initial support for remote url BINDing

config/example-config.php

@@ -188,6 +188,16 @@ $c->collections_always_exist = false;
 $c->schedule_private_key = 'PRIVATE-KEY-BASE-64-DATA';
 */
 
+/*
+* External subscription (BIND) minimum refresh interval
+* Required if you want to enable remote binding ( webcal subscriptions )
+* Default: none
+*/  
+/*
+$c->external_refresh = 60;
+*/
+
+
 
 
 /***************************************************************************

inc/DAVResource.php

@@ -97,6 +97,11 @@ class DAVResource
   */
   private $_is_binding;
 
+  /**
+  * @var True if this resource is a binding to an external resource
+  */
+  private $_is_external;
+
   /**
   * @var True if this resource is an addressbook collection
   */
@@ -158,6 +163,7 @@ class DAVResource
     $this->_is_principal     = false;
     $this->_is_calendar      = false;
     $this->_is_binding       = false;
+    $this->_is_external      = false;
     $this->_is_addressbook   = false;
     $this->_is_proxy_request = false;
     if ( isset($parameters) && is_object($parameters) ) {
@@ -400,7 +406,8 @@ EOSQL;
 SELECT collection.*, path_privs(:session_principal::int8, collection.dav_name,:scan_depth::int), p.principal_id,
     p.type_id AS principal_type_id, p.displayname AS principal_displayname, p.default_privileges AS principal_default_privileges,
     time_zone.tz_spec, dav_binding.access_ticket_id, dav_binding.parent_container AS bind_parent_container,
-    dav_binding.dav_displayname, owner.dav_name AS bind_owner_url, dav_binding.dav_name AS bound_to
+		dav_binding.dav_displayname, owner.dav_name AS bind_owner_url, dav_binding.dav_name AS bound_to,  
+    dav_binding.external_url AS external_url, dav_binding.type AS external_type, dav_binding.bind_id AS bind_id 
 FROM dav_binding
     LEFT JOIN collection ON (collection.collection_id=bound_source_id)
     LEFT JOIN principal p USING (user_no)
@@ -431,7 +438,16 @@ EOSQL;
           $this->collection->type = 'schedule-'. $matches[3]. 'box';
         else
           $this->collection->type = 'collection';
-
+        if ( strlen($row->external_url) > 8 ) {
+          $this->collection->bound_from = $row->external_url;
+          $this->_is_external = true;
+          if ( $row->external_type == 'calendar' )
+            $this->collection->type = 'calendar';
+          else if ( $row->external_type == 'addressbook' )
+            $this->collection->type = 'addressbook';
+          else
+            $this->collection->type = 'collection';
+        }
         $this->_is_binding = true;
         $this->bound_from = str_replace( $row->bound_to, $row->dav_name, $this->dav_name);
         if ( isset($row->access_ticket_id) ) {
@@ -1047,6 +1063,14 @@ EOQRY;
   }
 
 
+  /**
+  * Checks whether this resource is a bind to an external resource
+  */
+  function IsExternal() {
+    return $this->_is_external;
+  }
+
+
   /**
   * Checks whether this resource actually exists, in the virtual sense, within the hierarchy
   */

inc/caldav-BIND.php

@@ -47,45 +47,88 @@ if ( $destination->Exists() ) {
   $request->PreconditionFailed(403,'DAV::can-overwrite',translate('A resource already exists at the destination.'));
 }
 
