[TUT] Adding a Facebook share button to your forum

[Mark]

[TUT] Adding a Facebook share button to your forum

This is a tutorial on how to add a Facebook share button to the postbit, this means that it'll appear at the bottom of every post including the initial one.

Note: Any member that wishes to share the post to Facebook must have their own Facebook account.


Steps

1) Here is the button that i created, the code is below.

Code:

<script>
function fbs_click() {
u=location.href;
t=document.title;
window.open('http://www.facebook.com/sharer.php?u='+encodeURIComponent(u)+'&t='+encodeURIComponent(t),'sharer','toolbar=0,status=0,width=626,height=436' ​);
return false;
}
</script>

<style>
html .fb_share_button {
padding-top: 7px;
padding-right: 0px;
padding-bottom: 0px;
padding-left: 63px;
background:url(http://mcompute.co.uk/images/mcomputemark/facebook_share_button.png)no-repeat top right;
}
</style>

<a href="http://www.facebook.com/share.php?u=<url>" class="fb_share_button" onclick="return fbs_click()" target="_blank" style="text-decoration:none;"></a>

2) Log into your forum and go to

Admin CP > Templates & Style > Templates > *your template* > Post Bit Templates > postbit

Find:

Code:

{$post['button_email']}{$post['button_pm']}{$post['button_www']}{$post['button_rep']}

and add

Code:

{$post['button_facebook_share']}

to the end so it looks like

Code:

{$post['button_email']}{$post['button_pm']}{$post['button_www']}{$post['button_rep']}{$post['button_facebook_share']}

Save the template.

3) Now, go to Admin CP > Templates & Style > Templates > *your template* > Post Bit Templates > Add Template

Template name: postbit_facebook_share

And add the code in step 1 then save the template.


4) Download and open the file

Code:

inc/functions_post.php

And add the following

[code=php]
eval("\$post['button_facebook_share'] = \"".$templates->get("postbit_facebook_share")."\";");
[/code]

Save and re-upload the file, replacing the old one.


Further Explanation

So you've finished or.. you want to know what it looks like before you start changing things.

Live demo: http://mcompute.co.uk

postbit view


pop out view (When the button is pressed)


End result, what it looks like on Facebook.

[Mark]

The code you're trying to add to functions_post.php is correct.

This is what your fuctions_post.php file should look like.
Warning large copy & paste.

PHP Code:

<?php
/**
 * MyBB 1.6
 * Copyright 2010 MyBB Group, All Rights Reserved
 *
 * Website: http://mybb.com
 * License: http://mybb.com/about/license
 *
 * $Id: functions_post.php 5125 2010-07-27 07:28:03Z RyanGordon $
 */

/**
 * Build a post bit
 *
 * @param array The post data
 * @param int The type of post bit we're building (1 = preview, 2 = pm, 3 = announcement, else = post)
 * @return string The built post bit
 */
function build_postbit($post, $post_type=0)
{
    global $db, $altbg, $theme, $mybb, $postcounter;
    global $titlescache, $page, $templates, $forumpermissions, $attachcache;
    global $lang, $ismod, $inlinecookie, $inlinecount, $groupscache, $fid;
    global $plugins, $parser, $cache, $ignored_users, $hascustomtitle;
    
    $hascustomtitle = 0;

    // Set up the message parser if it doesn't already exist.
    if(!$parser)
    {
        require_once MYBB_ROOT."inc/class_parser.php";
        $parser = new postParser;
    }

