Give users more control over URL shortening

Users and administrators can set how long an URL can be before it's
shortened, and how long a notice can be before all its URLs are
shortened. They can also turn off shortening altogether.

Squashed commit of the following:

commit d136b390115829c4391b3666bb1967f190a0de35
Author: Evan Prodromou <evan@status.net>
Date:   Mon Apr 26 02:39:00 2010 -0400

    use site and user settings to determine when to shorten URLs

commit 1e1c851ff3cb2da5e0dc3a0b06239a9d9c618488
Author: Evan Prodromou <evan@status.net>
Date:   Mon Apr 26 02:38:40 2010 -0400

    add a method to force shortening URLs

commit 4d29ca0b91201f6df42940297ed5b64b070efe49
Author: Evan Prodromou <evan@status.net>
Date:   Mon Apr 26 02:37:41 2010 -0400

    static method for getting best URL shortening service

commit a9c6a3bace0af44bcf38d1c790425a7be9c72147
Author: Evan Prodromou <evan@status.net>
Date:   Mon Apr 26 02:37:11 2010 -0400

    allow 0 in numeric entries in othersettings

commit 767ff2f7ecfd7e76e8418fc79d45e61898f09382
Author: Evan Prodromou <evan@status.net>
Date:   Mon Apr 26 02:36:46 2010 -0400

    allow 0 or blank string in inputs

commit 1e21af42a685f600f4a53f49a194013e78b12f20
Author: Evan Prodromou <evan@status.net>
Date:   Mon Apr 26 02:01:11 2010 -0400

    add more URL-shortening options to othersettings

commit 869a6be0f5779aff69018d02f9ac0273946040d9
Author: Evan Prodromou <evan@status.net>
Date:   Sat Apr 24 14:22:51 2010 -0400

    move url shortener superclass to lib from plugin

commit 9c0c9863d532942b99184f14e923fc3c050f8177
Author: Evan Prodromou <evan@status.net>
Date:   Sat Apr 24 14:20:28 2010 -0400

    documentation and whitespace on UrlShortenerPlugin

commit 7a1dd5798f0fcf2c03d1257a18ddcb9008879de0
Author: Evan Prodromou <evan@status.net>
Date:   Sat Apr 24 14:05:46 2010 -0400

    add defaults for URL shortening

commit d259c37ad231ca0010c60e5cfd397bb1732874a4
Author: Evan Prodromou <evan@status.net>
Date:   Sat Apr 24 13:40:10 2010 -0400

    Add User_urlshortener_prefs

    Add a table for URL shortener prefs, a corresponding class, and the
    correct mumbo-jumbo in statusnet.ini to make everything work.

1 files changed, 34 insertions, 4 deletions

diff --git a/classes/File_redirection.php b/classes/File_redirection.php
index f128b3e07..00ec75309 100644
--- a/classes/File_redirection.php
+++ b/classes/File_redirection.php
@@ -176,22 +176,52 @@ class File_redirection extends Memcached_DataObject
      * @param string $long_url
      * @return string
      */
-    function makeShort($long_url) {
 
+    function makeShort($long_url)
+    {
         $canon = File_redirection::_canonUrl($long_url);
 
         $short_url = File_redirection::_userMakeShort($canon);
 
         // Did we get one? Is it shorter?
-        if (!empty($short_url) && mb_strlen($short_url) < mb_strlen($long_url)) {
+
+        if (!empty($short_url)) {
+            return $short_url;
+        } else {
+            return $long_url;
+        }
+    }
+
+    /**
+     * Shorten a URL with the current user's configured shortening
+     * options, if applicable.
+     *
+     * If it cannot be shortened or the "short" URL is longer than the
+     * original, the original is returned.
+     *
+     * If the referenced item has not been seen before, embedding data
+     * may be saved.
+     *
+     * @param string $long_url
+     * @return string
+     */
+
+    function forceShort($long_url)
+    {
+        $canon = File_redirection::_canonUrl($long_url);
+
+        $short_url = File_redirection::_userMakeShort($canon, true);
+
+        // Did we get one? Is it shorter?
+        if (!empty($short_url)) {
             return $short_url;
         } else {
             return $long_url;
         }
     }
 
-    function _userMakeShort($long_url) {
-        $short_url = common_shorten_url($long_url);
+    function _userMakeShort($long_url, $force = false) {
+        $short_url = common_shorten_url($long_url, $force);
         if (!empty($short_url) && $short_url != $long_url) {
             $short_url = (string)$short_url;
             // store it