如何用PHP或CKEditor去除首尾由其生成的<p>&nbsp;</p>空白行？

Absolutely! You can tackle this in two effective ways—either by configuring CKEditor to avoid generating those trailing/leading blank paragraphs in the first place, or by using a regex to clean up the existing content just like PHP's trim() function. Let's walk through both options:

If you want to stop those empty <p>&nbsp;</p> lines from appearing in the output altogether, tweak these editor settings:

• Control line break behavior: Make sure your enter/shift-enter modes are set consistently to avoid accidental empty paragraphs:

  CKEDITOR.config.enterMode = CKEDITOR.ENTER_P; // Default: Creates <p> on Enter
  CKEDITOR.config.shiftEnterMode = CKEDITOR.ENTER_BR; // Creates <br> on Shift+Enter
  

• Remove all empty paragraphs (caution!): The removeEmptyParagraph option will strip out any empty <p> tags (including those with only  ). But note: this removes all empty paragraphs, not just the ones at the start/end. Only use this if you don't need to keep blank lines in the middle of your content:

  CKEDITOR.config.removeEmptyParagraph = true;
  

If you need to keep middle blank lines but only strip the ones at the start and end, regex is the perfect fit. Here's how to do it in PHP:

Basic Version (matches exact <p>&nbsp;</p> lines) #

// Strip leading blank paragraphs (and any surrounding whitespace/newlines)
$str = preg_replace('/^(<p>&nbsp;<\/p>\s*)+/', '', $str);

// Strip trailing blank paragraphs (and any surrounding whitespace/newlines)
$str = preg_replace('/(\s*<p>&nbsp;<\/p>)+$/', '', $str);

Flexible Version (handles multiple   or spaces in paragraphs) #

If your blank paragraphs might contain multiple spaces or   characters, use this adjusted regex:

$str = preg_replace('/^(<p>(&nbsp;|\s)+<\/p>\s*)+/', '', $str);
$str = preg_replace('/(\s*<p>(&nbsp;|\s)+<\/p>)+$/', '', $str);

How this works: #

• ^ anchors the match to the start of the string
• $ anchors the match to the end of the string
• (<p>&nbsp;<\/p>\s*)+ matches one or more consecutive blank paragraphs, plus any trailing whitespace/newlines between them
• Replacing these matches with an empty string effectively "trims" the unwanted lines, just like trim() does for whitespace in plain text.

内容的提问来源于stack exchange，提问作者Tech settai -