Expand SamplePlugin to show other best practices

I modified the SamplePlugin to show how to do some real processing,
adding a data class and an action class and modifying the main
menu to link to the new action. I added documentation comments to
all the methods and made sure the modules were PHPCS-clean.

plugins/Sample/User_greeting_count.php

+<?php
+/**
+ * Data class for counting greetings
+ *
+ * PHP version 5
+ *
+ * @category Data
+ * @package  StatusNet
+ * @author   Evan Prodromou <evan@status.net>
+ * @license  http://www.fsf.org/licensing/licenses/agpl.html AGPLv3
+ * @link     http://status.net/
+ *
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2009, StatusNet, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.     See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+if (!defined('STATUSNET')) {
+    exit(1);
+}
+
+require_once INSTALLDIR . '/classes/Memcached_DataObject.php';
+
+/**
+ * Data class for counting greetings
+ *
+ * We use the DB_DataObject framework for data classes in StatusNet. Each
+ * table maps to a particular data class, making it easier to manipulate
+ * data.
+ *
+ * Data classes should extend Memcached_DataObject, the (slightly misnamed)
+ * extension of DB_DataObject that provides caching, internationalization,
+ * and other bits of good functionality to StatusNet-specific data classes.
+ *
+ * @category Action
+ * @package  StatusNet
+ * @author   Evan Prodromou <evan@status.net>
+ * @license  http://www.fsf.org/licensing/licenses/agpl.html AGPLv3
+ * @link     http://status.net/
+ *
+ * @see      DB_DataObject
+ */
+
+class User_greeting_count extends Memcached_DataObject
+{
+    public $__table = 'user_greeting_count'; // table name
+    public $user_id;                         // int(4)  primary_key not_null
+    public $greeting_count;                  // int(4)
+
+    /**
+     * Get an instance by key
+     *
+     * This is a utility method to get a single instance with a given key value.
+     *
+     * @param string $k Key to use to lookup (usually 'user_id' for this class)
+     * @param mixed  $v Value to lookup
+     *
+     * @return User_greeting_count object found, or null for no hits
+     *
+     */
+
+    function staticGet($k, $v=null)
+    {
+        return Memcached_DataObject::staticGet('User_greeting_count', $k, $v);
+    }
+
+    /**
+     * return table definition for DB_DataObject
+     *
+     * DB_DataObject needs to know something about the table to manipulate
+     * instances. This method provides all the DB_DataObject needs to know.
+     *
+     * @return array array of column definitions
+     */
+
+    function table()
+    {
+        return array('user_id' => DB_DATAOBJECT_INT + DB_DATAOBJECT_NOTNULL,
+                     'greeting_count' => DB_DATAOBJECT_INT);
+    }
+
+    /**
+     * return key definitions for DB_DataObject
+     *
+     * DB_DataObject needs to know about keys that the table has; this function
+     * defines them.
+     *
+     * @return array key definitions
+     */
+
+    function keys()
+    {
+        return array('user_id' => 'K');
+    }
+
+    /**
+     * Magic formula for non-autoincrementing integer primary keys
+     *
+     * If a table has a single integer column as its primary key, DB_DataObject
+     * assumes that the column is auto-incrementing and makes a sequence table
+     * to do this incrementation. Since we don't need this for our class, we
+     * overload this method and return the magic formula that DB_DataObject needs.
+     *
+     * @return array magic three-false array that stops auto-incrementing.
+     */
+
+    function sequenceKey()
+    {
+        return array(false, false, false);
+    }
+
+    /**
+     * Increment a user's greeting count and return instance
+     *
+     * This method handles the ins and outs of creating a new greeting_count for a
+     * user or fetching the existing greeting count and incrementing its value.
+     *
+     * @param integer $user_id ID of the user to get a count for
+     *
+     * @return User_greeting_count instance for this user, with count already incremented.
+     */
+
+    static function inc($user_id)
+    {
+        $gc = User_greeting_count::staticGet('user_id', $user_id);
+
+        if (empty($gc)) {
+
+            $gc = new User_greeting_count();
+
+            $gc->user_id        = $user_id;
+            $gc->greeting_count = 1;
+
+            $result = $gc->insert();
+
+            if (!$result) {
+                throw Exception(sprintf(_m("Could not save new greeting count for %d"),
+                                        $user_id));
+            }
+
+        } else {
+
+            $orig = clone($gc);
+
+            $gc->greeting_count++;
+
+            $result = $gc->update($orig);
+
+            if (!$result) {
+                throw Exception(sprintf(_m("Could not increment greeting count for %d"),
+                                        $user_id));
+            }
+        }
+
+        return $gc;
+    }
+}

