Basic script to sync from another caldav calendar.

inc/caldav-client-v2.php

@@ -151,6 +151,15 @@ class CalDAVClient {
     $this->headers[] = "Content-type: $type";
   }
 
+  /**
+  * Set the calendar_url we will be using for a while.
+  *
+  * @param string $url The calendar_url
+  */
+  function SetCalendar( $url ) {
+    $this->calendar_url = $url;
+  }
+
   /**
   * Split response into httpResponse and xmlResponse
   *
@@ -429,6 +438,27 @@ class CalDAVClient {
   }
 
 
+  /**
+  * Return the href containing this property
+  *
+  * @param string $tagname The tag name of the property to find the href for
+  * @param integer $which Which instance of the tag should we use
+  */
+  function HrefForProp( $tagname, $i = 0 ) {
+    if ( isset($this->xmltags[$tagname]) && isset($this->xmltags[$tagname][$i]) ) {
+      $j = $this->xmltags[$tagname][$i];
+      while( $j-- > 0 && $this->xmlnodes[$j]['tag'] != 'DAV::prop' );
+      if ( $j > 0 ) {
+        while( $j-- > 0 && $this->xmlnodes[$j]['tag'] != 'DAV::href' );
+        if ( $j > 0 && isset($this->xmlnodes[$j]['value']) ) {
+          return $this->xmlnodes[$j]['value'];
+        }
+      }
+    }
+    return null;
+  }
+
+
   /**
   * Return the href which has a resourcetype of the specified type
   *
@@ -489,11 +519,13 @@ class CalDAVClient {
     $xml = $this->DoPROPFINDRequest( $url, array('resourcetype', 'current-user-principal', 'owner', 'principal-URL',
                                   'urn:ietf:params:xml:ns:caldav:calendar-home-set'), 1);
 
-    $principal_url = $this->HrefForResourcetype('DAV::principal');
+    $principal_url = $this->HrefForProp('DAV::principal');
 
-    foreach( array('DAV::current-user-principal', 'DAV::principal-URL', 'DAV::owner') AS $v ) {
+    if ( !isset($principal_url) ) {
-      if ( !isset($principal_url) ) {
+      foreach( array('DAV::current-user-principal', 'DAV::principal-URL', 'DAV::owner') AS $href ) {
-        $principal_url = $this->HrefValueInside($v);
+        if ( !isset($principal_url) ) {
+          $principal_url = $this->HrefValueInside($href);
+        }
       }
     }
 
@@ -545,7 +577,7 @@ class CalDAVClient {
     if ( isset($this->xmltags['urn:ietf:params:xml:ns:caldav:calendar']) ) {
       $calendar_urls = array();
       foreach( $this->xmltags['urn:ietf:params:xml:ns:caldav:calendar'] AS $k => $v ) {
-        $calendar_urls[$this->HrefForResourcetype('urn:ietf:params:xml:ns:caldav:calendar', $k)] = 1;
+        $calendar_urls[$this->HrefForProp('urn:ietf:params:xml:ns:caldav:calendar', $k)] = 1;
       }
 
       foreach( $this->xmltags['DAV::href'] AS $i => $hnode ) {
@@ -576,6 +608,59 @@ class CalDAVClient {
   }
 
 
+  /**
+  * Get all etags for a calendar
+  */
+  function GetCollectionETags( $url = null ) {
+    if ( isset($url) ) $this->SetCalendar($url);
+
+    $this->DoPROPFINDRequest( $this->calendar_url, array('getetag'), 1);
+
+    $etags = array();
+    if ( isset($this->xmltags['DAV::getetag']) ) {
+      foreach( $this->xmltags['DAV::getetag'] AS $k => $v ) {
+        $events[$this->HrefForProp('DAV::getetag', $k)] = $v['value'];
+      }
+    }
+
+    return $etags;
+  }
+
+
+  /**
+  * Get a bunch of events for a calendar with a calendar-multiget report
+  */
+  function CalendarMultiget( $event_hrefs, $url = null ) {
+
+    if ( isset($url) ) $this->SetCalendar($url);
+
+    $hrefs = array();
+    foreach( $event_hrefs AS $k => $href ) {
+      $hrefs .= '<href>'.rawurlencode($url).'</href>';
+    }
+    $this->body = <<<EOXML
+<?xml version="1.0" encoding="utf-8" ?>
+<C:calendar-multiget xmlns="DAV:" xmlns:C="urn:ietf:params:xml:ns:caldav">
+<prop><getetag/><C:calendar-data/></prop>
+$hrefs
+</C:calendar-query>
+EOXML;
+
+    $this->requestMethod = "REPORT";
+    $this->SetContentType("text/xml");
+    $this->DoRequest( $this->calendar_url );
+
+    $etags = array();
+    if ( isset($this->xmltags['DAV::getetag']) ) {
+      foreach( $this->xmltags['DAV::getetag'] AS $k => $v ) {
+        $events[$this->HrefForProp('DAV::getetag', $k)] = $v['value'];
+      }
+    }
+
+    return $etags;
+  }
+
+
   /**
   * Given XML for a calendar query, return an array of the events (/todos) in the
   * response.  Each event in the array will have a 'href', 'etag' and '$response_type'
@@ -583,16 +668,17 @@ class CalDAVClient {
   * definition of the calendar data in iCalendar format.
   *
   * @param string $filter XML fragment which is the <filter> element of a calendar-query
-  * @param string $relative_url The URL relative to the base_url specified when the calendar was opened.  Default ''.
+  * @param string $url The URL of the calendar, or null to use the 'current' calendar_url
-  * @param string $report_type Used as a name for the array element containing the calendar data. @deprecated
   *
   * @return array An array of the relative URLs, etags, and events from the server.  Each element of the array will
   *               be an array with 'href', 'etag' and 'data' elements, corresponding to the URL, the server-supplied
   *               etag (which only varies when the data changes) and the calendar data in iCalendar format.
   */
-  function DoCalendarQuery( $filter, $relative_url = '' ) {
+  function DoCalendarQuery( $filter, $url = null ) {
 
