Merge branch 'subscription'

13 files changed, 655 insertions, 236 deletions

diff --git a/inc/actions.php b/inc/actions.php
index 92f817133..1fda0584e 100644
--- a/inc/actions.php
+++ b/inc/actions.php
@@ -47,12 +47,13 @@ function act_dispatch(){
         }
 
         //check if user is asking to (un)subscribe a page
-        if($ACT == 'subscribe' || $ACT == 'unsubscribe')
-            $ACT = act_subscription($ACT);
-
-        //check if user is asking to (un)subscribe a namespace
-        if($ACT == 'subscribens' || $ACT == 'unsubscribens')
-            $ACT = act_subscriptionns($ACT);
+        if($ACT == 'subscribe') {
+            try {
+                $ACT = act_subscription($ACT);
+            } catch (Exception $e) {
+                msg($e->getMessage(), -1);
+            }
+        }
 
         //check permissions
         $ACT = act_permcheck($ACT);
@@ -550,81 +551,102 @@ function act_export($act){
 }
 
 /**
- * Handle page 'subscribe', 'unsubscribe'
+ * Handle page 'subscribe'
  *
- * @author Steven Danz <steven-danz@kc.rr.com>
- * @todo   localize
+ * Throws exception on error.
+ *
+ * @author Adrian Lang <lang@cosmocode.de>
  */
 function act_subscription($act){
-    global $ID;
-    global $INFO;
     global $lang;
+    global $INFO;
+    global $ID;
 
-    $file=metaFN($ID,'.mlist');
-    if ($act=='subscribe' && !$INFO['subscribed']){
-        if ($INFO['userinfo']['mail']){
-            if (io_saveFile($file,$_SERVER['REMOTE_USER']."\n",true)) {
-                $INFO['subscribed'] = true;
-                msg(sprintf($lang[$act.'_success'], $INFO['userinfo']['name'], $ID),1);
-            } else {
-                msg(sprintf($lang[$act.'_error'], $INFO['userinfo']['name'], $ID),1);
-            }
-        } else {
-            msg($lang['subscribe_noaddress']);
-        }
-    } elseif ($act=='unsubscribe' && $INFO['subscribed']){
-        if (io_deleteFromFile($file,$_SERVER['REMOTE_USER']."\n")) {
-            $INFO['subscribed'] = false;
-            msg(sprintf($lang[$act.'_success'], $INFO['userinfo']['name'], $ID),1);
-        } else {
-            msg(sprintf($lang[$act.'_error'], $INFO['userinfo']['name'], $ID),1);
+    // get and preprocess data.
+    $params = array();
+    foreach(array('target', 'style', 'action') as $param) {
+        if (isset($_REQUEST["sub_$param"])) {
+            $params[$param] = $_REQUEST["sub_$param"];
         }
     }
 
+    // any action given? if not just return and show the subscription page
+    if(!$params['action']) return $act;
+
+    // Handle POST data, may throw exception.
+    trigger_event('ACTION_HANDLE_SUBSCRIBE', $params, 'subscription_handle_post');
+
+    $target = $params['target'];
+    $style  = $params['style'];
+    $data   = $params['data'];
+    $action = $params['action'];
+
+    // Perform action.
+    require_once DOKU_INC . 'inc/subscription.php';
+    if (!subscription_set($_SERVER['REMOTE_USER'], $target, $style, $data)) {
+        throw new Exception(sprintf($lang["subscr_{$action}_error"],
+                                    hsc($INFO['userinfo']['name']),
+                                    prettyprint_id($target)));
+    }
+    msg(sprintf($lang["subscr_{$action}_success"], hsc($INFO['userinfo']['name']),
+                prettyprint_id($target)), 1);
+    act_redirect($ID, $act);
+
+    // Assure that we have valid data if act_redirect somehow fails.
+    $INFO['subscribed'] = get_info_subscribed();
     return 'show';
 }
 
 /**
- * Handle namespace 'subscribe', 'unsubscribe'
+ * Validate POST data
+ *
+ * Validates POST data for a subscribe or unsubscribe request. This is the
+ * default action for the event ACTION_HANDLE_SUBSCRIBE.
  *
+ * @author Adrian Lang <lang@cosmocode.de>
  */
-function act_subscriptionns($act){
-    global $ID;
+function subscription_handle_post(&$params) {
     global $INFO;
     global $lang;
 
-    if(!getNS($ID)) {
-        $file = metaFN(getNS($ID),'.mlist');
-        $ns = "root";
-    } else {
-        $file = metaFN(getNS($ID),'/.mlist');
-        $ns = getNS($ID);
+    // Get and validate parameters.
+    if (!isset($params['target'])) {
+        throw new Exception('no subscription target given');
     }
-
-    // reuse strings used to display the status of the subscribe action
-    $act_msg = rtrim($act, 'ns');
-
-    if ($act=='subscribens' && !$INFO['subscribedns']){
-        if ($INFO['userinfo']['mail']){
-            if (io_saveFile($file,$_SERVER['REMOTE_USER']."\n",true)) {
-                $INFO['subscribedns'] = true;
-                msg(sprintf($lang[$act_msg.'_success'], $INFO['userinfo']['name'], $ns),1);
-            } else {
-                msg(sprintf($lang[$act_msg.'_error'], $INFO['userinfo']['name'], $ns),1);
+    $target = $params['target'];
+    $valid_styles = array('every', 'digest');
+    if (substr($target, -1, 1) === ':') {
+        // Allow “list” subscribe style since the target is a namespace.
+        $valid_styles[] = 'list';
+    }
+    $style  = valid_input_set('style', $valid_styles, $params,
+                              'invalid subscription style given');
+    $action = valid_input_set('action', array('subscribe', 'unsubscribe'),
+                              $params, 'invalid subscription action given');
+
+    // Check other conditions.
+    if ($action === 'subscribe') {
+        if ($INFO['userinfo']['mail'] === '') {
+            throw new Exception($lang['subscr_subscribe_noaddress']);
+        }
+    } elseif ($action === 'unsubscribe') {
+        $is = false;
+        foreach($INFO['subscribed'] as $subscr) {
+            if ($subscr['target'] === $target) {
+                $is = true;
             }
-        } else {
-            msg($lang['subscribe_noaddress']);
         }
-    } elseif ($act=='unsubscribens' && $INFO['subscribedns']){
-        if (io_deleteFromFile($file,$_SERVER['REMOTE_USER']."\n")) {
-            $INFO['subscribedns'] = false;
-            msg(sprintf($lang[$act_msg.'_success'], $INFO['userinfo']['name'], $ns),1);
-        } else {
-            msg(sprintf($lang[$act_msg.'_error'], $INFO['userinfo']['name'], $ns),1);
+        if ($is === false) {
+            throw new Exception(sprintf($lang['subscr_not_subscribed'],
+                                        $_SERVER['REMOTE_USER'],
+                                        prettyprint_id($target)));
         }
+        // subscription_set deletes a subscription if style = null.
+        $style = null;
     }
 