    $unapproved_shade = '';
    if($post['visible'] == 0 && $post_type == 0)
    {
        $altbg = $unapproved_shade = 'trow_shaded';
    }
    elseif($altbg == 'trow1')
    {
        $altbg = 'trow2';
    }
    else
    {
        $altbg = 'trow1';
    }
    $post['fid'] = $fid;
    switch($post_type)
    {
        case 1: // Message preview
            global $forum;
            $parser_options['allow_html'] = $forum['allowhtml'];
            $parser_options['allow_mycode'] = $forum['allowmycode'];
            $parser_options['allow_smilies'] = $forum['allowsmilies'];
            $parser_options['allow_imgcode'] = $forum['allowimgcode'];
            $parser_options['allow_videocode'] = $forum['allowvideocode'];
            $parser_options['me_username'] = $post['username'];
            $parser_options['filter_badwords'] = 1;
            $id = 0;
            break;
        case 2: // Private message
            global $message, $pmid;
            $parser_options['allow_html'] = $mybb->settings['pmsallowhtml'];
            $parser_options['allow_mycode'] = $mybb->settings['pmsallowmycode'];
            $parser_options['allow_smilies'] = $mybb->settings['pmsallowsmilies'];
            $parser_options['allow_imgcode'] = $mybb->settings['pmsallowimgcode'];
            $parser_options['allow_videocode'] = $mybb->settings['pmsallowvideocode'];
            $parser_options['me_username'] = $post['username'];
            $parser_options['filter_badwords'] = 1;
            $id = $pmid;
            break;
        case 3: // Announcement
            global $announcementarray, $message;
            $parser_options['allow_html'] = $announcementarray['allowhtml'];
            $parser_options['allow_mycode'] = $announcementarray['allowmycode'];
            $parser_options['allow_smilies'] = $announcementarray['allowsmilies'];
            $parser_options['allow_imgcode'] = 1;
            $parser_options['allow_videocode'] = 1;
            $parser_options['me_username'] = $post['username'];
            $parser_options['filter_badwords'] = 1;
            break;
        default: // Regular post
            global $forum, $thread, $tid;
            $oldforum = $forum;
            $id = intval($post['pid']);
            $parser_options['allow_html'] = $forum['allowhtml'];
            $parser_options['allow_mycode'] = $forum['allowmycode'];
            $parser_options['allow_smilies'] = $forum['allowsmilies'];
            $parser_options['allow_imgcode'] = $forum['allowimgcode'];
            $parser_options['allow_videocode'] = $forum['allowvideocode'];
            $parser_options['filter_badwords'] = 1;
            
            if(!$post['username'])
            {
                $post['username'] = $lang->guest;
            }
            
            if($post['userusername'])
            {
                $parser_options['me_username'] = $post['userusername'];
            }
            else
            {
                $parser_options['me_username'] = $post['username'];
            }
            break;
    }
    
    // Sanatize our custom profile fields for use in templates, if people choose to use them
    foreach($post as $post_field => $field_value)
    {
        if(substr($post_field, 0, 3) != 'fid')
        {
            continue;
        }
        $post[$post_field] = htmlspecialchars_uni($field_value);
    }

    if(!$postcounter)
    { // Used to show the # of the post
        if($page > 1)
        {
            if(!$mybb->settings['postsperpage'])
            {
                $mybb->settings['postperpage'] = 20;
            }
            
            $postcounter = $mybb->settings['postsperpage']*($page-1);
        }
        else
        {
            $postcounter = 0;
        }
        $post_extra_style = "border-top-width: 0;";
    }
    elseif($mybb->input['mode'] == "threaded")
    {
        $post_extra_style = "border-top-width: 0;";
    }
    else
    {
        $post_extra_style = "margin-top: 5px;";
    }
    
    if(!$altbg)
    { // Define the alternate background colour if this is the first post
        $altbg = "trow1";
    }
    $postcounter++;

    // Format the post date and time using my_date
    $post['postdate'] = my_date($mybb->settings['dateformat'], $post['dateline']);
    $post['posttime'] = my_date($mybb->settings['timeformat'], $post['dateline']);

    // Dont want any little 'nasties' in the subject
    $post['subject'] = $parser->parse_badwords($post['subject']);

    // Pm's have been htmlspecialchars_uni()'ed already.
    if($post_type != 2)
    {
        $post['subject'] = htmlspecialchars_uni($post['subject']);
    }
    
    if(empty($post['subject']))
    {
        $post['subject'] = '&nbsp;';
    }

    $post['author'] = $post['uid'];

    // Get the usergroup
    if($post['userusername'])
    {
        if(!$post['displaygroup'])
        {
            $post['displaygroup'] = $post['usergroup'];
        }
        $usergroup = $groupscache[$post['displaygroup']];
    }
    else
    {
        $usergroup = $groupscache[1];
    }

    if(!is_array($titlescache))
    {
        $cached_titles = $cache->read("usertitles");
        if(!empty($cached_titles))
        {
            foreach($cached_titles as $usertitle)
            {
                $titlescache[$usertitle['posts']] = $usertitle;
            }
        }
        
        if(is_array($titlescache))
        {
            krsort($titlescache);
        }
        unset($usertitle, $cached_titles);
    }