-$source = new DAVResource( $href );
+if ( preg_match ( '{^https?://[A-Za-z][^/]*/.+$}', $href ) ) {
-if ( !$source->Exists() ) {
+	require_once('external-fetch.php');
-  $request->PreconditionFailed(403,'DAV::bind-source-exists',translate('The BIND Request MUST identify an existing resource.'));
+	$qry = new AwlQuery( );
-}
+  $qry->QDo('SELECT collection_id FROM collection WHERE dav_name = :dav_name ', array( ':dav_name' => '/.external/'. md5($href) ));
+  if ( $qry->rows() == 1 && ($row = $qry->Fetch()) ) {
+		$dav_id = $row->dav_id;
+	}
+	else {
+		create_external ( '/.external/'. md5($href) ,true,false );
+	  $qry->QDo('SELECT collection_id FROM collection WHERE dav_name = :dav_name ', array( ':dav_name' => '/.external/'. md5($href) ));
+	  if ( $qry->rows() != 1 || !($row = $qry->Fetch()) ) 
+			$request->DoResponse(500,translate('Database Error1'));
+		$dav_id = $row->collection_id;
+	}
 
-if ( $source->IsPrincipal() || !$source->IsCollection() ) {
+	$sql = 'INSERT INTO dav_binding ( bound_source_id, access_ticket_id, dav_owner_id, parent_container, dav_name, dav_displayname, external_url, type )
-  $request->PreconditionFailed(403,'DAV::binding-allowed',translate('DAViCal only allows BIND requests for collections at present.'));
+	VALUES( :target_id, :ticket_id, :session_principal, :parent_container, :dav_name, :displayname, :external_url, :external_type )';
-}
+	$params = array(
-
+      ':target_id'    => $dav_id,
-/*
+      ':ticket_id'    => null,
-  bind_id INT8 DEFAULT nextval('dav_id_seq') PRIMARY KEY,
+      ':parent_container' => $parent->dav_name(),
-  bound_source_id INT8 REFERENCES collection(collection_id) ON UPDATE CASCADE ON DELETE CASCADE,
+      ':session_principal' => $session->principal_id,
-  access_ticket_id TEXT REFERENCES access_ticket(ticket_id) ON UPDATE CASCADE ON DELETE SET NULL,
+      ':dav_name'     => $destination_path,
-  parent_container TEXT NOT NULL,
+      ':displayname'  => $segment,
-  dav_name TEXT UNIQUE NOT NULL,
+      ':external_url' => $href,
-  dav_displayname TEXT
+      ':external_type' => 'calendar'
-*/
+  );
-
+	$qry = new AwlQuery( $sql, $params );
-$sql = 'INSERT INTO dav_binding ( bound_source_id, access_ticket_id, dav_owner_id, parent_container, dav_name, dav_displayname )
+	if ( $qry->Exec('BIND',__LINE__,__FILE__) ) {
-VALUES( :target_id, :ticket_id, :session_principal, :parent_container, :dav_name, :displayname )';
+		$qry = new AwlQuery( 'SELECT bind_id from dav_binding where dav_name = :dav_name', array( ':dav_name' => $destination_path ) );
-$params = array(
+	  if ( ! $qry->Exec('BIND',__LINE__,__FILE__) || $qry->rows() != 1 || !($row = $qry->Fetch()) ) 
-    ':target_id'    => $source->GetProperty('collection_id'),
+			$request->DoResponse(500,translate('Database Error1'));
-    ':ticket_id'    => (isset($request->ticket) ? $request->ticket->id() : null),
+		fetch_external ( $row->bind_id, '' );
-    ':parent_container' => $parent->dav_name(),
+	  $request->DoResponse(201);
-    ':session_principal' => $session->principal_id,
+ 	} 
-    ':dav_name'     => $destination_path,
+	else {
-    ':displayname'  => $source->GetProperty('displayname')
+	  $request->DoResponse(500,translate('Database Error2'));
-);
+	}
-$qry = new AwlQuery( $sql, $params );
+} 
-if ( $qry->Exec('BIND',__LINE__,__FILE__) ) {
-  header('Location: '. ConstructURL($destination_path) );
-
-  // Uncache anything to do with the target
-  $cache = getCacheInstance();
-  $cache_ns = 'collection-'.$destination_path;
-  $cache->delete( $cache_ns, null );
-
-  $request->DoResponse(201);
-}
 else {
-  $request->DoResponse(500,translate('Database Error'));
+	$source = new DAVResource( $href );
-}
+	if ( !$source->Exists() ) {
+	  $request->PreconditionFailed(403,'DAV::bind-source-exists',translate('The BIND Request MUST identify an existing resource.'));
+	}
+
+	if ( $source->IsPrincipal() || !$source->IsCollection() ) {
+	  $request->PreconditionFailed(403,'DAV::binding-allowed',translate('DAViCal only allows BIND requests for collections at present.'));
+	}
+	
+	/*
+	  bind_id INT8 DEFAULT nextval('dav_id_seq') PRIMARY KEY,
+	  bound_source_id INT8 REFERENCES collection(collection_id) ON UPDATE CASCADE ON DELETE CASCADE,
+	  access_ticket_id TEXT REFERENCES access_ticket(ticket_id) ON UPDATE CASCADE ON DELETE SET NULL,
+    parent_container TEXT NOT NULL,
+    dav_name TEXT UNIQUE NOT NULL,
+    dav_displayname TEXT,
+    external_url TEXT,
+    type TEXT
+	*/
+	
+	$sql = 'INSERT INTO dav_binding ( bound_source_id, access_ticket_id, dav_owner_id, parent_container, dav_name, dav_displayname )
+	VALUES( :target_id, :ticket_id, :session_principal, :parent_container, :dav_name, :displayname )';
+	$params = array(
+      ':target_id'    => $source->GetProperty('collection_id'),
+      ':ticket_id'    => (isset($request->ticket) ? $request->ticket->id() : null),
+      ':parent_container' => $parent->dav_name(),
+      ':session_principal' => $session->principal_id,
+      ':dav_name'     => $destination_path,
+      ':displayname'  => $source->GetProperty('displayname')
+  );
+  $qry = new AwlQuery( $sql, $params );
+	if ( $qry->Exec('BIND',__LINE__,__FILE__) ) {
+	  header('Location: '. ConstructURL($destination_path) );
+	
+	  // Uncache anything to do with the target
+	  $cache = getCacheInstance();
+	  $cache_ns = 'collection-'.$destination_path;
+	  $cache->delete( $cache_ns, null );
+	
+	  $request->DoResponse(201);
+	}
+	else {
+	  $request->DoResponse(500,translate('Database Error'));
+	}
+}

