Post to Twitter plugin

With this plugin a user can choose to post every _public_ message that
s/he posts on Friendika also on Twitter. The message will be shortened
to if longer then 140 characters in length. If shortened a link to the
original posting will be append to the Twitter posting.

3 files changed, 221 insertions, 7 deletions

diff --git a/addon/twitter/lighter.png b/addon/twitter/lighter.png
new file mode 100644
index 000000000..297bb0340
--- /dev/null
+++ b/addon/twitter/lighter.png
diff --git a/addon/twitter/twitter.css b/addon/twitter/twitter.css
new file mode 100644
index 000000000..899cfd173
--- /dev/null
+++ b/addon/twitter/twitter.css
@@ -0,0 +1,41 @@
+
+
+#twitter-avatar {
+	float: left;
+	width: 48px;
+	height: 48px;
+	padding: 2px;
+}
+#twitter-info-block {
+	height: 52px;
+	vertical-align: middle;
+}
+#twitter-disconnect-label {
+	float: left;
+	width: 200px;
+	margin-bottom: 25px;
+}
+
+#twitter-disconnect {
+	float: left;
+}
+#twitter-enable-label {
+	float: left;
+	width: 200px;
+	margin-bottom: 5px;
+}
+
+#twitter-checkbox {
+	float: left;
+}
+#twitter-pin-label {
+	float: left;
+	width: 200px;
+	margin-bottom: 25px;
+}
+
+#twitter-pin {
+	float: left;
+}
+
+
diff --git a/addon/twitter/twitter.php b/addon/twitter/twitter.php
index 9fccefbee..8faa5e5cf 100644
--- a/addon/twitter/twitter.php
+++ b/addon/twitter/twitter.php
@@ -1,16 +1,166 @@
 <?php
 
+/*   Twitter Plugin for Friendika
+ *
+ *   Author: Tobias Diekershoff
+ *           tobias.diekershoff@gmx.net
+ *
+ *   License:3-clause BSD license (same as Friendika)
+ *
+ *   Configuration:
+ *     To use this plugin you need a OAuth Consumer key pair (key & secret)
+ *     you can get it from Twitter at https://twitter.com/apps
+ *
+ *     Register your Friendika site as "Client" application with "Read & Write" access
+ *     we do not need "Twitter as login". When you've registered the app you get the
+ *     OAuth Consumer key and secret pair for your application/site.
+ *
+ *     Add this key pair to your global .htconfig.php
+ *
+ *     $a->config['twitter']['consumerkey'] = 'your consumer_key here';
+ *     $a->config['twitter']['consumersecret'] = 'your consumer_secret here';
+ *
+ *     To activate the plugin itself add it to the $a->config['system']['addon']
+ *     setting. After this, your user can configure their Twitter account settings
+ *     from "Settings -> Plugin Settings".
+ *
+ *     Documentation: http://diekershoff.homeunix.net/redmine/wiki/friendikaplugin/Twitter_Plugin
+ */
+
+/*   __TODO__
+ *
+ *   - deletion of the OAuth credentials does not work
+ *   - include short links to the original posting if possible
+ *   - what about multimedia content?
+ *     so far we just strip HTML tags from the message
+ *   - after entering the PIN reload page propperly
+ */
 
 function twitter_install() {
+	//  we need some hooks, for the configuration and for sending tweets
+	register_hook('plugin_settings', 'addon/twitter/twitter.php', 'twitter_settings'); 
+	register_hook('plugin_settings_post', 'addon/twitter/twitter.php', 'twitter_settings_post');
 	register_hook('post_local_end', 'addon/twitter/twitter.php', 'twitter_post_hook');
+	logger("installed twitter");
 }
 
 
 function twitter_uninstall() {
+	unregister_hook('plugin_settings', 'addon/twitter/twitter.php', 'twitter_settings'); 
+	unregister_hook('plugin_settings_post', 'addon/twitter/twitter.php', 'twitter_settings_post');
 	unregister_hook('post_local_end', 'addon/twitter/twitter.php', 'twitter_post_hook');
 }
 