-    return 'show';
+    $data = in_array($style, array('list', 'digest')) ? time() : null;
+    $params = compact('target', 'style', 'data', 'action');
 }
 
 //Setup VIM: ex: et ts=2 enc=utf-8 :
diff --git a/inc/common.php b/inc/common.php
index 85187f16d..9cadb56fd 100644
--- a/inc/common.php
+++ b/inc/common.php
@@ -13,6 +13,7 @@ require_once(DOKU_INC.'inc/utf8.php');
 require_once(DOKU_INC.'inc/mail.php');
 require_once(DOKU_INC.'inc/parserutils.php');
 require_once(DOKU_INC.'inc/infoutils.php');
+require_once DOKU_INC.'inc/subscription.php';
 
 /**
  * These constants are used with the recents function
@@ -117,8 +118,7 @@ function pageinfo(){
     if(isset($_SERVER['REMOTE_USER'])){
         $info['userinfo']     = $USERINFO;
         $info['perm']         = auth_quickaclcheck($ID);
-        $info['subscribed']   = is_subscribed($ID,$_SERVER['REMOTE_USER'],false);
-        $info['subscribedns'] = is_subscribed($ID,$_SERVER['REMOTE_USER'],true);
+        $info['subscribed']   = get_info_subscribed();
         $info['client']       = $_SERVER['REMOTE_USER'];
 
         if($info['perm'] == AUTH_ADMIN){
@@ -1061,10 +1061,13 @@ function notify($id,$who,$rev='',$summary='',$minor=false,$replace=array()){
     }elseif($who == 'subscribers'){
         if(!$conf['subscribers']) return; //subscribers enabled?
         if($conf['useacl'] && $_SERVER['REMOTE_USER'] && $minor) return; //skip minors
-        $bcc  = subscriber_addresslist($id,false);
+        $data = array('id' => $id, 'addresslist' => '', 'self' => false);
+        trigger_event('COMMON_NOTIFY_ADDRESSLIST', $data,
+                      'subscription_addresslist');
+        $bcc = $data['addresslist'];
         if(empty($bcc)) return;
         $to   = '';
-        $text = rawLocale('subscribermail');
+        $text = rawLocale('subscr_single');
     }elseif($who == 'register'){
         if(empty($conf['registernotify'])) return;
         $text = rawLocale('registermail');
@@ -1097,7 +1100,7 @@ function notify($id,$who,$rev='',$summary='',$minor=false,$replace=array()){
         $text = str_replace('@OLDPAGE@',wl($id,"rev=$rev",true,'&'),$text);
         require_once(DOKU_INC.'inc/DifferenceEngine.php');
         $df  = new Diff(explode("\n",rawWiki($id,$rev)),
-                explode("\n",rawWiki($id)));
+                        explode("\n",rawWiki($id)));
         $dformat = new UnifiedDiffFormatter();
         $diff    = $dformat->format($df);
     }else{
@@ -1273,97 +1276,6 @@ function obfuscate($email) {
 }
 
