通用模板機制
PHP通用的模板機制，流程一般是
1.初始化模板類
2.設置模板變量
3.分析模板中的的模板變量
4.輸出內容
discuz模板機制
解析流程
discuz中的模板機制，將這一流程全都寫在template()函數內的checktplrefresh()，編譯生成緩存文件（如果模板緩存文件不存在，或者緩存文件的更改時間小於模板文件的更改時間），
1.初始化模板類，$template = new template();
2.解析模板變量（編譯生成模板緩存文件），$template->parse_template($maintpl, $templateid, $tpldir, $file, $cachefile);
3.執行tempalte的php腳本中，直接 include template()返回的緩存文件，輸出編譯後內容。
下面是代碼解析
template（$tpl）,調用模板文件，
checktplrefresh($tplfile, $tplfile, @filemtime(DISCUZ_ROOT.$cachefile), $templateid, $cachefile, $tpldir, $file);filemtime(DISCUZ_ROOT.$cashefile)獲取緩存文件（文件路徑根據模板文件生成）的更改時間，
function checktplrefresh($maintpl, $subtpl, $timecompare, $templateid, $cachefile, $tpldir, $file) { static $tplrefresh, $timestamp, $targettplname; if($tplrefresh === null) { $tplrefresh = getglobal('config/output/tplrefresh'); $timestamp = getglobal('timestamp'); }//如果$timecompare爲空（編譯文件不存在），或者模板文件的更新時間（@filemtime(DISCUZ_ROOT.$subtpl)）大於$timecompar
//都會執行模板緩存重新編譯parse_template($maintpl, $templateid, $tpldir, $file, $cachefile)
if(empty($timecompare) || $tplrefresh == 1 || ($tplrefresh > 1 && !($timestamp % $tplrefresh))) { if(empty($timecompare) || @filemtime(DISCUZ_ROOT.$subtpl) > $timecompare) { require_once DISCUZ_ROOT.'/source/class/class_template.php'; $template = new template(); $template->parse_template($maintpl, $templateid, $tpldir, $file, $cachefile); if($targettplname === null) { $targettplname = getglobal('style/tplfile'); if(!empty($targettplname)) { include_once libfile('function/block'); $targettplname = strtr($targettplname, ':', '_'); update_template_block($targettplname, getglobal('style/tpldirectory'), $template->blocks); } $targettplname = true; } return TRUE; } } return FALSE;}
下面解析parse_template();
function parse_template($tplfile, $templateid, $tpldir, $file, $cachefile) { $basefile = basename(DISCUZ_ROOT.$tplfile, '.htm'); $file == 'common/header' && defined('CURMODULE') && CURMODULE && $file = 'common/header_'.CURMODULE; $this->file = $file; if($fp = @fopen(DISCUZ_ROOT.$tplfile, 'r')) { $template = @fread($fp, filesize(DISCUZ_ROOT.$tplfile)); fclose($fp); } elseif($fp = @fopen($filename = substr(DISCUZ_ROOT.$tplfile, 0, -4).'.php', 'r')) { $template = $this->getphptemplate(@fread($fp, filesize($filename))); fclose($fp); } else { $tpl = $tpldir.'/'.$file.'.htm'; $tplfile = $tplfile != $tpl ? $tpl.', '.$tplfile : $tplfile; $this->error('template_notfound', $tplfile); } $var_regexp = "((\\\$[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*(\-\>)?[a-zA-Z0-9_\x7f-\xff]*)(\[[a-zA-Z0-9_\-\.\"\'\[\]\$\x7f-\xff]+\])*)"; $const_regexp = "([a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*)"; $headerexists = preg_match("/{(sub)?template\s+[\w\/]+?header\}/", $template); $this->subtemplates = array(); for($i = 1; $i <= 3; $i++) { if(strexists($template, '{subtemplate')) { $template = preg_replace("/[\n\r\t]*(\<\!\-\-)?\{subtemplate\s+([a-z0-9_:\/]+)\}(\-\-\>)?[\n\r\t]*/ies", "\$this->loadsubtemplate('\\2')", $template); } } $template = preg_replace("/([\n\r]+)\t+/s", "\\1", $template); $template = preg_replace("/\<\!\-\-\{(.+?)\}\-\-\>/s", "{\\1}", $template); $template = preg_replace("/\{lang\s+(.+?)\}/ies", "\$this->languagevar('\\1')", $template); $template = preg_replace("/[\n\r\t]*\{block\/(\d+?)\}[\n\r\t]*/ie", "\$this->blocktags('\\1')", $template); $template = preg_replace("/[\n\r\t]*\{blockdata\/(\d+?)\}[\n\r\t]*/ie", "\$this->blockdatatags('\\1')", $template); $template = preg_replace("/[\n\r\t]*\{ad\/(.+?)\}[\n\r\t]*/ie", "\$this->adtags('\\1')", $template); $template = preg_replace("/[\n\r\t]*\{ad\s+([a-zA-Z0-9_\[\]]+)\/(.+?)\}[\n\r\t]*/ie", "\$this->adtags('\\2', '\\1')", $template); $template = preg_replace("/[\n\r\t]*\{date\((.+?)