使用 CSS 类中的样式将富文本复制到剪贴板

Question

我使用this method 从 html 元素复制富文本。问题是如果样式不是在html中内联，而是来自css，这个方法就行不通了。现有代码破坏了格式并且不考虑样式。这是代码。

HTML

<button onclick="copyToClip(document.getElementById('foo').innerHTML)">
  Copy the stuff
  </button>

<div id=foo>
  You can write some JS to generate this data. 
  It can contain rich stuff.
  <b> test </b> me <i> also </i>
  <div class="green">Hello world</div> You can use setData to put TWO COPIES into the same clipboard, one that is plain and one that is rich. That way your users can paste into either a
  <ul>
    <li>plain text editor</li>
    <li>or into a rich text editor</li>
  </ul>
</div>

CSS

.green {
  display: inline;
  color: green;
}

JavaScript

function copyToClip(str) {
  function listener(e) {
    e.clipboardData.setData("text/html", str);
    e.clipboardData.setData("text/plain", str);
    e.preventDefault();
  }
  document.addEventListener("copy", listener);
  document.execCommand("copy");
  document.removeEventListener("copy", listener);
};

示例in Codepen。

Answer 1

添加到复制文本的换行是因为“块级元素”，即使您在 css 表中添加 "display : inline"

见W3 HTML Block and Inline Elements

为避免这种情况，我们需要更改任何具有内联显示的块级元素并将所有样式包括默认样式恢复为新标签

最后代码如下：

Codepen

注意：代码注释中的解释

function CopyToClipboard(element) {
	// array off all block level elements
	var block_level_elements = ['P','H1', 'H2', 'H3', 'H4', 'H5', 'H6','OL', 'UL','DIV','FORM','HR','TABLE'];	

	//create new Element so we can change elments like we need
	var newelment = document.createElement("div");

	//copy target Element to the new Element
	newelment.innerHTML = document.getElementById(element).innerHTML;

	//hide new Element to body
	newelment.style.opacity  = 0;
	// add new Element to body
	document.body.appendChild(newelment);

	//get all element childs
	var descendents = newelment.getElementsByTagName('*');

	//loop in childs
	for (var i = 0; i < descendents.length; ++i) {
		//get defult Style
	    var style = window.getComputedStyle(descendents[i]);
	    var dis = style.getPropertyValue('display');
	    //get defult tag name
	    var tagname = descendents[i].tagName;
		
		//---------------------------
		//this part is little tricky
		//---------------------------
		//true : Element is a block level elements and css display is inline
	    if(dis.includes("inline") && block_level_elements.includes(tagname)){
	    	//get all Element style include default style
			var defultcss = document.defaultView.getComputedStyle(descendents[i], "").cssText;
			//chang Element tag from block level elements to inline level elements (span)
			descendents[i].outerHTML = descendents[i].outerHTML.replace(new RegExp(tagname, "ig"),"span");			//todo: need to change RegExp to tag name only not inner text 
			//add all Element style include default style to new tag
			descendents[i].style.cssText = defultcss;
		}
	}
	//-----------------copy new Element--------------
	var doc = document;
	var range, selection;
    
	if (doc.body.createTextRange)
    {
		range = doc.body.createTextRange();
		range.moveToElementText(newelment);
		range.select();
	} 
    
    else if (window.getSelection)
    {
		selection = window.getSelection();        
		range = doc.createRange();
		range.selectNodeContents(newelment);
		selection.removeAllRanges();
		selection.addRange(range);
 	}
	document.execCommand('copy');
	window.getSelection().removeAllRanges();
	
	// remove new Element from document
	document.body.removeChild(newelment);  
	
	document.getElementById("copybtn").innerHTML="Copied";
	
}

.green {
  display: inline;
  color: green;
  white-space: nowrap;
}

  <button id='copybtn' onclick="CopyToClipboard('foo')">
  Copy the stuff
  </button>
  
<div id='foo'>
  You can write some JS to generate this data. 
  It can contain rich stuff.
  <b> test </b> me <i> also </i>
  <div class="green" style="color: green;">Hello world</div> , <h3 class="green" style="color: green;">header3</h3> You can use setData to put TWO COPIES into the same clipboard, one that is plain and one that is rich. That way your users can paste into either a
  <ul>
    <li>plain text editor</li>
    <li>or into a rich text editor</li>
  </ul>
</div>