-    $xml = <<<EOXML
+    if ( isset($url) ) $this->SetCalendar($url);
+
+    $this->body = <<<EOXML
 <?xml version="1.0" encoding="utf-8" ?>
 <C:calendar-query xmlns:D="DAV:" xmlns:C="urn:ietf:params:xml:ns:caldav">
   <D:prop>
@@ -602,17 +688,14 @@ class CalDAVClient {
 </C:calendar-query>
 EOXML;
 
-    $this->DoXMLRequest( 'REPORT', $xml, $relative_url );
+    $this->requestMethod = "REPORT";
-    $xml_parser = xml_parser_create_ns('UTF-8');
+    $this->SetContentType("text/xml");
-    $this->xml_tags = array();
+    $this->DoRequest( $this->calendar_url );
-    xml_parser_set_option ( $xml_parser, XML_OPTION_SKIP_WHITE, 1 );
-    xml_parse_into_struct( $xml_parser, $this->xmlResponse, $this->xml_tags );
-    xml_parser_free($xml_parser);
 
     $report = array();
-    foreach( $this->xml_tags as $k => $v ) {
+    foreach( $this->xmltags as $k => $v ) {
       switch( $v['tag'] ) {
-        case 'DAV::RESPONSE':
+        case 'DAV::response':
           if ( $v['type'] == 'open' ) {
             $response = array();
           }
@@ -620,13 +703,13 @@ EOXML;
             $report[] = $response;
           }
           break;
-        case 'DAV::HREF':
+        case 'DAV::href':
           $response['href'] = basename( $v['value'] );
           break;
-        case 'DAV::GETETAG':
+        case 'DAV::getetag':
           $response['etag'] = preg_replace('/^"?([^"]+)"?/', '$1', $v['value']);
           break;
-        case 'URN:IETF:PARAMS:XML:NS:CALDAV:CALENDAR-DATA':
+        case 'urn:ietf:params:xml:ns:caldav:calendar-data':
           $response['data'] = $v['value'];
           break;
       }