    // Work out the usergroup/title stuff
    if(!empty($usergroup['image']))
    {
        if(!empty($mybb->user['language']))
        {
            $language = $mybb->user['language'];
        }
        else
        {
            $language = $mybb->settings['bblanguage'];
        }
        $usergroup['image'] = str_replace("{lang}", $language, $usergroup['image']);
        $usergroup['image'] = str_replace("{theme}", $theme['imgdir'], $usergroup['image']);
        eval("\$post['groupimage'] = \"".$templates->get("postbit_groupimage")."\";");
        if($mybb->settings['postlayout'] == "classic")
        {
            $post['groupimage'] .= "<br />";
        }
    }

    if($post['userusername'])
    { // This post was made by a registered user

        $post['username'] = $post['userusername'];
        $post['profilelink_plain'] = get_profile_link($post['uid']);
        $post['username_formatted'] = format_name($post['username'], $post['usergroup'], $post['displaygroup']);
        $post['profilelink'] = build_profile_link($post['username_formatted'], $post['uid']);
        
        if(trim($post['usertitle']) != "")
        {
            $hascustomtitle = 1;
        }
        
        if($usergroup['usertitle'] != "" && !$hascustomtitle)
        {
            $post['usertitle'] = $usergroup['usertitle'];
        }
        elseif(is_array($titlescache) && !$usergroup['usertitle'])
        {
            reset($titlescache);
            foreach($titlescache as $key => $titleinfo)
            {
                if($post['postnum'] >= $key)
                {
                    if(!$hascustomtitle)
                    {
                        $post['usertitle'] = $titleinfo['title'];
                    }
                    $post['stars'] = $titleinfo['stars'];
                    $post['starimage'] = $titleinfo['starimage'];
                    break;
                }
            }
        }

        if($usergroup['stars'])
        {
            $post['stars'] = $usergroup['stars'];
        }

        if(!$post['starimage'])
        {
            $post['starimage'] = $usergroup['starimage'];
        }

        if($post['starimage'] && $post['stars'])
        {
            // Only display stars if we have an image to use...
            $post['starimage'] = str_replace("{theme}", $theme['imgdir'], $post['starimage']);
        
            for($i = 0; $i < $post['stars']; ++$i)
            {
                $post['userstars'] .= "<img src=\"".$post['starimage']."\" border=\"0\" alt=\"*\" />";
            }

            $post['userstars'] .= "<br />";
        }

        $post['postnum'] = my_number_format($post['postnum']);

        // Determine the status to show for the user (Online/Offline/Away)
        $timecut = TIME_NOW - $mybb->settings['wolcutoff'];
        if($post['lastactive'] > $timecut && ($post['invisible'] != 1 || $mybb->usergroup['canviewwolinvis'] == 1) && $post['lastvisit'] != $post['lastactive'])
        {
            eval("\$post['onlinestatus'] = \"".$templates->get("postbit_online")."\";");
        }
        else
        {
            if($post['away'] == 1 && $mybb->settings['allowaway'] != 0)
            {
                eval("\$post['onlinestatus'] = \"".$templates->get("postbit_away")."\";");
            }
            else
            {
                eval("\$post['onlinestatus'] = \"".$templates->get("postbit_offline")."\";");
            }
        }

        if($post['avatar'] != "" && ($mybb->user['showavatars'] != 0 || !$mybb->user['uid']))
        {
            $post['avatar'] = htmlspecialchars_uni($post['avatar']);
            $avatar_dimensions = explode("|", $post['avatardimensions']);
            
            if($avatar_dimensions[0] && $avatar_dimensions[1])
            {
                list($max_width, $max_height) = explode("x", my_strtolower($mybb->settings['postmaxavatarsize']));
                 if($avatar_dimensions[0] > $max_width || $avatar_dimensions[1] > $max_height)
                {
                    require_once MYBB_ROOT."inc/functions_image.php";
                    $scaled_dimensions = scale_image($avatar_dimensions[0], $avatar_dimensions[1], $max_width, $max_height);
                    $avatar_width_height = "width=\"{$scaled_dimensions['width']}\" height=\"{$scaled_dimensions['height']}\"";
                }
                else
                {
                    $avatar_width_height = "width=\"{$avatar_dimensions[0]}\" height=\"{$avatar_dimensions[1]}\"";    
                }
            }
            
