cms/drupal/includes/mail.inc
changeset 541 e756a8c72c3d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cms/drupal/includes/mail.inc	Fri Sep 08 12:04:06 2017 +0200
@@ -0,0 +1,623 @@
+<?php
+
+/**
+ * @file
+ * API functions for processing and sending e-mail.
+ */
+
+/**
+ * Auto-detect appropriate line endings for e-mails.
+ *
+ * $conf['mail_line_endings'] will override this setting.
+ */
+define('MAIL_LINE_ENDINGS', isset($_SERVER['WINDIR']) || (isset($_SERVER['SERVER_SOFTWARE']) && strpos($_SERVER['SERVER_SOFTWARE'], 'Win32') !== FALSE) ? "\r\n" : "\n");
+
+/**
+ * Composes and optionally sends an e-mail message.
+ *
+ * Sending an e-mail works with defining an e-mail template (subject, text
+ * and possibly e-mail headers) and the replacement values to use in the
+ * appropriate places in the template. Processed e-mail templates are
+ * requested from hook_mail() from the module sending the e-mail. Any module
+ * can modify the composed e-mail message array using hook_mail_alter().
+ * Finally drupal_mail_system()->mail() sends the e-mail, which can
+ * be reused if the exact same composed e-mail is to be sent to multiple
+ * recipients.
+ *
+ * Finding out what language to send the e-mail with needs some consideration.
+ * If you send e-mail to a user, her preferred language should be fine, so
+ * use user_preferred_language(). If you send email based on form values
+ * filled on the page, there are two additional choices if you are not
+ * sending the e-mail to a user on the site. You can either use the language
+ * used to generate the page ($language global variable) or the site default
+ * language. See language_default(). The former is good if sending e-mail to
+ * the person filling the form, the later is good if you send e-mail to an
+ * address previously set up (like contact addresses in a contact form).
+ *
+ * Taking care of always using the proper language is even more important
+ * when sending e-mails in a row to multiple users. Hook_mail() abstracts
+ * whether the mail text comes from an administrator setting or is
+ * static in the source code. It should also deal with common mail tokens,
+ * only receiving $params which are unique to the actual e-mail at hand.
+ *
+ * An example:
+ *
+ * @code
+ *   function example_notify($accounts) {
+ *     foreach ($accounts as $account) {
+ *       $params['account'] = $account;
+ *       // example_mail() will be called based on the first drupal_mail() parameter.
+ *       drupal_mail('example', 'notice', $account->mail, user_preferred_language($account), $params);
+ *     }
+ *   }
+ *
+ *   function example_mail($key, &$message, $params) {
+ *     $data['user'] = $params['account'];
+ *     $options['language'] = $message['language'];
+ *     user_mail_tokens($variables, $data, $options);
+ *     switch($key) {
+ *       case 'notice':
+ *         // If the recipient can receive such notices by instant-message, do
+ *         // not send by email.
+ *         if (example_im_send($key, $message, $params)) {
+ *           $message['send'] = FALSE;
+ *           break;
+ *         }
+ *         $langcode = $message['language']->language;
+ *         $message['subject'] = t('Notification from !site', $variables, array('langcode' => $langcode));
+ *         $message['body'][] = t("Dear !username\n\nThere is new content available on the site.", $variables, array('langcode' => $langcode));
+ *         break;
+ *     }
+ *   }
+ * @endcode
+ *
+ * Another example, which uses drupal_mail() to format a message for sending
+ * later:
+ *
+ * @code
+ *   $params = array('current_conditions' => $data);
+ *   $to = 'user@example.com';
+ *   $message = drupal_mail('example', 'notice', $to, $language, $params, FALSE);
+ *   // Only add to the spool if sending was not canceled.
+ *   if ($message['send']) {
+ *     example_spool_message($message);
+ *   }
+ * @endcode
+ *
+ * @param $module
+ *   A module name to invoke hook_mail() on. The {$module}_mail() hook will be
+ *   called to complete the $message structure which will already contain common
+ *   defaults.
+ * @param $key
+ *   A key to identify the e-mail sent. The final e-mail id for e-mail altering
+ *   will be {$module}_{$key}.