 /**
- * Let us know if a user is tracking a page or a namespace
- *
- * @author Andreas Gohr <andi@splitbrain.org>
- */
-function is_subscribed($id,$uid,$ns=false){
-    if(!$ns) {
-        $file=metaFN($id,'.mlist');
-    } else {
-        if(!getNS($id)) {
-            $file = metaFN(getNS($id),'.mlist');
-        } else {
-            $file = metaFN(getNS($id),'/.mlist');
-        }
-    }
-    if (@file_exists($file)) {
-        $mlist = file($file);
-        $pos = array_search($uid."\n",$mlist);
-        return is_int($pos);
-    }
-
-    return false;
-}
-
-/**
- * Return a string with the email addresses of all the
- * users subscribed to a page
- *
- * @author Steven Danz <steven-danz@kc.rr.com>
- */
-function subscriber_addresslist($id,$self=true){
-    global $conf;
-    global $auth;
-
-    if (!$conf['subscribers']) return '';
-
-    $users = array();
-    $emails = array();
-
-    // load the page mlist file content
-    $mlist = array();
-    $file=metaFN($id,'.mlist');
-    if (@file_exists($file)) {
-        $mlist = file($file);
-        foreach ($mlist as $who) {
-            $who = rtrim($who);
-            if(!$self && $who == $_SERVER['REMOTE_USER']) continue;
-            $users[$who] = true;
-        }
-    }
-
-    // load also the namespace mlist file content
-    $ns = getNS($id);
-    while ($ns) {
-        $nsfile = metaFN($ns,'/.mlist');
-        if (@file_exists($nsfile)) {
-            $mlist = file($nsfile);
-            foreach ($mlist as $who) {
-                $who = rtrim($who);
-                if(!$self && $who == $_SERVER['REMOTE_USER']) continue;
-                $users[$who] = true;
-            }
-        }
-        $ns = getNS($ns);
-    }
-    // root namespace
-    $nsfile = metaFN('','.mlist');
-    if (@file_exists($nsfile)) {
-        $mlist = file($nsfile);
-        foreach ($mlist as $who) {
-            $who = rtrim($who);
-            if(!$self && $who == $_SERVER['REMOTE_USER']) continue;
-            $users[$who] = true;
-        }
-    }
-    if(!empty($users)) {
-        foreach (array_keys($users) as $who) {
-            $info = $auth->getUserData($who);
-            if($info === false) continue;
-            $level = auth_aclcheck($id,$who,$info['grps']);
-            if ($level >= AUTH_READ) {
-                if (strcasecmp($info['mail'],$conf['notify']) != 0) {
-                    $emails[] = $info['mail'];
-                }
-            }
-        }
-    }
-
-    return implode(',',$emails);
-}
-
-/**
  * Removes quoting backslashes
  *
  * @author Andreas Gohr <andi@splitbrain.org>
@@ -1545,4 +1457,30 @@ function send_redirect($url){
     exit;
 }
 
-//Setup VIM: ex: et ts=4 enc=utf-8 :
+/**
+ * Validate a value using a set of valid values
+ *
+ * This function checks whether a specified value is set and in the array
+ * $valid_values. If not, the function returns a default value or, if no
+ * default is specified, throws an exception.
+ *
+ * @param string $param        The name of the parameter
+ * @param array  $valid_values A set of valid values; Optionally a default may
+ *                             be marked by the key “default”.
+ * @param array  $array        The array containing the value (typically $_POST
+ *                             or $_GET)
+ * @param string $exc          The text of the raised exception
+ *
+ * @author Adrian Lang <lang@cosmocode.de>
+ */
+function valid_input_set($param, $valid_values, $array, $exc = '') {
+    if (isset($array[$param]) && in_array($array[$param], $valid_values)) {
+        return $array[$param];
+    } elseif (isset($valid_values['default'])) {
+        return $valid_values['default'];
+    } else {
+        throw new Exception($exc);
+    }
+}
+
+//Setup VIM: ex: et ts=2 enc=utf-8 :
diff --git a/inc/confutils.php b/inc/confutils.php
index abfde8a80..de63846de 100644
--- a/inc/confutils.php
+++ b/inc/confutils.php
@@ -248,7 +248,6 @@ function actionOK($action){
         if(isset($conf['resendpasswd']) && !$conf['resendpasswd']) $disabled[] = 'resendpwd';
         if(isset($conf['subscribers']) && !$conf['subscribers']) {
             $disabled[] = 'subscribe';
-            $disabled[] = 'subscribens';
         }
         $disabled = array_unique($disabled);
     }
diff --git a/inc/form.php b/inc/form.php
index 6d496f414..0a6bc2bba 100644
--- a/inc/form.php
+++ b/inc/form.php
@@ -283,6 +283,27 @@ class Doku_Form {
         echo $this->getForm();
     }
 
+    /**
+     * Add a radio set
+     *
+     * This function adds a set of radio buttons to the form. If $_POST[$name]
+     * is set, this radio is preselected, else the first radio button.
+     *
+     * @param string    $name    The HTML field name
+     * @param array     $entries An array of entries $value => $caption
+     *
+     * @author Adrian Lang <lang@cosmocode.de>
+     */
+
+    function addRadioSet($name, $entries) {
+        $value = (isset($_POST[$name]) && isset($entries[$_POST[$name]])) ?
+                 $_POST[$name] : key($entries);
+        foreach($entries as $val => $cap) {
+            $data = ($value === $val) ? array('checked' => 'checked') : array();
+            $this->addElement(form_makeRadioField($name, $val, $cap, '', '', $data));
+        }
+    }
+
 }
 