inc/caldav-GET.php

@@ -15,6 +15,9 @@ require_once("DAVResource.php");
 
 $dav_resource = new DAVResource($request->path);
 $dav_resource->NeedPrivilege( array('urn:ietf:params:xml:ns:caldav:read-free-busy','DAV::read') );
+if ( $dav_resource->IsExternal() ) {
+	update_external ( $dav_resource );
+}      
 
 if ( ! $dav_resource->Exists() ) {
   $request->DoResponse( 404, translate("Resource Not Found.") );

inc/caldav-REPORT.php

@@ -61,9 +61,15 @@ switch( $xmltree->GetTag() ) {
     include("caldav-REPORT-pps-set.php");
     exit; // Not that it should return anyway.
   case 'DAV::sync-collection':
+    require_once("external-fetch.php");
+		if ( $target->IsExternal() )
+      update_external ( $target );
     include("caldav-REPORT-sync-collection.php");
     exit; // Not that it should return anyway.
   case 'DAV::expand-property':
+    require_once("external-fetch.php");
+    if ( $target->IsExternal() )
+      update_external ( $target );
     include("caldav-REPORT-expand-property.php");
     exit; // Not that it should return anyway.
   case 'DAV::principal-match':
@@ -313,6 +319,10 @@ function component_to_xml( $properties, $item ) {
   return $response;
 }
 