+ * @param $to
+ *   The e-mail address or addresses where the message will be sent to. The
+ *   formatting of this string will be validated with the
+ *   @link http://php.net/manual/filter.filters.validate.php PHP e-mail validation filter. @endlink
+ *   Some examples are:
+ *   - user@example.com
+ *   - user@example.com, anotheruser@example.com
+ *   - User <user@example.com>
+ *   - User <user@example.com>, Another User <anotheruser@example.com>
+ * @param $language
+ *   Language object to use to compose the e-mail.
+ * @param $params
+ *   Optional parameters to build the e-mail.
+ * @param $from
+ *   Sets From to this value, if given.
+ * @param $send
+ *   If TRUE, drupal_mail() will call drupal_mail_system()->mail() to deliver
+ *   the message, and store the result in $message['result']. Modules
+ *   implementing hook_mail_alter() may cancel sending by setting
+ *   $message['send'] to FALSE.
+ *
+ * @return
+ *   The $message array structure containing all details of the
+ *   message. If already sent ($send = TRUE), then the 'result' element
+ *   will contain the success indicator of the e-mail, failure being already
+ *   written to the watchdog. (Success means nothing more than the message being
+ *   accepted at php-level, which still doesn't guarantee it to be delivered.)
+ */
+function drupal_mail($module, $key, $to, $language, $params = array(), $from = NULL, $send = TRUE) {
+  $default_from = variable_get('site_mail', ini_get('sendmail_from'));
+
+  // Bundle up the variables into a structured array for altering.
+  $message = array(
+    'id'       => $module . '_' . $key,
+    'module'   => $module,
+    'key'      => $key,
+    'to'       => $to,
+    'from'     => isset($from) ? $from : $default_from,
+    'language' => $language,
+    'params'   => $params,
+    'send'     => TRUE,
+    'subject'  => '',
+    'body'     => array()
+  );
+
+  // Build the default headers
+  $headers = array(
+    'MIME-Version'              => '1.0',
+    'Content-Type'              => 'text/plain; charset=UTF-8; format=flowed; delsp=yes',
+    'Content-Transfer-Encoding' => '8Bit',
+    'X-Mailer'                  => 'Drupal'
+  );
+  if ($default_from) {
+    // To prevent e-mail from looking like spam, the addresses in the Sender and
+    // Return-Path headers should have a domain authorized to use the originating
+    // SMTP server.
+    $headers['From'] = $headers['Sender'] = $headers['Return-Path'] = $default_from;
+  }
+  if ($from) {
+    $headers['From'] = $from;
+  }
+  $message['headers'] = $headers;
+
+  // Build the e-mail (get subject and body, allow additional headers) by
+  // invoking hook_mail() on this module. We cannot use module_invoke() as
+  // we need to have $message by reference in hook_mail().
+  if (function_exists($function = $module . '_mail')) {
+    $function($key, $message, $params);
+  }
+
+  // Invoke hook_mail_alter() to allow all modules to alter the resulting e-mail.
+  drupal_alter('mail', $message);
+
+  // Retrieve the responsible implementation for this message.
+  $system = drupal_mail_system($module, $key);
+
+  // Format the message body.
+  $message = $system->format($message);
+
+  // Optionally send e-mail.
+  if ($send) {
+    // The original caller requested sending. Sending was canceled by one or
+    // more hook_mail_alter() implementations. We set 'result' to NULL, because
+    // FALSE indicates an error in sending.
+    if (empty($message['send'])) {
+      $message['result'] = NULL;
+    }
+    // Sending was originally requested and was not canceled.
+    else {
+      $message['result'] = $system->mail($message);
+      // Log errors.
+      if (!$message['result']) {
+        watchdog('mail', 'Error sending e-mail (from %from to %to).', array('%from' => $message['from'], '%to' => $message['to']), WATCHDOG_ERROR);
+        drupal_set_message(t('Unable to send e-mail. Contact the site administrator if the problem persists.'), 'error');
+      }
+    }
+  }
+
+  return $message;
+}
+
+/**
+ * Returns an object that implements the MailSystemInterface interface.
+ *
+ * Allows for one or more custom mail backends to format and send mail messages
+ * composed using drupal_mail().