 /**
diff --git a/inc/lang/de/lang.php b/inc/lang/de/lang.php
index d0c1f8b70..c3fefd926 100644
--- a/inc/lang/de/lang.php
+++ b/inc/lang/de/lang.php
@@ -203,11 +203,25 @@ $lang['img_copyr']             = 'Copyright';
 $lang['img_format']            = 'Format';
 $lang['img_camera']            = 'Kamera';
 $lang['img_keywords']          = 'Schlagwörter';
-$lang['subscribe_success']     = '%s hat nun Änderungen der Seite %s abonniert';
-$lang['subscribe_error']       = '%s kann die Änderungen der Seite %s nicht abonnieren';
-$lang['subscribe_noaddress']   = 'Weil Ihre E-Mail-Adresse fehlt, können Sie das Thema nicht abonnieren';
-$lang['unsubscribe_success']   = 'Das Abonnement von %s für die Seite %s wurde aufgelöst';
-$lang['unsubscribe_error']     = 'Das Abonnement von %s für die Seite %s konnte nicht aufgelöst werden';
+
+$lang['subscr_subscribe_success']  = '%s hat nun Änderungen der Seite %s abonniert';
+$lang['subscr_subscribe_error']    = '%s kann die Änderungen der Seite %s nicht abonnieren';
+$lang['subscr_subscribe_noaddress']= 'Weil Ihre E-Mail-Adresse fehlt, können Sie das Thema nicht abonnieren';
+$lang['subscr_unsubscribe_success']= 'Das Abonnement von %s für die Seite %s wurde aufgelöst';
+$lang['subscr_unsubscribe_error']  = 'Das Abonnement von %s für die Seite %s konnte nicht aufgelöst werden';
+$lang['subscr_already_subscribed'] = '%s hat %s bereits abonniert';
+$lang['subscr_not_subscribed']     = '%s hat %s nicht abonniert';
+// Manage page for subscriptions
+$lang['subscr_m_not_subscribed']   = 'Sie haben die aktuelle Seite und ihre Namensräume nicht abonniert.';
+$lang['subscr_m_new_header']       = 'Abonnement hinzufügen';
+$lang['subscr_m_current_header']   = 'Aktuelle Abonnements';
+$lang['subscr_m_unsubscribe']      = 'Löschen';
+$lang['subscr_m_subscribe']        = 'Abonnieren';
+
+$lang['subscr_style_every']        = 'Email bei jeder Bearbeitung';
+$lang['subscr_style_digest']       = 'Übersichtsemail für jede veränderte Seite';
+$lang['subscr_style_list']         = 'Email mit Liste der geänderten Seiten';
+
 $lang['authmodfailed']         = 'Benutzerüberprüfung nicht möglich. Bitte wenden Sie sich an den Systembetreuer.';
 $lang['authtempfail']          = 'Benutzerüberprüfung momentan nicht möglich. Falls das Problem andauert, wenden Sie sich an den Systembetreuer.';
 $lang['i_chooselang']          = 'Wählen Sie Ihre Sprache';
diff --git a/inc/lang/en/lang.php b/inc/lang/en/lang.php
index cf5173d05..98ded12ca 100644
--- a/inc/lang/en/lang.php
+++ b/inc/lang/en/lang.php
@@ -39,10 +39,7 @@ $lang['btn_delete'] = 'Delete';
 $lang['btn_back']   = 'Back';
 $lang['btn_backlink']    = "Backlinks";
 $lang['btn_backtomedia'] = 'Back to Mediafile Selection';
-$lang['btn_subscribe']   = 'Subscribe Page Changes';
-$lang['btn_unsubscribe'] = 'Unsubscribe Page Changes';
-$lang['btn_subscribens']   = 'Subscribe Namespace Changes';
-$lang['btn_unsubscribens'] = 'Unsubscribe Namespace Changes';
+$lang['btn_subscribe']   = 'Manage Subscriptions';
 $lang['btn_profile']     = 'Update Profile';
 $lang['btn_reset']       = 'Reset';
 $lang['btn_resendpwd']   = 'Send new password';
@@ -158,6 +155,7 @@ $lang['download']   = 'Download Snippet';
 
 $lang['mail_newpage']  = 'page added:';
 $lang['mail_changed']  = 'page changed:';
+$lang['mail_subscribe_list'] = 'pages changed in namespace:';
 $lang['mail_new_user'] = 'new user:';
 $lang['mail_upload']   = 'file uploaded:';
 
@@ -212,11 +210,24 @@ $lang['img_format']  = 'Format';
 $lang['img_camera']  = 'Camera';
 $lang['img_keywords']= 'Keywords';
 
-$lang['subscribe_success']  = 'Added %s to subscription list for %s';
-$lang['subscribe_error']    = 'Error adding %s to subscription list for %s';
-$lang['subscribe_noaddress']= 'There is no address associated with your login, you cannot be added to the subscription list';
-$lang['unsubscribe_success']= 'Removed %s from subscription list for %s';
-$lang['unsubscribe_error']  = 'Error removing %s from subscription list for %s';
+$lang['subscr_subscribe_success']  = 'Added %s to subscription list for %s';
+$lang['subscr_subscribe_error']    = 'Error adding %s to subscription list for %s';
+$lang['subscr_subscribe_noaddress']= 'There is no address associated with your login, you cannot be added to the subscription list';
+$lang['subscr_unsubscribe_success']= 'Removed %s from subscription list for %s';
+$lang['subscr_unsubscribe_error']  = 'Error removing %s from subscription list for %s';
+$lang['subscr_already_subscribed'] = '%s is already subscribed to %s';
+$lang['subscr_not_subscribed']     = '%s is not subscribed to %s';
+// Manage page for subscriptions
+$lang['subscr_m_not_subscribed']   = 'You are currently not subscribed to the current page or namespace.';
+$lang['subscr_m_new_header']       = 'Add subscription';
+$lang['subscr_m_current_header']   = 'Current subscriptions';
+$lang['subscr_m_unsubscribe']      = 'Unsubscribe';
+$lang['subscr_m_subscribe']        = 'Subscribe';
+$lang['subscr_m_receive']          = 'Receive';
+$lang['subscr_style_every']        = 'email on every change';
+$lang['subscr_style_digest']       = 'digest email of changes for each page';
+$lang['subscr_style_list']         = 'list of changed pages since last email';
+
 