-
+function twitter_settings_post ($a,$post) {
+	if(! local_user())
+		return;
+	if (isset($_POST['twitter-disconnect'])) {
+		/***
+		 * if the twitter-disconnect checkbox is set, clear the OAuth key/secret pair
+		 * from the user configuration
+                 * TODO this does not work that way!?
+		 * TODO can we revoke the access tokens at Twitter and do we need to do so?
+		 */
+		del_pconfig( local_user(), 'twitter', 'consumerkey'  );
+		del_pconfig( local_user(), 'twitter', 'consumersecret' );
+		del_pconfig( local_user(), 'twitter', 'post' );
+	} else {
+	if (isset($_POST['twitter-pin'])) {
+		//  if the user supplied us with a PIN from Twitter, let the magic of OAuth happen
+		logger('got a Twitter PIN');
+		require_once('addon/twitter/twitteroauth.php');
+		$ckey    = get_config('twitter', 'consumerkey'  );
+		$csecret = get_config('twitter', 'consumersecret' );
+		//  the token and secret for which the PIN was generated were hidden in the settings
+		//  form as token and token2, we need a new connection to Twitter using these token
+		//  and secret to request a Access Token with the PIN
+		$connection = new TwitterOAuth($ckey, $csecret, $_POST['twitter-token'], $_POST['twitter-token2']);
+		$token   = $connection->getAccessToken( $_POST['twitter-pin'] );
+		//  ok, now that we have the Access Token, save them in the user config
+ 		set_pconfig(local_user(),'twitter', 'oauthtoken',  $token['oauth_token']);
+		set_pconfig(local_user(),'twitter', 'oauthsecret', $token['oauth_token_secret']);
+                set_pconfig(local_user(),'twitter', 'post', 1);
+                //  reload the Addon Settings page, if we don't do it see Bug #42
+                header('Location: '.$a->get_baseurl().'/settings/addon');
+	} else {
+		//  if no PIN is supplied in the POST variables, the user has changed the setting
+		//  to post a tweet for every new __public__ posting to the wall
+		set_pconfig(local_user(),'twitter','post',intval($_POST['twitter']));
+	}}
+}
+function twitter_settings(&$a,&$s) {
+        if(! local_user())
+                return;
+        $a->page['htmlhead'] .= '<link rel="stylesheet"  type="text/css" href="' . $a->get_baseurl() . '/addon/twitter/twitter.css' . '" media="all" />' . "\r\n";
+	/***
+	 * 1) Check that we have global consumer key & secret
+	 * 2) If no OAuthtoken & stuff is present, generate button to get some
+	 * 3) Checkbox for "Send public notices (140 chars only)
+	 */
+	$ckey    = get_config('twitter', 'consumerkey' );
+	$csecret = get_config('twitter', 'consumersecret' );
+	$otoken  = get_pconfig(local_user(), 'twitter', 'oauthtoken'  );
+	$osecret = get_pconfig(local_user(), 'twitter', 'oauthsecret' );
+        $enabled = get_pconfig(local_user(), 'twitter', 'post');
+	$checked = (($enabled) ? ' checked="checked" ' : '');
+	$s .= '<h3>'.t('Twitter Posting Settings').'</h3>';
+
+	if ( (!$ckey) && (!$csecret) ) {
+		/***
+		 * no global consumer keys
+		 * display warning and skip personal config
+		 */
+		$s .= '<p>'.t('No consumer key pair for Twitter found. Please contact your site administrator.').'</p>';
+	} else {
+		/***
+		 * ok we have a consumer key pair now look into the OAuth stuff
+		 */
+		if ( (!$otoken) && (!$osecret) ) {
+			/***
+			 * the user has not yet connected the account to twitter...
+			 * get a temporary OAuth key/secret pair and display a button with
+			 * which the user can request a PIN to connect the account to a
+			 * account at Twitter.
+			 */
+			require_once('addon/twitter/twitteroauth.php');
+			$connection = new TwitterOAuth($ckey, $csecret);
+			$request_token = $connection->getRequestToken();
+			$token = $request_token['oauth_token'];
+			/***
+			 *  make some nice form
+			 */
+			$s .= '<p>'.t('At this Friendika instance the Twitter plugin was enabled but you have not yet connected your account to your Twitter account. To do so click the button below to get a PIN from Twitter which you have to copy into the input box below and submit the form. Only your <strong>public</strong> posts will be posted to Twitter.').'</p>';
+			$s .= '<a href="'.$connection->getAuthorizeURL($token).'" target="_twitter"><img src="addon/twitter/lighter.png" alt="'.t('Log in with Twitter').'></a>';
+			$s .= '<div id="twitter-pin-wrapper">';
+			$s .= '<label id="twitter-pin-label" for="twitter-pin">'.t('Copy the PIN from Twitter here').'</label>';
+			$s .= '<input id="twitter-pin" type="text" name="twitter-pin" />';
+			$s .= '<input id="twitter-token" type="hidden" name="twitter-token" value="'.$token.'" />';
+			$s .= '<input id="twitter-token2" type="hidden" name="twitter-token2" value="'.$request_token['oauth_token_secret'].'" />';
+                        $s .= '</div><div class="clear"></div>';
+                        $s .= '<div class="settings-submit-wrapper" ><input type="submit" name="submit" class="settings-submit" value="' . t('Submit') . '" /></div>';
+		} else {
+			/***
+			 *  we have an OAuth key / secret pair for the user
+			 *  so let's give a chance to disable the postings to Twitter
+			 */
+                        require_once('addon/twitter/twitteroauth.php');
+			$connection = new TwitterOAuth($ckey,$csecret,$otoken,$osecret);
+			$details = $connection->get('account/verify_credentials');
+			$s .= '<div id="twitter-info" ><img id="twitter-avatar" src="'.$details->profile_image_url.'" /><p id="twitter-info-block">'.t('Currently connected to: ').'<a href="https://twitter.com/'.$details->screen_name.'" target="_twitter">'.$details->screen_name.'</a><br /><em>'.$details->description.'</em></p></div>';
+			$s .= '<p>'.t('If enabled all your <strong>public</strong> postings will be posted to the associated Twitter account as well.').'</p>';
+			$s .= '<div id="twitter-enable-wrapper">';
+			$s .= '<label id="twitter-enable-label" for="twitter-checkbox">'.t('Send public postings to Twitter').'</label>';
+			$s .= '<input id="twitter-checkbox" type="checkbox" name="twitter" value="1" ' . $checked . '/>';
+			$s .= '</div><div class="clear"></div>';
+			$s .= '<div id="twitter-disconnect-wrapper">';
+                        $s .= '<label id="twitter-disconnect-label" for="twitter-disconnect">'.t('Clear OAuth configuration').'</label>';
+                        $s .= '<input id="twitter-disconnect" type="checkbox" name="twitter-disconnect" value="1" />';
+			$s .= '</div><div class="clear"></div>';
+			$s .= '<div class="settings-submit-wrapper" ><input type="submit" name="submit" class="settings-submit" value="' . t('Submit') . '" /></div>'; 
+		}
+	}
+        $s .= '</div><div class="clear"></div>';
+}
 