+ *
+ * An implementation needs to implement the following methods:
+ * - format: Allows to preprocess, format, and postprocess a mail
+ *   message before it is passed to the sending system. By default, all messages
+ *   may contain HTML and are converted to plain-text by the DefaultMailSystem
+ *   implementation. For example, an alternative implementation could override
+ *   the default implementation and additionally sanitize the HTML for usage in
+ *   a MIME-encoded e-mail, but still invoking the DefaultMailSystem
+ *   implementation to generate an alternate plain-text version for sending.
+ * - mail: Sends a message through a custom mail sending engine.
+ *   By default, all messages are sent via PHP's mail() function by the
+ *   DefaultMailSystem implementation.
+ *
+ * The selection of a particular implementation is controlled via the variable
+ * 'mail_system', which is a keyed array.  The default implementation
+ * is the class whose name is the value of 'default-system' key. A more specific
+ * match first to key and then to module will be used in preference to the
+ * default. To specify a different class for all mail sent by one module, set
+ * the class name as the value for the key corresponding to the module name. To
+ * specify a class for a particular message sent by one module, set the class
+ * name as the value for the array key that is the message id, which is
+ * "${module}_${key}".
+ *
+ * For example to debug all mail sent by the user module by logging it to a
+ * file, you might set the variable as something like:
+ *
+ * @code
+ * array(
+ *   'default-system' => 'DefaultMailSystem',
+ *   'user' => 'DevelMailLog',
+ * );
+ * @endcode
+ *
+ * Finally, a different system can be specified for a specific e-mail ID (see
+ * the $key param), such as one of the keys used by the contact module:
+ *
+ * @code
+ * array(
+ *   'default-system' => 'DefaultMailSystem',
+ *   'user' => 'DevelMailLog',
+ *   'contact_page_autoreply' => 'DrupalDevNullMailSend',
+ * );
+ * @endcode
+ *
+ * Other possible uses for system include a mail-sending class that actually
+ * sends (or duplicates) each message to SMS, Twitter, instant message, etc, or
+ * a class that queues up a large number of messages for more efficient bulk
+ * sending or for sending via a remote gateway so as to reduce the load
+ * on the local server.
+ *
+ * @param $module
+ *   The module name which was used by drupal_mail() to invoke hook_mail().
+ * @param $key
+ *   A key to identify the e-mail sent. The final e-mail ID for the e-mail
+ *   alter hook in drupal_mail() would have been {$module}_{$key}.
+ *
+ * @return MailSystemInterface
+ */
+function drupal_mail_system($module, $key) {
+  $instances = &drupal_static(__FUNCTION__, array());
+
+  $id = $module . '_' . $key;
+
+  $configuration = variable_get('mail_system', array('default-system' => 'DefaultMailSystem'));
+
+  // Look for overrides for the default class, starting from the most specific
+  // id, and falling back to the module name.
+  if (isset($configuration[$id])) {
+    $class = $configuration[$id];
+  }
+  elseif (isset($configuration[$module])) {
+    $class = $configuration[$module];
+  }
+  else {
+    $class = $configuration['default-system'];
+  }
+
+  if (empty($instances[$class])) {
+    $interfaces = class_implements($class);
+    if (isset($interfaces['MailSystemInterface'])) {
+      $instances[$class] = new $class();
+    }
+    else {
+      throw new Exception(t('Class %class does not implement interface %interface', array('%class' => $class, '%interface' => 'MailSystemInterface')));
+    }
+  }
+  return $instances[$class];
+}
+
+/**
+ * An interface for pluggable mail back-ends.
+ */
+interface MailSystemInterface {
+  /**
+   * Format a message composed by drupal_mail() prior sending.
+   *
+   * @param $message
+   *   A message array, as described in hook_mail_alter().
+   *
+   * @return
+   *   The formatted $message.
+   */
+   public function format(array $message);
+
+  /**
+   * Send a message composed by drupal_mail().
+   *
+   * @param $message
+   *   Message array with at least the following elements:
+   *   - id: A unique identifier of the e-mail type. Examples: 'contact_user_copy',
+   *     'user_password_reset'.
