このスクリプトはhttp://www.intert3chmedia.net/2011/12/minify-html-javascript-css-without.htmlで見つけました。HTMLを縮小する（クラス名が示すように圧縮しない）ことになっています：
<?php
class WP_HTML_Compression
{
// Settings
protected $compress_css = true;
protected $compress_js = true;
protected $info_comment = true;
protected $remove_comments = true;
// Variables
protected $html;
public function __construct($html)
{
if (!empty($html))
{
$this->parseHTML($html);
}
}
public function __toString()
{
return $this->html;
}
protected function bottomComment($raw, $compressed)
{
$raw = strlen($raw);
$compressed = strlen($compressed);
$savings = ($raw-$compressed) / $raw * 100;
$savings = round($savings, 2);
return '<!--HTML compressed, size saved '.$savings.'%. From '.$raw.' bytes, now '.$compressed.' bytes-->';
}
protected function minifyHTML($html)
{
$pattern = '/<(?<script>script).*?<\/script\s*>|<(?<style>style).*?<\/style\s*>|<!(?<comment>--).*?-->|<(?<tag>[\/\w.:-]*)(?:".*?"|\'.*?\'|[^\'">]+)*>|(?<text>((<[^!\/\w.:-])?[^<]*)+)|/si';
preg_match_all($pattern, $html, $matches, PREG_SET_ORDER);
$overriding = false;
$raw_tag = false;
// Variable reused for output
$html = '';
foreach ($matches as $token)
{
$tag = (isset($token['tag'])) ? strtolower($token['tag']) : null;
$content = $token[0];
if (is_null($tag))
{
if ( !empty($token['script']) )
{
$strip = $this->compress_js;
}
else if ( !empty($token['style']) )
{
$strip = $this->compress_css;
}
else if ($content == '<!--wp-html-compression no compression-->')
{
$overriding = !$overriding;
// Don't print the comment
continue;
}
else if ($this->remove_comments)
{
if (!$overriding && $raw_tag != 'textarea')
{
// Remove any HTML comments, except MSIE conditional comments
$content = preg_replace('/<!--(?!\s*(?:\[if [^\]]+]|<!|>))(?:(?!-->).)*-->/s', '', $content);
}
}
}
else
{
if ($tag == 'pre' || $tag == 'textarea')
{
$raw_tag = $tag;
}
else if ($tag == '/pre' || $tag == '/textarea')
{
$raw_tag = false;
}
else
{
if ($raw_tag || $overriding)
{
$strip = false;
}
else
{
$strip = true;
// Remove any empty attributes, except:
// action, alt, content, src
$content = preg_replace('/(\s+)(\w++(?<!\baction|\balt|\bcontent|\bsrc)="")/', '$1', $content);
// Remove any space before the end of self-closing XHTML tags
// JavaScript excluded
$content = str_replace(' />', '/>', $content);
}
}
}
if ($strip)
{
$content = $this->removeWhiteSpace($content);
}
$html .= $content;
}
return $html;
}
public function parseHTML($html)
{
$this->html = $this->minifyHTML($html);
if ($this->info_comment)
{
$this->html .= "\n" . $this->bottomComment($html, $this->html);
}
}
protected function removeWhiteSpace($str)
{
$str = str_replace("\t", ' ', $str);
$str = str_replace("\n", '', $str);
$str = str_replace("\r", '', $str);
while (stristr($str, ' '))
{
$str = str_replace(' ', ' ', $str);
}
return $str;
}
}
function wp_html_compression_finish($html)
{
return new WP_HTML_Compression($html);
}
function wp_html_compression_start()
{
ob_start('wp_html_compression_finish');
}
add_action('get_header', 'wp_html_compression_start');
?>
私の HTML の上部には、次のような IE 条件があります。
<!--[if lt IE 7 ]><html class="ie ie6" lang="en"><![endif]-->
<!--[if IE 7 ]><html class="ie ie7" lang="en"><![endif]-->
<!--[if IE 8 ]><html class="ie ie8" lang="en"><![endif]-->
<!--[if (gte IE 9)|!(IE)]><!--><html lang="en"><!--<![endif]-->
IE 条件の下のすべてが正しく縮小されます。その結果、HTML の 1 行が長くなります。問題は、IE 条件より上のすべてが縮小されていないように見えることです。キャリッジ リターンは引き続き保持されます。何が問題なのですか？