 /* auth.class language support */
 $lang['authmodfailed']   = 'Bad user authentication configuration. Please inform your Wiki Admin.';
diff --git a/inc/lang/en/subscr_digest.txt b/inc/lang/en/subscr_digest.txt
new file mode 100644
index 000000000..35011b6e6
--- /dev/null
+++ b/inc/lang/en/subscr_digest.txt
@@ -0,0 +1,20 @@
+Hello!
+
+The page @PAGE@ in the @TITLE@ wiki changed.
+Here are the changes:
+
+--------------------------------------------------------
+@DIFF@
+--------------------------------------------------------
+
+Old Revision: @OLDPAGE@
+New Revision: @NEWPAGE@
+
+To cancel the page notifications, log into the wiki at
+@DOKUWIKIURL@ then visit
+@SUBSCRIBE@
+and unsubscribe page and/or namespace changes.
+
+-- 
+This mail was generated by DokuWiki at
+@DOKUWIKIURL@
diff --git a/inc/lang/en/subscr_form.txt b/inc/lang/en/subscr_form.txt
new file mode 100644
index 000000000..d606508c6
--- /dev/null
+++ b/inc/lang/en/subscr_form.txt
@@ -0,0 +1,3 @@
+====== Subscription Management ======
+
+This page allows you to manage your subscriptions for the current page and namespace.
diff --git a/inc/lang/en/subscr_list.txt b/inc/lang/en/subscr_list.txt
new file mode 100644
index 000000000..efe27d866
--- /dev/null
+++ b/inc/lang/en/subscr_list.txt
@@ -0,0 +1,17 @@
+Hello!
+
+Pages in the namespace @PAGE@ of the @TITLE@ wiki changed.
+Here are the changed pages:
+
+--------------------------------------------------------
+@DIFF@
+--------------------------------------------------------
+
+To cancel the page notifications, log into the wiki at
+@DOKUWIKIURL@ then visit
+@SUBSCRIBE@
+and unsubscribe page and/or namespace changes.
+
+--
+This mail was generated by DokuWiki at
+@DOKUWIKIURL@
diff --git a/inc/lang/en/subscribermail.txt b/inc/lang/en/subscr_single.txt
index 673c4c32a..673c4c32a 100644
--- a/inc/lang/en/subscribermail.txt
+++ b/inc/lang/en/subscr_single.txt
diff --git a/inc/pageutils.php b/inc/pageutils.php
index 9c192e5e6..239ff41c5 100644
--- a/inc/pageutils.php
+++ b/inc/pageutils.php
@@ -534,4 +534,21 @@ function isVisiblePage($id){
     return !isHiddenPage($id);
 }
 
+/**
+ * Format an id for output to a user
+ *
+ * Namespaces are denoted by a trailing “:*”. The root namespace is
+ * “*”. Output is escaped.
+ *
+ * @author Adrian Lang <lang@cosmocode.de>
+ */
 
