New Year, New Ideas, Problems Solved

Well its now 2010, Happy New Year!!!, and my mailserver guide is still not on the site. It has not been forgotten and in fact part of the guide is already hidden away under going editing. One of the issues that was delaying progress was finding the best way to display code on the site. There are alot of plugins for WordPress that will do syntax highlighting using Geshi. What I have wanted to do is highlight specific lines of highlighted syntax to make it easier to show changes. I did a little research and found that Geshi already supports the functionality I required but it hadn't been implemented in any WordPress plugins. So I decided to modify one. I selected CodeColorer to modify as it already had a method of processing arguments within the "cc" tag it uses.

The modification is simple but has a few limitations. Firstly each line that needs to be selectively highlighted needs to be referenced by line number. This is easy for a few lines but is going to mean alot of number typing for large chunks of code. That said for really big chunks of code they are probably best split off from the rest of the file anyway. The line highlight only stretches to the limit of the longest line and not the whole of the code window. Only a single colour can be specified for the selective highlight and it only works if the Geshi style is selected rather the the custom CodeColorer themes.

Lets now have a look at the modification and what it does. I only needed to modify the codecolorer-core.php file in the plugin directory with a few lines. I have highlighted the changes on lines 161-167 using the modification. To achieve this I placed a new argument 'highlight' into the tag after the language argument [cc lang="php" highlight="161,162,163,164,165,166,167"]. The 'highlight' argument takes a comma separated list of line numbers to highlight. Thats basically it, the modification takes the line numbers, puts them into an array and passes it on to the inbuilt functionality of Geshi which handles the rest.

codecolorer-core.php

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<?php
/*
CodeColorer plugin core part
http://kpumuk.info/projects/wordpress-plugins/codecolorer
*/
/*
    Copyright 2006 - 2009  Dmytro Shteflyuk <kpumuk@kpumuk.info>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

class CodeColorer {
  var $blocks = array();
  var $comments = array();

  var $geshiExternal = false;
  var $geshiVersion = '1.0.8.4';

  var $samplePhpCode = '
   [cc_php]
   /**
    * Comment
    */
   function hello() {
     echo "Hello!";
     return null;
   }
   exit();
   [/cc_php]
 ';

  /** Search content for code tags and replace it */
  function BeforeHighlightCodeBlock($content) {
    $content = preg_replace('#(\s*)\[cc([^\s\]_]*(?:_[^\s\]]*)?)([^\]]*)\](.*?)\[/cc\2\](\s*)#sie', '$this->PerformHighlightCodeBlock(\'\\4\', \'\\3\', $content, \'\\2\', \'\\1\', \'\\5\');', $content);
    $content = preg_replace('#(\s*)\<code (.*?)\>(.*?)\</code>(\s*)#sie', '$this->PerformHighlightCodeBlock(\'\\3\', \'\\2\', $content, \'\', \'\\1\', \'\\4\');', $content);

    return $content;
  }

  function AfterHighlightCodeBlock($content) {
    $content = str_replace(array_keys($this->blocks), array_values($this->blocks), $content);

    return $content;
  }

  function BeforeProtectComment($content) {
    $content = preg_replace('#(\s*)(\[cc[^\s\]_]*(?:_[^\s\]]*)?[^\]]*\].*?\[/cc\1\])(\s*)#sie', '$this->PerformProtectComment(\'\\2\', $content, \'\\1\', \'\\3\');', $content);
    $content = preg_replace('#(\s*)(\<code .*?\>.*?\</code>)(\s*)#sie', '$this->PerformProtectComment(\'\\2\', $content, \'\\1\', \'\\3\');', $content);

    return $content;
  }

  function AfterProtectComment($content) {
    $content = str_replace(array_keys($this->comments), array_values($this->comments), $content);
    $this->comments = array();

    return $content;
  }

  /**
   * Perform code highlightning
   */
  function PerformHighlightCodeBlock($text, $opts, $content, $suffix = '', $before = '', $after = '') {
    // Preprocess source text
    $text = str_replace(array("\\"", "\\'"), array (""", "\'"), $text);
   $text = preg_replace('/(< \?php)/i', '<?php', $text);
   $text = preg_replace('/(?:^(?:\s*[\r\n])+|\s+$)/', '', $text);

   // Parse options
   $options = CodeColorerOptions::ParseOptions($opts, $suffix);

   if ($options['escaped']) {
     $text = html_entity_decode($text, ENT_QUOTES);
     $text = preg_replace('~&#x0*([0-9a-f]+);~ei', 'chr(hexdec("\\1"))', $text);
     $text = preg_replace('~&#0*([0-9]+);~e', 'chr(\\1)', $text);
    }

