tp5源码分析之模板标签库
1 标签库
标签库，可以用来自定义模板文件中的标签解析方式
在tp5中自定义了内置标签库(Cx.php)
$taglib->__construct()
标签库构造函数，创建标签库对象
public function __construct($template)
{
$this->tpl = $template;
}
2 标签库的标签解析
2-1 标签库的标签解析
标签库可以用来解析模板文件中的自定义标签
$taglib->parseTag()
public function parseTag(&$content, $lib = '')
{
$tags = [];
$lib = $lib ? strtolower($lib) . ':' : '';
foreach ($this->tags as $name => $val) {
$close = !isset($val['close']) || $val['close'] ? 1 : 0;
$tags[$close][$lib . $name] = $name;
if (isset($val['alias'])) {
// 别名设置
$array = (array) $val['alias'];
foreach (explode(',', $array[0]) as $v) {
$tags[$close][$lib . $v] = $name;
}
}
}
// 闭合标签
if (!empty($tags[1])) {
$nodes = [];
$regex = $this->getRegex(array_keys($tags[1]), 1);
if (preg_match_all($regex, $content, $matches, PREG_SET_ORDER | PREG_OFFSET_CAPTURE)) {
$right = [];
foreach ($matches as $match) {
if ('' == $match[1][0]) {
$name = strtolower($match[2][0]);
// 如果有没闭合的标签头则取出最后一个
if (!empty($right[$name])) {
// $match[0][1]为标签结束符在模板中的位置
$nodes[$match[0][1]] = [
'name' => $name,
'begin' => array_pop($right[$name]), // 标签开始符
'end' => $match[0], // 标签结束符
];
}
} else {
// 标签头压入栈
$right[strtolower($match[1][0])][] = $match[0];
}
}
unset($right, $matches);
// 按标签在模板中的位置从后向前排序
krsort($nodes);
}
$break = '';
if ($nodes) {
$beginArray = [];
// 标签替换 从后向前
foreach ($nodes as $pos => $node) {
// 对应的标签名
$name = $tags[1][$node['name']];
$alias = $lib . $name != $node['name'] ? ($lib ? strstr($node['name'], $lib) : $node['name']) : '';
// 解析标签属性
$attrs = $this->parseAttr($node['begin'][0], $name, $alias);
$method = 'tag' . $name;
// 读取标签库中对应的标签内容 replace[0]用来替换标签头，replace[1]用来替换标签尾
$replace = explode($break, $this->$method($attrs, $break));
if (count($replace) > 1) {
while ($beginArray) {
$begin = end($beginArray);
// 判断当前标签尾的位置是否在栈中最后一个标签头的后面，是则为子标签
if ($node['end'][1] > $begin['pos']) {
break;
} else {
// 不为子标签时，取出栈中最后一个标签头
$begin = array_pop($beginArray);
// 替换标签头部
$content = substr_replace($content, $begin['str'], $begin['pos'], $begin['len']);
}
}
// 替换标签尾部
$content = substr_replace($content, $replace[1], $node['end'][1], strlen($node['end'][0]));
// 把标签头压入栈
$beginArray[] = ['pos' => $node['begin'][1], 'len' => strlen($node['begin'][0]), 'str' => $replace[0]];
}
}
while ($beginArray) {
$begin = array_pop($beginArray);
// 替换标签头部
$content = substr_replace($content, $begin['str'], $begin['pos'], $begin['len']);
}
}
}
// 自闭合标签
if (!empty($tags[0])) {
$regex = $this->getRegex(array_keys($tags[0]), 0);
$content = preg_replace_callback($regex, function ($matches) use (&$tags, &$lib) {
// 对应的标签名
$name = $tags[0][strtolower($matches[1])];
$alias = $lib . $name != $matches[1] ? ($lib ? strstr($matches[1], $lib) : $matches[1]) : '';
// 解析标签属性
$attrs = $this->parseAttr($matches[0], $name, $alias);
$method = 'tag' . $name;
return $this->$method($attrs, '');
}, $content);
}
return;
}
$taglib->getRegex()
标签的正则表达式
private function getRegex($tags, $close)
{
$begin = $this->tpl->config('taglib_begin');
$end = $this->tpl->config('taglib_end');
$single = strlen(ltrim($begin, '\\')) == 1 && strlen(ltrim($end, '\\')) == 1 ? true : false;
$tagName = is_array($tags) ? implode('|', $tags) : $tags;
if ($single) {
if ($close) {
// 如果是闭合标签
$regex = $begin . '(?:(' . $tagName . ')\b(?>[^' . $end . ']*)|\/(' . $tagName . '))' . $end;
} else {
$regex = $begin . '(' . $tagName . ')\b(?>[^' . $end . ']*)' . $end;
}
} else {
if ($close) {
// 如果是闭合标签
$regex = $begin . '(?:(' . $tagName . ')\b(?>(?:(?!' . $end . ').)*)|\/(' . $tagName . '))' . $end;
} else {
$regex = $begin . '(' . $tagName . ')\b(?>(?:(?!' . $end . ').)*)' . $end;
}
}
return '/' . $regex . '/is';
}
$taglib->parseAttr()
使用正则表达式分析标签属性
public function parseAttr($str, $name, $alias = '')
{
$regex = '/\s+(?>(?P[\w-]+)\s*)=(?>\s*)([\"\'])(?P(?:(?!\\2).)*)\\2/is' ;
$result = [];
if (preg_match_all($regex, $str, $matches)) {
foreach ($matches['name'] as $key => $val) {
$result[$val] = $matches['value'][$key];
}
if (!isset($this->tags[$name])) {
// 检测是否存在别名定义
foreach ($this->tags as $key => $val) {
if (isset($val['alias'])) {
$array = (array) $val['alias'];
if (in_array($name, explode(',', $array[0]))) {
$tag = $val;
$type = !empty($array[1]) ? $array[1] : 'type';
$result[$type] = $name;
break;
}
}
}
} else {
$tag = $this->tags[$name];
// 设置了标签别名
if (!empty($alias) && isset($tag['alias'])) {
$type = !empty($tag['alias'][1]) ? $tag['alias'][1] : 'type';
$result[$type] = $alias;
}
}
if (!empty($tag['must'])) {
$must = explode(',', $tag['must']);
foreach ($must as $name) {
if (!isset($result[$name])) {
throw new Exception('tag attr must:' . $name);
}
}
}
} else {
// 允许直接使用表达式的标签
if (!empty($this->tags[$name]['expression'])) {
static $_taglibs;
if (!isset($_taglibs[$name])) {
$_taglibs[$name][0] = strlen(ltrim($this->tpl->config('taglib_begin'), '\\') . $name);
$_taglibs[$name][1] = strlen(ltrim($this->tpl->config('taglib_end'), '\\'));
}
$result['expression'] = substr($str, $_taglibs[$name][0], -$_taglibs[$name][1]);
// 清除自闭合标签尾部/
$result['expression'] = rtrim($result['expression'], '/');
$result['expression'] = trim($result['expression']);
} elseif (empty($this->tags[$name]) || !empty($this->tags[$name]['attr'])) {
throw new Exception('tag error:' . $name);
}
}
return $result;
}
2-2 标签库的其他辅助解析函数
$taglib->getTags()
获取标签定义
public function getTags()
{
return $this->tags;
}
3 内置标签库
TP5在\template\tablig\Cx.php中，定义了内置标签的解析方式
每个标签的解析实现为相应标签的tagxx()方法