scripts/sync-pull.php

@@ -0,0 +1,174 @@
+#!/usr/bin/php
+<?php
+
+if ( @file_exists('../../awl/inc/AWLUtilities.php') ) {
+  set_include_path('../inc:../../awl/inc');
+}
+else if ( @file_exists('../awl/inc/AWLUtilities.php') ) {
+  set_include_path('inc:../awl/inc:.');
+}
+else {
+  set_include_path('../inc:/usr/share/awl/inc');
+}
+include('always.php');
+require_once('AwlQuery.php');
+require_once('caldav-PUT-functions.php');
+
+include('caldav-client-v2.php');
+
+$args = (object) null;
+$args->sync_all = false;
+
+function parse_arguments() {
+  global $args;
+
+  $opts = getopt( 'u:U:p:a' );
+  foreach( $opts AS $k => $v ) {
+    switch( $k ) {
+      case 'u':   $args->url  = $v;  break;
+      case 'U':   $args->user = $v;  break;
+      case 'p':   $args->pass = $v;  break;
+      case 'a':   $args->sync_all = 1;  break;
+      case 'c':   $args->local_collection_path = $v;  break;
+      default:    $args->{$k} = $v;
+    }
+  }
+}
+
+parse_arguments();
+
+// E.g.
+// sync-pull.php -U andrew@example.net -p 53cret -u https://www.google.com/calendar/dav/andrew@example.net/events -c /andrew/gsync/
+//
+
+if ( !preg_match( '{/$}', $args->url ) ) $args->url .= '/';
+
+$caldav = new CalDAVClient( $args->url, $args->user, $args->pass );
+
+// This will find the 'Principal URL' which we can query for user-related
+// properties.
+$principal_url = $caldav->FindPrincipal($args->url);
+
+// This will find the 'Calendar Home URL' which will be the folder(s) which
+// contain all of the user's calendars
+$calendar_home_set = $caldav->FindCalendarHome();
+
+$calendar = null;
+
+// This will go through the calendar_home_set and find all of the users
+// calendars on the remote server.
+$calendars = $caldav->FindCalendars();
+if ( count($calendars) < 1 ) {
+  printf( "No calendars found based on '%s'\n", $args->url );
+}
+
+// Now we have all of the remote calendars, we will look for the URL that
+// matches what we were originally supplied.  While this seems laborious
+// because we already have it, it means we could provide a match in some
+// other way (e.g. on displayname) and we could also present a list to
+// the user which is built from following the above process.
+foreach( $calendars AS $k => $a_calendar ) {
+  if ( rawurldecode($a_calendar->url) == rawurldecode($args->url) ) $calendar = $a_calendar;
+}
+if ( !isset($calendar) ) $calendar = $calendars[0];
+
+// In reality we could have omitted all of the above parts, If we really do
+// know the correct URL at the start.
+printf( "Calendar '%s' is at %s\n", $calendar->displayname, $calendar->url );
+
+// Generate a consistent filename for our synchronisation cache
+$sync_cache_filename = md5($args->url . $args->user . $calendar->url);
+
+// Do we just need to sync everything across and overwrite all the local stuff?
+$sync_all = ( !file_exists($sync_cache_filename) || $args->sync_all);
+
+if ( ! $sync_all ) {
+  /**
+  * Read a structure out of the cache file containing:
+  *   server_getctag - A collection tag (string)
+  *   server_etags   - An array of event tags (strings) keyed on filename, from the server
+  *   local_etags    - An array of event tags (strings) keyed on filename, from local DAViCal
+  */
+  $cache = unserialize( file_get_contents($sync_cache_filename) );
+
+  // First compare the ctag for the calendar
+  if ( isset($cache) && isset($cache->server_ctag) && isset($calendar->getctag) && $calendar->getctag == $cache->server_ctag ) {
+    printf( 'No changes to calendar "%s"'."\n", $args->url );
+    exit(0);
+  }
+}
+if ( !isset($cache) || !isset($cache->server_ctag) ) $sync_all = true;
+
+// Everything now will be at our calendar URL
+$caldav->SetCalendar($calendar->url);
+
+// So it seems we do need to sync.  We now need to check each individual event
+// which might have changed, so we pull a list of event etags from the server.
+$server_etags = $caldav->GetCollectionETags($calendar->url);
+
+$newcache = (object) array( 'server_ctag' => $calendar->getctag, 'server_etags' => array(), 'local_etags' => array() );
+
+if ( $sync_all ) {
+  // The easy case.  Sync them all, delete nothing
+  $insert_urls = array_flip($server_etags);
+  $update_urls = array();
+  $delete_urls = array();
+  foreach( $server_etags AS $href => $etag ) {
+    $fname = preg_replace('{^.*/}', '', $href);
+    $newcache->server_etags[$fname] = $etag;
+  }
+}
+else {
+  // Only sync the ones where the etag has changed.  Delete any that are no
+  // longer present at the remote end.
+  $insert_urls = array();
+  $update_urls = array();
+  foreach( $server_etags AS $href => $etag ) {
+    $fname = preg_replace('{^.*/}', '', $href);
+    $newcache->server_etags[$fname] = $etag;
+    if ( isset($cache->server_etags[$fname]) ) {
+      $cache_etag = $cache->server_etags[$fname];
+      unset($cache->server_etags[$fname]);
+      if ( $cache_etag == $etag ) continue;
+      $update_urls[] = $href;
+    }
+    else {
+      $insert_urls[] = $href;
+    }
+  }
+  $delete_urls = array_flip($cache->server_etags);
+}
+
+
+// Fetch the calendar data
+$events = $caldav->CalendarMultiget( array_merge( $insert_urls, $update_urls) );
+
+/**
+* @TODO: We should really check for collisions locally in case the local ETag is
+* also different to the one we saved earlier.
+*/
+// Update the local system with these events
+foreach( $events AS $href => $event ) {
+  // Do what we need to write $v into the local calendar we are syncing to
+  // at the
+  $fname = preg_replace('{^.*/}', '', $href);
+  $local_fname = $args->local_collection_path . $fname;
+  simple_write_resource( $local_fname, $event, (isset($insert_urls[$href]) ? 'INSERT' : 'UPDATE') );
+}
+
+/**
+* @TODO: We should not delete locally in the case that the local ETag is different
+* to the one we saved earlier.
+*/
+// Delete any events which were present in our cache, but are not on the master server
+foreach( $delete_urls AS $k => $v ) {
+  $fname = preg_replace('{^.*/}', '', $href);
+  $local_fname = $args->local_collection_path . $fname;
+  $qry = new AwlQuery('DELETE FROM caldav_data WHERE dav_name = :dav_name', array( ':dav_name' => $local_fname ) );
+  $qry->Exec('sync_pull',__LINE__,__FILE__);
+}
+
+// Now (re)write the cache file reflecting the current state.
+$cache_file = fopen($sync_cache_filename, 'w');
+fwrite( $cache_file, serialize($newcache) );
+fclose($cache_file);