如何使用 html 标签将文本包装在多个节点内

Question

我正在使用 contenteditable 并尝试创建一个简单的编辑器。不幸的是我不能使用document.execCommand() 并且必须自己实现它。我在这里要做的是，如果用户按下粗体按钮，我想让文本变为粗体。 The code I have written below works, but it only works when the selection is in one node, not multiple nodes.

document.getElementById("bold").onclick = function() {
  var selection = document.getSelection(),
      range = selection.getRangeAt(0).cloneRange();
  range.surroundContents(document.createElement("b"));
  selection.removeAllRanges();
  selection.addRange(range);
}

<div contenteditable="true" id="div">This is the editor. If you embolden only **this**, it will work. But if you try to embolden **this <i>and this**</i>, it will not work because they are in different nodes</div>
<button id="bold">Bold</button>

我的问题是：有没有一种解决方案，我可以单击粗体，即使它们位于不同的节点中，它也可以使文本加粗？如果是这样，我该怎么做？我正在寻找简单而优雅的东西，但如果它必须很复杂，我会很感激对代码的一些解释。非常感谢。

Answer 1

这既不简单也不优雅，但按预期工作，没有额外的标记，是我能想到的最好的。

基本上，你必须遍历与选择范围相交的dom树，并在遍历过程中收集仅由文本节点组成的子范围。

查看Range documentation 以获取有关startContainer 和endContainer 的信息。 简而言之，它们在选择单个文本节点时是相同的，否则它们会为您提供遍历的起点和终点。

收集完这些范围后，您可以将它们包装在您喜欢的标签中。

它工作得很好，但不幸的是我无法在加粗后保留初始选择（用selection.setRange(..) 尝试了一切，但没有运气）：

document.getElementById("bold").onclick = function() {
    var selection = document.getSelection(),
    range = selection.getRangeAt(0).cloneRange();
    // start and end are always text nodes
    var start = range.startContainer;
    var end = range.endContainer;
    var ranges = [];

    // if start === end then it's fine we have selected a portion of a text node
	while (start !== end) {

        var startText = start.nodeValue;
        var currentRange = range.cloneRange();
        // pin the range at the end of this text node
        currentRange.setEnd(start, startText.length);
        // keep the range for later
        ranges.push(currentRange);

        var sibling = start;
        do {
            if (sibling.hasChildNodes()) {
                // if it has children then it's not a text node, go deeper
                sibling = sibling.firstChild;
            } else if (sibling.nextSibling) {
                // it has a sibling, go for it
                sibling = sibling.nextSibling;
            } else {
                // we're into a corner, we have to go up one level and go for next sibling
                while (!sibling.nextSibling && sibling.parentNode) {
                    sibling = sibling.parentNode;
                }
                if (sibling) {
                    sibling = sibling.nextSibling;
                }
            }
        } while (sibling !== null && sibling.nodeValue === null);
        if (!sibling) {
            // out of nodes!
            break;
        }
        // move range start to the identified next text node (sibling)
        range.setStart(sibling, 0);
        start = range.startContainer;
	}
    // surround all collected range by the b tag
    for (var i = 0; i < ranges.length; i++) {
        var currentRange = ranges[i];
  	    currentRange.surroundContents(document.createElement("b"));
    }
    // surround the remaining range by a b tag
    range.surroundContents(document.createElement("b"));

    // unselect everything because I can't presere the original selection
    selection.removeAllRanges();

}

<div contenteditable="true" id="div">This is the editor. If you embolden only **this**, it will work. If you try <font color="red">to embolden **this <i>and this**</i>, it will work <font color="green">because</font> we are traversing the</font> nodes<table rules="all">
<tr><td>it</td><td>will<td>even</td><td>work</td></tr>
<tr><td>in</td><td>more</td><td>complicated</td><td><i>markup</i></td></tr>
</table></div>
<button id="bold">Bold</button>

Answer 2

function makeItBold() {
	const x = document.querySelectorAll(".selected");
	for (let i = 0; i < x.length; i++) {
    	x[i].style.fontWeight = "bold"
	}
}

function makeItNormal() {
	const x = document.querySelectorAll(".selected");
	for (let i = 0; i < x.length; i++) {
    	x[i].style.fontWeight = "normal"
        x[i].style.fontStyle = "normal"
	}
}

function makeItItalic() {
	const x = document.querySelectorAll(".selected");
	for (let i = 0; i < x.length; i++) {
    	x[i].style.fontStyle = "italic"
	}
}

<!DOCTYPE html>
<html>
<body>

<h4>A simple demonstration:</h4>

<button onclick="makeItBold()">Bold</button>
<button onclick="makeItNormal()">Normal</button>
<button onclick="makeItItalic()">Italic</button>

<p class="selected">Test me out</p>

</body>
</html>