            eval("\$post['useravatar'] = \"".$templates->get("postbit_avatar")."\";");
            $post['avatar_padding'] = "padding-right: 10px;";
        }
        else
        {
            $post['useravatar'] = "";
        }
        
        eval("\$post['button_find'] = \"".$templates->get("postbit_find")."\";");
        
        if($mybb->settings['enablepms'] == 1 && $post['receivepms'] != 0 && $mybb->usergroup['cansendpms'] == 1 && my_strpos(",".$post['ignorelist'].",", ",".$mybb->user['uid'].",") === false)
        {
            eval("\$post['button_pm'] = \"".$templates->get("postbit_pm")."\";");
        }
        
        if($mybb->settings['enablereputation'] == 1 && $mybb->settings['postrep'] == 1 && $mybb->usergroup['cangivereputations'] == 1 && $usergroup['usereputationsystem'] == 1)
        {
            if(!$post['pid'])
            {
                $post['pid'] = 0;
            }

            eval("\$post['button_rep'] = \"".$templates->get("postbit_rep_button")."\";");
        }
        
        if($post['website'] != "")
        {
            $post['website'] = htmlspecialchars_uni($post['website']);
            eval("\$post['button_www'] = \"".$templates->get("postbit_www")."\";");
        }
        else
        {
            $post['button_www'] = "";
        }
        
        if($post['hideemail'] != 1 && $mybb->usergroup['cansendemail'] == 1)
        {
            eval("\$post['button_email'] = \"".$templates->get("postbit_email")."\";");
        }
        else
        {
            $post['button_email'] = "";
        }

        //Added by Mark (start)
        eval("\$post['button_facebook_share'] = \"".$templates->get("postbit_facebook_share")."\";");
        //Added by Mark (end)
        
        $post['userregdate'] = my_date($mybb->settings['regdateformat'], $post['regdate']);

        // Work out the reputation this user has (only show if not announcement)
        if($post_type != 3 && $usergroup['usereputationsystem'] != 0 && $mybb->settings['enablereputation'] == 1)
        {
            $post['userreputation'] = get_reputation($post['reputation'], $post['uid']);
            eval("\$post['replink'] = \"".$templates->get("postbit_reputation")."\";");
        }

        // Showing the warning level? (only show if not announcement)
        if($post_type != 3 && $mybb->settings['enablewarningsystem'] != 0 && $usergroup['canreceivewarnings'] != 0 && ($mybb->usergroup['canwarnusers'] != 0 || ($mybb->user['uid'] == $post['uid'] && $mybb->settings['canviewownwarning'] != 0)))
        {
            $warning_level = round($post['warningpoints']/$mybb->settings['maxwarningpoints']*100);
            if($warning_level > 100)
            {
                $warning_level = 100;
            }
            $warning_level = get_colored_warning_level($warning_level);
            
            // If we can warn them, it's not the same person, and we're in a PM or a post.
            if($mybb->usergroup['canwarnusers'] != 0 && $post['uid'] != $mybb->user['uid'] && ($post_type == 0 || $post_type == 2))
            {
                eval("\$post['button_warn'] = \"".$templates->get("postbit_warn")."\";");
                $warning_link = "warnings.php?uid={$post['uid']}";
            }
            else
            {
                $warning_link = "usercp.php";
            }
            eval("\$post['warninglevel'] = \"".$templates->get("postbit_warninglevel")."\";");
        }
        
        eval("\$post['user_details'] = \"".$templates->get("postbit_author_user")."\";");
    }
    else
    { // Message was posted by a guest or an unknown user
        $post['username'] = $post['username'];
        $post['profilelink'] = format_name($post['username'], 1);
        
        if($usergroup['usertitle'])
        {
            $post['usertitle'] = $usergroup['usertitle'];
        }
        else
        {
            $post['usertitle'] = $lang->guest;
        }
        
        $usergroup['title'] = $lang->na;

        $post['userregdate'] = $lang->na;
        $post['postnum'] = $lang->na;
        $post['button_profile'] = '';
        $post['button_email'] = '';
        $post['button_www'] = '';
        $post['signature'] = '';
        $post['button_pm'] = '';
        $post['button_find'] = '';
        $post['onlinestatus'] = '';
        $post['replink'] = '';
        eval("\$post['user_details'] = \"".$templates->get("postbit_author_guest")."\";");
    }
    