    $result = '';
    // Check if CodeColorer has been disabled for this particular block
    if (!$options['enabled']) {
      $result = '<code>' . $text . '';
    } else {
      // See if we should force a height
      $num_lines = count(explode("\n", $text));

      $result = $this->PerformHighlightGeshi($text, $options);

      $result = $this->AddContainer($result, $options, $num_lines);
    }

    if ($options['inline']) {
      $blockID = $this->GetBlockID($content, false, '<span>', '</span>');
    } else {
      $blockID = $this->GetBlockID($content);
    }
    $this->blocks[$blockID] = $result;

    if ($options['inline']) {
      $result = $before . $blockID . $after;
    } else {
      $result = "\n\n$blockID\n\n";
    }

    return $result;
  }

  /**
   * Perform code protecting from mangling by Wordpress (used in Comments)
   */
  function PerformProtectComment($text, $content, $before, $after) {
    $text = str_replace(array("\\"", "\\'"), array (""", "\'"), $text);

   $blockID = $this->GetBlockID($content, true, '', '');
   $this->comments[$blockID] = $text;

   return $before . $blockID . $after;
 }

 /**
  * Perform code highlighting using GESHi engine
  */
 function PerformHighlightGeshi($content, $options) {
   /* Geshi configuration */
   if (!$this->geshi) {
     $this->geshi = new GeSHi();
     $this->geshi->enable_line_numbers(GESHI_NO_LINE_NUMBERS, 1);
     if (is_feed()) {
       $this->geshi->set_overall_style('padding:5px;font:normal 12px/1.4em Monaco, Lucida Console, monospace;white-space:nowrap');
     }
   }

   $geshi = $this->geshi;
   $geshi->set_source($content);
   $geshi->set_language($options['lang']);
   $geshi->set_overall_class('codecolorer');
   $geshi->set_tab_width($options['tab_size']);
   if (!is_feed()) {
     $geshi->enable_classes($options['theme'] != 'geshi');
     if ($options['nowrap']) {
       $geshi->set_overall_style('white-space:nowrap');
     } else {
       $geshi->set_overall_style('');
     }
   } else {
     $geshi->enable_classes(false);
   }
   if (!is_null($options['strict'])) $geshi->enable_strict_mode($options['strict']);
   if ($options['no_links']) $geshi->enable_keyword_links(false);
   /* My Custom Bit */    
    if ($options['highlight']){
       $myarray = explode(",",$options['highlight']);
       $geshi->highlight_lines_extra($myarray);
       $geshi->set_highlight_lines_extra_style('background-color: #ffff66;'); /* Select the colour of the highlight */
   }
    /* End My Custom Bit */  
    if ($options['inline']) {
      $geshi->set_header_type(GESHI_HEADER_NONE);
    } else {
      $geshi->set_header_type(GESHI_HEADER_DIV);
    }

    $result = $geshi->parse_code();

    if ($geshi->error()) {
      return $geshi->error();
    }

    if ($options['line_numbers'] && !$options['inline']) {
      $table = '<table cellspacing="0" cellpadding="0"><tbody><tr><td ';
      if (is_feed()) {
        $table .= 'style="padding:5px;text-align:center;color:#888888;background-color:#EEEEEE;border-right: 1px solid #9F9F9F;font: normal 12px/1.4em Monaco, Lucida Console, monospace;"';
      } else {
        $table .= 'class="line-numbers"';
      }
      $table .= '><div>';
      for ($i = 0, $count = substr_count($result, '<br />') + 1; $i < $count; $i++) {
        $table .= ($i + $options['first_line']) . '<br />';
      }
      $result = $table . '</div></td><td>' . $result . '</td></tr></tbody></table>';
    }

    return $result;
  }

  function AddContainer($html, $options, $num_lines) {
    $custom_css_class = empty($options['class']) ? '' : ' ' . $options['class'];
    if ($options['inline']) {
      $theme = empty($options['inline_theme']) ? 'default' : $options['inline_theme'];
      $result  = '<code class="codecolorer ' . $options['lang'] . ' ' . $theme . $custom_css_class . '">';
      $result .= '<span class="' . $options['lang'] . '">' . $html . '</span>';
      $result .= '</code>';
    } else {
      $theme = empty($options['theme']) ? 'default' : $options['theme'];
      $style = 'style="';
      if ($options['nowrap']) $style .= 'overflow:auto;white-space:nowrap;';
      if (is_feed()) $style .= 'border: 1px solid #9F9F9F;';
      $style .= $this->GetDimensionRule('width', is_feed() ? $options['rss_width'] : $options['width']);
      if($num_lines > $options['lines'] && $options['lines'] > 0) {
        $style .= $this->GetDimensionRule('height', $options['height']);
      }
      $style .= '"';