\)\}[\n\r\t]*/ie", "\$this->datetags('\\1')", $template); $template = preg_replace("/[\n\r\t]*\{avatar\((.+?)\)\}[\n\r\t]*/ie", "\$this->avatartags('\\1')", $template); $template = preg_replace("/[\n\r\t]*\{eval\s+(.+?)\s*\}[\n\r\t]*/ies", "\$this->evaltags('\\1')", $template); $template = preg_replace("/[\n\r\t]*\{csstemplate\}[\n\r\t]*/ies", "\$this->loadcsstemplate('\\1')", $template); $template = str_replace("{LF}", "<?=\"\\n\"?>", $template); $template = preg_replace("/\{(\\\$[a-zA-Z0-9_\-\>\[\]\'\"\$\.\x7f-\xff]+)\}/s", "<?=\\1?>", $template); $template = preg_replace("/\{hook\/(\w+?)(\s+(.+?))?\}/ie", "\$this->hooktags('\\1', '\\3')", $template); $template = preg_replace("/$var_regexp/es", "template::addquote('<?=\\1?>')", $template); $template = preg_replace("/\<\?\=\<\?\=$var_regexp\?\>\?\>/es", "\$this->addquote('<?=\\1?>')", $template); $headeradd = $headerexists ? "hookscriptoutput('$basefile');" : ''; if(!empty($this->subtemplates)) { $headeradd .= "\n0\n"; foreach($this->subtemplates as $fname) { $headeradd .= "|| checktplrefresh('$tplfile', '$fname', ".time().", '$templateid', '$cachefile', '$tpldir', '$file')\n"; } $headeradd .= ';'; } if(!empty($this->blocks)) { $headeradd .= "\n"; $headeradd .= "block_get('".implode(',', $this->blocks)."');"; } $template = "<? if(!defined('IN_DISCUZ')) exit('Access Denied'); {$headeradd}?>\n$template"; $template = preg_replace("/[\n\r\t]*\{template\s+([a-z0-9_:\/]+)\}[\n\r\t]*/ies", "\$this->stripvtags('<? include template(\'\\1\'); ?>')", $template); $template = preg_replace("/[\n\r\t]*\{template\s+(.+?)\}[\n\r\t]*/ies", "\$this->stripvtags('<? include template(\'\\1\'); ?>')", $template); $template = preg_replace("/[\n\r\t]*\{echo\s+(.+?)\}[\n\r\t]*/ies", "\$this->stripvtags('<? echo \\1; ?>')", $template); $template = preg_replace("/([\n\r\t]*)\{if\s+(.+?)\}([\n\r\t]*)/ies", "\$this->stripvtags('\\1<? if(\\2) { ?>\\3')", $template); $template = preg_replace("/([\n\r\t]*)\{elseif\s+(.+?)\}([\n\r\t]*)/ies", "\$this->stripvtags('\\1<? } elseif(\\2) { ?>\\3')", $template); $template = preg_replace("/\{else\}/i", "<? } else { ?>", $template); $template = preg_replace("/\{\/if\}/i", "<? } ?>", $template); $template = preg_replace("/[\n\r\t]*\{loop\s+(\S+)\s+(\S+)\}[\n\r\t]*/ies", "\$this->stripvtags('<? if(is_array(\\1)) foreach(\\1 as \\2) { ?>')", $template); $template = preg_replace("/[\n\r\t]*\{loop\s+(\S+)\s+(\S+)\s+(\S+)\}[\n\r\t]*/ies", "\$this->stripvtags('<? if(is_array(\\1)) foreach(\\1 as \\2 => \\3) { ?>')", $template); $template = preg_replace("/\{\/loop\}/i", "<? } ?>", $template); $template = preg_replace("/\{$const_regexp\}/s", "<?=\\1?>", $template); if(!empty($this->replacecode)) { $template = str_replace($this->replacecode['search'], $this->replacecode['replace'], $template); } $template = preg_replace("/ \?\>[\n\r]*\<\? /s", " ", $template); if(!@$fp = fopen(DISCUZ_ROOT.$cachefile, 'w')) { $this->error('directory_notfound', dirname(DISCUZ_ROOT.$cachefile)); } $template = preg_replace("/\"(http)?[\w\.\/:]+\?[^\"]+?&[^\"]+?\"/e", "\$this->transamp('\\0')", $template); $template = preg_replace("/\<script[^\>]*?src=\"(.+?)\"(.*?)\>\s*\<\/script\>/ies", "\$this->stripscriptamp('\\1', '\\2')", $template); $template = preg_replace("/[\n\r\t]*\{block\s+([a-zA-Z0-9_\[\]]+)\}(.+?)\{\/block\}/ies", "\$this->stripblock('\\1', '\\2')", $template); $template = preg_replace("/\<\?(\s{1})/is", "<?php\\1", $template); $template = preg_replace("/\<\?\=(.+?)\?\>/is", "<?php echo \\1;?>", $template); flock($fp, 2); fwrite($fp, $template); fclose($fp); }解析重點
解析的重點主要是
變量輸出 ：{$var}
條件判斷
<!--{if $var}-->
html
<!--{/if}-->
循環語句：
<!--{loop $arr $key $val}-->
HTML語句
<!--{/loop}-->
嵌套模板內容：
<!--{template common/header}-->
插件鉤子：
<!--{hook/index_top}-->
