Joomla是目前比較盛行的CMS系統，良好的框架結構使越來越多的開發人員加入進來。使用Joomla有一段時間的人都知道Joomla所生成的站點一般都是基於動態URL的對於搜索引擎來說動態URL的站點並不是就不能搜索到就一定會排在後面而是不太友好，這個不友好也是暫時的目前的個別現象，事物都是進步的GOOGLE也會在不斷進步，其實我並不喜歡那些把搜索引擎吹呼的不得了的人，這個優化大師那個優化姥姥的，那些人八成都是有一點點個人的私慾在裏面，要是不小心刺激到你，抱歉我不是有意在說你！
Joomla中的SEF說白了就是一個對URL的重寫的過程將原來參數衆多，層次很深的URL改寫爲一個簡單的更容易被記住被搜索的URL。通過分析Joomla站點的URL結果就會發現規律很明顯:
域名+index.php?option=com_content&task=category§ionid=4&id=13&Itemid=27
以上就是一個最普通不過的URL，其中包含的元素有option(組件參數，告訴系統一下內容來自哪個組件)、task(任務參數，組件內執行什麼任務上面的例子中代表執行分類列表，sectionid內容的單元號JOOMLA特有，id,itemid項目號)。Joomla本身就自帶一個URL優化的組件，也就是一個函數實現對上述地址的重寫爲index.php/content/view/4/13/27.html,是不是貌似靜態，嚴格來說應該是僞裝的靜態。
下面的函數sefRelToAbs就是實現上述改寫的
/** * Converts an absolute URL to SEF format * @param string The URL * @return string */function sefRelToAbs( $string ) { global $mosConfig_live_site, $mosConfig_sef, $mosConfig_mbf_content, $mosConfig_multilingual_support; global $iso_client_lang; //multilingual code url support if( $mosConfig_sef && ($mosConfig_mbf_content || $mosConfig_multilingual_support) && $string!='index.php' && !eregi("^(([^:/?#]+):)",$string) && !strcasecmp(substr($string,0,9),'index.php') && !eregi('lang=', $string) ) { $string .= '&lang='. $iso_client_lang; } // SEF URL Handling if ($mosConfig_sef && !eregi("^(([^:/?#]+):)",$string) && !strcasecmp(substr($string,0,9),'index.php')) { // Replace all & with & $string = str_replace( '&', '&', $string ); // Home index.php if ($string == 'index.php') { $string = ''; } // break link into url component parts $url = parse_url( $string ); // check if link contained fragment identifiers (ex. #foo) $fragment = ''; if ( isset($url['fragment']) ) { // ensure fragment identifiers are compatible with HTML4 if (preg_match('@^[A-Za-z][A-Za-z0-9:_.-]*$@', $url['fragment'])) { $fragment = '#'. $url['fragment']; } } // check if link contained a query component if ( isset($url['query']) ) { // special handling for javascript $url['query'] = stripslashes( str_replace( '+', '%2b', $url['query'] ) ); // clean possible xss attacks $url['query'] = preg_replace( "'%3Cscript[^%3E]*%3E.*?%3C/script%3E'si", '', $url['query'] ); // break url into component parts parse_str( $url['query'], $parts ); // special handling for javascript foreach( $parts as $key => $value) { if ( strpos( $value, '+' ) !== false ) { $parts[$key] = stripslashes( str_replace( '%2b', '+', $value ) ); } } //var_dump($parts); $sefstring = ''; // Component com_content urls if ( ( ( isset($parts['option']) && ( $parts['option'] == 'com_content' || $parts['option'] == 'content' ) ) ) && ( $parts['task'] != 'new' ) && ( $parts['task'] != 'edit' ) ) { // index.php?option=com_content [&task=$task] [§ionid=$sectionid] [&id=$id] [&Itemid=$Itemid] [&limit=$limit] [&limitstart=$limitstart] [&year=$year] [&month=$month] [&module=$module] $sefstring .= 'content/'; // task if ( isset( $parts['task'] ) ) { $sefstring .= $parts['task'].'/'; } // sectionid if ( isset( $parts['sectionid'] ) ) { $sefstring .= $parts['sectionid'].'/'; } // id if ( isset( $parts['id'] ) ) { $sefstring .= $parts['id'].'/'; } // Itemid if ( isset( $parts['Itemid'] ) ) { //only add Itemid value if it does not correspond with the 'unassigned' Itemid value if ( $parts['Itemid'] != 99999999 && $parts['Itemid'] != 0 ) { $sefstring .= $parts['Itemid'].'/'; } } // order if ( isset( $parts['order'] ) ) { $sefstring .= 'order,'. $parts['order'].'/'; } // filter if ( isset( $parts['filter'] ) ) { $sefstring .= 'filter,'. $parts['filter'].'/'; } // limit if ( isset( $parts['limit'] ) ) { $sefstring .= $parts['limit'].'/'; } // limitstart if ( isset( $parts['limitstart'] ) ) { $sefstring .= $parts['limitstart'].'/'; } // year if ( isset( $parts['year'] ) ) { $sefstring .= $parts['year'].'/'; } // month if ( isset( $parts['month'] ) ) { $sefstring .= $parts['month'].'/'; } // module if ( isset( $parts['module'] ) ) { $sefstring .= $parts['module'].'/'; } // lang if ( isset( $parts['lang'] ) ) { $sefstring .= 'lang,'. $parts['lang'].'/'; } $string = $sefstring; // all other components // index.php?option=com_xxxx &... } else if ( isset($parts['option']) && ( strpos($parts['option'], 'com_' ) !== false ) ) { // do not SEF where com_content - `edit` or `new` task link if ( !( ( $parts['option'] == 'com_content' ) && ( ( isset($parts['task']) == 'new' ) || ( isset($parts['task']) == 'edit' ) ) ) ) { $sefstring = 'component/'; foreach($parts as $key => $value) { // remove slashes automatically added by parse_str $value = stripslashes($value); $sefstring .= $key .','. $value.'/'; } $string = str_replace( '=', ',', $sefstring ); } } } // allows SEF without mod_rewrite // comment line below if you dont have mod_rewrite return $mosConfig_live_site .'/'. $string . $fragment; // allows SEF without mod_rewrite // uncomment Line 512 and comment out Line 514 // uncomment line below if you dont have mod_rewrite // return $mosConfig_live_site .'/index.php/'. $string . $fragment; // If the above doesnt work - try uncommenting this line instead // return $mosConfig_live_site .'/index.php?/'. $string . $fragment; } else { // Handling for when SEF is not activated // Relative link handling if ( (strpos( $string, $mosConfig_live_site ) !== 0) ) { // if URI starts with a "/", means URL is at the root of the host... if (strncmp($string, '/', 1) == 0) { // splits http(s)://xx.xx/yy/zz..." into [1]="http(s)://xx.xx" and [2]="/yy/zz...": $live_site_parts = array(); eregi("^(https?:[/]+[^/]+)(.*$)", $mosConfig_live_site, $live_site_parts); $string = $live_site_parts[1] . $string; } else { $check = 1; // array list of non http/https URL schemes $url_schemes = explode( ', ', _URL_SCHEMES ); $url_schemes[] = 'http:'; $url_schemes[] = 'https:'; foreach ( $url_schemes as $url ) { if ( strpos( $string, $url ) === 0 ) { $check = 0; } } if ( $check ) { $string = $mosConfig_live_site .'/'. $string; } } } return $string; }}要想使用這個函數首先要確定你的服務器是否支持URL重寫，一般來說只有APACHE服務器支持，IIS就不要打算了。