 
 function twitter_post_hook(&$a,&$b) {
@@ -19,12 +169,14 @@ function twitter_post_hook(&$a,&$b) {
 	 * Post to Twitter
 	 */
 
+        logger('twitter post invoked');
+
 	if((local_user()) && (local_user() == $b['uid']) && (! $b['private'])) {
 
 		load_pconfig(local_user(), 'twitter');
 
-		$ckey    = get_pconfig(local_user(), 'twitter', 'consumerkey'  );
-		$csecret = get_pconfig(local_user(), 'twitter', 'consumersecret' );
+		$ckey    = get_config('twitter', 'consumerkey'  );
+		$csecret = get_config('twitter', 'consumersecret' );
 		$otoken  = get_pconfig(local_user(), 'twitter', 'oauthtoken'  );
 		$osecret = get_pconfig(local_user(), 'twitter', 'oauthsecret' );
 
@@ -35,12 +187,33 @@ function twitter_post_hook(&$a,&$b) {
 			if($twitter_post) {
 				require_once('addon/twitter/twitteroauth.php');
 				require_once('include/bbcode.php');	
-
 				$tweet = new TwitterOAuth($ckey,$csecret,$otoken,$osecret);
-				$tweet->post('statuses/update', array('status' => bbcode($b['body'])));
+				$max_char = 140; // max. length for a tweet
+				$msg = strip_tags(bbcode($b['body']));
+                                if ( strlen($msg) > $max_char) {
+                                        $shortlink = "";
+                                        require_once('addon/twitter/slinky.php');
+                                        // post url = base url + /display/ + owner + post id
+                                        // we construct this from the Owner link and replace
+                                        // profile by display - this will cause an error when
+                                        // /profile/ is in the owner url twice but I don't
+                                        // think this will be very common...
+					$posturl = str_replace('/profile/','/display/',$b['owner-link']).'/'.$b['id'];
+					$slinky = new Slinky( $posturl );
+					// setup a cascade of shortening services
+					// try to get a short link from these services
+					// in the order ur1.ca, trim, id.gd, tinyurl
+					$slinky->set_cascade( array( new Slinky_UR1ca(), new Slinky_Trim(), new Slinky_IsGd(), new Slinky_TinyURL() ) );
+                                        $shortlink = $slinky->short();
+                                        // the new message will be shortened such that "... $shortlink"
+                                        // will fit into the character limit
+                                        $msg = substr($msg, 0, $max_char-strlen($shortlink)-4);
+                                        $msg .= '... ' . $shortlink;
+                                }
+                                // and now tweet it :-)
+				$tweet->post('statuses/update', array('status' => $msg));
 			}
 		}
-	}
+        }
 }
 
-