php: 如何将 HTML 标题 (h2,h3,h4) 转换为嵌套无序列表？

Question

输入数组，其中包含 WordPress 帖子中的 html 标题

<?php

$headings = array(

0 => "<h2>Number One</h2>",

1 => "<h2>Number Two</h2>",

2 => "<h2>Number Three</h2>",

3 => "<h3>Number Four</h3>",

4 => "<h2 id='iamanexistingid'>Number Five</h2>",

5 => "<h3>Number Six</h4>",

6 => "<h4>Number Seven</h2>",

7 => "<h2>Number Eight</h2>"

);

现在我想在嵌套无序列表中生成一个结构。

输出

<ul>

<li>Number One</li>

<li>Number Two</li>

<li>Number Three

   <ul>

      <li>Number Four</li>

   </ul>

<li>Number Five</li>

<li>Number Five

   <ul>

      <li>Number Six

         <ul>

            <li>Number Seven</li>

         </ul>

     </li>

   </ul>

</li>

<li>Number Eight</li>

</ul>

有没有简单的方法可以使用 Simple HTML DOM Parser 生成它？还是诡计？

我最初的解决方案对于比一级更深的级别实际上不起作用，并且总体来说不好。我也不知道如何处理 H3 之后的 H4 或 H3 之后的 H3。

<?php

$headings = array(

0 => "<h2>H2 Number One</h2>",

1 => "<h2>H2 Number Two</h2>",

2 => "<h2>H2 Number Three</h2>",

3 => "<h3>H3 Number Four</h3>",

4 => "<h2 id='iamanexistingid'>H2 Number Five</h2>",

5 => "<h3>H3 Number Six</h4>",

6 => "<h4>H4 Number Seven</h2>",

7 => "<h3>H3 Number Eight</h2>",

8 => "<h2>H2 Number Nine</h2>"

);

$array = array();

$lastlevel = 2;

foreach ($headings as $key => $value) {

  preg_match("/\<(?<name>\w+)(?<attributes>\s+[^>]*|)>/", $value, $matches);

  $tagname = $matches[1];

  $currentlevel = str_replace("h", "", "$tagname");

  if($currentlevel == $lastlevel OR $currentlevel < $lastlevel) {

      array_push($array, $value);

  } elseif ($currentlevel > $lastlevel) {

      array_push($array, [$value]);

  }

  $lastlevel = $currentlevel;

}

echo printArrayList($array);

function printArrayList($array)

{

    echo "<ul>";

    foreach($array as $k => $v) {

        if (is_array($v)) {

            printArrayList($v);

            continue;

        }

        echo "<li>" . $v . "</li>";

    }

    echo "</ul>";

}

Answer 1

function generateToc($matches) {    $list ='';    $current_depth      = 7;    $numbered_items     = array();    $numbered_items_min = null;    array_walk($matches,"removelines");    // find the minimum heading to establish our baseline    //for ( $i = 0; $i < count( $matches ); $i ++ ) {    foreach ( $matches as $i => $match ) {      if ( $current_depth > $matches[ $i ][2] ) {        $current_depth = (int) $matches[ $i ][2];      }    }    $numbered_items[ $current_depth ] = 0;    $numbered_items_min               = 7;    foreach ( $matches as $i => $match ) {      $level = $matches[ $i ][2];      $count = $i + 1;      if ( $current_depth == (int) $matches[ $i ][2] ) {        $list .= '<li>';      }      // start lists      if ( $current_depth != (int) $matches[ $i ][2] ) {        for ( $current_depth; $current_depth < (int) $matches[ $i ][2]; $current_depth++ ) {          $numbered_items[ $current_depth + 1 ] = 0;          $list .= '<ul><li>';        }      }      $list .= strip_tags($match);      // end lists      if ( $i != count( $matches ) - 1 ) {        if ( $current_depth > (int) $matches[ $i + 1 ][2] ) {          for ( $current_depth; $current_depth > (int) $matches[ $i + 1 ][2]; $current_depth-- ) {            $list .= '</li></ul>';            $numbered_items[ $current_depth ] = 0;          }        }        if ( $current_depth == (int) @$matches[ $i + 1 ][2] ) {          $list .= '</li>';        }      }    }    return '<ul class="toc">' . $list . "</li></ul>";}echo generateToc($headings);