+function prettyprint_id($id) {
+    if (!$id || $id === ':') {
+        return '*';
+    }
+    if ((substr($id, -1, 1) === ':')) {
+        $id .= '*';
+    }
+    return hsc($id);
+}
diff --git a/inc/subscription.php b/inc/subscription.php
new file mode 100644
index 000000000..12f0a4b82
--- /dev/null
+++ b/inc/subscription.php
@@ -0,0 +1,349 @@
+<?php
+/**
+ * Utilities for handling (email) subscriptions
+ *
+ * The public interface of this file consists of the functions
+ * - subscription_find
+ * - subscription_send_digest
+ * - subscription_send_list
+ * - subscription_set
+ * - get_info_subscribed
+ * - subscription_addresslist
+ *
+ * @author  Adrian Lang <lang@cosmocode.de>
+ * @license GPL 2 (http://www.gnu.org/licenses/gpl.html)
+ */
+
+require_once DOKU_INC.'/inc/pageutils.php';
+
+/**
+ * Get the name of the metafile tracking subscriptions to target page or
+ * namespace
+ *
+ * @param string $id The target page or namespace, specified by id; Namespaces
+ *                   are identified by appending a colon.
+ *
+ * @author Adrian Lang <lang@cosmocode.de>
+ */
+function subscription_filename($id) {
+    $meta_fname = '.mlist';
+    if ((substr($id, -1, 1) === ':')) {
+        $meta_froot = getNS($id);
+        if ($meta_froot === false) {
+            $meta_fname = '/' . $meta_fname;
+        }
+    } else {
+        $meta_froot = $id;
+    }
+    return metaFN($meta_froot, $meta_fname);
+}
+
+/**
+ * Set subscription information
+ *
+ * Allows to set subscription informations for permanent storage in meta files.
+ * Subscriptions consist of a target object, a subscribing user, a subscribe
+ * style and optional data.
+ * A subscription may be deleted by specifying an empty subscribe style.
+ * Only one subscription per target and user is allowed.
+ * The function returns false on error, otherwise true. Note that no error is
+ * returned if a subscription should be deleted but the user is not subscribed
+ * and the subscription meta file exists.
+ *
+ * @param string $user      The subscriber or unsubscriber
+ * @param string $page      The target object (page or namespace), specified by
+ *                          id; Namespaces are identified by a trailing colon.
+ * @param string $style     The subscribe style; DokuWiki currently implements
+ *                          “every”, “digest”, and “list”.
+ * @param string $data      An optional data blob
+ * @param bool   $overwrite Whether an existing subscription may be overwritten
+ *
+ * @author Adrian Lang <lang@cosmocode.de>
+ */
+function subscription_set($user, $page, $style, $data = null,
+                          $overwrite = false) {
+    global $lang;
+    if (is_null($style)) {
+        // Delete subscription.
+        $file = subscription_filename($page);
+        if (!@file_exists($file)) {
+            msg(sprintf($lang['subscr_not_subscribed'], $user,
+                        prettyprint_id($page)), -1);
+            return false;
+        }
+
+        // io_deleteFromFile does not return false if no line matched.
+        return io_deleteFromFile($file,
+                                 subscription_regex(array('user' => $user)),
+                                 true);
+    }
+
+    // Delete subscription if one exists and $overwrite is true. If $overwrite
+    // is false, fail.
+    $subs = subscription_find($page, array('user' => $user));
+    if (count($subs) > 0 && array_pop(array_keys($subs)) === $page) {
+        if (!$overwrite) {
+            msg(sprintf($lang['subscr_already_subscribed'], $user,
+                        prettyprint_id($page)), -1);
+            return false;
+        }
+        // Fail if deletion failed, else continue.
+        if (!subscription_set($user, $page, null)) {
+            return false;
+        }
+    }
+
+    $file = subscription_filename($page);
+    $content = auth_nameencode($user) . ' ' . $style;
+    if (!is_null($data)) {
+        $content .= ' ' . $data;
+    }
+    return io_saveFile($file, $content . "\n", true);
+}
+
+/**
+ * Recursively search for matching subscriptions
+ *
+ * This function searches all relevant subscription files for a page or
+ * namespace.
+ *
+ * @param string $page The target object’s (namespace or page) id
+ * @param array  $pre  A hash of predefined values
+ *
+ * @see function subscription_regex for $pre documentation
+ *
+ * @author Adrian Lang <lang@cosmocode.de>
+ */
+function subscription_find($page, $pre) {
+    // Construct list of files which may contain relevant subscriptions.
+    $filenames = array(':' => subscription_filename(':'));
+    do {
+        $filenames[$page] = subscription_filename($page);
+        $page = getNS(rtrim($page, ':')) . ':';
+    } while ($page !== ':');
+
+    // Handle files.
+    $matches = array();
+    foreach ($filenames as $cur_page => $filename) {
+        if (!@file_exists($filename)) {
+            continue;
+        }
+        $subscriptions = file($filename);
+        foreach ($subscriptions as $subscription) {
+            if (strpos($subscription, ' ') === false) {
+                // This is an old subscription file.
+                $subscription = trim($subscription) . " every\n";
+            }
+            if (preg_match(subscription_regex($pre), $subscription,
+                           &$line_matches) === 0) {
+                continue;
+            }
+            $match = array_slice($line_matches, 1);
+            if (!isset($matches[$cur_page])) {
+                $matches[$cur_page] = array();
+            }
+            $matches[$cur_page][] = $match;
+        }
+    }
+    return array_reverse($matches);
+}
+
+/**
+ * Get data for $INFO['subscribed']
+ *
+ * $INFO['subscribed'] is either false if no subscription for the current page
+ * and user is in effect. Else it contains an array of arrays with the fields
+ * “target”, “style”, and optionally “data”.
+ *
+ * @author Adrian Lang <lang@cosmocode.de>
+ */
+function get_info_subscribed() {
+    global $ID;
+    global $conf;
+    if (!$conf['subscribers']) {
+        return false;
+    }
+
+    $subs = subscription_find($ID, array('user' => $_SERVER['REMOTE_USER']));
+    if (count($subs) === 0) {
+        return false;
+    }
+
+    $_ret = array();
+    foreach ($subs as $target => $subs_data) {
+        $new = array('target' => $target,
+                     'style'  => $subs_data[0][0]);
+        if (count($subs_data[0]) > 1) {
+            $new['data'] = $subs_data[0][1];
+        }
+        $_ret[] = $new;
+    }
+
+    return $_ret;
+}
+
+/**
+ * Construct a regular expression parsing a subscription definition line
+ *
+ * @param array $pre A hash of predefined values; “user”, “style”, and
+ *                   “data” may be set to limit the results to
+ *                   subscriptions matching these parameters. If
+ *                   “escaped” is true, these fields are inserted into the
+ *                   regular expression without escaping.
+ *
+ * @author Adrian Lang <lang@cosmocode.de>
+ */
+function subscription_regex($pre = array()) {
+    if (!isset($pre['escaped']) || $pre['escaped'] === false) {
+        $pre = array_map('preg_quote_cb', $pre);
+    }
+    foreach (array('user', 'style', 'data') as $key) {
+        if (!isset($pre[$key])) {
+            $pre[$key] = '(\S+)';
+        }
+    }
+    return '/^' . $pre['user'] . '(?: ' . $pre['style'] .
+           '(?: ' . $pre['data'] . ')?)?$/';
+}
+
+/**
+ * Return a string with the email addresses of all the
+ * users subscribed to a page
+ *
+ * This is the default action for COMMON_NOTIFY_ADDRESSLIST.
+ *
+ * @param array $data Containing $id (the page id), $self (whether the author
+ *                    should be notified, $addresslist (current email address
+                      list)
+ *
+ * @author Steven Danz <steven-danz@kc.rr.com>
+ * @author Adrian Lang <lang@cosmocode.de>
+ */
+function subscription_addresslist($data){
+    global $conf;
+    global $auth;
+
+    $id = $data['id'];
+    $self = $data['self'];
+    $addresslist = $data['addresslist'];
+
+    if (!$conf['subscribers']) {
+        return '';
+    }
+    $pres = array('style' => 'every', 'escaped' => true);