+   *   - to: The mail address or addresses where the message will be sent to.
+   *     The formatting of this string will be validated with the
+   *     @link http://php.net/manual/filter.filters.validate.php PHP e-mail validation filter. @endlink
+   *     Some examples are:
+   *     - user@example.com
+   *     - user@example.com, anotheruser@example.com
+   *     - User <user@example.com>
+   *     - User <user@example.com>, Another User <anotheruser@example.com>
+   *   - subject: Subject of the e-mail to be sent. This must not contain any
+   *     newline characters, or the mail may not be sent properly.
+   *   - body: Message to be sent. Accepts both CRLF and LF line-endings.
+   *     E-mail bodies must be wrapped. You can use drupal_wrap_mail() for
+   *     smart plain text wrapping.
+   *   - headers: Associative array containing all additional mail headers not
+   *     defined by one of the other parameters.  PHP's mail() looks for Cc and
+   *     Bcc headers and sends the mail to addresses in these headers too.
+   *
+   * @return
+   *   TRUE if the mail was successfully accepted for delivery, otherwise FALSE.
+   */
+   public function mail(array $message);
+}
+
+/**
+ * Performs format=flowed soft wrapping for mail (RFC 3676).
+ *
+ * We use delsp=yes wrapping, but only break non-spaced languages when
+ * absolutely necessary to avoid compatibility issues.
+ *
+ * We deliberately use LF rather than CRLF, see drupal_mail().
+ *
+ * @param string $text
+ *   The plain text to process.
+ * @param string $indent (optional)
+ *   A string to indent the text with. Only '>' characters are repeated on
+ *   subsequent wrapped lines. Others are replaced by spaces.
+ *
+ * @return string
+ *   The content of the email as a string with formatting applied.
+ */
+function drupal_wrap_mail($text, $indent = '') {
+  // Convert CRLF into LF.
+  $text = str_replace("\r", '', $text);
+  // See if soft-wrapping is allowed.
+  $clean_indent = _drupal_html_to_text_clean($indent);
+  $soft = strpos($clean_indent, ' ') === FALSE;
+  // Check if the string has line breaks.
+  if (strpos($text, "\n") !== FALSE) {
+    // Remove trailing spaces to make existing breaks hard, but leave signature
+    // marker untouched (RFC 3676, Section 4.3).
+    $text = preg_replace('/(?(?<!^--) +\n|  +\n)/m', "\n", $text);
+    // Wrap each line at the needed width.
+    $lines = explode("\n", $text);
+    array_walk($lines, '_drupal_wrap_mail_line', array('soft' => $soft, 'length' => strlen($indent)));
+    $text = implode("\n", $lines);
+  }
+  else {
+    // Wrap this line.
+    _drupal_wrap_mail_line($text, 0, array('soft' => $soft, 'length' => strlen($indent)));
+  }
+  // Empty lines with nothing but spaces.
+  $text = preg_replace('/^ +\n/m', "\n", $text);
+  // Space-stuff special lines.
+  $text = preg_replace('/^(>| |From)/m', ' $1', $text);
+  // Apply indentation. We only include non-'>' indentation on the first line.
+  $text = $indent . substr(preg_replace('/^/m', $clean_indent, $text), strlen($indent));
+
+  return $text;
+}
+
+/**
+ * Transforms an HTML string into plain text, preserving its structure.
+ *
+ * The output will be suitable for use as 'format=flowed; delsp=yes' text
+ * (RFC 3676) and can be passed directly to drupal_mail() for sending.
+ *
+ * We deliberately use LF rather than CRLF, see drupal_mail().
+ *
+ * This function provides suitable alternatives for the following tags:
+ * <a> <em> <i> <strong> <b> <br> <p> <blockquote> <ul> <ol> <li> <dl> <dt>
+ * <dd> <h1> <h2> <h3> <h4> <h5> <h6> <hr>
+ *
+ * @param $string
+ *   The string to be transformed.
+ * @param $allowed_tags (optional)
+ *   If supplied, a list of tags that will be transformed. If omitted, all
+ *   all supported tags are transformed.
+ *
+ * @return
+ *   The transformed string.
