PHP implements detection and completion functions for end tags in html tags

This article mainly introduces the PHP implementation of the detection and completion function of the end tag in the HTML tag. Interested friends can refer to it. I hope it will be helpful to everyone. ,

The example in this article describes how to implement html tag closure detection and repair in PHP. The details are as follows:

HTML tag closure detection and repair is a bit big, and it has not been fully considered. There is no Using regular expressions is suitable for situations where there is only a start tag but no end tag in the html file, or there is an end tag but no start tag. The closing position of the label needs to be adjusted according to the needs

<?php
$str = &#39;
<p data="<li></li>">
  <img  src="/static/imghwm/default1.png"  data-src="http://www.baidu.com/123123.png"  class="lazy"  / alt="PHP implements detection and completion functions for end tags in html tags" >
  <p2>
    <a>content</a>
  </p2>
    <ul>
      <li>
      </li>
    </ul>
    <p>
    content full
    </p>
    this is content</test1>
    this is content</test2>
    <test4 data="liujinjing"> This is cont
    <li></li>
    <test3 data="liujinjing"> This is content
<p3>
</p3>
</p4>
</p>
</p>
<p6 style="width:90px; "> this is content&#39;;
$str_len = strlen($str);
//记录起始标签
$pre_data = array();
//记录起始标签位置
$pre_pos = array();
$last_data = array();
$error_data = array();
$error_pos = array();
$i = 0;
//标记为 < 开始
$start_flag = false;
while( $i < $str_len ) {
  if($str[$i]=="<" && $str[$i+1]!=&#39;/&#39; && $str[$i+1]!=&#39;!&#39;) {
    $i++;
    $_tmp_str = &#39;&#39;;
    //标记为 < 开始
    $start_flag = true;
    //标记空白
    $space_flag = false;
    while($str[$i]!=">" && $str[$i]!="&#39;" && $str[$i]!=&#39;"&#39; && $str[$i] !=&#39;/&#39; && $i<$str_len){
      if($str[$i]==&#39; &#39;) {
        $space_flag = true;
      }
      if(!$space_flag) {
        $_tmp_str .= $str[$i];  
      }
      $i++;
    }
    $pre_data[] = $_tmp_str;
    $pre_pos[] = $i;
  } else if ($str[$i]=="<" && $str[$i+1]==&#39;/&#39;) {
    $i += 2;
    $_tmp_str = &#39;&#39;;
    while($str[$i]!=">" && $i<$str_len){
      $_tmp_str .= $str[$i];
      $i++;
    }
    $last_data[] = $_tmp_str;
    //查看开始标签的上一个值
    if(count($pre_data)>0) {
      $last_pre_node = getLastNode($pre_data, 1);
      if($last_pre_node == $_tmp_str) {
        //配对上, 删除对应位置的值
        array_pop($pre_data);
        array_pop($pre_pos);
        array_pop($last_data);
      } else {
      //没有配对上， 有两种情况
        //情况一： 只有闭合标签， 没有开始标签
        //情况二：只有开始标签， 没有闭合标签
        array_pop($last_data);
        $error_data[] = $_tmp_str;
        $error_pos[] = $i;
      }
    } else {
        array_pop($last_data);
        $error_data[] = $_tmp_str;
        $error_pos[] = $i;      
    }
  }else if ($str[$i]=="<" && $str[$i+1]=="!") {
    $i++;
    while($i<$str_len) {
      if($str[$i]=="-" && $str[$i+1]=="-" && $str[$i+2]==">") {
        $i++;
        break;
      } else {
        $i++;
      }
    }
    $i++;
  }else if($str[$i]==&#39;/&#39; && $str[$i+1]==&#39;>&#39;) {
    //跳过自动单个闭合标签
    if($start_flag) {
      array_pop($pre_data);
      array_pop($pre_pos);
      $i+=2;
    }
  }else if($str[$i]=="/" && $str[$i+1]=="*"){
    $i++;
    while($i<$str_len) {
      if($str[$i]=="*" && $str[$i+1]=="/") {
        $i++;
        break;
      } else {
        $i++;
    }
    $i++;
  }
  }else if($str[$i]=="&#39;"){
    $i++;
    while($str[$i]!="&#39;" && $i<$str_len) {
      $i++;
    }
    $i++;
  } else if($str[$i]==&#39;"&#39;){
    $i++;
    while($str[$i]!=&#39;"&#39; && $i<$str_len ) {
      $i++;
    }
    $i++;
  } else {
    $i++;
  }
}
//确定起始标签的位置
function confirm_pre_pos($str, $pre_pos){
  $str_len = strlen($str);
  $j=$pre_pos;
  while($j < $str_len) {
    if($str[$j] == &#39;"&#39;) {
      $j++;
      while ($j<$str_len) {
        if($str[$j]==&#39;"&#39;) {
          $j++;
          break;
        }
        $j++;
      }
    }
    else if($str[$j] == "&#39;") {
      $j++;
      while ($j<$str_len) {
        if($str[$j]=="&#39;") {
          $j++;
          break;
        }
        $j++;
      }
    }
    else if($str[$j]==">") {
      $j++;
      while ($j<$str_len) {
        if($str[$j]=="<") {
          //退回到原有内容位置
          $j--;