    $post['button_edit'] = '';
    $post['button_quickdelete'] = '';
    $post['button_quote'] = '';
    $post['button_quickquote'] = '';
    $post['button_report'] = '';
    
    // For private messages, fetch the reply/forward/delete icons
    if($post_type == 2 && $post['pmid'])
    {
        global $replyall;        
        
        eval("\$post['button_reply_pm'] = \"".$templates->get("postbit_reply_pm")."\";");
        eval("\$post['button_forward_pm'] = \"".$templates->get("postbit_forward_pm")."\";");
        eval("\$post['button_delete_pm'] = \"".$templates->get("postbit_delete_pm")."\";");
        
        if($replyall == true)
        {
            eval("\$post['button_replyall_pm'] = \"".$templates->get("postbit_replyall_pm")."\";");
        }
    }
    
    if(!$post_type)
    {
        // Figure out if we need to show an "edited by" message
        if($post['edituid'] != 0 && $post['edittime'] != 0 && $post['editusername'] != "" && ($mybb->settings['showeditedby'] != 0 && $usergroup['cancp'] == 0 || $mybb->settings['showeditedbyadmin'] != 0 && $usergroup['cancp'] == 1))
        {
            $post['editdate'] = my_date($mybb->settings['dateformat'], $post['edittime']);
            $post['edittime'] = my_date($mybb->settings['timeformat'], $post['edittime']);
            $post['editnote'] = $lang->sprintf($lang->postbit_edited, $post['editdate'], $post['edittime']);
            $post['editedprofilelink'] = build_profile_link($post['editusername'], $post['edituid']);
            eval("\$post['editedmsg'] = \"".$templates->get("postbit_editedby")."\";");
        }
        
        if((is_moderator($fid, "caneditposts") || ($forumpermissions['caneditposts'] == 1 && $mybb->user['uid'] == $post['uid'])) && $mybb->user['uid'] != 0)
        {
            eval("\$post['button_edit'] = \"".$templates->get("postbit_edit")."\";");
        }
        
        // Quick Delete button
        $can_delete = 0;
        if($mybb->user['uid'] == $post['uid'])
        {
            if($forumpermissions['candeletethreads'] == 1 && $postcounter == 1)
            {
                $can_delete = 1;
            }
            else if($forumpermissions['candeleteposts'] == 1 && $postcounter != 1)
            {
                $can_delete = 1;
            }
        }
        
        if((is_moderator($fid, "candeleteposts") || $can_delete == 1) && $mybb->user['uid'] != 0)
        {
            eval("\$post['button_quickdelete'] = \"".$templates->get("postbit_quickdelete")."\";");
        }
        
        // Inline moderation stuff
        if($ismod)
        {
            if(my_strpos($mybb->cookies[$inlinecookie], "|".$post['pid']."|"))
            {
                $inlinecheck = "checked=\"checked\"";
                $inlinecount++;
            }
            else
            {
                $inlinecheck = "";
            }
            
            eval("\$post['inlinecheck'] = \"".$templates->get("postbit_inlinecheck")."\";");
            
            if($post['visible'] == 0)
            {
                $invisiblepost = 1;
            }
        }
        else
        {
            $post['inlinecheck'] = "";
        }
        $post['postlink'] = get_post_link($post['pid'], $post['tid']);
        eval("\$post['posturl'] = \"".$templates->get("postbit_posturl")."\";");
        global $forum, $thread;
        
        if($forum['open'] != 0 && ($thread['closed'] != 1 || is_moderator($forum['fid'])))
        {
            eval("\$post['button_quote'] = \"".$templates->get("postbit_quote")."\";");
        }
        
        if($forumpermissions['canpostreplys'] != 0 && ($thread['closed'] != 1 || is_moderator($fid)) && $mybb->settings['multiquote'] != 0 && $forum['open'] != 0 && !$post_type)
        {
            eval("\$post['button_multiquote'] = \"".$templates->get("postbit_multiquote")."\";");
        }
        
        if($mybb->user['uid'] != "0")
        {
            eval("\$post['button_report'] = \"".$templates->get("postbit_report")."\";");
        }
        