+require_once("external-fetch.php");
+if ( $target->IsExternal() )
+  update_external ( $target );
+
 if ( $xmltree->GetTag() == "urn:ietf:params:xml:ns:caldav:calendar-query" ) {
   $calquery = $xmltree->GetPath("/urn:ietf:params:xml:ns:caldav:calendar-query/*");
   include("caldav-REPORT-calquery.php");

inc/external-fetch.php

@@ -0,0 +1,73 @@
+<?PHP
+/**
+* Functions for managing external BIND resources
+*
+*
+* @package   davical
+* @subpackage   external-bind
+* @author    Rob Ostensen <rob@boxacle.net>
+* @copyright Rob Ostensen
+* @license   http://gnu.org/copyleft/gpl.html GNU GPL v3 or later
+*/
+
+function create_external ( $path,$is_calendar,$is_addressbook )
+{
+  global $request;
+  $resourcetypes = '<DAV::collection/>';
+  if ($is_calendar) $resourcetypes .= '<urn:ietf:params:xml:ns:caldav:calendar/>';
+  $qry = new AwlQuery();
+  if ( ! $qry->QDo( 'INSERT INTO collection ( user_no, parent_container, dav_name, dav_etag, dav_displayname,
+                                 is_calendar, is_addressbook, resourcetypes, created, modified )
+              VALUES( :user_no, :parent_container, :dav_name, :dav_etag, :dav_displayname,
+                      :is_calendar, :is_addressbook, :resourcetypes, current_timestamp, current_timestamp )',
+           array(
+              ':user_no'          => $request->user_no,
+              ':parent_container' => '/.external/',
+              ':dav_name'         => $path,
+              ':dav_etag'         => md5($request->user_no. $path),
+              ':dav_displayname'  => $path,
+              ':is_calendar'      => ($is_calendar ? 't' : 'f'),
+              ':is_addressbook'   => ($is_addressbook ? 't' : 'f'),
+              ':resourcetypes'    => $resourcetypes
+            ) ) ) {
+    $request->DoResponse( 500, translate('Error writing calendar details to database.') );
+  }
+}
+
+function fetch_external ( $bind_id, $min_age )
+{
+  $sql = 'SELECT collection.*, collection.dav_name as path, dav_binding.external_url as external_url FROM dav_binding LEFT JOIN collection ON (collection.collection_id=bound_source_id) WHERE bind_id = :bind_id';
+  $params = array( ':bind_id' => $bind_id );
+  if ( strlen ( $min_age ) > 2 ) {
+    $sql .= ' and collection.modified + interval :interval > NOW()';
+    $params[':interval'] = $min_age;
+  }
+  $qry = new AwlQuery( $sql, $params );
+  if ( $qry->Exec('DAVResource') && $qry->rows() > 0 && $row = $qry->Fetch() ) {
+    $curl = curl_init ( $row->external_url );
+    curl_setopt ( $curl, CURLOPT_RETURNTRANSFER, true );
+    $ics = curl_exec ( $curl );
+    curl_close ( $curl );
+    if ( is_string ( $ics ) && strlen ( $ics ) > 20 ) {
+      $qry = new AwlQuery( 'UPDATE collection SET modified=NOW() where collection_id = :cid', array ( ':cid' => $row->collection_id ) );
+      $qry->Exec('DAVResource');  
+      require_once ( 'caldav-PUT-functions.php');
+      import_collection ( $ics , $row->user_no, $row->path, 'External Fetch' , false ) ;
+      return true;
+    }
+  }
+  return false;
+}
+
+function update_external ( $request )
+{
+  global $c;
+  if ( $c->external_refresh < 1 )
+    return ;
+  $sql = 'SELECT bind_id from dav_binding LEFT JOIN collection ON (collection.collection_id=bound_source_id) collection where dav_name = :dav_name and collection.modified + interval :interval < NOW()';
+  $qry = new AwlQuery( $sql, array ( ':dav_name' => $request->dav_name, ':interval' => $c->external_refresh + ' minutes' ) );
+  if ( $qry->Exec('DAVResource') && $qry->rows() > 0 && $row = $qry->Fetch() ) {
+    if ( $row->bind_id != 0 )
+      fetch_external ( $row->bind_id );
+  }
+}