          break;
        }
        $j++;
      }
      break;
    } 
    else {
      $j++;
    }
  }
  return $j;
}
//确定起始标签的位置
function confirm_err_pos($str, $err_pos){
  $j=$err_pos;
  $j--;
  while($j > 0) {
    if($str[$j] == &#39;"&#39;) {
      $j--;
      while ($j<$str_len) {
        if($str[$j]==&#39;"&#39;) {
          $j--;
          break;
        }
        $j--;
      }
    }
    else if($str[$j] == "&#39;") {
      $j--;
      while ($j<$str_len) {
        if($str[$j]=="&#39;") {
          $j--;
          break;
        }
        $j--;
      }
    }
    else if($str[$j]==">") {
      $j++;
      break;
    } 
    else {
      $j--;
    }
  }
  return $j;
}
//获取数组的倒数第num个值
function getLastNode(array $arr, $num){
  $len = count($arr);
  if($len > $num) {
    return $arr[$len-$num];
  } else {
    return $arr[0];
  }
}
//整理数据， 主要是向后看， 进一步进行检查
function sort_data(&$pre_data, &$pre_pos, &$error_data, &$error_pos){
  $rem_key_array = array();
  $rem_i_array = array();
  //获取需要删除的值
  foreach($error_data as $key=>$value){
    $count = count($pre_data);
    for($i=($count-1) ; $i>=0; $i--) {
      if($pre_data[$i] == $value && !in_array($i, $rem_i_array)) {
        $rem_key_array[] = $key;
        $rem_i_array[] = $i;
        break;
      }
    }
  }
  //删除起始标签相应的值
  foreach($rem_key_array as $_item) {
    unset($error_pos[$_item]);
    unset($error_data[$_item]);
  }
  //删除结束标签相应的值
  foreach($rem_i_array as $_item) {
    unset($pre_data[$_item]);
    unset($pre_pos[$_item]);
  }
}
//整理数据， 闭合标签
function modify_data($str, $pre_data, $pre_pos, $error_data, $error_pos){
  $move_log = array();
  //只有闭合标签的数据
  foreach ($error_data as $key => $value) {
    // code...
    $_tmp_move_count = 0;
    foreach ($move_log as $pos_key => $move_value) {
      // code...
      if($error_pos[$key]>=$pos_key) {
        $_tmp_move_count += $move_value;
      }
    }
    $data = insert_data($str, $value, $error_pos[$key]+$_tmp_move_count, false);
    $str = $data[&#39;str&#39;];
    $move_log[$data[&#39;pos&#39;]] = $data[&#39;move_count&#39;];
  }
  //只有起始标签的数据
  foreach ($pre_data as $key => $value) {
    // code...
    $_tmp_move_count = 0;
    foreach ($move_log as $pos_key => $move_value) {
      // code...
      if($pre_pos[$key]>=$pos_key) {
        $_tmp_move_count += $move_value;
      }
    }
    $data = insert_data($str, $value, $pre_pos[$key]+$_tmp_move_count, true);
    $str = $data[&#39;str&#39;];
    $move_log[$data[&#39;pos&#39;]] = $data[&#39;move_count&#39;];
  }
  return $str;
}
//插入数据， $type 表示插入数据的方式
function insert_data($str, $insert_data, $pos, $type) {
  $len = strlen($str);
  //起始标签类型
  if($type==true) {
    $move_count = strlen($insert_data)+3;
    $pos = confirm_pre_pos($str, $pos);
    $pre_str = substr($str, 0, $pos);
    $end_str = substr($str, $pos);
    $mid_str = "</" . $insert_data . ">";
  //闭合标签类型
  } else {
    $pos = confirm_err_pos($str, $pos);
    $move_count = strlen($insert_data) + 2;
    $pre_str = substr($str, 0, $pos);
    $end_str = substr($str, $pos);
    $mid_str = "<" . $insert_data . ">";
  }
  $str = $pre_str.$mid_str.$end_str;
  return array(&#39;str&#39;=>$str, &#39;pos&#39;=>$pos, &#39;move_count&#39;=>$move_count);
}
sort_data($pre_data, $pre_pos, $error_data, $error_pos);
$new_str = modify_data($str, $pre_data, $pre_pos, $error_data, $error_pos);
echo $new_str;
// print_r($pre_data);
// print_r($pre_pos);
// print_r($error_data);
// print_r($error_pos);
// echo strlen($str);
// foreach($pre_pos as $value){
//   $value = confirm_pre_pos($str, $value);
//   for($i=$value-5; $i<=$value; $i++) {
//     echo $str[$i];
//   }
//   echo "\n";
// }
// foreach($error_pos as $value){
//   for($i=$value-5; $i<=$value; $i++) {
//     echo $str[$i];
//   }
//   echo "\n";
// }
?>

Summary: The above is the entire content of this article, I hope it will be helpful to everyone's learning.

Related recommendations:

PHP implementation of converting images into ASCII codes

Get Chinese characters in the php program Method for the first letter of Pinyin

PHP Mysql jQuery counts the number of current online users

The above is the detailed content of PHP implements detection and completion functions for end tags in html tags. For more information, please follow other related articles on the PHP Chinese website!