        if($mybb->settings['logip'] != "no")
        {
            if($mybb->settings['logip'] == "show")
            {
                eval("\$post['iplogged'] = \"".$templates->get("postbit_iplogged_show")."\";");
            }
            else if($mybb->settings['logip'] == "hide" && is_moderator($fid, "canviewips"))
            {
                eval("\$post['iplogged'] = \"".$templates->get("postbit_iplogged_hiden")."\";");
            }
            else
            {
                $post['iplogged'] = "";
            }
        }
        else
        {
            $post['iplogged'] = "";
        }
    }
    elseif($post_type == 3) // announcement
    {
        if($mybb->usergroup['issupermod'] == 1 || is_moderator($fid))
        {
            eval("\$post['button_edit'] = \"".$templates->get("announcement_edit")."\";");
            eval("\$post['button_quickdelete'] = \"".$templates->get("announcement_quickdelete")."\";");
        }
    }
    
    if($post['smilieoff'] == 1)
    {
        $parser_options['allow_smilies'] = 0;
    }
    
    // If we have incoming search terms to highlight - get it done.
    if($mybb->input['highlight'])
    {
        $parser_options['highlight'] = $mybb->input['highlight'];
        $post['subject'] = $parser->highlight_message($post['subject'], $parser_options['highlight']);
    }
    
    $post['message'] = $parser->parse_message($post['message'], $parser_options);

    get_post_attachments($id, $post);

    if($post['includesig'] != 0 && $post['username'] && $post['signature'] != "" && ($mybb->user['uid'] == 0 || $mybb->user['showsigs'] != 0) && ($post['suspendsignature'] == 0 || $post['suspendsignature'] == 1 && $post['suspendsigtime'] != 0 && $post['suspendsigtime'] < TIME_NOW))
    {
        $sig_parser = array(
            "allow_html" => $mybb->settings['sightml'],
            "allow_mycode" => $mybb->settings['sigmycode'],
            "allow_smilies" => $mybb->settings['sigsmilies'],
            "allow_imgcode" => $mybb->settings['sigimgcode'],
            "me_username" => $post['username']
        );

        $post['signature'] = $parser->parse_message($post['signature'], $sig_parser);
        eval("\$post['signature'] = \"".$templates->get("postbit_signature")."\";");
    }
    else
    {
        $post['signature'] = "";
    }

    $icon_cache = $cache->read("posticons");
    
    if($post['icon'] > 0 && $icon_cache[$post['icon']])
    {
        $icon = $icon_cache[$post['icon']];
        $post['icon'] = "<img src=\"{$icon['path']}\" alt=\"{$icon['name']}\" style=\"vertical-align: middle;\" />&nbsp;";
    }
    else
    {
        $post['icon'] = "";
    }
    
    $post_visibility = '';
    switch($post_type)
    {
        case 1: // Message preview
            $plugins->run_hooks_by_ref("postbit_prev", $post);
            break;
        case 2: // Private message
            $plugins->run_hooks_by_ref("postbit_pm", $post);
            break;
        case 3: // Announcement
            $plugins->run_hooks_by_ref("postbit_announcement", $post);
            break;
        default: // Regular post
            $plugins->run_hooks_by_ref("postbit", $post);

            // Is this author on the ignore list of the current user? Hide this post
            if(is_array($ignored_users) && $post['uid'] != 0 && $ignored_users[$post['uid']] == 1)
            {
                $ignored_message = $lang->sprintf($lang->postbit_currently_ignoring_user, $post['username']);
                eval("\$ignore_bit = \"".$templates->get("postbit_ignored")."\";");
                $post_visibility = "display: none;";
            }
            break;
    }
    
    if($mybb->settings['postlayout'] == "classic")
    {
        eval("\$postbit = \"".$templates->get("postbit_classic")."\";");
    }
    else
    {
        eval("\$postbit = \"".$templates->get("postbit")."\";");        
    }
    $GLOBALS['post'] = "";
    
    return $postbit;
}

/**
 * Fetch the attachments for a specific post and parse inline [attachment=id] code.
 * Note: assumes you have $attachcache, an array of attachments set up.
 *
 * @param int The ID of the item.
 * @param array The post or item passed by reference.
 */
function get_post_attachments($id, &$post)
{
    global $attachcache, $mybb, $theme, $templates, $forumpermissions, $lang;