+ */
+function drupal_html_to_text($string, $allowed_tags = NULL) {
+  // Cache list of supported tags.
+  static $supported_tags;
+  if (empty($supported_tags)) {
+    $supported_tags = array('a', 'em', 'i', 'strong', 'b', 'br', 'p', 'blockquote', 'ul', 'ol', 'li', 'dl', 'dt', 'dd', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'hr');
+  }
+
+  // Make sure only supported tags are kept.
+  $allowed_tags = isset($allowed_tags) ? array_intersect($supported_tags, $allowed_tags) : $supported_tags;
+
+  // Make sure tags, entities and attributes are well-formed and properly nested.
+  $string = _filter_htmlcorrector(filter_xss($string, $allowed_tags));
+
+  // Apply inline styles.
+  $string = preg_replace('!</?(em|i)((?> +)[^>]*)?>!i', '/', $string);
+  $string = preg_replace('!</?(strong|b)((?> +)[^>]*)?>!i', '*', $string);
+
+  // Replace inline <a> tags with the text of link and a footnote.
+  // 'See <a href="http://drupal.org">the Drupal site</a>' becomes
+  // 'See the Drupal site [1]' with the URL included as a footnote.
+  _drupal_html_to_mail_urls(NULL, TRUE);
+  $pattern = '@(<a[^>]+?href="([^"]*)"[^>]*?>(.+?)</a>)@i';
+  $string = preg_replace_callback($pattern, '_drupal_html_to_mail_urls', $string);
+  $urls = _drupal_html_to_mail_urls();
+  $footnotes = '';
+  if (count($urls)) {
+    $footnotes .= "\n";
+    for ($i = 0, $max = count($urls); $i < $max; $i++) {
+      $footnotes .= '[' . ($i + 1) . '] ' . $urls[$i] . "\n";
+    }
+  }
+
+  // Split tags from text.
+  $split = preg_split('/<([^>]+?)>/', $string, -1, PREG_SPLIT_DELIM_CAPTURE);
+  // Note: PHP ensures the array consists of alternating delimiters and literals
+  // and begins and ends with a literal (inserting $null as required).
+
+  $tag = FALSE; // Odd/even counter (tag or no tag)
+  $casing = NULL; // Case conversion function
+  $output = '';
+  $indent = array(); // All current indentation string chunks
+  $lists = array(); // Array of counters for opened lists
+  foreach ($split as $value) {
+    $chunk = NULL; // Holds a string ready to be formatted and output.
+
+    // Process HTML tags (but don't output any literally).
+    if ($tag) {
+      list($tagname) = explode(' ', strtolower($value), 2);
+      switch ($tagname) {
+        // List counters
+        case 'ul':
+          array_unshift($lists, '*');
+          break;
+        case 'ol':
+          array_unshift($lists, 1);
+          break;
+        case '/ul':
+        case '/ol':
+          array_shift($lists);
+          $chunk = ''; // Ensure blank new-line.
+          break;
+
+        // Quotation/list markers, non-fancy headers
+        case 'blockquote':
+          // Format=flowed indentation cannot be mixed with lists.
+          $indent[] = count($lists) ? ' "' : '>';
+          break;
+        case 'li':
+          $indent[] = isset($lists[0]) && is_numeric($lists[0]) ? ' ' . $lists[0]++ . ') ' : ' * ';
+          break;
+        case 'dd':
+          $indent[] = '    ';
+          break;
+        case 'h3':
+          $indent[] = '.... ';
+          break;
+        case 'h4':
+          $indent[] = '.. ';
+          break;
+        case '/blockquote':
+          if (count($lists)) {
+            // Append closing quote for inline quotes (immediately).
+            $output = rtrim($output, "> \n") . "\"\n";
+            $chunk = ''; // Ensure blank new-line.
+          }
+          // Fall-through
+        case '/li':
+        case '/dd':
+          array_pop($indent);
+          break;
+        case '/h3':
+        case '/h4':
+          array_pop($indent);
+        case '/h5':
+        case '/h6':
+          $chunk = ''; // Ensure blank new-line.