      $css_class = 'codecolorer-container ' . $options['lang'] . ' ' . $theme . $custom_css_class;
      if ($options['noborder']) $css_class .= ' codecolorer-noborder';
      $result = '<div class="' . $css_class . '" ' . $style . '>' . $html . '</div>';
    }
    return $result;
  }

  /**
   * Generate a block ID that will be replaced at the end (after all that
   * crazy WP text work!) with the right code
   */
  function GetBlockID($content, $comment = false, $before = '<div>', $after = '</div>') {
    static $num = 0;

    $block = $comment ? 'COMMENT' : 'BLOCK';
    $before = $before . '::CODECOLORER_' . $block . '_';
    $after = '::' . $after;

    // Just do a check to make sure the user
    // hasn't (however unlikely) input block replacements
    // as legit text
    do {
      ++$num;
      $blockID = $before . $num . $after;
    } while (strpos($content, $blockID) !== false);

    return $blockID;
  }

  function GetDimensionRule($dimension, $value) {
    $rule = '';
    if (!empty($value)) $rule = "$dimension:$value" . (is_numeric($value) ? 'px;' : ';');
    return $rule;
  }

  function ShowWarning($type, $title, $message) {
    $disable = ' <a href="options-general.php?page=codecolorer.php&amp;disable=' . $type . '">' . __('Close', 'codecolorer') . '</a>';
    echo '<div id="codecolorer-' . $type . '" class="updated fade"><p><strong>' . $title . "</strong> " . $message . $disable . "</p></div>\n";
  }

  function ShowGeshiWarning() {
    if ($this->geshiExternal) {
      $this->ShowWarning('concurrent', __('CodeColorer has detected a problem.', 'codecolorer'), sprintf(__('We found another plugin based on GeSHi library in your system. CodeColorer will work, but our version of GeSHi contain some patches, so we can\'t guarantee an ideal code highlighting now. Please review your <a href="%1$s">plugins</a>, maybe you don\'t need them all.', 'codecolorer'), "plugins.php"));
    }
  }

  function ShowOptionsPage() {
    $page = $this->GetOptionsPage();
    $page->Show();
  }

  function GetOptionsPage() {
    if (!$this->optionsPage) {
      if (!class_exists('CodeColorerAdmin')) {
        $path = dirname(__FILE__);
        if (!file_exists("$path/codecolorer-admin.php")) return false;
        require_once("$path/codecolorer-admin.php");
      }
      $this->optionsPage = new CodeColorerAdmin($this);
    }
    return $this->optionsPage;
  }

  function GetCodeHighlighted($code) {
    $content = $this->BeforeHighlightCodeBlock($code);
    return $this->AfterHighlightCodeBlock($content);
  }

  function GetSampleCodeHighlighted() {
    return $this->GetCodeHighlighted($this->samplePhpCode);
  }

  function &GetInstance() {
    static $instance = null;

    if (null === $instance) {
      $path = dirname(__FILE__);
      if (!class_exists('CodeColorerOptions')) {
        if (!file_exists("$path/codecolorer-options.php")) return null;
        require_once("$path/codecolorer-options.php");
      }

      $instance = new CodeColorer();

      # Maybe GeSHi has been loaded by some another plugin?
     if (!class_exists('GeSHi')) {
        if (!file_exists("$path/lib/geshi.php")) return null;
        require_once("$path/lib/geshi.php");
      } else {
        $instance->geshiExternal = true;
      }
    }

    return $instance;
  }
}

Thunderbird 3 Bug: A Workaround

I recently upgraded from Mozilla Thunderbird 2 to the new Thunderbird 3 release. For a few days everything was working fine with the new default settings. I have a few email accounts which Thunderbird fetches mail for and I didn't want to use the new Smart Folder mode. So I changed back to not using it. Everything appeared ok, until the next day. I returned home from work to find no new email. This is highly unusual as there is usually some for of advert for an online store showing me the latest offers, especially around christmas time. This lack of email continued for a few days, to begin with I attributed this to my ISP who were reporting problems with the email system. Today after 4 days with no new mail it was time to explore more options within Thunderbird and try to find a solution to the problem.

