使用CSS类中的样式将富文本复制到剪贴板

Question

我已经使用this method从html元素复制富文本。问题是，如果样式未在html中内联，而是来自css，则此方法无效。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

即使您在CSS工作表中添加了#id-where-content-is-added { content: string-produced; } ，也会因为“ 块级元素”而添加到复制文本的换行符

请参见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，代码将类似于：

Codepen

注意：代码注释中的说明

"display : inline"

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;
}