report, not just status codes.
 157  
 158          $this->curl->head($this->url->get_value(), $options);
 159          $errorno = $this->curl->get_errno();
 160          $this->curl->resetopt();
 161  
 162          if ($errorno !== 0) {
 163              $message = 'Problem during HEAD request for remote resource \''.$this->url->get_value().'\'. Curl Errno: ' . $errorno;
 164              throw new \coding_exception($message);
 165          }
 166          $this->headinfo = $this->curl->get_info();
 167      }
 168  
 169  }