plugins/Sample/hello.php

+<?php
+/**
+ * Give a warm greeting to our friendly user
+ *
+ * PHP version 5
+ *
+ * @category Sample
+ * @package  StatusNet
+ * @author   Evan Prodromou <evan@status.net>
+ * @license  http://www.fsf.org/licensing/licenses/agpl.html AGPLv3
+ * @link     http://status.net/
+ *
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2009, StatusNet, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+if (!defined('STATUSNET')) {
+    exit(1);
+}
+
+/**
+ * Give a warm greeting to our friendly user
+ *
+ * This sample action shows some basic ways of doing output in an action
+ * class.
+ *
+ * Action classes have several output methods that they override from
+ * the parent class.
+ *
+ * @category Sample
+ * @package  StatusNet
+ * @author   Evan Prodromou <evan@status.net>
+ * @license  http://www.fsf.org/licensing/licenses/agpl.html AGPLv3
+ * @link     http://status.net/
+ */
+
+class HelloAction extends Action
+{
+    var $user = null;
+    var $gc   = null;
+
+    /**
+     * Take arguments for running
+     *
+     * This method is called first, and it lets the action class get
+     * all its arguments and validate them. It's also the time
+     * to fetch any relevant data from the database.
+     *
+     * Action classes should run parent::prepare($args) as the first
+     * line of this method to make sure the default argument-processing
+     * happens.
+     *
+     * @param array $args $_REQUEST args
+     *
+     * @return boolean success flag
+     */
+
+    function prepare($args)
+    {
+        parent::prepare($args);
+
+        $this->user = common_current_user();
+
+        if (!empty($this->user)) {
+            $this->gc = User_greeting_count::inc($this->user->id);
+        }
+
+        return true;
+    }
+
+    /**
+     * Handle request
+     *
+     * This is the main method for handling a request. Note that
+     * most preparation should be done in the prepare() method;
+     * by the time handle() is called the action should be
+     * more or less ready to go.
+     *
+     * @param array $args $_REQUEST args; handled in prepare()
+     *
+     * @return void
+     */
+
+    function handle($args)
+    {
+        parent::handle($args);
+
+        $this->showPage();
+    }
+
+    /**
+     * Title of this page
+     *
+     * Override this method to show a custom title.
+     *
+     * @return string Title of the page
+     */
+
+    function title()
+    {
+        if (empty($this->user)) {
+            return _m('Hello');
+        } else {
+            return sprintf(_m('Hello, %s'), $this->user->nickname);
+        }
+    }
+
+    /**
+     * show content in the content area
+     *
+     * The default StatusNet page has a lot of decorations: menus,
+     * logos, tabs, all that jazz. This method is used to show
+     * content in the content area of the page; it's the main
+     * thing you want to overload.
+     *
+     * @return void
+     */
+
+    function showContent()
+    {
+        if (empty($this->user)) {
+            $this->element('p', array('class' => 'greeting'),
+                           _m('Hello, stranger!'));
+        } else {
+            $this->element('p', array('class' => 'greeting'),
+                           sprintf(_m('Hello, %s'), $this->user->nickname));
+            $this->element('p', array('class' => 'greeting_count'),
+                           sprintf(_m('I have greeted you %d time(s).'),
+                                   $this->gc->greeting_count));
+        }
+    }
+
+    /**
+     * Return true if read only.
+     *
+     * Some actions only read from the database; others read and write.
+     * The simple database load-balancer built into StatusNet will
+     * direct read-only actions to database mirrors (if they are configured),
+     * and read-write actions to the master database.
+     *
+     * This defaults to false to avoid data integrity issues, but you
+     * should make sure to overload it for performance gains.
+     *
+     * @param array $args other arguments, if RO/RW status depends on them.
+     *
+     * @return boolean is read only action?
+     */
+
+    function isReadOnly($args)
+    {
+        return false;
+    }
+}