The solution came about by chance whilst browsing the Account Settings screen. The route to the solution from the main screen is shown below.

Tools > Account Settings > Click 'Server Settings' option under your problem account(s) > Click 'Advanced' button towards the bottom right > Select 'Global Inbox' option and check the 'Include this server when getting new mail' box.

This process should re-enable your account and allow you to get your missing emails.

Thunderbird 3 Account Settings Menu
Thunderbird 3 Account Settings Menu

Thunderbird 3 Settings Dialog
Thunderbird 3 Settings Dialog

November Update

As usual it has taken me until the end of the month to get round to posting something. Normally this is just an update of the mail server saga or something about a site update. Not wanting to miss out such information that will follow. More interesting news is that I am changing my job, moving from a Field Engineer covering the entire country to something a little more localised. It should mean that I have a bit more of a life outside work; about time too.

Now the mail server is still working and I need to keep working on it to ensure stability and security but its mostly running itself. The website as a whole needs a few tweaks, the design is looking a little old. I am thinking of moving to a darker theme. Currently viewing the site in a darkened room on a 24" monitor is quite blinding. Something less intense and more readable is in order.

Since I am on holiday this week I may get some changes rolled out sooner rather than later.

Mailserver Project – October Update

The mailserver project which I have been working on for many months now is getting to the point where it will soon be taking over the role of hosting all my email. No problems have been discovered over the past month and my upgrade script to regenerate the security certificates worked perfectly. A recent update to Dovecot, the IMAP system, means that a little more testing is in order due to modifications made to the config files.

When I finally release my documentation for the process it will outline the working setup at that time. No point in releasing something out of date.

Mailserver – Another Stage Completed

Over the past couple of weeks I have been moving the mailserver project closer to being ready for actual use and another milestone has been passed. I have now reached the stage where my hotmail and gmail accounts are collected onto the server and made availiable via IMAP.

This has not been without problems, I experinced a problem with mail not getting through the spam filter when sent from the local machine but working fine for the exernally received mail. This has now been resolved, although I have to admit I'm not sure how, mainly because I never fully isolated the actual cause of the problem. I suspect it was the system calling the spam filter multiple times whilst processing a single email. Now the next stage is to test how things work for a week or so and watch out for any more bugs.

There is plenty more documentation to write, every thing about the mailserver configuration is full of options to configure it and I want to make sure I have a reference for the future. I still might be on target for having all my other email accounts on the server by the end of the year.

Quick Mailserver Update

I have at long last done a little more work on the mailserver project. The latest thing to report is the addition of dspam to filter out spam. In addition to this clamAV is also integrated.

The next step will be to do some more testing and then plug in another application which should make training and using the spam filter a little easier.

The documentation surrounding the addition of dspam and antivirus to the setup I am working on has been very hard to come by and in some cases is conflicting. Having made significant progress recently I am hoping to eventually have my setup production ready by the end of the year*. *Might as well give myself plenty of time.

Mailserver Update

I posted a few weeks (possibly months) ago that I would get my guide to setting up a mailserver onto the site. Unfortunately I ran into a few security realted problems that needed to resolved. The good news is I have made plenty of notes of the process and it should just be a case of typing them up.

I hope to have the notes up soon after I have a basic secure working setup. This should take no more than a couple of weeks if I am able to dedicate time to the project.

May and Mailservers

May 2008 has been somewhat uneventful on the traveling front, work has mainly taken my to and from the office (3 miles a day). On the plus side being based at home I have invested some time into trying to setup a mail server. Now setting up a mail server was never going to be an easy task, the fact that I still don't have a working setup after several weeks of attempts is testament to this.

I did discover one solution that may be of use to somebody wishing to setup a headless server. ClarkConnect is a modular server and gateway operating system which can be setup for your needs. There are commercial and community editions available, I tried the community edition. What was obvious for the brief test installation is how polished ClarkConnect is; but you would expect this from an established commercial product. The fact that as a home user I can use this product for free is fantastic. ClarkConnect is linux based but its essentially a highly customised single purpose distribution. You can't for example install a gnome desktop on it, its a headless server and as such is a web interface for the server processes only. If I wasn't wanting to run non-server applications on the same machine as the mailserver then ClarkConnect would be my first choice for a simple and secure home server setup. Give it a try.

When I finally get a solution for my own mailserver setup I'll try to create an install guide, I've not found a good guide yet so I may as well try and create one.