+          break;
+
+        // Fancy headers
+        case 'h1':
+          $indent[] = '======== ';
+          $casing = 'drupal_strtoupper';
+          break;
+        case 'h2':
+          $indent[] = '-------- ';
+          $casing = 'drupal_strtoupper';
+          break;
+        case '/h1':
+        case '/h2':
+          $casing = NULL;
+          // Pad the line with dashes.
+          $output = _drupal_html_to_text_pad($output, ($tagname == '/h1') ? '=' : '-', ' ');
+          array_pop($indent);
+          $chunk = ''; // Ensure blank new-line.
+          break;
+
+        // Horizontal rulers
+        case 'hr':
+          // Insert immediately.
+          $output .= drupal_wrap_mail('', implode('', $indent)) . "\n";
+          $output = _drupal_html_to_text_pad($output, '-');
+          break;
+
+        // Paragraphs and definition lists
+        case '/p':
+        case '/dl':
+          $chunk = ''; // Ensure blank new-line.
+          break;
+      }
+    }
+    // Process blocks of text.
+    else {
+      // Convert inline HTML text to plain text; not removing line-breaks or
+      // white-space, since that breaks newlines when sanitizing plain-text.
+      $value = trim(decode_entities($value));
+      if (drupal_strlen($value)) {
+        $chunk = $value;
+      }
+    }
+
+    // See if there is something waiting to be output.
+    if (isset($chunk)) {
+      // Apply any necessary case conversion.
+      if (isset($casing)) {
+        $chunk = $casing($chunk);
+      }
+      // Format it and apply the current indentation.
+      $output .= drupal_wrap_mail($chunk, implode('', $indent)) . MAIL_LINE_ENDINGS;
+      // Remove non-quotation markers from indentation.
+      $indent = array_map('_drupal_html_to_text_clean', $indent);
+    }
+
+    $tag = !$tag;
+  }
+
+  return $output . $footnotes;
+}
+
+/**
+ * Wraps words on a single line.
+ *
+ * Callback for array_walk() winthin drupal_wrap_mail().
+ */
+function _drupal_wrap_mail_line(&$line, $key, $values) {
+  // Use soft-breaks only for purely quoted or unindented text.
+  $line = wordwrap($line, 77 - $values['length'], $values['soft'] ? " \n" : "\n");
+  // Break really long words at the maximum width allowed.
+  $line = wordwrap($line, 996 - $values['length'], $values['soft'] ? " \n" : "\n", TRUE);
+}
+
+/**
+ * Keeps track of URLs and replaces them with placeholder tokens.
+ *
+ * Callback for preg_replace_callback() within drupal_html_to_text().
+ */
+function _drupal_html_to_mail_urls($match = NULL, $reset = FALSE) {
+  global $base_url, $base_path;
+  static $urls = array(), $regexp;
+
+  if ($reset) {
+    // Reset internal URL list.
+    $urls = array();
+  }
+  else {
+    if (empty($regexp)) {
+      $regexp = '@^' . preg_quote($base_path, '@') . '@';
+    }
+    if ($match) {
+      list(, , $url, $label) = $match;
+      // Ensure all URLs are absolute.
+      $urls[] = strpos($url, '://') ? $url : preg_replace($regexp, $base_url . '/', $url);
+      return $label . ' [' . count($urls) . ']';
+    }
+  }
+  return $urls;
+}
+
+/**
+ * Replaces non-quotation markers from a given piece of indentation with spaces.
+ *
+ * Callback for array_map() within drupal_html_to_text().
+ */
+function _drupal_html_to_text_clean($indent) {
+  return preg_replace('/[^>]/', ' ', $indent);
+}
+
+/**
+ * Pads the last line with the given character.
+ *
+ * @see drupal_html_to_text()
+ */
+function _drupal_html_to_text_pad($text, $pad, $prefix = '') {
+  // Remove last line break.
+  $text = substr($text, 0, -1);
+  // Calculate needed padding space and add it.
+  if (($p = strrpos($text, "\n")) === FALSE) {
+    $p = -1;
+  }
+  $n = max(0, 79 - (strlen($text) - $p) - strlen($prefix));
+  // Add prefix and padding, and restore linebreak.
+  return $text . $prefix . str_repeat($pad, $n) . "\n";
+}