    $validationcount = 0;
    $tcount = 0;
    if(is_array($attachcache[$id]))
    { // This post has 1 or more attachments
        foreach($attachcache[$id] as $aid => $attachment)
        {
            if($attachment['visible'])
            { // There is an attachment thats visible!
                $attachment['filename'] = htmlspecialchars_uni($attachment['filename']);
                $attachment['filesize'] = get_friendly_size($attachment['filesize']);
                $ext = get_extension($attachment['filename']);
                if($ext == "jpeg" || $ext == "gif" || $ext == "bmp" || $ext == "png" || $ext == "jpg")
                {
                    $isimage = true;
                }
                else
                {
                    $isimage = false;
                }
                $attachment['icon'] = get_attachment_icon($ext);
                // Support for [attachment=id] code
                if(stripos($post['message'], "[attachment=".$attachment['aid']."]") !== false)
                {
                    // Show as thumbnail IF image is big && thumbnail exists && setting=='thumb'
                    // Show as full size image IF setting=='fullsize' || (image is small && permissions allow)
                    // Show as download for all other cases 
                    if($attachment['thumbnail'] != "SMALL" && $attachment['thumbnail'] != "" && $mybb->settings['attachthumbnails'] == "yes")
                    {
                        eval("\$attbit = \"".$templates->get("postbit_attachments_thumbnails_thumbnail")."\";");
                    }
                    elseif((($attachment['thumbnail'] == "SMALL" && $forumpermissions['candlattachments'] == 1) || $mybb->settings['attachthumbnails'] == "no") && $isimage)
                    {
                        eval("\$attbit = \"".$templates->get("postbit_attachments_images_image")."\";");
                    }
                    else
                    {
                        eval("\$attbit = \"".$templates->get("postbit_attachments_attachment")."\";");
                    }
                    $post['message'] = preg_replace("#\[attachment=".$attachment['aid']."]#si", $attbit, $post['message']);
                }
                else
                {
                    // Show as thumbnail IF image is big && thumbnail exists && setting=='thumb'
                    // Show as full size image IF setting=='fullsize' || (image is small && permissions allow)
                    // Show as download for all other cases 
                    if($attachment['thumbnail'] != "SMALL" && $attachment['thumbnail'] != "" && $mybb->settings['attachthumbnails'] == "yes")
                    {
                        eval("\$post['thumblist'] .= \"".$templates->get("postbit_attachments_thumbnails_thumbnail")."\";");
                        if($tcount == 5)
                        {
                            $thumblist .= "<br />";
                            $tcount = 0;
                        }
                        ++$tcount;
                    }
                    elseif((($attachment['thumbnail'] == "SMALL" && $forumpermissions['candlattachments'] == 1) || $mybb->settings['attachthumbnails'] == "no") && $isimage)
                    {
                        eval("\$post['imagelist'] .= \"".$templates->get("postbit_attachments_images_image")."\";");
                    }
                    else
                    {
                        eval("\$post['attachmentlist'] .= \"".$templates->get("postbit_attachments_attachment")."\";");
                    }
                }
            }
            else
            {
                $validationcount++;
            }
        }
        if($validationcount > 0 && is_moderator($post['fid']))
        {
            if($validationcount == 1)
            {
                $postbit_unapproved_attachments = $lang->postbit_unapproved_attachment;
            }
            else
            {
                $postbit_unapproved_attachments = $lang->sprintf($lang->postbit_unapproved_attachments, $validationcount);
            }
            eval("\$post['attachmentlist'] .= \"".$templates->get("postbit_attachments_attachment_unapproved")."\";");
        }
        if($post['thumblist'])
        {
            eval("\$post['attachedthumbs'] = \"".$templates->get("postbit_attachments_thumbnails")."\";");
        }
        if($post['imagelist'])
        {
            eval("\$post['attachedimages'] = \"".$templates->get("postbit_attachments_images")."\";");
        }
        if($post['attachmentlist'] || $post['thumblist'] || $post['imagelist'])
        {
            eval("\$post['attachments'] = \"".$templates->get("postbit_attachments")."\";");
        }
    }
}
?>

Find the same position in the file and then add the code. (Mine was on line 366)

Code:

        //Added by Mark (start)
        eval("\$post['button_facebook_share'] = \"".$templates->get("postbit_facebook_share")."\";");
        //Added by Mark (end)

Hope this helps. :happy