+    if (!$self && isset($_SERVER['REMOTE_USER'])) {
+        $pres['user'] = '((?:(?!' . preg_quote_cb($_SERVER['REMOTE_USER']) .
+                        ')\S?)+)';
+    }
+    $subs = subscription_find($id, $pres);
+    $emails = array();
+    foreach ($subs as $by_targets) {
+        foreach ($by_targets as $sub) {
+            $info = $auth->getUserData($sub[0]);
+            if ($info === false) continue;
+            $level = auth_aclcheck($id, $sub[0], $info['grps']);
+            if ($level >= AUTH_READ) {
+                if (strcasecmp($info['mail'], $conf['notify']) != 0) {
+                    $emails[$sub[0]] =  $info['mail'];
+                }
+            }
+        }
+    }
+    $data['addresslist'] = trim($addresslist . ',' . implode(',', $emails), ',');
+}
+
+/**
+ * Send a digest mail
+ *
+ * Sends a digest mail showing a bunch of changes.
+ *
+ * @param string $subscriber_mail The target mail address
+ * @param array  $change          The newest change
+ * @param int    $lastupdate      Time of the last notification
+ *
+ * @author Adrian Lang <lang@cosmocode.de>
+ */
+function subscription_send_digest($subscriber_mail, $change, $lastupdate) {
+    $id = $change['id'];
+    $n = 0;
+    do {
+        $rev = getRevisions($id, $n++, 1);
+        $rev = (count($rev) > 0) ? $rev[0] : null;
+    } while (!is_null($rev) && $rev > $lastupdate);
+
+    $ip = $change['ip'];
+    $replaces = array('NEWPAGE'   => wl($id, '', true, '&'),
+                      'SUBSCRIBE' => wl($id, array('do' => 'subscribe'), true, '&'));
+    if (!is_null($rev)) {
+        $subject = 'changed';
+        $replaces['OLDPAGE'] = wl($id, "rev=$rev", true, '&');
+        require_once DOKU_INC.'inc/DifferenceEngine.php';
+        $df = new Diff(explode("\n", rawWiki($id, $rev)),
+                        explode("\n", rawWiki($id)));
+        $dformat = new UnifiedDiffFormatter();
+        $replaces['DIFF'] = $dformat->format($df);
+    } else {
+        $subject = 'newpage';
+        $replaces['OLDPAGE'] = 'none';
+        $replaces['DIFF'] = rawWiki($id);
+    }
+    subscription_send($subscriber_mail, $replaces, $subject, $id,
+                      'subscr_digest');
+}
+
+/**
+ * Send a list mail
+ *
+ * Sends a list mail showing a list of changed pages.
+ *
+ * @param string $subscriber_mail The target mail address
+ * @param array  $changes         Array of changes
+ * @param string $id              The id of the namespace
+ *
+ * @author Adrian Lang <lang@cosmocode.de>
+ */
+function subscription_send_list($subscriber_mail, $changes, $id) {
+    $list = '';
+    foreach ($changes as $change) {
+        $list .= '* ' . $change['id'] . NL;
+    }
+    subscription_send($subscriber_mail,
+                      array('DIFF'      => rtrim($list),
+                            'SUBSCRIBE' => wl($changes[0]['id'],
+                                              array('do' => 'subscribe'),
+                                              true, '&')),
+                      'subscribe_list',
+                      prettyprint_id($id),
+                      'subscr_list');
+}
+
+/**
+ * Helper function for sending a mail
+ *
+ * @param string $subscriber_mail The target mail address
+ * @param array  $replaces        Predefined parameters used to parse the
+ *                                template
+ * @param string $subject         The lang id of the mail subject (without the
+ *                                prefix “mail_”)
+ * @param string $id              The page or namespace id
+ * @param string $template        The name of the mail template
+ *
+ * @author Adrian Lang <lang@cosmocode.de>
+ */
+function subscription_send($subscriber_mail, $replaces, $subject, $id, $template) {
+    global $conf;
+
+    $text = rawLocale($template);
+    $replaces = array_merge($replaces, array('TITLE'       => $conf['title'],
+                                             'DOKUWIKIURL' => DOKU_URL,
+                                             'PAGE'        => $id));
+
+    foreach ($replaces as $key => $substitution) {
+        $text = str_replace('@'.strtoupper($key).'@', $substitution, $text);
+    }
+
+    global $lang;
+    $subject = $lang['mail_' . $subject] . ' ' . $id;
+    mail_send('', '['.$conf['title'].'] '. $subject, $text,
+              $conf['mailfrom'], '', $subscriber_mail);
+}
diff --git a/inc/template.php b/inc/template.php
index 4681300eb..84fbda051 100644
--- a/inc/template.php
+++ b/inc/template.php
@@ -126,6 +126,9 @@ function tpl_content_core(){
     case 'admin':
       tpl_admin();
       break;
+    case 'subscribe':
+      tpl_subscribe();
+      break;
     default:
       $evt = new Doku_Event('TPL_ACT_UNKNOWN',$ACT);
       if ($evt->advise_before())
@@ -540,31 +543,10 @@ function tpl_button($type,$return=false){
       }
       break;
     case 'subscribe':
-    case 'subscription':
-      if($conf['useacl'] && $auth && $ACT == 'show' && $conf['subscribers'] == 1){
-        if($_SERVER['REMOTE_USER']){
-          if($INFO['subscribed']){
-            if(actionOK('unsubscribe'))
-              $out .= html_btn('unsubscribe',$ID,'',array('do' => 'unsubscribe',));
-          } else {
-            if(actionOK('subscribe'))
-              $out .= html_btn('subscribe',$ID,'',array('do' => 'subscribe',));
-          }
-        }
-      }
-      if($type == 'subscribe') break;
-      // else: fall through for backward compatibility
-    case 'subscribens':
-      if($conf['useacl'] && $auth && $ACT == 'show' && $conf['subscribers'] == 1){
-        if($_SERVER['REMOTE_USER']){
-          if($INFO['subscribedns']){
-            if(actionOK('unsubscribens'))
-              $out .= html_btn('unsubscribens',$ID,'',array('do' => 'unsubscribens',));
-          } else {
-            if(actionOK('subscribens'))
-              $out .= html_btn('subscribens',$ID,'',array('do' => 'subscribens',));
-          }
-        }
+      if ($conf['useacl'] && $auth && $ACT == 'show' &&
+          $conf['subscribers'] && isset($_SERVER['REMOTE_USER']) &&
+          actionOK('subscribe')) {
+        $out .= html_btn('subscribe',$ID,'',array('do' => 'subscribe',));
       }
       break;
     case 'backlink':
@@ -712,37 +694,12 @@ function tpl_actionlink($type,$pre='',$suf='',$inner='',$return=false){
       break;
    case 'subscribe':
    case 'subscription':
-      if($conf['useacl'] && $auth && $ACT == 'show' && $conf['subscribers'] == 1){
+      if($conf['useacl'] && $auth && $ACT == 'show' && $conf['subscribers']) {
         if($_SERVER['REMOTE_USER']){
-          if($INFO['subscribed']) {
-            if(actionOK('unsubscribe'))
-              $out .= tpl_link(wl($ID,'do=unsubscribe'),
-                     $pre.(($inner)?$inner:$lang['btn_unsubscribe']).$suf,
-                     'class="action unsubscribe" rel="nofollow"',1);
-          } else {
             if(actionOK('subscribe'))
               $out .= tpl_link(wl($ID,'do=subscribe'),
                      $pre.(($inner)?$inner:$lang['btn_subscribe']).$suf,
                      'class="action subscribe" rel="nofollow"',1);
-          }
-        }
-      }
-      if($type == 'subscribe') break;
-      // else: fall through for backward compatibility
-    case 'subscribens':
-      if($conf['useacl'] && $auth && $ACT == 'show' && $conf['subscribers'] == 1){
-        if($_SERVER['REMOTE_USER']){
-          if($INFO['subscribedns']) {
-            if(actionOK('unsubscribens'))
-              $out .= tpl_link(wl($ID,'do=unsubscribens'),
-                     $pre.(($inner)?$inner:$lang['btn_unsubscribens']).$suf,
-                     'class="action unsubscribens" rel="nofollow"',1);
-          } else {
-            if(actionOK('subscribens'))
-              $out .= tpl_link(wl($ID,'do=subscribens'),
-                     $pre.(($inner)?$inner:$lang['btn_subscribens']).$suf,
-                     'class="action subscribens" rel="nofollow"',1);
-          }
         }
       }
       break;
@@ -1323,23 +1280,9 @@ function tpl_actiondropdown($empty='',$button='&gt;'){
             echo '<option value="profile">'.$lang['btn_profile'].'</option>';
         }
 
-        if($conf['useacl'] && $auth && $ACT == 'show' && $conf['subscribers'] == 1){
+        if($conf['useacl'] && $auth && $ACT == 'show' && $conf['subscribers']){
             if($_SERVER['REMOTE_USER']){
-                if($INFO['subscribed']) {
-                    echo '<option value="unsubscribe">'.$lang['btn_unsubscribe'].'</option>';
-                } else {
                     echo '<option value="subscribe">'.$lang['btn_subscribe'].'</option>';
-                }
-            }
-        }
-
-        if($conf['useacl'] && $auth && $ACT == 'show' && $conf['subscribers'] == 1){
-            if($_SERVER['REMOTE_USER']){
-                if($INFO['subscribedns']) {
-                    echo '<option value="unsubscribens">'.$lang['btn_unsubscribens'].'</option>';
-                } else {
-                    echo '<option value="subscribens">'.$lang['btn_subscribens'].'</option>';
-                }
             }
         }
 
@@ -1406,5 +1349,70 @@ function tpl_include_page($pageid,$print=true){
     echo $html;
 }
 
+/**
+ * Display the subscribe form
+ *
+ * @author Adrian Lang <lang@cosmocode.de>
+ */
+function tpl_subscribe() {
+    global $INFO;
+    global $ID;
+    global $lang;
+
+    echo p_locale_xhtml('subscr_form');
+    echo '<h2>' . $lang['subscr_m_current_header'] . '</h2>';
+    echo '<div class="level2">';
+    if ($INFO['subscribed'] === false) {
+        echo '<p>' . $lang['subscr_m_not_subscribed'] . '</p>';
+    } else {
+        echo '<ul>';
+        foreach($INFO['subscribed'] as $sub) {
+            echo '<li><div class="li">';
+            if ($sub['target'] !== $ID) {
+                echo '<code class="ns">'.hsc(prettyprint_id($sub['target'])).'</code>';
+            } else {
+                echo '<code class="page">'.hsc(prettyprint_id($sub['target'])).'</code>';
+            }
+            $sstl = $lang['subscr_style_'.$sub['style']];
+            if(!$sstl) $sstl = hsc($sub['style']);
+            echo ' ('.$sstl.') ';
+
+            echo '<a href="'.wl($ID,array('do'=>'subscribe','sub_target'=>$sub['target'],'sub_style'=>$sub['style'],'sub_action'=>'unsubscribe')).'" class="unsubscribe">'.$lang['subscr_m_unsubscribe'].'</a>';
+
+
+            echo '</div></li>';
+        }
+        echo '</ul>';
+    }
+    echo '</div>';
+
+    // Add new subscription form
+    echo '<h2>' . $lang['subscr_m_new_header'] . '</h2>';
+    echo '<div class="level2">';
+    $ns = getNS($ID).':';
+    $targets = array(
+        $ID => '<code class="page">'.prettyprint_id($ID).'</code>',
+        $ns => '<code class="ns">'.prettyprint_id($ns).'</code>',
+    );
+    $styles = array(
+        'every'  => $lang['subscr_style_every'],
+        'digest' => $lang['subscr_style_digest'],
+        'list'   => $lang['subscr_style_list'],
+    );
+
+    $form = new Doku_Form(array('id' => 'subscribe__form'));
+    $form->startFieldset($lang['subscr_m_subscribe']);
+    $form->addRadioSet('sub_target', $targets);
+    $form->startFieldset($lang['subscr_m_receive']);
+    $form->addRadioSet('sub_style', $styles);
+    $form->addHidden('sub_action', 'subscribe');
+    $form->addHidden('do', 'subscribe');
+    $form->addHidden('id', $ID);
+    $form->endFieldset();
+    $form->addElement(form_makeButton('submit', 'subscribe', $lang['subscr_m_subscribe']));
+    html_form('SUBSCRIBE', $form);
+    echo '</div>';
+}
+
 //Setup VIM: ex: et ts=4 enc=utf-8 :